C o n s u l t a n t Pat h o l o g y
liver pathology
Consultant Pathology Series David E. Elder, MB, ChB, FRCPA Series Editor Tumorigenic Melanocytic Proliferations David E. Elder Brain Tumors Richard Prayson, Bette Kleinschmidt-DeMasters, and Mark L. Cohen Head and Neck Pathology Leon Barnes, Raja Seethala, and Simion Chiosea Liver Pathology Linda D. Ferrell and Sanjay Kakar
Forthcoming Volumes in the Series Thyroid Papillary Lesions Virginia A. LiVolsi and Jennifer L. Hunt Urinary Bladder Diagnosis Robert O. Petersen
C o n s u l t a n t Pat h o l o g y Volume 4
liver pathology EDITORS Linda D. Ferrell, MD Professor and Vice Chair of Clinical Affairs Director of Surgical Pathology Department of Pathology University of California San Francisco San Francisco, California Sanjay Kakar, MD Associate Professor and Vice Chair of Pathology University of California, San Francisco Chief of Pathology San Francisco VA Medical Center San Francisco, California
New York
Acquisitions Editor: Richard Winters Cover Design: Joe Tenerelli Compositor: S4Carlisle Publishing Services Printer: SCI Visit our website at www.demosmedpub.com © 2011 Demos Medical Publishing, LLC. All rights reserved. This book is protected by copyright. No part of it may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Medicine is an ever-changing science. Research and clinical experience are continually expanding our knowledge, in particular our understanding of proper treatment and drug therapy. The authors, editors, and publisher have made every effort to ensure that all information in this book is in accordance with the state of knowledge at the time of production of the book. Nevertheless, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the contents of the publication. Every reader should examine carefully the package inserts accompanying each drug and should carefully check whether the dosage schedules mentioned therein or the contraindications stated by the manufacturer differ from the statements made in this book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Library of Congress Cataloging-in-Publication Data Liver pathology / Linda D. Ferrell and Sanjay Kakar, editors. p. ; cm. — (Consultant pathology series ; 4) Includes bibliographical references. ISBN 978-1-933864-93-8 1. Liver — Diseases. I. Ferrell, Linda D. II. Kakar, Sanjay.
III. Series: Consultant pathology series ; 4.
[DNLM: 1. Liver Diseases — pathology. 2. Liver — pathology. WI 700] RC846.9.L582 2011 616.3'623071 — dc22
2011001173
Special discounts on bulk quantities of Demos Medical Publishing books are available to corporations, professional associations, pharmaceutical companies, health care organizations, and other qualifying groups. For details, please contact: Special Sales Department Demos Medical Publishing 11 W. 42nd Street, 15th Floor New York, NY 10036 Phone: 800–532–8663 or 212–683–0072 Fax: 212–941–7842 E-mail:
[email protected] Made in the United States of America 11 12 13 14 15
5 4 3 2 1
My parents, Savita and Ramesh, for guiding me to make erudite choices and inculcating a simple uncomplicated view of life. My late uncle Vinni, for being a treasure trove of inspiration and an unending source of the zeal to excel. My sister, Shalini, for always considering me an unconditional hero capable of achieving anything. My mentors, Larry and Linda, for shepherding me in the world of pathology, and for sharing their penchant of making the correct diagnosis, both in life and in liver biopsies. My patients, whose condition I hope this exercise will help to ameliorate in some small way. My wife Shalini and son Soham for making everything worthwhile. SANJAY KAKAR
My husband, Rick, for his support, even when I was working late and at home on the book. Roddy and Peter, for helping me start along the pathway of liver. All the co-authors, who helped make this book possible. LINDA D. FERRELL
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C on ten ts
Series Foreword Preface Acknowledgments Contributors
xv xvii xix xxi
1. Acute Hepatitis
1
Sanjay Kakar 1.1 Acute Hepatitis With Inflammation-Dominant Pattern 1.2 Acute Hepatitis With Bridging Necrosis 1.3 Resolving Hepatitis 1.4 Nonspecific Reactive Hepatitis
2. Acute Liver Failure
7 9 11 13
15
Rageshree Ramachandran and Sanjay Kakar 2.1
Acute Liver Failure With Necrosis-Dominant Injury Pattern Sanjay Kakar
3. Autoimmune Hepatitis/Overlap Syndromes
18
21
Kay Washington 3.1 3.2 3.3 3.4 3.5
Autoimmune Hepatitis With Bile Duct Injury Versus Primary Biliary Cirrhosis Autoimmune Hepatitis–Primary Biliary Cirrhosis Overlap Syndrome Autoimmune Hepatitis–Primary Sclerosing Cholangitis Overlap Syndrome Chronic Hepatitis C With Autoantibodies Versus Autoimmune Hepatitis Syncytial Giant Cell Hepatitis
4. Fatty Liver Disease
26 30 32 34 36
39
Matthew M. Yeh and Elizabeth M. Brunt 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8
Steatosis With Inflammation Versus Steatohepatitis Steatohepatitis With Minimal Ballooning Steatohepatitis Without Activity Nonalcoholic Steatohepatitis With Moderate/Marked Portal Inflammation Steatohepatitis With Elevated Serum Iron Indices and Siderosis Alcoholic Steatohepatitis Drugs and NAFLD Microvesicular Steatosis
vii
41 43 45 47 52 54 56 57
viii
CONTENTS
4.9 4.10 4.11
Pediatric Fatty Liver Disease Cynthia Behling Chemotherapy-Associated Steatohepatitis Due to Irinotecan Vikram Deshpande and Gregory Y. Lauwers Subacute Steatohepatitis Linda D. Ferrell
5. Hepatic Granulomas and Granulomatous Hepatitis
58 61 64
67
Laura W. Lamps 5.1 5.2 5.3 5.4 5.5 5.6
Necrotizing Epithelioid Granulomas Sarcoidosis Fibrin Ring Granulomas Schistosomiasis Cat Scratch Disease Chronic Granulomatous Disease David E. Kleiner
6. Cholestasis
70 73 77 79 82 85
89
Jay H. Lefkowitch 6.1 6.2 6.3 6.4 6.5 6.6 6.7
Drug-Induced Pure Cholestasis Bile Ductular Cholestasis Associated With Sepsis Crohn Disease With Primary Sclerosing Cholangitis Chronic Large Bile Duct Obstruction of Uncertain Cause Primary Sclerosing Cholangitis, Exclude Cholangiocarcinoma Immunoglobin G4–Associated Cholangitis Versus Primary Sclerosing Cholangitis Vikram Deshpande Hepatolithiasis Polly W. Y. Lam and Wilson M. S. Tsui
7. Bile Duct Damage and Ductopenia
96 99 102 104 107 110 113
117
Kay Washington 7.1 7.2 7.3 7.4
Primary Biliary Cirrhosis With Nonspecific Changes and Positive Antimitochondrial Antibody Antimitochondrial Antibody-Negative Primary Biliary Cirrhosis Primary Biliary Cirrhosis With Ductopenia Primary Biliary Cirrhosis With Cirrhosis
8. Ductal Plate Malformations and Cystic Diseases of the Liver
120 123 125 128
131
Barton Kenney and Dhanpat Jain 8.1 8.2 8.3 8.4 8.5
Congenital Hepatic Fibrosis Versus Cirrhosis Caroli Disease/Syndrome Versus Other Cystic Disease Adult Polycystic Liver Disease Versus Caroli Disease Choledochal Cyst Solitary Hepatic Cyst Versus Hydatid Cyst
143 145 147 149 151
CONTENTS
9. Hereditary Hyperbilirubinemias
ix
153
Sarangarajan Ranganathan 9.1
Dubin-Johnson Syndrome
10. Neonatal Cholestatic Liver Disease
157
159
Grace E. Kim and Linda D. Ferrell 10.1 Biliary Atresia 10.2 Neonatal Hepatitis With Hypopituitarism 10.3 Paucity of Intrahepatic Bile Ducts 10.4 Neonatal Hepatitis Due to Alpha-1-Antitrypsin Deficiency
11. Sinusoidal Dilatation and Congestion
164 167 170 172
175
Sanjay Kakar 11.1 Budd-Chiari Syndrome Versus Biliary Disease 11.2 Sinusoidal Obstruction 11.3 Veno-Occlusive Disease (Sinusoidal Obstruction Syndrome) 11.4 Amyloidosis
12. Peliosis Hepatis
177 180 182 184
187
Sandra Fischer and Maha Guindi 12.1 Alcoholic Lipopeliosis 12.2 Lipopeliosis in Transplanted Donor Livers
13. Portal Hypertension Without Cirrhosis
188 189
191
Sandra Fischer and Maha Guindi 13.1 Hepatoportal Sclerosis 13.2 Portal Vein Thrombosis 13.3 Budd-Chiari Syndrome 13.4 Regressed Cirrhosis Case
14. Clinical and Morphological Spectrum of Liver Diseases in Pregnancy
191 193 195 199
203
Andrew Kenneth Burroughs and Amar Paul Dhillon 14.1 14.2 14.3
Recurrent Cholestasis of Pregnancy Acute Fatty Liver of Pregnancy Toxemia/HELLP Syndrome
15. Drug-Induced Liver Injury
205 207 210
213
David E. Kleiner 15.1 15.2 15.3 15.4 15.5
Acetaminophen-Induced Fulminant Liver Failure Statin-Associated Acute Hepatotoxicity Drug-Induced Autoimmune Hepatitis Drug-Induced Cholestatic Hepatitis Drug-Induced Ductopenia
217 220 223 226 229
x
CONTENTS
15.6 15.7 15.8 15.9
Methotrexate-Induced Chronic Liver Disease Liver Injury Due to Total Parenteral Nutrition Amiodarone-Induced Phospholipidosis Drug-Induced Microvesicular Steatosis
16. Cytoplasmic Globules
232 235 237 240
243
Elaine S. Chan and Matthew M. Yeh 16.1 16.2
Alpha-1-Antitrypsin Deficiency Alpha-1-Antichymotrypsin Deficiency
17. Glycogenic Abnormalities on Liver Biopsy
245 249
251
Michael Torbenson 17.1 17.2 17.3 17.4 17.5 17.6
Glycogenic Hepatopathy Glycogen in the Liver: Abnormal Versus Normal Glycogenic Hepatopathy, Cause Uncertain Glycogenic Hepatopathy, Type II Diabetes Glycogen Pseudo–Ground-Glass Smooth Endoplasmic Reticulum Proliferation
18. Macrophage Infiltrate
255 257 258 260 261 263
265
Ryan M. Gill, Sanjay Kakar, and Linda D. Ferrell 18.1 Gaucher Disease 18.2 Niemann-Pick Disease
19. Approach to Liver Biopsy With Minimal or Nonspecific Histologic Findings
271 273
275
Dhanpat Jain and Sanjay Kakar 19.1
Mild Hepatic Steatosis Versus Ito Cell Lipidosis Katharine van Patten, Sanjay Kakar, and Dhanpat Jain
20. Interpreting Iron in Liver Specimens
278
281
Michael Torbenson 20.1 20.2 20.3 20.4 20.5 20.6
Genetic Hemochromatosis Grading Iron Hepatic Iron Index Marked Hepatic Iron but No Genetic Mutation Iron in the Setting of Chronic Hepatitis C Neonatal Hemochromatosis Linda D. Ferrell
21. Wilson Disease
284 289 291 293 294 296
299
Linda D. Ferrell 21.1 21.2 21.3
Fulminant Form of Wilson Disease Chronic Hepatitis Due to Wilson Disease Cirrhosis With Chronic Hepatitis Consistent With Wilson Disease
301 304 305
CONTENTS
22. Liver Transplant Pathology
xi
307
Oyedele Adeyi 22.1 22.2 22.3 22.4 22.5 22.6 22.7 22.8 22.9 22.10
Acute Cellular Rejection Recurrent Hepatitis C Acute Cellular Rejection Versus Recurrent Hepatitis C Late Cellular Rejection Versus Autoimmune Hepatitis Versus Recurrent Hepatitis C Fibrosing Cholestatic Hepatitis C Versus Biliary Obstruction Versus Adverse Reaction to Medication Mechanical Biliary Obstruction Versus Chronic Rejection Chronic Rejection Versus Recurrent Primary Sclerosing Cholangitis Versus Non-PSC Stricture Zone 3 (Centrilobular) Necrosis Cytomegalovirus Hepatitis Graft Versus Host Disease
23. Benign Hepatocellular Lesions
309 311 313 315 319 323 326 330 337 340
343
Valérie Paradis 23.1 23.2 23.3 23.4 23.5 23.6
Atypical Focal Nodular Hyperplasias on Imaging Focal Nodular Hyperplasia Versus Inflammatory/Telangiectatic Hepatocellular Adenoma Hepatocellular Adenoma Subtyping: Inflammatory/Telangiectatic Versus Steatotic Adenoma Hepatocellular Adenoma Subtyping: Associated Liver Nodules Hepatocellular Adenoma Subtyping: Inflammatory/ Telangiectatic Adenoma Hepatocellular Adenoma Subtyping: Adenoma With Atypical Features
24. Biliary Neoplasms
347 349 351 354 356 359
361
Kisha Mitchell and Dhanpat Jain 24.1 24.2 24.3 24.4 24.5 24.6 24.7
Bile Duct Adenoma Versus Biliary Hamartoma Intrahepatic Cholangiocarcinoma Versus Hepatocellular Carcinoma Cholangiocarcinoma in Association With Von Meyenburg Complexes Diagnosis of Hilar/Extrahepatic Cholangiocarcinoma Bile Duct Cystadenoma/Carcinoma Versus Foregut Cyst Biliary Adenofibroma Vikram Deshpande and Gregory Y. Lauwers Biliary Papillomatosis/Intraductal Cholangiocarcinoma Wilson M. S. Tsui
25. Hepatocellular Carcinoma
365 370 373 375 378 381 383
387
Prodromos Hytiroglou 25.1 25.2 25.3
Well-Differentiated Hepatocellular Carcinoma Poorly Differentiated Hepatocellular Carcinoma Early Hepatocellular Carcinoma
394 398 403
xii
CONTENTS
26. Hepatocellular Carcinoma Variants
407
Shriram Jakate and Deborah Giusto 26.1
Pseudoglandular Hepatocellular Carcinoma Versus Cholangiocarcinoma and Metastatic Adenocarcinoma 26.2 Hepatocellular Versus Neuroendocrine Carcinoma 26.3 Hepatocellular Carcinoma, Clear Cell Variant 26.4 Scirrhous Hepatocellular Carcinoma 26.5 Combined Hepatocellular-Cholangiocarcinoma 26.6 Diffuse Cirrhosis-Like Hepatocellular Carcinoma 26.7 Spectrum of Cytoplasmic Contents in Hepatocellular Carcinoma 26.8 Poor Differentiation and Vascular Invasion in Hepatocellular Carcinoma 26.9 Pedunculated Hepatocellular Carcinoma 26.10 Ablated Hepatocellular Carcinoma
27. Metastatic Tumors: Illustration of Immunohistochemical Workup
409 412 414 417 419 421 423 425 427 428
431
Rageshree Ramachandran and Sanjay Kakar 27.1 27.2
Hepatocellular Carcinoma Versus Metastatic Adenocarcinoma Hepatocellular Carcinoma Versus Metastatic Polygonal Cell Tumor
28. Hepatoblastoma
436 438
441
Sarangarajan Ranganathan 28.1 28.2 28.3 28.4
Biopsy Diagnosis of Hepatoblastoma Macrotrabecular Hepatoblastoma Versus Hepatocellular Carcinoma Small Cell Hepatoblastoma Versus Other Small Round Cell Tumors Teratoid Hepatoblastoma Versus Malignant Teratoma/Yolk Sac Tumor
29. Vascular Tumors 29.1 29.2 29.3 29.4
Cavernous Hemangioma Variants Linda D. Ferrell Epithelioid Hemangioendothelioma Hala R. Makhlouf and Zachary D. Goodman Hepatic Angiosarcoma Hala R. Makhlouf and Zachary D. Goodman Infantile Hemangioma Michael Torbenson
30. Hematopoietic Tumors of the Liver
447 449 452 455
457 457 459 462 465
469
Patrick A. Treseler and John P. Higgins 30.1 30.2 30.3 30.4 30.5 30.6 30.7
Dense Small B-Cell Infiltrate With Reactive Follicles Diffuse Large B-Cell Infiltrate Portal Infiltrate With Reed-Sternberg Cells Polymorphic Lymphoid Infiltrate in a Transplant Patient Sinusoidal T-Cell Infiltrate Portal and Lobular Infiltration by Blasts Portal and Lobular Infiltration by Mature Granulocytes
476 480 482 485 487 490 492
CONTENTS
31. Other Infiltrative Neoplasms of Liver
xiii
495
Lawrence Burgart 31.1
Portal-Based Infiltrative Neoplasm Versus Biliary Disease
32. Mesenchymal Tumors of the Liver 32.1 32.2 32.3 32.4 32.5
Mesenchymal Hamartoma Wendy L. Frankel and Xiaoping Zhou Embryonal Sarcoma Wendy L. Frankel and Xiaoping Zhou Angiomyolipoma Cherise Marie Cortese and Raouf E. Nakhleh Angiomyolipoma, Inflammatory Variant Linda D. Ferrell Malignant Angiomyolipoma—Malignant Perivascular Epithelioid Cell Tumor William A. Ahrens
496
499 499 502 505 508 510
Appendices A. Adequacy of Needle Biopsy B. Grading and Staging C. Special Stains in Liver Biopsy Pathology
515 515 517 521
Index
523
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S e r i e s Forewo rd
D
iagnostic surgical pathology remains the gold standard for diagnosis of most tumors and many inflammatory conditions in most, if not all, organ systems. The power of the morphologic method is such that, in many instances, a glance at a thin section of tissue stained with two vegetable dyes is sufficient to determine with absolute certainty whether a patient should undergo a major procedure or not, or whether a patient is likely to live a healthy life or die of an inoperable tumor. In such cases, the diagnostic process is one of “gestalt,” a form of almost instantaneous pattern recognition that is similar to the recognition of faces, different brands of automobiles, or breeds of dogs. In other “difficult” cases, the diagnosis is not so obvious. In many of these cases, a diagnosis may be possible, but may be outside of the experience of the routine practitioner. In such a circumstance, it may be possible for a practitioner with more experience—a consultant—to make a diagnosis rather readily. In other cases, the problem may really not be suited to the histologic method. In these cases as well, a consultant may be invaluable in determining that it is simply not possible to make a reliable diagnosis with the materials available. In yet other cases, the diagnosis may be ambiguous, and again a consultant’s opinion can be important in establishing a differential diagnosis that may guide clinical investigation. There are many fine consultants available to the practicing surgical pathology community. Many of them have authored textbooks, and many of them give presentations at national meetings. However, these materials can offer only a superficial insight into the vast amount of knowledge that is
embedded in these individuals’ cerebral cortices—and in their filing cabinets. This series represents an effort to enable the dissemination of this hitherto-inaccessible knowledge to the wider community. Our authors are individuals who have accumulated large collections of difficult cases and are willing to share their material and their knowledge. The cases are based on actual consultations, and the indications for the consultation, when available, are presented, because these are the records of the manner in which these cases presented themselves as being problematic. We have asked the consultants, when possible, to present their consultation letters in much the same form (albeit edited to some degree) as that in which they were first presented, because these represent the true records of the clinical encounter. In addition, we asked the authors to amplify upon these descriptions, with brief reference to the literature, and to richly illustrate the case reports with high-quality digital images. Images from books in the series, as well as additional images to amplify the presentation of the cases, will be made available on a website for downloading, study, and use in education. These images, in some cases, have been derived from virtual slides, which also may be made available in the future from a digital repository for their additional educational value. David E. Elder, MB, ChB, FRCPA Professor of Pathology and Laboratory Medicine Hospital of the University of Pennsylvania Philadelphia, Pennsylvania
xv
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Preface
T
he Hippocratic Oath enshrines the idea of medicine as more of art than science. This is particularly true of liver pathology, where the blend of the myriad H&E patterns, the intricate maze of reticulin network, the rich hues of a trichrome, the deep azure of the Prussian blue, and the blithe shades of PASD can inspire even the most insipid of imaginations. This text is an attempt to amalgamate the art and science of liver pathology using histologic patterns as a template to embark upon the diagnostic exercise. This book is part of the Consultant Pathology Series and will focus on diagnostic problems in liver pathology through case examples. The book is divided into two sections: non-neoplastic and neoplastic liver diseases. Liver biopsy interpretation in non-neoplastic liver diseases involves two steps: recognition of the morphological pattern of injury and identification of the disease processes that led to the identified pattern. The first step is essentially a morphological exercise and since the liver has a limited repertoire of response to injury, there is considerable overlap of morphological patterns across diverse disease processes. The second step requires correlation of the morphological pattern with clinical presentation, radiological findings, and laboratory data to establish an etiological diagnosis. It can be valuable to examine the biopsy without knowledge of clinical information for an unbiased appraisal of histologic abnormalities and perhaps as an act of showmanship for an uninitiated trainee or clinical colleague, but any attempt to establish the final liver biopsy diagnosis without the requisite clinical information is an act of brashness that is avoided by the astute pathologist. The non-neoplastic diseases section follows a patternbased approach comprising an introduction that defines the clinical and morphological features of the pattern and the relevant differential diagnoses. The individual disease entities and the exercise of reaching an etiological diagnosis are illustrated through case examples. The examples have been chosen from cases referred to experts in the field and highlight
the wide spectrum of problems in liver biopsy diagnosis. The format includes a case history, relevant laboratory data, imaging information and histologic features, followed by a discussion. The latter focuses on how the diagnosis was established based on the provided clinical and histologic features, and how the relevant differential diagnoses were excluded. The initial chapters cover patterns encountered in the most hepatitic and biliary disorders, followed by developmental, genetic, and pediatric diseases. Adverse drug reaction is one of the most common causes of liver injury and a systematic evidencebased approach is presented in chapter 15, embellished with numerous case examples. Both academic and community pathologists are increasingly presented with allograft-related problems. Chapter 22 outlines a pragmatic approach to determining the etiology of allograft liver dysfunction with emphasis on differential diagnosis. The neoplastic diseases section also follows a case-based approach with emphasis on the morphological and immunohistochemical features that establish the diagnosis and exclude other close mimics. Since limited tissue is available in needle biopsies, judicious use of immunohistochemistry is critical for diagnosis and a practical approach is outlined in chapter 27. In addition to typical hepatocellular and biliary tumors and biliary neoplasms, the approach to challenging situations like histological variants, hematopoietic disorders, and mesenchymal tumors is also illustrated through case examples. We hope that the style of this text and of this series in general will provide the requisite ammunition to the pathologist for assimilation of clinical and histological data to solve diagnostic conundrums, judiciously employ the immunohistochemical armamentarium, and generate pathology reports that provide the missing pieces of the jigsaw puzzle to the hepatologist.
xvii
Linda D. Ferrell, MD Sanjay Kakar, MD
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Ac k n ow ledg m en ts
We would like to acknowledge the help of Caren Hale for organizing the manuscript and images. We appreciate the efforts of our publisher, Demos Medical Publishing, in their meticulous scrutiny of the written material and molding the text into its final shape. Special mention is due to Rich Winters, Executive Editor, for his unstinting effort and support throughout the gestation of this text as it evolved from an idea to its present final form.
xix
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C o ntribu to rs
Oyedele Adeyi, MB, BS, FCAP, FRCP(C) Staff Pathologist Laboratory Medicine Program University Health Network Assistant Professor Laboratory Medicine and Pathobiology University of Toronto Toronto, Ontario, Canada William A. Ahrens, MD Adjunct Assistant Professor Department of Pathology University of North Carolina, Chapel Hill Chapel Hill, North Carolina Director of Gastrointestinal and Hepatobiliary Pathology Department of Pathology Carolinas Medical Center Charlotte, North Carolina Cynthia Behling, MD, PhD Staff Pathologist Department of Pathology Pacific Rim Pathology Group Sharp Memorial Hospital San Diego, California Elizabeth M. Brunt, MD Professor Department of Pathology and Immunology Washington University St. Louis, Missouri Lawrence Burgart, MD Clinical Professor of Pathology Department of Pathology University of Minnesota College of Medicine Minneapolis, Minnesota
Andrew Kenneth Burroughs, MBChB, Hons, FEBG, FRCP, FMedSci Consultant Physician and Hepatologist Royal Free and University College Medical School Professor of Hepatology University College London London, United Kingdom
Sandra Fischer, MD Assistant Professor of Pathology Laboratory Medicine Program Department of Laboratory Medicine and Pathobiology University Health Network University of Toronto Toronto, Ontario, Canada
Elaine S. Chan, MD Resident Department of Pathology University of Washington Seattle, Washington
Wendy L. Frankel, MD Vice Chair and Director of Anatomic Pathology Department of Pathology The Ohio State University Columbus, Ohio
Cherise Marie Cortese, MD Assistant Professor and Consultant Department of Laboratory Medicine and Pathology Mayo Clinic, Florida Jacksonville, Florida Vikram Deshpande, MD Assistant Professor of Pathology Department of Pathology Massachusetts General Hospital Assistant Professor of Pathology Department of Pathology Harvard Medical School Boston, Massachusetts Amar Paul Dhillon, MD, FRCP, FRCPath Professor of Histopathology Department of Cellular Pathology University College of London Medical School London, United Kingdom Linda D. Ferrell, MD Professor and Vice Chair of Clinical Affairs Director of Surgical Pathology Department of Pathology University of California, San Francisco San Francisco, California
xxi
Ryan M. Gill, MD, PhD Clinical Instructor Department of Pathology University of California San Francisco, California Deborah Giusto, MD Associate Pathologist Department of Pathology 4path Pathology Services Justice, Illinois Zachary D. Goodman, MD, PhD Director, Liver Pathology Research Department of Pathology Center for Liver Diseases Inova Fairfax Hospital Falls Church, Virginia Maha Guindi, FRCPC Associate Professor of Pathology Laboratory Medicine Program Department of Laboratory Medicine and Pathobiology University Health Network University of Toronto Toronto, Ontario, Canada
xxii
John P. Higgins, MD Associate Professor of Pathology Department of Pathology Stanford University Stanford, California Prodomos Hytiroglou, MD Professor of Pathology Department of Pathology Aristotle University Medical School Thessaloniki, Greece Dhanpat Jain, MBBS, MD Director of Gastrointestinal Pathology Associate Professor Department of Anatomic Pathology Yale University School of Medicine New Haven, Connecticut Shriram Jakate, MD, FRCPath Professor of Pathology, Gastroenterology, and Hepatology Department of Pathology Rush University Medical Center Chicago, Illinois Sanjay Kakar, MD Associate Professor and Vice Chair of Pathology University of California, San Francisco Chief of Pathology San Francisco VA Medical Center San Francisco, California Barton Kenney, MD Assistant Professor Department of Anatomic Pathology Yale University School of Medicine New Haven, Connecticut Grace E. Kim, MD Professor of Pathology Associate Director of Surgical Pathology Director of Pediatric Pathology Department of Anatomic Pathology University of California, San Francisco San Francisco, California David E. Kleiner, MD, PhD Director, Clinical Operations Laboratory of Pathology National Cancer Institute National Institutes of Health Bethesda, Maryland Polly W. Y. Lam, FRCPA, FHKCPath Senior Medical Officer Department of Pathology Queen Elizabeth Hospital Hong Kong, China
CONTRIBUTORS
Laura W. Lamps, MD Professor and Vice Chair Director, Diagnostic Laboratories Department of Pathology University of Arkansas for Medical Sciences Little Rock, Arkansas Gregory Y. Lauwers, MD Vice Chairman Department of Pathology Massachusetts General Hospital Chief, Gastrointestinal Pathology Service Department of Pathology Massachusetts General Hospital Professor of Pathology Department of Pathology Harvard Medical School Boston, Massachusetts Jay H. Lefkowitch, MD Professor of Clinical Pathology Department of Pathology College of Physicians and Surgeons Columbia University New York, New York Hala R. Makhlouf, MD, PhD Chief, Division of Hepatic Pathology Department of Hepatic and Gastrointestinal Pathology Armed Forces Institute of Pathology Washington, DC Kisha Mitchell, MD Assistant Professor Department of Anatomic Pathology Yale University School of Medicine New Haven, Connecticut Raouf E. Nakhleh, MD Professor Laboratory Medicine and Pathology Mayo Clinic, Florida Jacksonville, Florida Valérie Paradis, PD, PhD Professor Department of Pathology Beaujon Hospital INSERM U773 Beaujon Hospital Clichy, France Rageshree Ramachandran, MD, PhD Department of Pathology University of California San Francisco, California
Sarangarajan Ranganathan, MD Director, Anatomic Pathology Pediatric Pathology Division Associate Professor Department of Pathology Children’s Hospital University of Pittsburgh Medical Center Pittsburgh, Pennysylvania Michael Torbenson, MD Associate Professor Department of Pathology The Johns Hopkins School of Medicine Baltimore, Maryland Patrick A. Treseler, MD, PhD Professor of Pathology Department of Pathology University of California, San Francisco San Francisco, California Wilson M. S. Tsui, FRCPath, FHKCPath Consultant Pathologist Department of Pathology Caritas Medical Centre Hong Kong, China Katharine van Patten, MD Clinical Instructor Department of Anatomic Pathology Yale University School of Medicine New Haven, Connecticut Kay Washington, MD, PhD Professor Department of Pathology Vanderbilt University Medical Center Nashville, Tennessee Matthew M. Yeh, MD, PhD Associate Professor Department of Pathology University of Washington School of Medicine Seattle, Washington Xiaoping Zhou, MD, PhD Fellow, Gastrointestinal and Liver Pathology Department of Pathology The Ohio State University Columbus, Ohio
1 Acute Hepatitis SANJAY KAKAR
D E F I N I T I ON
4. Absence of fibrosis: Fibrosis is the morphological hallmark of chronicity in liver disease. By definition, there is no fibrosis in acute hepatitis. In clinical terms, chronicity is defined by persistence of clinical, biochemical, or serological evidence of liver dysfunction for more than 6 months.
Acute hepatitis is clinically defined by elevation of alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) (at least twice normal). Markers of biliary disease like alkaline phosphatase (ALP) are either normal or the ratio of serum activity of ALT to serum activity of ALP is greater than or equal to 5 (1). By definition, there is no prior history of chronic liver disease. Histologically, acute hepatitis is defined by lobular hepatocellular injury. This pattern of injury typically comprises the following four features:
RO LE O F T H E PAT H O LO GIST
The diagnosis of acute hepatitis can be established in most cases from clinical and serological data. When liver biopsy is performed, the role of the pathologist is two-fold: (i) to confirm the diagnosis of acute hepatitis and exclude other etiologies like biliary disease, (ii) to help in establishing the etiology of acute hepatitis based on the morphological features. Several subpatterns can be recognized within the acute hepatitis pattern of injury. These subpatterns can be very helpful in narrowing the differential diagnosis.
1. Hepatocellular injury with or without necrosis: This is the hallmark of acute hepatitis and may be observed in the form of hepatocellular swelling and/or hepatocellular dropout (acidophil bodies/Councilman bodies/apoptosis). In severe cases, there may be necrosis of groups of hepatocytes (confluent necrosis). The necrosis may be random and nonzonal, or it may show predilection for certain zones such as around central veins. Bridging necrosis with centro-portal, centro-central, or less commonly portoportal bridging can be present, and may carry higher risk of progression to chronic hepatitis. When confluent necrosis is widespread (multiacinar confluent necrosis or panacinar necrosis), it constitutes the morphologic counterpart of fulminant hepatitis or acute liver failure (Chapter 2). The terms massive and submassive hepatic necrosis have also been used for these situations.
SUBPAT T ER NS O F ACUT E H EPAT IT IS Inflammation-Dominant Acute Hepatitis Defining features
1. Hepatocellular damage: hepatocellular swelling, acidophil bodies, necrosis (Figures 1.1 and 1.2). 2. Lobular inflammation: lymphocyte-predominant in most cases, variable numbers of other inflammatory cells can be present. 3. Portal inflammation may be present, but is not sufficient or necessary for the diagnosis.
Regenerative features like binucleate hepatocytes, mitoses, and thicker cell plates are common. Prominent Kupffer cells are often present in the sinusoids and can form small aggregates (microgranulomas). If the hepatocellular injury is severe enough to interfere with bile secretion, cholestasis can be present (cholestatic hepatitis). 2. Inflammation: The inflammatory infiltrate typically involves the hepatic parenchyma with variable involvement of portal tracts. Interface inflammation, characteristic of chronic hepatitis, can be present in some cases and is prominent in some etiologies like acute hepatitis A. The infiltrate is predominantly composed of lymphocytes, but depending on the underlying etiology and duration of illness, other types of cells like macrophages, plasma cells, and eosinophils can be present. 3. Absence of bile duct injury: Injury to interlobular bile ducts is absent or minimal. Bile ductular reaction can occur in the areas of hepatocellular necrosis and should not be misinterpreted as biliary injury. Neutrophils are commonly present in association with ductules. This phenomenon has been referred to as pericholangitis, but it should not be mistaken for acute cholangitis.
F I G U R E 1 . 1 Inflammation-dominant pattern of injury highlighting portal and lobular inflammation. The bile duct is intact. Interface activity is present. Hepatocellular swelling are not seen in the lobule.
1
2
CHAPTER
1:
ACUTE
FIGURE 1. 2 Same case as in Figure 1.1 emphasizing the hepato-
cellular swelling, dropout, lobular inflammation, and prominent Kupffer cells.
H E PAT I T I S
F I G U R E 1 . 4 Hepatocellular ballooning with Mallory-Denk bodies helps in the identification of steatohepatitic pattern of injury.
FIGURE 1. 3 Lobular inflammation and hepatocellular swelling in acute alcoholic hepatitis can mimic inflammation-dominant pattern of acute hepatitis when fat is absent or minimal.
F I G U R E 1 . 5 Same case as Figure 1.3. Pericellular fibrosis also points
Differential diagnosis
present clinically as acute hepatitis. The presence of fibrosis is helpful in establishing chronicity in these cases. The leading differential diagnoses of inflammationdominant acute hepatitis pattern are acute viral hepatitis, adverse drug reaction, autoimmune hepatitis, and Wilson disease. The etiology remains undetermined in 10% to 15% of cases.
Distinction from biliary disease is generally not a problem as the predominant pattern of hepatocellular injury is obvious and there is hepatitic pattern of liver enzyme elevations. Acute alcoholic hepatitis can clinically present as acute hepatitis. The histological pattern of injury is steatohepatitis (steatosis, hepatocellular swelling, Mallory-Denk bodies with or without pericellular fibrosis) and is usually different from the inflammation-dominant pattern of acute hepatitis. In some cases, the steatosis is minimal or absent and the hepatocellular swelling may be mistaken for acute hepatitis pattern of injury. The presence of Mallory-Denk bodies and pericellular fibrosis, along with history of alcohol intake help in establishing the correct diagnosis (Figures 1.3–1.5). In some instances, acute exacerbation of previously unknown chronic disease can
toward a steatohepatitic etiology.
1. Acute viral hepatitis: diagnosis rests on serological tests. Since these assays can occasionally yield false-negative results, polymerase chain reaction (PCR) for viral RNA/ DNA can be obtained. 2. Adverse drug reaction: diagnosis rests on history of exposure to drugs known to cause the pattern of injury observed on liver biopsy (see Chapter 15). Herbal supplements and over-the-counter medications should be
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specifically sought. The temporal profile of disease onset and drug exposure is important in establishing causality. The disease usually subsides after cessation of the offending agent, but it can persist for weeks to months in some cases. Prominent eosinophilic infiltrate, granulomas, relatively sparse portal inflammatory component, sharply defined perivenular necrosis with minimal inflammation, and cholestasis out of proportion to hepatocellular injury (with or without bile duct damage) favor adverse drug reaction, but all these features lack specificity and sensitivity (see Chapter 15). 3. Autoimmune hepatitis (AIH) is a form of chronic hepatitis but can present clinically as acute hepatitis. Most cases with acute presentation also have fibrosis on liver biopsy and are classified as chronic hepatitis. However, around 10% of AIH lack fibrosis at initial presentation and need to be distinguished from other causes of acute hepatitis (2,3). High necroinflammatory activity and numerous plasma cells are typical of AIH, but are not specific. These features are seen in the active phase of the disease and are less prominent during the quiescent phase. Plasma cells can be observed in other causes of acute hepatitis and in biliary diseases like primary biliary cirrhosis (PBC). In some cases of AIH, plasma cells may be inconspicuous or absent. Hence, AIH does not have any specific histological features. The diagnosis is dependent on a scoring system based on clinical, laboratory, and histological findings (see Chapter 3). 4. Wilson disease can show steatosis or a steatohepatitis-like picture with glycogenated nuclei, acute hepatitis or fulminant hepatic failure, or chronic hepatitis or cirrhosis (see Chapter 21). Hepatic disease usually manifests earlier than neurological disease (mean age 8–12 years), and onset of liver disease after 50 years is rare. Low ceruloplasmin level and elevated 24-hour urinary copper can be obtained. Ceruloplasmin is an acute phase reactant and can be normal in 10% of cases. Histochemical stains for copper (rubeanic acid, rhodanine) or copper binding protein (orcein) are unreliable (4,5). Quantitative determination of copper by spectrophotometry using the tissue from the paraffin block is a reliable indicator of hepatic copper in Wilson disease. Normal hepatic copper levels are 15 to 55 μg/g of dry liver tissue. Patients with untreated Wilson disease invariably have levels exceeding 250 μg/g, and often exceeding 1000 μg/g. Normal hepatic copper excludes the possibility of untreated Wilson disease. Since copper is excreted in the bile, conditions with chronic cholestasis (like PBC and primary sclerosing cholangitis) also show elevated hepatic copper. However, these conditions rarely enter the clinical or histological differential diagnosis of Wilson disease. 5. Celiac disease is primarily considered a gastrointestinal disease, but can involve other organ systems. The most frequent manifestation of liver involvement by celiac disease is mild elevations of transaminases. This can be observed in 40% to 50% of untreated patients (6,7). Histologically, these patients show nonspecific reactive
H E PAT I T I S
3
hepatitis and revert to normal within 6 to 12 months of gluten-free diet. Other histological manifestations include acute hepatitis, chronic hepatitis, nodular regenerative hyperplasia and, rarely, cirrhosis. In addition, coexisting celiac disease is seen in 3% to 6% of AIH, PBC, and primary sclerosing cholangitis. The relationship of celiac disease and autoimmune liver disease is not clear. Autoimmune liver dysfunction often does not respond to gluten-free diet. Serological tests for celiac disease should be done in all cases of unexplained liver dysfunction. Cholestatic Hepatitis Pathologic features
This pattern shows features of inflammation-dominant acute hepatitis accompanied by cholestasis. This pattern is different from other acute hepatitis patterns both clinically and histologically. Clinically, a mixed hepatitis/cholestatic pattern of liver enzymes is often present with ALT and/or AST elevated (at least twice normal), ALP elevated (typically less than 5 times normal), and ratio of ALT activity to ALP activity is less than 5. Histologically, the picture can be dominated by cholestasis with only mild hepatocellular injury. Differential diagnosis
Most cases are drug related (Case 15.4). Any etiologies listed under inflammation-dominant acute hepatitis pattern can potentially lead to cholestatic hepatitis. Viral hepatitis A is well known to be associated with cholestasis (8,9). Acute Hepatitis, “Toxic” Pattern Pathologic features
The histologic picture is dominated by necrosis, whereas the inflammation is minimal or absent. Differential diagnosis
1. Dose-dependent drug toxicity: Most drugs lead to inflammation-dominant pattern of liver injury as the liver damage is immune mediated (idiosyncratic). In few instances (acetaminophen, halothane), the damage is due to direct dose-dependent toxicity of the drug or its metabolite (Case 15.1). 2. Toxins: organic solvents, mushroom poisoning, herbal medications. 3. Nonhepatotropic viruses: herpes simplex, adenovirus (Chapter 2). 4. Vascular etiologies: ischemia, acute onset of venous outflow obstruction as in Budd-Chiari syndrome. Vascular events superimposed on underlying chronic liver disease or cirrhosis can clinically present as acute hepatitis (Figure 1.6). Clinical or serological data and presence of fibrosis in areas unaffected by ischemic injury help in identifying the underlying chronic liver disease.
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H E PAT I T I S
FIGURE 1. 6 Necrosis-dominant pattern of liver injury evidenced
F I G U R E 1 . 7 Acute hepatitis with centrizonal necrosis related
by parenchymal extinction and minimal inflammation. This was the result of an ischemic event in the setting of chronic hepatitis C and cirrhosis. Without this history, this would be interpreted as parenchymal extinction due to acute/subacute event since there is no definite fibrosis.
to Chaparral leaf, a herbal drug.
Acute Hepatitis With Bridging Necrosis Pathologic features
The morphology is similar to inflammation-dominant acute hepatitis pattern with the additional presence of bridging necrosis. Regenerative nodules can also be present. These features can be mistaken for bridging fibrosis and interpreted as chronic hepatitis or even cirrhosis. The distinction between bridging necrosis and fibrosis can be challenging on needle biopsies, but can be accomplished in most cases by trichrome and elastic stains (Case 1.2). Differential diagnosis
Same as inflammation-dominant acute hepatitis pattern.
F I G U R E 1 . 8 Same case as in Figure 1.7. Trichrome stain is helpful in highlighting the centrizonal necrosis. The pale staining cells around the central vein are macrophages. There is no fibrosis.
Acute Hepatitis With Centrizonal Necrosis Pathologic features
Inflammation-dominant acute hepatitis pattern with varying degrees of hepatocellular injury and inflammation accompanied by necrosis around the central vein (Figures 1.7 and 1.8). Differential diagnosis
Most cases are associated with adverse drug reaction, especially if the centrizonal necrosis is sharply circumscribed and is out of proportion to the inflammation. Prominent centrizonal necrosis can also occur in AIH (10).
Resolving Hepatitis Pathologic features
Mild portal and lobular inflammation with scattered pigmentladen macrophages in the sinusoids, often more prominent around the central vein. Hepatocellular damage is typically mild. Periodic acid-Schiff diastase (PASd) stain can highlight the macrophages. The PASd-positive macrophages are the most characteristic feature of this pattern, but their numbers can vary depending on the duration of the disease.
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H E PAT I T I S
5
Differential diagnosis
A vast majority of cases with this pattern represent adverse drug reaction, but the resolving phase of any acute hepatitis can lead to this picture. Mild Hepatitis Pattern Pathologic features
The features are similar to inflammation-dominant acute hepatitis pattern, but are mild. Hepatocellular swelling or dropout can be minimal, and lobular inflammation can be focal. This makes it challenging to recognize this as acute hepatitis pattern and distinguish it from biliary disease. A combination of clinical and biopsy features are necessary for this distinction: 1. Liver enzymes: Elevated ALT and/or AST, with normal or near-normal ALP favors hepatitic disease. If ALP is elevated, the ratio of serum activity of ALT to serum activity of ALP 5 favors a hepatitic process. 2. Autoantibodies: Elevated IgG, smooth muscle antibodies, and liver-kidney microsomal antibodies are typical of AIH, whereas elevated IgM and antimitochondrial antibodies favor PBC. 3. Biopsy: Since only mild hepatocellular injury can be seen in biliary disease, it does not establish hepatitic etiology (Figure 1.9). Both portal and lobular inflammation can also be seen in biliary diseases. On the other hand, nondestructive inflammatory involvement of the bile ducts can be seen as a minor finding in hepatitic disease (Figure 1.10), but destructive bile duct features or ductopenia are not seen. Hence liver enzymes and autoantibodies play an important role in distinguishing mild hepatitic pattern from biliary disease. 4. Copper: Since copper is secreted in the bile, it accumulates in periportal hepatocytes in biliary diseases.
F I G U R E 1 . 1 0 Lymphocytic infiltration of bile duct in chronic hepatitis C. Destructive bile duct lesions or granulomatous cholangitis is not seen.
Demonstration of copper in periportal hepatocytes by histochemical stains (rhodanine, rubeanic acid, or orcein) favors biliary disease (11,12). Negative copper stain is not informative. Differential diagnosis
1. All the 4 etiologies listed above for inflammationdominant acute hepatitis pattern can also lead to mild hepatitis pattern of injury, although AIH is less likely with mild injury. 2. Nonspecific reactive hepatitis is a term used to describe portal and lobular inflammation, with or without mild hepatocellular damage that can occur in systemic inflammatory disorders (like systemic lupus erythematosus [SLE], rheumatoid arthritis, celiac disease) and infections, especially in the abdomen (see Chapter 1.4). 3. Chronic hepatitis. Mild hepatitis pattern without fibrosis can be seen early in the course of chronic hepatitis, especially chronic hepatitis C. Screening for anti-HCV antibodies is carried out by enzyme immunoassays. False-positive and less commonly false-negative results can occur (13). False negativity typically occurs in recent infections, immunocompromised states, dialysis, and cryoglobulinemia (14). Recombinant immunoblot assays or direct testing for viral RNA by PCR are considered confirmatory tests. Giant Cell Hepatitis Pathologic features
FIGURE 1. 9 Prominent lobular inflammation in PBC.
The features are similar to inflammation-dominant acute hepatitis pattern with additional presence of multinucleated hepatocytes. This feature is well described in neonatal hepatitis.
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Small multinucleated cells can occur in acute hepatitis due to any cause, but true syncytial giant cells are uncommon in older children and adults. Differential diagnosis
The majority of these cases represent AIH, and autoantibodies are present in a significant number of cases (see Chapter 3.5). The overlap syndrome of AIH and primary sclerosing cholangitis has also been linked to giant cell hepatitis. Viral infections like measles, Epstein-Barr virus, paramyxovirus, HIV, and hepatotropic viruses (A, B, and C) have been associated with giant cell hepatitis. Certain drugs like 6-mercaptopurine and methotrexate have been implicated but the evidence is not strong. PAT H OL OG Y R E P ORT
The diagnosis should encompass the morphologic subpattern of acute hepatitis followed by a discussion of etiological diagnosis in the comment. The term “active hepatitis” can be used in place of “acute hepatitis” in pathology diagnosis. This term connotes active hepatocellular injury without specifying the acute or chronic nature of the process. The 2 scenarios where the term “active hepatitis” can be useful are: 1. If necrosis is present in the liver biopsy, areas of liver parenchymal collapse can be extremely difficult to distinguish from fibrosis. Trichrome and elastic stains can be helpful in this distinction. If this distinction cannot be made based on the histologic features, the use of “active hepatitis” as the diagnostic term avoids definite categorization of the disease process as acute or chronic. 2. By definition, acute hepatitis resolves within 6 months. In the absence of complete clinical information, the term “active hepatitis” can be used.
H E PAT I T I S
References 1. Watkins PB, Seeff LB. Drug-induced liver injury: summary of a single topic clinical research conference. Hepatology. 2006;43:618–631. 2. Burgart LJ, Batts KP, Ludwig J, Nikias GA, Czaja AJ. Recent-onset autoimmune hepatitis. Biopsy findings and clinical correlations. Am J Surg Pathol. 1995;19:699–708. 3. Fujiwara K, Fukuda Y, Yokosuka O. Precise histological evaluation of liver biopsy specimen is indispensable for diagnosis and treatment of acute-onset autoimmune hepatitis. J Gastroenterol. 2008;43:951–958. 4. Gollan JL, Gollan TJ. Wilson disease in 1998: genetic, diagnostic and therapeutic aspects. J Hepatol. 1998;28(suppl 1):28–36. 5. Davies SE, Williams R, Portmann B. Hepatic morphology and histochemistry of Wilson’s disease presenting as fulminant hepatic failure: a study of 11 cases. Histopathology. 1989;15:385–394. 6. Duggan JM, Duggan AE. Systematic review: the liver in coeliac disease. Aliment Pharmacol Ther. 2005;21:515–518. 7. Volta U. Pathogenesis and clinical significance of liver injury in celiac disease. Clin Rev Allergy Immunol. 2009;36:62–70. 8. Gordon SC, Reddy KR, Schiff L, Schiff ER. Prolonged intrahepatic cholestasis secondary to acute hepatitis A. Ann Intern Med. 1984;101:635–637. 9. Glikson M, Galun E, Oren R, Tur-Kaspa R, Shouval D. Relapsing hepatitis A. Review of 14 cases and literature survey. Medicine (Baltimore). 1992;71:14–23. 10. Hofer H, Oesterreicher C, Wrba F, Ferenci P, Penner E. Centrilobular necrosis in autoimmune hepatitis: a histological feature associated with acute clinical presentation. J Clin Pathol. 2006;59:246–249. 11. Lefkowitch JH. Special stains in diagnostic liver pathology. Semin Diagn Pathol. 2006;23:190–198. 12. Nemolato S, Serra S, Saccani S, Faa G. Deparaffination time: a crucial point in histochemical detection of tissue copper. Eur J Histochem. 2008;52:175–178. 13. Kesli R, Ozdemir M, Kurtoglu MG, Baykan M, Baysal B. Evaluation and comparison of three different anti-hepatitis C virus antibody tests based on chemiluminescence and enzyme-linked immunosorbent assay methods used in the diagnosis of hepatitis C infections in Turkey. J Int Med Res. 2009;37:1420–1429. 14. Chronic hepatitis C. Current disease management. National Institute of Health. http://digestive.niddk.nih.gov/ddiseases/pubs/chronichepc/ chronichepc.pdf
Case 1.1
Acute Hepatitis With Inflammation-Dominant Pattern SANJAY KAKAR
C L I N IC AL I N F OR M AT I ON
A 38-year-old man presented with a 6-week history of weakness, abdominal pain, jaundice, dark urine, and light colored stools. On examination, there was mild hepatomegaly but no stigmata of chronic liver disease. Liver enzyme results showed ALT 569 U/L, AST 621 U/L, ALP 136 U/L, total bilirubin 12.7 mg/dl, direct bilirubin 7.1 mg/dl. Serological tests for hepatitis A, B, C, D, and E were negative. There were no autoantibodies, and ceruloplasmin levels, and serum IgG were normal. No significant drug history could be elicited. Radiology studies did not reveal any evidence of venous outflow obstruction. R E A SON F OR R E F E R R AL
The clinical and histologic impression was acute hepatitis, but the etiology could not be determined.
F I G U R E 1 . 1 . 2 The hepatic parenchyma shows foci of hepatocyte dropout and prominent Kupffer cells along the sinusoids.
PAT H OL OG I C F E AT U R E S
The liver biopsy showed mild portal inflammation comprising of lymphocytes, few plasma cells, and rare eosinophils (Figure 1.1.1). There was no significant interface inflammation, and the bile ducts were intact. The hepatic parenchyma demonstrated mild hepatocellular swelling as well as several foci of hepatocyte dropout (Figure 1.1.2). Scattered foci of lobular lymphocytic inflammation were present (Figure 1.1.3). Prominent Kupffer cells were seen in the sinusoids, some forming small clusters (Figure 1.1.2). In addition, there was mild steatosis with no evidence of steatohepatitis (Figure 1.1.2).
F I G U R E 1 . 1 . 3 There are foci of lobular inflammation and mild
steatosis.
There was no fibrosis on trichrome stain. PASd stain highlighted macrophages in the sinusoids (Figure 1.1.4). There were no globules to suggest alpha-1-antitrypsin deficiency.
DIAGNO SIS
Acute hepatitis C .
FIGURE 1. 1. 1 Mild predominantly lymphocytic portal inflammation
with minimal interface activity and normal bile duct.
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FIGURE 1. 1. 4 PASd stain highlights the macrophages in the
sinusoids. D I SC U SSI ON
The histologic picture shows inflammation-dominant acute hepatitis pattern of injury. The typical differential diagnosis in this setting is acute viral hepatitis, adverse drug reaction, AIH, and Wilson disease. In this patient, serological tests for hepatitis A, B, and C were negative arguing against acute viral hepatitis. After thorough review of medication history, no offending drugs or herbal supplements were identified. The lack of prominent plasma cells and absence of high necroinflammatory activity were not characteristic of AIH, although this diagnosis cannot be excluded on histologic grounds. The lack of elevated IgG and autoantibodies did not favor this possibility. Workup for Wilson disease revealed normal serum ceruloplasmin and urinary copper. Celiac disease, a rare cause of acute hepatitis, was considered but serological test for tissue transglutaminase antibodies was negative, making this unlikely.
H E PAT I T I S
The cause of 10% to 15% of acute hepatitis cases cannot be determined after complete workup. On further exploration, it was found that the patient got a tattoo 2 months prior to biopsy. He was tested for hepatitis B virus DNA, hepatitis C virus RNA, and human immunodeficiency virus (HIV) RNA. The PCR results for hepatitis C virus RNA yielded a copy number of 105/ml; tests for hepatitis B and HIV were negative. The clinical presentation, history of exposure, and positive hepatitis C virus (HCV) RNA led to the diagnosis of acute hepatitis C. Most cases of acute hepatitis C are asymptomatic and remain clinically undetected (1–4). Symptomatic disease occurs in around 25% of cases (4). Rare cases of fulminant hepatitis have been reported (1). Symptomatic disease, history of recent exposure, and demonstration of HCV RNA help to establish the diagnosis in the setting of clinical presentation of acute hepatitis. The viral RNA appears in the serum within 1 to 2 weeks of the infection (4). However, seroconversion can take 2 to 6 months and hence serological testing for antiHCV antibodies alone may yield false-negative results (1–4). Majority of the patients (50%–80%) will progress to chronic hepatitis C (1–3), defined by persistence of viral RNA after 6 months. Spontaneous resolution is more likely to occur in patients younger than 40 years, women, and those with symptomatic disease, whereas immunosuppressed individuals are more likely to progress to chronic disease (4). There is no correlation between HCV genotype or viral copy numbers and disease clearance.
References 1. Thomas DL, Seeff LB. Natural history of hepatitis C. Clin Liver Dis. 2005;9:383–398. 2. Heller T, Rehermann B. Acute hepatitis C: a multifaceted disease. Semin Liver Dis. 2005;25:7–17. 3. Chung RT. Acute hepatitis C virus infection. Clin Infect Dis. 2005;41:S14–S17. 4. Kamal SM. Acute hepatitis C: a systematic review. Am J Gastroenterol. 2008;103:1283–1297.
Case 1.2
Acute Hepatitis With Bridging Necrosis SANJAY KAKAR
C L I N IC AL I N F OR M AT I ON
A 42-year-old man presented with abdominal pain, jaundice, and tender hepatomegaly of 4 weeks’ duration. ALT and AST levels were greater than 1000 U/L, and ALP was minimally elevated. Ultrasound showed multiple liver nodules raising the possibility of cirrhosis. There was no history of prior liver disease. Serological tests for hepatitis A, B, and C as well as autoantibodies were negative. Serum ceruloplasmin was normal, and urinary copper was not elevated. There was no significant medication history. R E A SON F OR R E F E R R AL
The biopsy was preliminarily interpreted as chronic hepatitis with marked activity and possible cirrhosis, etiology undetermined. F I G U R E 1 . 2 . 2 Confluent necrosis associated with florid ductular
reaction.
PAT H OL OG I C F E AT U R E S
The liver biopsy showed marked portal and panacinar lymphoplasmacytic infiltrate (Figure 1.2.1). The bile ducts were intact. The hepatic parenchyma showed hepatocellular swelling, dropout, and confluent necrosis associated with ductular reaction (Figure 1.2.2). A nodular architecture was seen in several areas in the biopsy (Figure 1.2.3). It was difficult to determine whether this represents bridging necrosis or bridging fibrosis. The areas of bridging showed pale staining on trichrome in contrast to dense staining of portal tract collagen (Figures 1.2.4 A and B). No elastic fibers were seen in the area of bridging (Figure 1.2.5). These features support an acute process with necrosis and parenchyma collapse.
F I G U R E 1 . 2 . 3 Several areas in the biopsy showed a nodular architecture raising the possibility of cirrhosis.
DIAGNO SIS
Acute hepatitis with bridging necrosis and regenerative nodules, etiology undetermined.
DISCUSSIO N
The histologic picture shows inflammation-dominant pattern of injury with bridging necrosis and regenerative nodules. The distinction between bridging necrosis and bridging fibrosis in this setting can be challenging. The differentiation of acute
1. 2. 1 Dense portal and lobular lymphoplasmacytic infiltrate. The bile duct is intact.
FIGURE
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A F I G U R E 1 . 2 . 5 Orcein stain shows absence of elastic fibers in the areas of bridging supporting necrosis with parenchymal collapse rather than fibrosis. Elastic fibers are present in the portal tract (left).
B FIGURE 1. 2. 4 (A) The trichrome stain showed pale staining in the
areas of bridging indicating that this represents necrosis rather than fibrosis. The portal tract shows dense staining of collagen. (B) The trichrome stain showed pale staining in the areas of bridging indicating that this represents necrosis rather than fibrosis. The portal tract shows dense staining of collagen.
hepatitis with confluent necrosis versus acute exacerbation of chronic disease can have important therapeutic implications. Although this can be challenging on hematoxylin and eosin (HE) stain on liver biopsy, histochemical stains for trichrome, elastic fibers, and reticulin can be very helpful. The combination of these 3 stains can distinguish necrosis from fibrosis in nearly all cases (1,2). 1. Trichrome stain: Areas with necrosis with parenchymal collapse are characterized by loose stroma with spaces between collagen fibers. Congestion or hemorrhage is often present in these areas. The trichrome stain shows a characteristic two-toned appearance in acute hepatitis with necrosis. The portal areas and walls of central veins
show dark and dense staining that reflects the presence of normal collagen bundles. The areas of necrosis with parenchymal collapse show lighter staining. Fibrous septa in chronic liver disease also show darkly staining dense collagen. It is important to have a good trichrome stain to appreciate the two-toned appearance. Areas of necrosis can be easily interpreted as fibrosis in overstained trichrome stain. 2. Elastic stain: Elastic fibers are present in normal portal tracts as well as in fibrous septa of chronic liver disease. They get deposited 2 to 3 months after injury. Absence of elastic fibers on elastic stains (Verhoeff elastic or orcein stain) favors necrosis over fibrosis. 3. Reticulin stain: Necrosis is accompanied by collapse of liver architecture. In these areas, reticulin stain outlines the collapsed residual architecture, but shows dense indistinct staining in fibrotic areas. The differential diagnosis in this setting is acute viral hepatitis, adverse drug reaction, AIH, and Wilson disease. Rare cases of celiac disease can also present with acute hepatitis (3,4). The clinical and laboratory workup does not support any of these possibilities in this case. The etiology of acute hepatitis cannot be determined in 10% to 15% of cases.
References 1. Scheuer PJ, Maggi G. Hepatic fibrosis and collapse: histological distinction by orcein staining. Histopathology. 1980;4:487–490. 2. Ferrell LD, Greenberg MS. Special stains can distinguish hepatic necrosis with regenerative nodules from cirrhosis. Liver Int. 2007;27: 681–686. 3. Duggan JM, Duggan AE. Systematic review: the liver in coeliac disease. Aliment Pharmacol Ther. 2005;21:515–518. 4. Volta U. Pathogenesis and clinical significance of liver injury in celiac disease. Clin Rev Allergy Immunol. 2009;36:62–70.
Case 1.3
Resolving Hepatitis SANJAY KAKAR
C L I N IC AL I N F OR M AT I ON
A 54-year-old woman presented with abdominal pain and mild jaundice for 2 weeks. Serological tests for viral hepatitis and autoantibodies were negative. ALT and AST were 400 to 500 U/L, and ALP was normal. The patient had been on lisinopril for hypertension for 2 months. Based on the clinical features, a diagnosis of lisinopril-induced liver injury was made. The drug was discontinued, but the ALT and AST did not return to normal 2 months after withdrawal, and a liver biopsy was performed. R E A SON F OR R E F E R R AL
The biopsy showed mild hepatocellular injury, and was referred for a definite diagnosis. PAT H OL OG I C F E AT U R E S F I G U R E 1 . 3 . 1 (B) The hepatic parenchyma shows mild lobular inflammation and pigment-laden macrophages along the sinusoids, especially around the central veins.
The liver biopsy shows mild portal inflammation composed of lymphocytes. The bile ducts are intact and there is no interface inflammation. Mild hepatocellular swelling is seen. There are small foci of lobular inflammation and scattered pigmentladen macrophages along the sinusoids (Figures 1.3.1A and B). PASd stain highlights these macrophages, especially around the central veins (Figure 1.3.2). D I AG N OS I S
Resolving hepatitis likely related to lisinopril-induced liver injury.
F I G U R E 1 . 3 . 2 The pigmented macrophages are highlighted by the
PASd stain. DISCUSSIO N
The histologic picture shows the resolving hepatitis pattern of injury. Mild hepatocellular damage and PASd-positive macrophages in the sinusoids are the characteristic features of this pattern. Most cases are due to adverse drug reaction. Clinical and biochemical resolution of drug-induced acute hepatitis occurs promptly in most cases following cessation of the offending agent. In a few instances, the resolution can be delayed for several weeks to months and these cases are more likely to be biopsied.
FIGURE 1. 3. 1 (A) The hepatic parenchyma shows mild lobular
inflammation and pigment-laden macrophages along the sinusoids, especially around the central veins.
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This pattern can be seen in the resolving phase of acute hepatitis of any etiology. Viral hepatitis serologies and workup for AIH and Wilson disease should be considered in these cases, especially if a drug-related etiology is not readily apparent. Since hepatitis C serological tests can be false negative, testing for HCV RNA by PCR should be considered to exclude the diagnosis with certainty. Similar histological findings can be observed in nonspecific reactive hepatitis, a term used to describe mild hepatocellular injury in systemic diseases (1). These diseases include autoimmune diseases like SLE, rheumatoid arthritis, and celiac disease, and systemic infectious or inflammatory disorders.
H E PAT I T I S
Abdominal infections are particularly prone to show nonspecific reactive hepatitis. The patient was on lisinopril, which has been related to acute and fulminant hepatitis, and helped to establish the diagnosis (2).
References 1. Burt AD. Nonspecific reactive hepatitis. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 5th ed. Churchill Livingstone, Elsevier, Philadelphia, PA; 2007: 881–883. 2. Larrey D, Babany G, Bernuau J, et al. Fulminant hepatitis after lisinopril administration. Gastroenterology. 1990;99:1832–1833.
Case 1.4
Nonspecific Reactive Hepatitis SANJAY KAKAR
C L I N IC AL I N F OR M AT I ON
A 64-year-old woman presented with acute cholecystitis and underwent cholecystectomy. Mild dilatation of the common bile duct was seen in the intrahepatic cholangiogram. The liver enzymes at the time of surgery showed mild elevation of ALT and AST (150–200 U/L), and ALP was mildly elevated (less than twice normal). Serological tests for viral hepatitis were negative. Antinuclear antibodies (ANAs) were present (1:160); test for smooth muscle antibodies was negative. An intraoperative core-needle liver biopsy was performed. R E A SON F OR R E F E R R AL
The biopsy showed mild hepatocellular inflammation and no definite cholestatic features, but a definite etiological diagnosis was not apparent.
F I G U R E 1 . 4 . 2 Mild lobular inflammation with minimal hepatocel-
lular injury.
PAT H OL OG I C F E AT U R E S
DISCUSSIO N
The liver biopsy shows mild lymphocytic portal inflammation without significant interface inflammation (Figure 1.4.1). The bile ducts are intact and there is no ductular reaction. Small foci of lobular inflammation are present (Figure 1.4.2). There is no fibrosis.
The histologic picture shows a mild hepatitis pattern of injury characterized by mild inflammation and hepatocellular damage. The patient has dilated biliary tree raising the possibility of large duct obstruction. However, the absence of portal expansion, edema, and ductular reaction does not support this possibility. The mild hepatitis pattern seen in this biopsy does not reliably distinguish between a mild acute hepatitis pattern and biliary disease. The following steps are essential to achieve this distinction:
D I AG N OS I S
Nonspecific reactive hepatitis, possibly related to acute cholecystitis.
1. Pattern of liver enzyme elevation: The mild elevation of ALT and AST with normal ALP, in this case, favors hepatitic disease. 2. Autoantibodies: ANA are not useful in distinguishing hepatitic versus biliary disease. Antimitochondrial antibodies were subsequently obtained to exclude PBC. ALP level can be normal in early PBC, and the biopsy may show nonspecific changes resembling the mild hepatitis pattern. 3. Serum immunoglobulins: Elevated serum IgG is characteristic of AIH, whereas increase in IgM level is typical of PBC. Both IgG and IgM were normal in this case. 4. Copper stain: Since copper is secreted in the bile, it tends to accumulate in biliary disease in periportal hepatocytes. Presence of periportal copper favors biliary disease, but a negative result is not helpful in excluding biliary disease. The copper stain was negative in this case. This exercise establishes a hepatitic pattern of biliary disease. The differential diagnosis includes a mild form of the 4 conditions that cause inflammation-dominant acute hepatitis
FIGURE 1. 4. 1 Mild lymphocytic inflammation in the portal tract
without interface activity.
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pattern of injury: viral hepatitis, adverse drug reaction, AIH, and Wilson disease. The positive ANA had originally raised the clinical question of AIH. However, ANA can be positive in up to 30% of the normal population using 1:40 as the cutoff and in 3% with 1:320 as the cutoff. The modest transaminase elevations, negative SMA, normal IgG, absence of prominent necroinflammatory activity, and paucity of plasma cells do not provide support for AIH (1,2). The clinical and laboratory data do not support the other three possibilities. Rare possibilities like celiac disease should be evaluated with tissue transglutaminase antibodies depending on the clinical situation. In this case, the patient was undergoing surgery for acute cholecystitis. Nonspecific liver involvement is very common
H E PAT I T I S
in abdominal infections and manifests as mild hepatocellular injury and inflammation. The overall clinical and histological information points toward the diagnosis of nonspecific reactive hepatitis (3).
References 1. Czaja AJ, Norman GL. Autoantibodies in the diagnosis and management of liver disease. J Clin Gastroenterol. 2003;37:315–329. 2. Czaja AJ. Behavior and significance of autoantibodies in type 1 autoimmune hepatitis. J Hepatol. 1999;30:394–401. 3. Burt AD. Nonspecific reactive hepatitis. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 5th ed. Churchill Livingstone Elsevier, Philadelphia, PA; 2007: 881–883.
2 Acute Liver Failure RAGESHREE RAMACHANDRAN AND SANJAY KAKAR
In Asia, viral hepatitis is the most common cause of ALF. Hepatitis B is common in China, Hong Kong, and Taiwan, whereas hepatitis E accounts for many cases in India (9). Acute flares of chronic HBV may present clinically as ALF in previously asymptomatic chronic HBV carriers. The 2000–2006 data from the Pediatric Acute Liver Failure Study Group shows that the cause cannot be identified in approximately 50% of cases (10). In the population aged 0 to 3 years, acetaminophen accounts for only 3% of cases compared with 12% overall in children. Metabolic disease represents 10% to 15%, and viral causes comprise 6% to 8% of cases. Ischemia and autoimmune disease each account for less than 10% of pediatric cases. The outcome in the pediatric setting is more favorable than that of adults, with high rates of survival for acetaminophen toxicity and hepatitis A–induced ALF. Death is attributed to cerebral edema or sepsis in most cases. Morbidities include respiratory distress with mechanical ventilatory support, acute renal failure, and infection (7). In the United States, approximately 5% to 10% of liver transplantations are performed every year for ALF (11). Outcome is predicted by degree of encephalopathy and patient age. The role of underlying etiology and histopathology (including severity of confluent necrosis) in predicting outcome is unclear (12), though biopsy diagnosis can be useful in assigning etiology, as in the case of AIH (13).
D E FI N I T I ON A N D T E R M I N OL OG Y
Acute liver failure (ALF) is defined as the onset of hepatic encephalopathy and coagulopathy within 8 to 26 weeks of the onset of symptoms in patients without known underlying liver disease (1). It can progress rapidly to multiorgan failure within a matter of days, necessitating emergency liver transplantation. Overall mortality rate is high and can reach up to 85% (2). Other terms that have been used are fulminant hepatitis, massive necrosis, and submassive necrosis. Since necrosis may not be present in every case and some cases may not be due to hepatitic causes, the term ALF is more appropriate. C L IN I C AL F E AT U R E S
In the United States, drugs are the most common cause of ALF in adults (Table 2.1), accounting for 25% to 50% of cases (3–6). Of these, acetaminophen accounts for the majority of drug-related cases. Based on the Acute Liver Failure Study Group data collected from 1998 to 2007, the remaining causes in the adult population include hepatitis B virus (HBV) (7%), hepatitis A virus (3%), autoimmune hepatitis (AIH) (5%), ischemia (4%), and Wilson disease (2%). In 14% of cases, the cause of fulminant hepatitis cannot be identified (7). Rare instances of ALF have been reported with amyloidosis (8).
PAT H O LO GIC FEAT UR ES A ND DIFFER ENT IA L DIAGNO SIS
TA B LE 2. 1 Causes of acute liver failure Disease Category
Specific Etiologies
Infectious (viral)
Hepatotropic viruses Hepatitis A, B, less commonly D, E Nonhepatotropic viruses HSV-1, HSV-2, adenovirus
Drugs/toxins
Dose-dependent toxicity Acetaminophen Ecstasy, cocaine Idiosyncratic reaction Isoniazid, halothane, herbal medications Toxins Amanita phalloides (mushrooms)
Metabolic
Wilson disease, Reye syndrome, nonalcoholic steatohepatitis (rare)
Pregnancy-associated
Acute fatty liver of pregnancy, HELLP syndrome
Vascular
Budd-Chiari syndrome, veno-occlusive disease, shock/sepsis (ischemia)
Other
AIH, metastatic neoplasms, amyloidosis
Liver biopsy is often contraindicated due to the risk of severe bleeding. In cases where biopsy is performed, the histologic features can be a useful guide to the etiology of ALF. Based on the morphological features, ALF can be divided into 3 histological patterns (Table 2.2): TA BL E 2 . 2 Histological patterns of injury in acute liver failure
and their differential diagnosis
Abbreviations: AIH, autoimmune hepatitis; HSV, herpes simplex virus.
Histological Pattern
Common Disease Entities
Necrosis with prominent inflammatory activity
Acute viral hepatitis, idiosyncratic drug reaction, AIH, Wilson disease
Necrosis with little inflammation
Dose-dependent drug toxicity (acetaminophen), toxins, nonhepatotropic viruses (herpes simplex), vascular etiologies
Microvesicular steatosis
Drugs (tetracycline, zidovudine, valproic acid), acute fatty liver of pregnancy, rare metabolic conditions
Abbreviation: AIH, autoimmune hepatitis.
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2. Necrosis with little or no inflammation. The liver shows confluent necrosis, with negligible inflammation. The leading cause in this category is dose-dependent drug injury exemplified by acetaminophen. The anesthetic agent halothane, recreational drugs such as cocaine and 3,4-methylenedioxymethylamphetamine (MDMA, Ecstasy), industrial organic compounds such as carbon tetrachloride, and herbal agents such as pennyroyal, glue thistle, and germander can lead to the same pattern. Some cases of ALF due to Wilson disease can also have this morphology. Infections with nonhepatotropic viruses typically result in necrosis with negligible inflammation. Herpes simplex and adenoviral hepatitis are the most common in this category. Other less common causes of ALF with minimal inflammation include metastatic carcinoma, acute Budd-Chiari syndrome, and ischemic hepatitis. FIGURE 2. 1 Atorvastatin-induced ALF showing confluent necrosis, prominent inflammatory activity, and a small area of residual liver parenchyma (left).
3. Extensive microvesicular steatosis. The liver biopsy shows diffuse microvesicular steatosis with little inflammation. A variable degree of cholestasis and necrosis may be present. These morphological changes are a manifestation of mitochondrial injury and are often accompanied by lactic acidosis (16).
1. Necrosis with prominent inflammatory activity. The liver shows confluent necrosis accompanied by prominent portal and panacinar inflammation (Figure 2.1). The confluent necrosis often involves the majority of the liver parenchyma (massive/submassive hepatic necrosis) and can be associated with prominent ductular reaction. Cholestasis may be present. The inflammation is dominated by lymphocytes and plasma cells; neutrophils can be seen in association with ductular reaction. Necrosis can be distinguished from fibrosis on trichrome and elastic stains (see Case 1.2).
Most cases result from drug toxicity (see Cases 4.8 and 15.9) related to tetracycline (antibiotic), valproic acid (anticonvulsant), zidovudine (nucleoside analog used in human immunodeficiency virus [HIV]), L-asparaginase (chemotherapeutic drug), and amineptine (antidepressant) (17–23). Other settings that can lead to microvesicular steatosis include alcohol foamy degeneration, Reye syndrome, acute fatty liver of pregnancy, Jamaican vomiting sickness, and rare metabolic conditions like congenital deficiency in urea-cycle enzymes and carnitine deficiency.
The differential diagnosis of this pattern of injury includes viral hepatitis, AIH, idiosyncratic drug reaction, and Wilson disease. The distinction may not be possible on histologic grounds alone, and correlation with clinical and laboratory tests is necessary. Serological tests and/or viral titers are necessary for the diagnosis of hepatotropic viral hepatitides. Immunohistochemical stains for hepatitis B core antigen and hepatitis B surface antigen can be useful in cases of acute exacerbation of chronic hepatitis but are negative in acute hepatitis B. Travel history to areas where viral hepatitis E is endemic can be helpful. The presence of numerous plasma cells raises the possibility of AIH, but it is not a specific finding. The diagnosis can be supported by elevated immunoglobulin G (IgG) levels and serum autoantibodies smooth muscle antibody. If liver biopsy is undertaken after preemptive treatment with steroids, inflammation may not be marked and plasma cells may not be prominent. Commonly implicated drugs in ALF include isoniazid, other antimicrobials (sulfonamides, cotrimoxazole, ketoconazole), monoamine oxidase inhibitors, and anticonvulsants (phenytoin, valproate) (14,15). Any drug that causes acute hepatitis can potentially cause ALF. Wilson disease should always be considered in patients younger than 50 years and especially if there is associated hemolysis.
References 1. Schiødt FV, Lee WM. Fulminant liver disease. Clin Liver Dis. 2003;7: 331–349, vi. 2. Ichai P, Samuel D. Etiology and prognosis of fulminant hepatitis in adults. Liver Transpl. 2008;14(suppl 2):S67–S79. 3. Williams R. Classification, etiology, and considerations of outcome in acute liver failure. Semin Liver Dis. 1996;16:343–348. 4. Lee WM. Acute liver failure. Clin Perspect Gastroenterol. 2001;2:101–110. 5. Williams R. Changing clinical patterns in acute liver failure. J Hepatol. 2003;39:660–661. 6. Hanje AJ, Chalasani N. How common is chronic liver disease from acute drug-induced liver injury? Gastroenterology. 2007;132:2067–2068, discussion 2068–2069. 7. Lee WM, Squires RH Jr, Nyberg SL, Doo E, Hoofnagle JH. Acute liver failure: summary of a workshop. Hepatology. 2008;47:1401–1415. 8. Hung HH, Huang DF, Tzeng CH, et al. Systemic amyloidosis manifesting as a rare cause of hepatic failure. J Chin Med Assoc. 2010;73:161–165. 9. Cheng VC, Lo CM, Lau GK. Current issues and treatment of hepatic failure including transplantation in Hong Kong and the Far East. Semin Liver Dis. 2003;23:239–250. 10. Squires RH Jr, Shneider BL, Bucuvalas J, et al. Acute liver failure in children: the first 348 patients in the pediatric acute liver failure study group. J Pediatr. 2006;148:652–658. 11. Gotthardt D, Riediger C, Weiss KH, et al. Fulminant hepatic failure: etiology and indications for liver transplantation. Nephrol Dial Transplant. 2007;22(suppl 8):viii5–viii8.
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12. Hanau C, Munoz SJ, Rubin R. Histopathological heterogeneity in fulminant hepatic failure. Hepatology. 1995;21:345–351. 13. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31:929–938. 14. Russo MW, Galanko JA, Shrestha R, Fried MW, Watkins P. Liver transplantation for acute liver failure from drug-induced liver injury in the United States. Liver Transpl. 2004;10:1018–1023. 15. Saukkonen JJ, Cohn DL, Jasmer RM, et al. An official ATS statement: hepatotoxicity of antituberculosis therapy. Am J Respir Crit Care Med. 2006;174:935–952. 16. Pessayre D, Mansouri A, Berson A, Fromenty B. Mitochondrial involvement in drug-induced liver injury. Handb Exp Pharmacol. 2010;196: 311–365. 17. De Bus L, Depuydt P, Libbrecht L, et al. Severe drug-induced liver injury associated with prolonged use of linezolid. J Med Toxicol. 2010;6: 322–326.
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FAILURE
17
18. Haas S, Rockstroh JK, Spengler U, Fischer HP. Nucleoside induced hepatopathy in HIV patients. Diagnostic value of liver biopsy assessment. Pathologe. 2004;25:406–411. 19. Koch RO, Graziadei IW, Zangerle R, Romani N, Maier H, Vogel W. Acute hepatic failure and lactate acidosis associated with antiretroviral treatment for HIV. Wien Klin Wochenschr. 2003;115:135–140. 20. Bodmer M, Sulz M, Stadlmann S, Droll A, Terracciano L, Krähenbühl S. Fatal liver failure in an adult patient with acute lymphoblastic leukemia following treatment with L-asparaginase. Digestion. 2006;74:28–32. 21. Huang YL, Hong HS, Wang ZW, Kuo TT. Fatal sodium valproateinduced hypersensitivity syndrome with lichenoid dermatitis and fulminant hepatitis. J Am Acad Dermatol. 2003;49:316–319. 22. Uchida T, Kao H, Quispe-Sjogren M, Peters RL. Alcoholic foamy degeneration—a pattern of acute alcoholic injury of the liver. Gastroenterology. 1983;84:683–692. 23. Lionte C. Lethal complications after poisoning with chloroform—case report and literature review. Hum Exp Toxicol. 2010;29:615–622.
Case 2.1
Acute Liver Failure With Necrosis-Dominant Injury Pattern SANJAY KAKAR
C L I N I C AL I N F OR M AT I ON
A previously healthy 65-year-old man presented with abrupt onset of fever and abdominal pain. Regular medications included aspirin and acetaminophen. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was markedly elevated (>1500 U/L). Serological studies for hepatitis A, B, and C as well as autoantibodies were negative. A liver biopsy was obtained. The patient was presumptively treated for acetaminophen toxicity but developed renal failure and hepatic encephalopathy. R E A S ON F OR R E F E R R A L
To establish etiology of liver failure. PAT H OL OG I C F E AT U R E S
F I G U R E 2 . 1 . 2 The nuclei of the hepatocytes at the periphery of the necrotic areas show eosinophilic ground-glass appearance with smudging and margination of nuclear chromatin.
The liver biopsy showed widespread hemorrhage and confluent nonzonal hepatocellular necrosis (Figure 2.1.1). The inflammatory infiltrate was scant. At the periphery of the necrotic areas, the nuclei of viable hepatocytes showed ground-glass or smudged appearance with margination of nuclear chromatin (Figure 2.1.2). Some nuclei showed large eosinophilic inclusions with a surrounding halo (Figure 2.1.3). Occasional multinucleated cells were present. Macrovesicular steatosis was also present, perhaps as an incidental finding. Portal tracts were largely unremarkable with intact bile ducts. Immunohistochemistry for herpes simplex virus (HSV) was positive, confirming the diagnosis (Figure 2.1.4).
F I G U R E 2 . 1 . 3 Some hepatocytes show prominent eosinophilic intranuclear inclusions surrounded by a halo.
DIAGNO SIS
Herpes simplex virus hepatitis leading to acute liver failure.
DISCUSSIO N
The histologic pattern of necrosis with minimal inflammation is typical of HSV hepatitis. The presence of viral inclusions excludes other etiologies that can cause a similar pattern of
FIGURE 2. 1. 1 Widespread hemorrhagic nonzonal necrosis with no
significant inflammation.
18
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FAILURE
FIGURE 2. 1. 4 Immunohistochemistry shows herpes simplex virus
inclusions in the nuclei of infected cells.
injury, such as dose-dependent adverse drug reaction (acetaminophen), toxin-mediated injury, and vascular etiologies. HSV hepatitis usually occurs in neonates, pregnant women, or immunocompromised patients. However, fulminant HSV infection can affect otherwise healthy people. Hepatic involvement is the result of disseminated infection and can occur with both HSV types 1 and 2. Symptoms are generally nonspecific but may include fever, headache, and abdominal or muscle pain. Marked elevation of transaminases in the absence of jaundice and hepatomegaly is typical. Mucocutaneous manifestations are observed in half of the cases (1,2). Since the disease can follow a rapidly progressive course, early diagnosis and treatment with acyclovir are imperative. The presence of mucocutaneous rash, genital symptoms, and anicteric hepatitis with prominent transaminase elevations helps in raising clinical suspicion for HSV hepatitis. In cases of ALF of unknown etiology, preemptive antiviral therapy (acyclovir) is recommended during evaluation for liver transplantation (3). Survival rate is greater than 40% after transplantation for HSV-induced ALF and patients are advised to stay on lifelong antiviral prophylaxis, usually acyclovir (4). HSV-1 and HSV-2 are synonymous with human herpes viruses 1 and 2 (HHV-1 and HHV-2). Varicella-zoster virus (VZV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV), are also part of the human herpes virus family (HHV-3, -4, and -5, respectively) and have the potential to cause hepatitis. EBV causes an infectious mononucleosis-like syndrome, with frequent but mild liver involvement in most cases. Liver transaminases can be elevated but jaundice is rare. The liver usually shows a diffuse lymphocytic sinusoidal infiltrate. A few atypical lymphocytes and occasional nonnecrotizing granulomas can be present. Focal apoptotic bodies can be seen, but cholestasis or prominent hepatocellular damage is not present. In situ hybridization and/or polymerase chain
WITH
NECROSIS-DOMINANT
INJURY
19
reaction can be used to confirm EBV infection (5). However, these cases are rarely biopsied. Rare cases of ALF have been reported with EBV (6). CMV is a cause of neonatal hepatitis in infancy. In immunocompetent individuals, it causes an infectious mononucleosis-like syndrome similar to EBV. Nonnecrotizing granulomas can be present. Among the immunocompromised hosts, CMV is especially common in renal transplant recipients. In liver transplant recipients, CMV hepatitis has to be distinguished from acute rejection. Characteristic CMV inclusions can be identified in hepatocytes, but significant inflammation or necrosis seen in other forms of acute hepatitis is often not present. Small neutrophilic collections resembling microabscesses can be present around the hepatocytes with viral inclusions (7,8). HHV-6 can cause mild, nonspecific hepatitis. HHV-8 seropositivity is common in patients with cirrhosis (9), but its role in ALF is unclear. Adenoviral hepatitis is histologically similar to HSV hepatitis and usually occurs in immunocompromised hosts but may rarely involve healthy individuals (10). Immunohistochemistry or in situ hybridization is necessary to confirm the diagnosis. Other less-common viral infections that can cause acute hepatitis with widespread necrosis include yellow fever, dengue fever, and Ebola fever. Parvovirus B19 can cause fulminant hepatitis in children. Mild nonspecific liver inflammation can also be seen with Coxsackie virus, rubella, and measles.
References 1. Peters DJ, Greene WH, Ruggiero F, McGarrity TJ. Herpes simplexinduced fulminant hepatitis in adults: a call for empiric therapy. Dig Dis Sci. 2000;45:2399–2404. 2. Sharma S, Mosunjac M. Herpes simplex hepatitis in adults: a search for muco-cutaneous clues. J Clin Gastroenterol. 2004;38:697–704. 3. Norvell JP, Blei AT, Jovanovic BD, Levitsky J. Herpes simplex virus hepatitis: an analysis of the published literature and institutional cases. Liver Transpl. 2007:1428–1434. 4. Riediger C, Sauer P, Matevossian E, Müller MW, Büchler P, Friess H. Herpes simplex virus sepsis and acute liver failure. Clin Transplant. 2009;23(suppl 21):37–41. 5. Suh N, Liapis H, Misdraji J, Brunt EM, Wang HL. Epstein-Barr virus hepatitis: diagnostic value of in situ hybridization, polymerase chain reaction, and immunohistochemistry on liver biopsy from immunocompetent patients. Am J Surg Pathol. 2007;31:1403–1409. 6. Ader F, Chatellier D, Le Berre R, Morand P, Fourrier F. Fulminant Epstein-Barr virus (EBV) hepatitis in a young immunocompetent subject. Med Mal Infect. 2006;36:396–398. 7. Seehofer D, Rayes N, Tullius SG, et al. CMV hepatitis after liver transplantation: incidence, clinical course, and long-term follow-up. Liver Transpl. 2002;8:1138–1146. 8. Razonable RR. Cytomegalovirus infection after liver transplantation: current concepts and challenges. World J Gastroenterol. 2008;14: 4849–4860. 9. Chou AL, Huang WW, Tsao SM, Li CT, Su CC. Human herpesvirus type 8 in patients with cirrhosis: correlation with sex, alcoholism, hepatitis B virus, disease severity, and thrombocytopenia. Am J Clin Pathol. 2008;130:231–237. 10. Wang WH, Wang HL. Fulminant adenovirus hepatitis following bone marrow transplantation. A case report and brief review of the literature. Arch Pathol Lab Med. 2003;127:e246–e248.
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3 Autoimmune Hepatitis/Overlap Syndromes KAY WASHINGTON
modified in 1999 (2,3) (Table 3.2). This system classifies cases as definite or probable AIH, based on weighted parameters. In multiple reports, this system has a high degree of sensitivity (97%–100%) for diagnosis of AIH. The system also effectively
AU TOI M M U N E H E PAT I T I S Definition
Autoimmune hepatitis (AIH) is characterized as an unresolving hepatitis usually associated with hypergammaglobulinemia and tissue-directed autoantibodies and responding in most cases to immunosuppressive therapy. The pathogenesis appears to be aberrant autoreactivity in genetically susceptible individuals (1), with molecular mimicry between viral and self-antigens the likely basis for the autoimmune response.
TA BL E 3 . 2 The revised international autoimmune hepatitis group
modified scoring system
Diagnosis and Scoring Criteria
AIH is diagnosed by consideration of the combination of clinical and laboratory features with exclusion of other causes of liver disease such as viral hepatitis, Wilson disease, alpha1-antitrypsin deficiency, primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), alcohol abuse, and drug reaction (Table 3.1). Essential features are elevated serum transaminase levels, usually with antinuclear antibody (ANA) and/or smooth muscle antibody (SMA) seropositivity; immunoglobulin G (IgG) levels greater than 1.5 times normal; and compatible liver histology. Serum bilirubin levels are variable, but alkaline phosphatase is usually only mildly elevated. Diagnosis of AIH is straightforward in 50% of cases and is aided by serum studies and the scoring system developed by the International Autoimmune Hepatitis Working Group and TA B LE 3. 1 Histologic differential diagnosis of autoimmune
hepatitis Disease
Distinguishing Features
AIH
Prominent plasma cells Often very active necroinflammatory activity May show centrilobular necrosis and inflammation early in disease course
Chronic viral hepatitis
Portal lymphoid aggregates (HCV); steatosis (HCV); ground glass hepatocytes (HBV)
Drug-induced hepatitis
No helpful distinguishing features; may mimic AIH
Wilson disease
Mallory’s hyaline; copper deposition; prominent glycogenated nuclei
Primary biliary cirrhosis
Florid duct lesions and ductopenia
Primary sclerosing cholangitis
Fibrous obliteration of bile ducts
Category
Score
Female sex
2
ALP:AST (or ALT) ratio 1.5 1.5–3.0 3.0
2 0 2
Serum globulins or IgG above normal 2.0 1.5–2.0 1.0–1.5 1.0
3 2 1 0
Autoantibodies (ANA, SMA, or LKM-1) 1:80 1:80 1:40 1:40
3 2 1 0
Hepatitis viral markers Positive Negative
3 3
Drug history Positive Negative
4 1
Average alcohol consumption Low (25 grams/day) High (60 grams/day)
2 2
Liver histology Interface hepatitis Lymphoplasmacytic infiltrate Hepatocyte rosette pattern of regeneration None of the above Biliary changes Other features Other autoimmune disorders in patients or first-degree relatives
Abbreviations: AIH, autoimmune hepatitis; HBV, hepatitis B virus; HCV, hepatitis C virus.
3 1 1 5 3 3
Comments
Lower titers are considered significant in children and should be scored at least 1.
The patient should be tested for markers of hepatitis A, B, and C infection; tests for other viruses such as EBV and CMV may be considered. Recent use of known or suspected hepatotoxic drugs.
“Biliary changes” refers to bile duct patterns of injury typical of PBC or PSC or with ductopenia in an adequate biopsy. “Other features” are any suggesting an alternative etiology, eg, nonalcoholic fatty liver disease.
2
(continued)
21
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TA B LE 3. 2 The revised international autoimmune hepatitis group
modified scoring system (continued) Category Optional parameters in patients who are seronegative for ANA, SMA, and LKM-1 Seropositivity for other defined autoantibodies HLA DR3 or DR4
Score
Comments
2
Other defined antibodies are those with published evidence of relevance to AIH and include p-ANCA, anti-LC1, anti-SLA, and anti-ASGPR.
1 2 3
Response to therapy Complete relapse Interpretation of aggregate scores Pretreatment Definite AIH Probable AIH
15 10–15
Post-treatment Definite AIH Probable AIH
17 12–17
SYNDROMES
system that is more widely applicable in routine clinical practice (4). In this simplified system, 3 categories for grading histology are defined: 1. Typical histology for AIH. Each of the following 3 features is required: i. Interface hepatitis, with lymphocytic/lymphoplasmacytic inflammation in portal tracts and extending into the lobule (Figures 3.1 and 3.2) ii. Emperipolesis (engulfment of lymphocytes by hepatocytes) (Figure 3.1) iii. Hepatocyte rosette formation (Figure 3.3) 2. Histology compatible with AIH. Chronic hepatitis pattern of injury with lymphocytic infiltration but lacking some of the features considered “typical.” 3. Atypical histology for AIH. Features suggestive of other diagnoses (eg, steatohepatitis) are present.
Abbreviations: AIH, autoimmune hepatitis; ALP, alkaline phosphatase; ALT, alanine aminotransferase; ANA, antinuclear antibody; ASGPR, asialoglycoprotein receptor; AST, aspartate aminotransferase; CMV, cytomegalovirus; EBV, Epstein-Barr virus; HLA, human leukocyte antigen; IgG, immunoglobulin G; SMA, smooth muscle antibody; LC1, liver cytosol 1 antibody; anti-LKM-1, anti–liver-kidney microsomal antibody; p-ANCA, protoplasmic antineutrophil cytoplasmic antibodies; PBC, primary biliary cirrhosis; PSC, primary sclerosing cholangitis; SLA, soluble liver antigen. From Ref. 2.
TA B LE 3. 3 Simplified diagnostic criteria for AIH Feature
Cutoff
Points
ANA or SMA
1:40
1
ANA or SMA
1:80
2*
OR LKM
1:40
OR SLM
Positive
IgG
Liver histology
Absence of viral hepatitis
FIGURE 3.1 Prominent interface hepatitis with emperipolesis (engulfment of lymphocytes by hepatocytes, arrow) in autoimmune hepatitis.
upper limit of normal
1
1.10 times upper limit of normal
2
Compatible with AIH
1
Typical AIH
2
Yes
2 6: probably AIH 7: definite AIH
*Addition of points achieved for all antibodies (maximum, 2 points) Abbreviations: AIH, autoimmune hepatitis; ANA, antinuclear antibody; IgG, immunoglobulin G; LKM, liver-kidney microsomal antibody; SMA, smooth muscle antibody. From Ref. 4.
excludes AIH in patients with PSC and biliary disorders (96%–100% accuracy for exclusion of definite AIH). The overall diagnostic accuracy of the scoring system is roughly 90%. Recently, a simplified scoring system (Table 3.3) has been proposed by the same group, with the goal of producing a
F I G U R E 3 . 2 Lobular necroinflammatory activity with apoptotic hepatocyte (arrow) in autoimmune hepatitis.
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SYNDROMES
23
TA BL E 3 . 4 Helpful clinicopathologic features for distinguishing
autoimmune hepatitis, primary biliary cirrhosis, primary biliary cirrhosis, and hepatitis C virus
FIGURE 3. 3 Hepatocellular regeneration resulting in “rosettes” in autoimmune hepatitis.
Clinical and Immunologic Features of AIH Clinical features
AIH, like most autoimmune disorders, is more common in female patients, with a male:female ratio of roughly 1:4. It can present at any age, but younger patients appear to have a more severe form of the disease. Presentation varies widely, ranging from asymptomatic elevations of serum liver enzymes, to massive hepatic necrosis resulting in fulminant hepatic failure, to cirrhosis with portal hypertension. Approximately 30% of patients, usually younger patients, will have an acute presentation mimicking acute viral hepatitis. Roughly 20% of patients will be asymptomatic, with elevated transaminases identified on screening examination or during evaluation for amenorrhea, thyroid disease, arthralgia, or diabetes mellitus. Such patients tend to be older (mean age, 48 years) than patients symptomatic at diagnosis (mean age, 41 years). About 50% of patients with AIH will have concurrent autoimmune disorders, most commonly thyroid disease or rheumatoid arthritis. The presence of ulcerative colitis, however, should raise questions about the diagnosis of AIH; such patients are more likely to have PSC (Table 3.4). Immunologic features
The 3 most commonly reported antibodies in AIH are ANA, SMA, and anti-liver-kidney microsomal (LKM) antibodies (Table 3.5). In general, though useful for diagnosis, the autoantibody titer does not reliably reflect disease severity or outcome. Of the patients with AIH, 70% to 80% have ANA or SMA antibodies or both (1:40). The ANA react mainly with histones and DNA, yielding a homogeneous pattern, but other patterns also occur, with no apparent clinical significance (5–22). The SMA reacts with several cytoskeletal components, including F-actin. Overall, 3% to 4% of the patients (usually children) present with anti-LKM-1 antibodies, without ANA or SMA.
Disease
Most Useful Features
AIH
• “Definite AIH” or “probable AIH” on modified AIH scoring system • Prominent lobular hepatitis • Prominent interface hepatitis with numerous plasma cells • Negative viral studies, including HCV RNA
PBC
• • • •
PSC
• Abnormal cholangiogram • Concentric periductal fibrosis • Ductopenia
HCV
• HCV RNA in serum • Plasma cells usually not prominent • Lobular activity is usually mild; severely active chronic hepatitis favors AIH
Florid duct lesion Ductopenia High titer AMA High alkaline phosphatase with lower transaminase levels
Abbreviations: AIH, autoimmune hepatitis; AMA, antimitochondrial antibodies; HCV, hepatitis C virus; PBC, primary biliary cirrhosis; PBV, primary biliary cirrhosis; PSC, primary sclerosing cholangitis.
TA BL E 3 . 5 Autoantibodies in autoimmune hepatitis Antibody
Test
Comments
ANA
Usual test is indirect IF. Hep-2 cells give higher values than tissue sections; ELISAs not sufficiently standardized.
Specific IF pattern has no clinical significance. Other liver diseases associated with ANA include PBC, PSC, HCV, drug injury, NASH.
SMA
IF and ELISA
Directed against F-actin; found alone or in conjunction with ANA in up to 87% of patients.
SLA/LP
Immunoassay or Western blot; commercial ELISA assay now approved
High specificity for AIH but limited sensitivity.
LKM
Indirect IF
Patients with Type 2 AIH usually have only LKM antibodies. LKM antibodies may be found in other conditions, notably hepatitis C.
Abbreviations: AIH, autoimmune hepatitis; ANA, antinuclear antibody; ELISA, enzyme linked immunosorbent assay; F-actin, filamentous-actin; HCV, hepatitis C virus; IF, immunofluorescence; LKM, liver-kidney microsomal antibody; anti-LKM, anti–liver-kidney microsomal antibody; NASH, nonalcoholic steatohepatitis; PBC, primary biliary cirrhosis; PSC, primary sclerosing cholangitis; SLA/LP, soluble liver antigen/liver pancreas antigen; SMA, anti–smooth muscle antibody.
This serologic marker is more common in southern Europe, but the true prevalence is not known; less than 4% of patients in the United States have LKM-1 antibodies compared with 20% in Europe. Antibodies against the soluble liver antigen/ liver pancreas antigen (SLA/LP) are found in 10% to 30% with AIH; although testing for this autoantibody is not routine, it appears to have a global distribution. Protoplasmic
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H E PAT I T I S / O V E R L A P
antineutrophil cytoplasmic antibodies (p-ANCA), though not specific, are present in 60% to 90% of patients (23). AIH may be subclassified based on the autoantibody profile (Table 3.6); Type 1 AIH is defined as ANA and/or SMA positive and has a bimodal age distribution with peaks between 10 and 20 and 45 and 70 years of age. Type 2 AIH is characterized by the presence of anti-LKM-1 antibodies; the majority of these patients are young women with severe disease. However, because Type 1 AIH is much more common than Type 2, most young women with severe disease are Type 1 AIH. Patients with Type 2 AIH present between ages 2 and 4 years and may have ectodermal dysplasia, mucocutaneous candidiasis, and endocrinopathies suggesting autoimmune polyglandular syndrome Type 1 (24). Type 3 AIH, characterized by positivity for SLA/LP antibodies, is clinically indistinguishable from Type 1. Approximately 10% to 20% of AIH patients are initially seronegative for the conventional autoantibodies, which may appear after immunosuppressive therapy is begun. p-ANCA testing may be helpful in this subgroup of patients, and viral hepatitis B and C should be excluded prior to initiation of treatment. Natural History and Treatment of AIH
AIH is characterized by a fluctuating clinical course, with waxing and waning of necroinflammatory activity, but symptomatic AIH is considered a progressive disease that if untreated will usually result in cirrhosis. About one-third of patients are cirrhotic at presentation and have a less favorable outcome (62% vs 94% 10-year survival) (5). Rarely, patients present with acute liver failure (ALF). The mainstay of treatment for AIH is long-term immunosuppression, typically corticosteroid therapy with or without azathioprine. In most cases, the necroinflammatory process responds promptly to immunosuppressive therapy, although relapses with withdrawal of therapy are common and the disease can recur following liver transplantation. After a biochemical response is achieved, many patients can be maintained on azathioprine monotherapy. A second liver biopsy to determine treatment endpoints based on histologic response is not uniform medical practice.
SYNDROMES
F I G U R E 3 . 4 Normal histologic findings after resolution of autoimmune hepatitis with corticosteroid therapy.
It is generally felt that histologic improvement lags behind biochemical improvement by several months, and often biopsies show low-grade necroinflammatory activity as long as 6 months after normalization of transaminase levels. Some hepatologists require normal histology on liver biopsy before withdrawal of treatment (Figure 3.4). However, histologic resolution does not guarantee that the patient will remain in remission. Portal plasma cell infiltrates during immunosuppressant therapy are associated with relapse upon drug cessation (6,7). For patients who present with fulminant hepatic failure secondary to AIH, liver transplantation may be necessary. Recurrence of AIH in the hepatic allograft is relatively common, occurring in approximately one-third of adult patients (8), and is more common in children. Outcome in most cases appears to be favorable, with few patients requiring retransplantation (8–10). Hepatocellular carcinoma, a relatively common complication of chronic viral hepatitis, is rarely seen in AIH, occurring only in the setting of cirrhosis (11).
References TA B LE 3. 6 Serologic classification of autoimmune hepatitis Autoantibodies
Features
Type 1
ANA and/or SMA
Most common type
Type 2
LKM, ANA, and SMA negative
Young children in the United States; initially thought to have worse prognosis but responds well to treatment.
Type 3
SLA/LP
Indistinguishable clinically from Type 1; clinical course is controversial, possibly more likely to relapse after corticosteroids.
Abbreviations: AIH, autoimmune hepatitis; ANA, antinuclear antibody; LKM, liverkidney microsomal antibody; SMA, smooth muscle antibody; SLA/LP, soluble liver antigen/liver pancreas antigen.
1. Krawitt EL. Autoimmune hepatitis. N Engl J Med. 2006;354:54–66. 2. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31(5):929–938. 3. Johnson PJ, McFarlane IG. Meeting report: International Autoimmune Hepatitis Group. Hepatology. 1993;18:998–1005. 4. Hennes EM, Zeniya M, Czaja AJ, et al. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48(1):169–176. 5. Feld JJ, Dinh H, Arenovich T, Marcus VA, Wanless IR, Heathcote EJ. Autoimmune hepatitis: effect of symptoms and cirrhosis on natural history and outcome. Hepatology. 2005;42(1):53–62. 6. Verma S, Gunuwan B, Mendler M, Govindrajan S, Redecker A. Factors predicting relapse and poor outcome in type I autoimmune hepatitis: role of cirrhosis development, patterns of transaminases during remission and plasma cell activity in the liver biopsy. Am J Gastroenterol. 2004;99:1510–1516.
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7. Czaja AJ, Carpenter HA. Histological features associated with relapse after corticosteroid withdrawal in type 1 autoimmune hepatitis. Liver Int. 2003;23(2):116–123. 8. Campsen J, Zimmerman MA, Trotter JF, et al. Liver transplantation for autoimmune hepatitis and the success of aggressive corticosteroid withdrawal. Liver Transpl. 2008;14(9):1281–1286. 9. Gonzalez-Koch A, Czaja AJ, Carpenter HA, et al. Recurrent autoimmune hepatitis after orthotopic liver transplantation. Liver Transpl. 2001;7(4):302–310. 10. Vogel A, Heinrich E, Bahr MJ, et al. Long-term outcome of liver transplantation for autoimmune hepatitis. Clin Transplant. 2004;18(1):62–69. 11. Yeoman AD, Al-Chalabi T, Karani JB, et al. Evaluation of risk factors in the development of hepatocellular carcinoma in autoimmune hepatitis: implications for follow-up and screening. Hepatology. 2008;48(3): 863–870. 12. Batts KP, Ludwig J. Chronic hepatitis: an update on terminology and reporting. Am J Surg Pathol. 1995;19(12):1409–1417. 13. Scheuer PJ. Classification of chronic viral hepatitis: a need for reassessment. J Hepatol. 1991;13:372–374. 14. Czaja AJ, Carpenter HA. Sensitivity, specificity, and predictability of biopsy interpretations in chronic hepatitis. Gastroenterology. 1993;105:1824–1832. 15. Singh R, Nair S, Farr G, Mason A, Perrillo R. Acute autoimmune hepatitis presenting with centrizonal liver disease: case report and review of the literature. Am J Gastroenterol. 2002;97:2670–2673. 16. Pratt DS, Fawaz KA, Rabson A, Dellelis R, Kaplan MM. A novel histological lesion in glucocorticoid-responsive chronic hepatitis. Gastroenterology. 1997;113:664–668.
SYNDROMES
25
17. Czaja AJ, Carpenter HA. Autoimmune hepatitis with incidental features of bile duct injury. Hepatology. 2001;34:659–665. 18. Bach N, Thung SN, Schaffner F. The histological features of chronic hepatitis C and autoimmune chronic hepatitis: a comparative analysis. Hepatology. 1992;15:572–577. 19. Zen Y, Harada K, Sasaki M, et al. Are bile duct lesions of primary biliary cirrhosis distinguishable from those of autoimmune hepatitis? Interobserver histological agreement on trimmed bile ducts. J Gastroenterol. 2005;40:164–170. 20. Daniels JA, Torbenson M, Anders RA, Boitnott JK. Immunostaining of plasma cells in primary biliary cirrhosis. Am J Clin Pathol. 2009;131(2):243–249. 21. Umemura T, Zen Y, Hamano H, Kawa S, Nakanuma Y, Kiyosawa K. Immunoglobin G4-hepatopathy: association of immunoglobin G4bearing plasma cells in liver with autoimmune pancreatitis. Hepatology. 2007;46(2):463–471. 22. Czaja AJ, Cassani F, Cataleta M, Valentini P, Bianchi FB. Antinuclear antibodies and patterns of nuclear immunofluorescence in type 1 autoimmune hepatitis. Dig Dis Sci. 1997;42(8):1688–1696. 23. McFarlane IG. Autoimmune hepatitis: diagnostic criteria, subclassifications, and clinical features. Clin Liver Dis. 2002;6(3): 605–621. 24. Gregorio GV, Portmann B, Karani J, et al. Autoimmune hepatitis/sclerosing cholangitis overlap syndrome in childhood: a 16-year prospective study. Hepatology. 2001;33(3):544–553.
Case 3.1
Autoimmune Hepatitis With Bile Duct Injury Versus Primary Biliary Cirrhosis KAY WASHINGTON
C L I N I C AL I N F OR M AT I ON
A 35-year-old woman presented with fatigue. There was no history of medication use other than occasional nonsteroidal anti-inflammatory agents for headache, and the patient did not consume alcohol. Physical examination revealed mild icterus and no hepatomegaly or splenomegaly. There were no stigmata of chronic liver disease. Laboratory testing revealed elevated serum transaminases (10 times normal), mildly elevated alkaline phosphatase (twice normal), elevated total bilirubin (3 times normal), and serum IgG (2 times normal). Serologic studies for hepatitis A and B were negative; polymerase chain reaction testing for hepatitis C RNA was negative. R E A S ON F OR R E F E R R A L
The biopsy shows a hepatitic pattern of injury with lymphocytic infiltration of bile ducts but without bile duct loss. Do the findings represent autoimmune hepatitis (AIH) or PBC?
FIGURE
3.1.2
Prominent lobular hepatitis and sinusoidal
lymphocytosis.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows a hepatitis pattern of injury, with portal and periportal lymphoplasmacytic infiltrates, moderate interface hepatitis (Figure 3.1.1), and spotty hepatocyte necrosis with acidophilic bodies in the lobule (Figure 3.1.2). Plasma cells are prominent in the portal infiltrate and are present in clusters both in the lobule (Figure 3.1.3) and in portal tracts. Although bile ducts are focally infiltrated by
F I G U R E 3 . 1 . 3 Cluster of lobular plasma cells.
lymphocytes and show reactive changes (Figure 3.1.1), there is minimal bile duct loss and no florid duct lesions are seen. No hepatocyte “rosettes” are noted, and there is minimal emperipolesis.
DIAGNO SIS
Autoimmune hepatitis with moderate activity, with minor bile duct injury.
FIGURE 3. 1. 1 Portal lymphoplasmacytic inflammatory infiltrate with interface hepatitis and infiltration of bile duct by lymphocytes.
26
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27
D I S C U S S I ON
The pathologic features when considered in concert with the laboratory findings are strongly suggestive of AIH. Further serologic tests were positive for antinuclear and smooth muscle-directed antibodies at less than 1:80 and negative for antimitochondrial antibodies. Application of the modified scoring system for AIH (see Table 3.2 in Chapter 3) based upon the available information provided yields a pretreatment score in the “definite AIH” range. Based on the biopsy and serologic findings, PBC can be excluded, and in the absence of a significant drug history and of evidence of viral hepatitis, the diagnosis of AIH can be made. Grading and Staging
Although not specifically developed for AIH, grading systems developed for chronic hepatitis are often used to grade and stage the necroinflammatory activity and extent of fibrosis. Four-tiered systems such as those described by Batts and Ludwig (1) and Scheuer (2) are perhaps the most widely used in everyday practice. In the Batts and Ludwig system, lobular and interface hepatitis are graded as minimal, mild, moderate, or severe, with the more severe determining the overall grade if a discrepancy exists between portal and lobular necroinflammatory activity. Staging is based on fibrosis, with stage 1 characterized by portal expansion of portal tracts without periportal extension, stage 2 by periportal fibrosis, stage 3 by portal-portal and portal-central bridging fibrosis, and stage 4 by cirrhosis (1).
F I G U R E 3 . 1 . 4 Cirrhosis in autoimmune hepatitis often shows no distinguishing features; degree of activity ranges from minimal in “burned out” cases to severe.
Distinction of Chronic Hepatitis From Chronic Biliary Disease
Distinction of chronic hepatitis from chronic cholestatic disorders such as PBC and PSC is based upon clinical and laboratory findings and histologic features (see Table 3.4 in Chapter 3). AIH is characterized by a hepatitis pattern of injury, usually with prominent interface hepatitis. In the acute phase, lobular inflammation may predominate and fibrosis is minimal. Plasma cells are often prominent and are sometimes seen singly and in clusters in the lobule; however, roughly one-third of biopsies from patients with well-documented AIH will have few or no plasma cells (3). The severity of necroinflammatory activity is quite variable, ranging from mildly active hepatitis to bridging necrosis to massive hepatic necrosis. Hepatocyte regeneration may be prominent, with regenerating rosettelike structures. Ballooning degeneration, spotty hepatocyte necrosis, and apoptotic bodies are common but not specific. As the disease progresses, periportal fibrosis with bile ductular reaction, formation of portal-portal and portal-central bridges, and nodular regeneration result in cirrhosis (Figure 3.1.4) with variable necroinflammatory activity. In PBC, destruction of interlobular bile ducts by a nonsuppurative inflammatory process (Figure 3.1.5) eventually results in chronic cholestasis. In advanced stages of the disease, feathery degeneration of hepatocytes (cholate stasis), due to accumulation of bile salts within the cytoplasm,
F I G U R E 3 . 1 . 5 Bile duct infiltration by lymphocytes in early-stage primary biliary cirrhosis. Note lobular lymphoplasmacytic infiltrate with mild interface inflammation.
imparts a pale appearance to periportal or periseptal hepatocytes (Figure 3.1.6). Canalicular bile plugs are scarce to nonexistent. Although interface inflammation may be identified, it is not as prominent as in AIH, and lobular inflammation is minimal. Bile ductular reaction is common in intermediate stages of PBC but disappears in late-stage disease, leaving empty-appearing fibrous septa. Periportal and periseptal hepatocytes accumulate copper in chronic cholestasis but not in AIH, and this copper storage can be demonstrated with a variety of special stains. Orcein or aldehyde fuchsin stains, which are generally used to demonstrate accumulation of hepatitis B surface antigen, will also highlight increased copper-binding protein, which, like hepatitis B surface antigen, contains a large number of sulfhydryl groups. Positive
28
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SYNDROMES
FIGURE 3. 1. 6 Feathery degeneration in late stage primary biliary cirrhosis is a result of chronic cholestasis and imparts a pale appearance to periportal or periseptal hepatocytes.
F I G U R E 3 . 1 . 7 Zone 3 hepatocyte necrosis and lymphoplasmacytic
staining is seen as granular deposition in periportal hepatocytes. Any of the special stains for copper itself, such as rhodanine or rubeanic acid stain, may also be used. This copper accumulation is not specific, but when found in a precirrhotic liver biopsy, it is highly suggestive of chronic cholestasis, if rare entities such as Wilson disease and Indian childhood cirrhosis have been excluded. Mallory’s hyaline may also be found in periportal hepatocytes in chronic cholestasis and is morphologically indistinguishable from that found in alcoholic liver disease but is not a feature of AIH.
whereas the fact that in PBC an appreciable number of the plasma cells express IgM has prompted investigation as to whether this differential expression can be used to distinguish among the autoimmune liver diseases. However, the utility of this approach has not been validated (9). IgG4-bearing plasma cells have been described in liver disease associated with autoimmune pancreatitis, but are not present in significant numbers in typical AIH (10).
Morphologic Overlap Between PBC and AIH
The liver biopsy findings in AIH vary with the stage of the disease but always reflect a hepatitis pattern of injury. Although distinction of AIH with interface and lobular hepatitis from the classic form of PBC with florid duct lesions and ductopenia is not difficult, some cases of PBC contain appreciable numbers of plasma cells in the portal inflammatory infiltrate and exhibit interface inflammation. However, AIH lacks florid duct lesions and extensive bile duct injury and loss. Prominent lobular necroinflammatory activity is not a feature of PBC, and its presence favors AIH. Centrilobular injury with prominent hepatocellular necrosis and mononuclear inflammation in some cases of AIH, probably representing an early stage of the disease (4,5) (Figure 3.1.7), is also not seen in PBC. Bile duct destruction is generally not prominent in AIH, but up to 12% of AIH biopsies may show duct destruction, and an additional 12% show lymphocytic infiltration of bile duct epithelium without ductopenia (6,7). Taken in isolation the bile duct injury may be indistinguishable from early-stage PBC (8), but consideration of the overall histologic pattern of injury and correlation with serologic, laboratory, and clinical findings will help establish the diagnosis of AIH. It has been observed that plasma cells in AIH are predominantly IgG positive, with few IgM-expressing cells,
infiltration is prominent in some cases of autoimmune hepatitis and may represent an early phase of the disease.
CLINIC A L SIGNIFIC A NCE O F DIST INGUISH ING A IH FRO M P BC
Accurate distinction of AIH from PBC is critically important for selection of appropriate medical therapy. The majority of cases of AIH respond to immunosuppressive therapy, which can be lifesaving in severely active cases and can prevent progression to cirrhosis. In contrast, PBC is treated with the choleretic agent UDCA; in patients with a biochemical response, defined as a greater than 40% decrease in alkaline phosphatase levels within 1 year, survival is improved (11) and transplantation may be avoided. Immunosuppression has been shown in randomized clinical trials to be ineffective in PBC. In addition to being ineffective, steroids can exacerbate osteoporosis that commonly affects elderly women with PBC.
References 1. Batts KP, Ludwig J. Chronic hepatitis: an update on terminology and reporting. Am J Surg Pathol. 1995;19(12):1409–1417. 2. Scheuer PJ. Classification of chronic viral hepatitis: a need for reassessment. J Hepatology. 1991;13:372–374. 3. Czaja AJ, Carpenter HA. Sensitivity, specificity, and predictability of biopsy interpretations in chronic hepatitis. Gastroenterology. 1993;105:1824–1832. 4. Singh R, Nair S, Farr G, Mason A, Perrillo R. Acute autoimmune hepatitis presenting with centrizonal liver disease: case report and review of the literature. Am J Gastroenterol. 2002;97:2670–2673.
CASE
3.1:
AU T O I M M U N E
5. Pratt DS, Frwaz KA, Rabson A, Dellelis R, Kaplan MM. A novel histological lesion in glucocorticoid-responsive chronic hepatitis. Gastroenterology. 1997;113:664–668. 6. Czaja AJ, Carpenter HA. Autoimmune hepatitis with incidental features of bile duct injury. Hepatology. 2001;34:659–665. 7. Bach N, Thung SN, Schaffner F. The histological features of chronic hepatitis C and autoimmune chronic hepatitis: a comparative analysis. Hepatology. 1992;15:572–577. 8. Zen Y, Harada K, Sasaki M, et al. Are bile duct lesions of primary biliary cirrhosis distinguishable from those of autoimmune hepatitis? Interobserver histological agreement on trimmed bile ducts. J Gastroenterol. 2005;40:164–170.
H E PAT I T I S
29
9. Daniels JA, Torbenson M, Anders RA, Boitnott JK. Immunostaining of plasma cells in primary biliary cirrhosis. Am J Clin Pathol. 2009;131(2):243–249. 10. Umemura T, Zen Y, Hamano H, Kawa S, Nakanuma Y, Kiyosawa K. Immunoglobin G4-hepatopathy: association of immunoglobin G4bearing plasma cells in liver with autoimmune pancreatitis, Hepatology. 2007;46(2):463–471. 11. Kuiper EM, Hansen BE, De Vries RA, et al. Improved prognosis of patients with primary biliary cirrhosis that have a biochemical response to ursodeoxycholic acid. Gastroenterology. 2009;136(4):1281–1287.
Case 3.2
Autoimmune Hepatitis–Primary Biliary Cirrhosis Overlap Syndrome KAY WASHINGTON
with numerous collections of mononuclear cells within the lobule and scattered acidophilic bodies (Figure 3.2.3), without bridging necrosis. No hepatocyte rosettes are identified.
C L I N I C AL I N F OR M AT I ON
A 68-year-old woman presented with fatigue. She had elevated liver tests (ALT and AST 4 times normal, alkaline phosphatase 3 times normal, total bilirubin twice normal) and high titer autoantibodies, with ANA, SMA, and AMA positive at 1:1280. Liver biopsy was performed to clarify the nature of the liver disease and to assess for fibrosis.
DIAGNO SIS
Autoimmune hepatitis/primary biliary cirrhosis overlap syndrome .
R E A S ON F OR R E F E R R A L
The liver biopsy shows a combination of bile duct loss and prominent interface and lobular hepatitis with plasma cells. Do the findings represent AIH, PBC, or AIH/PBC overlap syndrome? PAT H OL OG I C F E AT U R E S
The biopsy shows a hepatitis pattern of injury with significant bile duct loss. Most portal tracts contain a moderately dense lymphoplasmacytic infiltrate, with circumferential interface hepatitis and minimal bile ductular reaction (Figure 3.2.1). Focal emperipolesis is seen. The majority of portal tracts in the biopsy lack identifiable bile ducts, although granulomatous florid duct lesions are not seen (Figure 3.2.2). Periportal hepatocytes show mild swelling and cytoplasmic rarefaction, without Mallory’s hyaline accumulation. Plasma cells are present in clusters in the portal inflammatory infiltrate and at the limiting plate. There is moderate to severe lobular hepatitis
F I G U R E 3 . 2 . 2 Portal tract with bile duct loss, without significant
ductular reaction.
FIGURE 3. 2. 1 Portal mononuclear cell infiltrate with plasma cells, interface inflammation, and with no identifiable interlobular bile duct.
F I G U R E 3 . 2 . 3 Prominent lobular necroinflammatory activity similar to autoimmune hepatitis.
30
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H E PAT I T I S – P R I M A RY
D I S C U S S I ON
The diagnosis of AIH/PBC overlap syndrome in this case is based upon an aggregate score of “probable AIH” using the modified scoring system, the presence of high-titer AMA, and the combination of bile duct loss with a hepatitic pattern of injury. The existence of such overlap cases has been controversial, but there is agreement that the term should not be overused, and cases must demonstrate histologic, clinical, and serologic overlap to be classified as such. Up to 10% to 14% of AIH or PBC patients in some series may belong in the AIH/PBC overlap category (1,2), although criteria have varied among studies. Aggregate scores of definite or probable AIH using the modified scoring system of the International Autoimmune Hepatitis Group (3) and cholestatic biochemical studies combined with seropositivity for AMA are helpful. Alternatively, 2 out of 3 criteria for diagnosis of AIH and PBC have been required (Table 3.2.1) (1,4) for diagnosis. Liver biopsies in AIH/PBC overlap cases show features of both PBC (granulomatous inflammation and bile duct lesions) and autoimmune hepatitis (lobular hepatitis with spotty hepatocyte necrosis and acidophil bodies and moderate to severe interface hepatitis) (5). Granulomatous bile duct destruction and well-developed florid duct lesions are not seen in typical AIH. Because interface hepatitis and portal inflammatory infiltrates are common in typical PBC cases, these features alone cannot be used as discriminating features for AIH/PBC overlap. Lobular hepatitis with acidophilic bodies has been reported to be a more useful feature for discriminating between AIH and a spurious AIH/PBC overlap syndrome and may be more reliable than identification of mild forms of bile duct injury (6). Because some patients with clinical and histologic features of autoimmune hepatitis will have serum antimitochondrial antibodies, the presence of AMA in a patient with otherwise typical AIH is not considered sufficient for diagnosis of overlap syndrome. In some cases this apparent AMA positivity is caused by misreading of IF-type tests (confusing anti-LKM antibodies with AMA). In other patients, however, the AMA is truly positive but usually in low titer. Conversely, patients with PBC may have a positive ANA and are not considered to have AIH/PBC overlap unless there is clear evidence of a hepatitic component of liver injury. TABLE 3.2.1 Diagnostic criteria for AIH/PBC overlap syndrome AIH features (2 out of 3 criteria required) • ALT levels 5 times upper limit of normal • Serum IgG levels 2 times upper limit of normal or positive SMA • Liver biopsy with moderate to severe interface hepatitis or lobular acidophilic bodies PBC features (2 out of 3 criteria required) • Alkaline phosphatase levels 2 or GGT levels 5 times upper limit of normal • Positive AMA • Liver biopsy showing florid duct lesions Abbreviations: AIH, autoimmune hepatitis; ALT, alanine aminotransferase; AMA, antimitochondrial antibodies; GGT, gamma glutamyl transpeptidase; IgG, immunoglobulin G; PBC, primary biliary cirrhosis. From Refs. 1, 4.
BILIARY
CIRRHOSIS
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The combination of seropositivity for AMA and for antibodies directed against double-stranded DNA has been described in almost 50% of AIH/PBC overlap syndrome patients compared with 2% of AIH or PBC patients and may represent a useful serologic profile for diagnosis of a subset of overlap syndrome cases (7), although validation studies are needed. In addition to the more commonly encountered cases with “overlapping” simultaneous features of both diseases, rare patients who switch from one disease to another over time have been reported (8). Implications for Therapy and Outcome
Combination therapy with ursodeoxycholic acid (UDCA) and immunosuppression has been advocated, largely on an empiric basis, for treatment of AIH/PBC overlap syndrome, although in some retrospective cohorts in which AIH/PBC overlap patients were identified from treatment trials of PBC patients, response to UDCA without immunosuppression was similar for both groups (4). However, some small nonrandomized studies do offer support for combined UDCA and immunosuppression, and some clinicians advocate dual therapy especially in cases that meet classic criteria for diagnosis of AIH (9) or when treatment with UDCA alone does not result in rapid biochemical response. Higher rates of liver transplantation and complications of portal hypertension in AIH/PBC overlap compared with PBC have been reported, suggesting that the higher risk of adverse outcome associated with overlap with AIH may justify the addition of immunosuppression to the therapeutic regimen in selected patients (10).
References 1. Chazouilleres O, Wendum D, Serfaty L, Montembault S, Rosmorduc O, Poupon R. Primary biliary cirrhosis-autoimmune hepatitis overlap syndrome: clinical features and response to therapy. Hepatology. 1998;28:296–301. 2. Heurgue A, Vitry F, Diebold MD, et al. Overlap syndrome of primary biliary cirrhosis and autoimmune hepatitis: a retrospective study of 115 cases of autoimmune liver disease. Gastroenterol Clin Biol. 2007;31(1):17–25. 3. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31(5):929–938. 4. Joshi S, Cauch-Dudek K, Wanless IR, et al. Primary biliary cirrhosis with additional features of autoimmune hepatitis: response to therapy with ursodeoxycholic acid. Hepatology. 2002;35(2):409–413. 5. Terracciano LM, Patzina RA, Lehmann FS, et al. A spectrum of histopathologic findings in autoimmune liver disease. Am J Clin Pathol. 2000;114(5):705–711. 6. Suzuki S, Arase Y, Ikeda K, et al. Clinical and pathologic characteristics of the autoimmune hepatitis and primary biliary cirrhosis overlap syndrome. J Gastroenterol Hepatol. 2004;19:699–706. 7. Muratori P, Granito A, Pappas G, et al. The serological profile of the autoimmune hepatitis/primary biliary cirrhosis overlap syndrome. Am J Gastroenterol. 2009;104(6):1420–1425. 8. Angulo P, El-Amin O, Carpenter HA, Lindor KD. Development of autoimmune hepatitis in the setting of long-standing primary biliary cirrhosis. Am J Gastroenterol. 2001;3021–3027. 9. Poupon R. Autoimmune overlapping syndromes. Clin Liver Dis. 2003;7:865–878. 10. Silveira MG, Talwalkar JA, Angulo P, Lindor KD. Overlap of autoimmune hepatitis and primary biliary cirrhosis: long-term outcomes. Am J Gastroenterol. 2007;102(6):1244–1250.
Case 3.3
Autoimmune Hepatitis–Primary Sclerosing Cholangitis Overlap Syndrome KAY WASHINGTON
tract contains an interlobular bile duct, but many ducts are distorted and show reactive epithelial change; concentric periductal fibrosis is not noted. There is a moderate degree of lobular inflammation (Figure 3.3.3). Canalicular bile plugs are not present.
C L I N I C AL I N F OR M AT I ON
A 16-year-old girl presented with chronic diarrhea and elevated liver tests (serum ALT and AST 4 times normal, alkaline phosphatase 2 times normal), with normal total bilirubin. The ceruloplasmin level was slightly higher than normal. ANA and anti-SMA were positive, both at 1:80. Endoscopic retrograde cholangiopancreatography (ERCP) showed minimal narrowing of large bile ducts just proximal to the common bile duct, with normal intrahepatic ducts. R E A S ON F OR R E F E R R A L
The liver biopsy shows features of chronic hepatitis and subtle evidence of bile duct loss and injury. Do the findings represent AIH or PSC? PAT H OL OG I C F E AT U R E S
The biopsy shows a hepatitic pattern of injury with a moderate portal chronic inflammatory infiltrate consisting primarily of lymphocytes and plasma cells, and a moderate degree of interface hepatitis (Figure 3.3.1). Portal tracts are enlarged by periportal fibrosis and bile ductular reaction, with focal bridging fibrosis (Figure 3.3.2). Each portal
F I G U R E 3 . 3 . 2 Prominent portal plasma cells with degenerative
changes in interlobular bile duct. Note lack of concentric periductal fibrosis.
FIGURE 3. 3. 1 Lymphoplasmacytic portal inflammatory infiltrate
and mild interface hepatitis. Note degenerative changes in interlobular bile duct, without bile duct loss.
F I G U R E 3 . 3 . 3 Lobular hepatitis and sinusoidal lymphocytosis.
32
CASE
3.3:
AU T O I M M U N E
H E PAT I T I S – P R I M A RY
D I AG N OS I S
Autoimmune hepatitis/primary sclerosing cholangitis overlap syndrome.
D I S C U S S I ON
AIH/PSC overlap has been reported in up to 50% of pediatric patients initially identified as PSC or AIH (1,2). In adults, this overlap syndrome is rarer and is reported in roughly 6% of patients initially diagnosed with AIH (3) and 8% of PSC patients (4). Many pediatric cases are initially diagnosed as AIH; in one 16-year prospective study in which 55 children with AIH were followed, 27 (49%) developed cholangiographic findings typical of PSC (1). Such overlap cases tend to have a worse outcome, with reduction in survival (5) compared with classic AIH and are more likely to require liver transplantation (1). The term “autoimmune sclerosing cholangitis” has been proposed by Gregorio and colleagues for AIH/PSC overlap syndrome (1) in children. Criteria for Diagnosis
AIH/PSC overlap is defined as definite or probable AIH (see Table 3.3 in Chapter 3) with cholangiographic evidence of PSC (6). Use of magnetic resonance cholangiopancreatography (MRCP) imaging techniques is becoming more common in the diagnostic evaluation of autoimmune liver disease and may facilitate early identification of AIH/PSC overlap cases. The liver biopsy in AIH/PSC overlap syndrome (Figures 3.3.1–3.3.3) shows portal inflammation, interface hepatitis, and lobular necroinflammatory activity typical of AIH combined with varying degrees of bile duct injury. As in typical PSC, the liver biopsy may show subtle bile duct injury or loss, and the presence of biliary lesions must be established by cholangiographic studies. The classic lesion for PSC, well-established periductal fibrosis, is rarely seen in biopsies from children with PSC or with AIH/PSC overlap. The finding of ductopenia in a liver biopsy from a young patient suspected of having AIH should prompt consideration of AIH/PSC overlap syndrome. Simultaneous or Sequential Presentation
Sequential syndromes of AIH evolving into PSC are rare in adults but have also been reported (7); such patients may be identified by biliary imaging techniques when their disease
SCLEROSING
CHOLANGITIS
33
becomes refractory to immunosuppression. Early studies interpreted as evolution of AIH to PSC must be interpreted in light of new information regarding prevalence of bile duct changes at diagnosis of AIH (8). In studies performed without ERCP or MRCP at diagnosis, concurrence of AIH and PSC may not have been adequately excluded. Implications for Therapy and Outcome
In most series, these AIH/PSC overlap patients are treated empirically with a combination of immunosuppression and ursodeoxycholic acid (UDCA) (9,10). Although UDCA may lead to improvement in liver tests in PSC, it has not been shown to improve overall survival. As in classic PSC, there is an increased risk of cholangiocarcinoma.
References 1. Gregorio GV, Portmann B, Karani J, et al. Autoimmune hepatitis/sclerosing cholangitis overlap syndrome in childhood: a 16-year prospective study. Hepatology. 2001;33(3):544–553. 2. el-Shabrawi M, Wilkinson ML, Portmann B, et al. Primary sclerosing cholangitis in childhood. Gastroenterology. 1987;92(5 pt 1):1226–1235. 3. Czaja AJ. The variant forms of autoimmune hepatitis. Ann Intern Med. 1996;125:588–598. 4. van Buuren HR, van Hoogstraten HJE, Terkivatan T, Schalm SW, Vleggaar FP. High prevalence of autoimmune hepatitis among patients with primary sclerosing cholangitis. J Hepatol. 2000; 33:543–548. 5. Al-Chalabi T, Portmann BC, Bernal W, McFarlane IG, Heneghan MA. Autoimmune hepatitis overlap syndromes: an evaluation of treatment response, long-term outcome and survival. Aliment Pharmacol Ther. 2008;28(2):209–220. 6. Kaya M, Angulo P, Lindor KD. Overlap of autoimmune hepatitis and primary sclerosing cholangitis: an evaluation of a modified scoring system. J Hepatol. 2000;33(4):537–542. 7. Abdo AA, Bain VG, Kichian K, Lee SS. Evolution of autoimmune hepatitis to primary sclerosing cholangitis: a sequential syndrome. Hepatol. 2002;36(6):1393–1399. 8. Abdalian R, Dhar P, Jhaveri K, Haider M, Guindi M, Heathcote EJ. Prevalence of sclerosing cholangitis in adults with autoimmune hepatitis: evaluating the role of routine magnetic resonance imaging. Hepatology. 2008;47(3):949–957. 9. Floreani A, Rizzotto ER, Ferrara F, et al. Clinical course and outcome of autoimmune hepatitis/primary sclerosing cholangitis overlap syndrome. Am J Gastroenterol. 2005;100:1516–1522. 10. Miloh T, Arnon R, Shneider B, Suchy F, Kerkar N. A retrospective single-center review of primary sclerosing cholangitis in children. Clin Gastroenterol Hepatol. 2009;7(2):239–245.
Case 3.4
Chronic Hepatitis C With Autoantibodies Versus Autoimmune Hepatitis KAY WASHINGTON
C L I N I C AL I N F OR M AT I ON
A 30-year-old woman with hypothyroidism presented with fatigue and had elevated transaminase levels (AST and ALT 3 times normal, alkaline phosphatase normal, total bilirubin normal). Hepatitis virus serologies were negative for hepatitis A and B; hepatitis C antibody test was positive. Serum ANA was positive at 1:640 and SMA at 1:320. R E A S ON F OR R E F E R R A L
The biopsy shows chronic hepatitis with prominent plasma cells. Do the findings represent AIH or chronic hepatitis C? PAT H OL OG I C F E AT U R E S
The liver biopsy shows a portal lymphoplasmacytic infiltrate (Figure 3.4.1) without nodular lymphoid aggregates and germinal centers. Circumferential interface hepatitis is present, with minimal bile ductular reaction. Interlobular bile ducts are unremarkable, and there is no cholestasis. Numerous aggregates of small lymphocytes associated with hepatocyte loss and scattered acidophilic bodies are noted in the lobule (Figure 3.4.2). Periportal fibrosis is present, without bridging. No steatosis is seen. Further investigation reveals that the patient is negative for hepatitis C RNA by PCR-based testing methods and is positive for p-ANCA.
F I G U R E 3 . 4 . 2 Spotty hepatocyte necrosis and sinusoidal lymphocytosis.
DIAGNO SIS
Chronic hepatitis with moderate activity and periportal fibrosis, favor autoimmune hepatitis.
DISCUSSIO N
This patient was considered to have autoimmune hepatitis with false-positive HCV antibodies based on negative PCR for HCV-RNA and clinical features, such as concurrent thyroid disease and positive p-ANCA, favoring an autoimmune etiology. Such cases can present diagnostic and management challenges, as antiviral therapy with interferon may exacerbate autoimmune conditions, whereas immunosuppression, the mainstay of therapy for AIH, can enhance viral replication. Of the patients with chronic HBV or HCV 20% to 40% are persistently positive for various autoantibodies, usually at low titers (~1:20 or 1:40) (1). The use of the AIH Scoring System can be helpful in excluding AIH in patients known to have HCV (2). Conversely, patients with AIH can have a false-positive test for anti-HCV antibodies but will have undetectable HCV-RNA. Three categories of patients with potential concurrent AIH/hepatitis C may be identified: • Patients with true AIH and false-positive anti-HCV antibodies (undetectable HCV-RNA)
FIGURE 3. 4. 1 Prominent plasma cells in portal tracts, with interface
hepatitis.
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H E PAT I T I S
C
35
• Patients with true HCV and autoantibodies at low titers but no other signs of AIH • Patients with true HCV and features of AIH including young age, female gender, high autoantibody titers (1:320), hypergammaglobulinemia, and history of extrahepatic autoimmune disorders There has been considerable controversy about the diagnosis and management of chronic hepatitis patients with autoimmune markers, particularly regarding the presence of anti-LKM antibodies in HCV patients in southern Europe. It has recently been shown that anti-LKM1 antibodies directed against cytochrome P450 2D6 (CYP2D6) can cross-react with HCV proteins, perhaps as a result of molecular mimicry at the B cell level (3). The current general consensus is that interferon therapy is usually safe in HCV patients with anti-LKM1 F I G U R E 3 . 4 . 4 Minimal lobular inflammation in chronic hepatitis C.
autoantibodies. Patients with chronic viral hepatitis should be screened for autoantibodies before starting interferon therapy and monitored carefully. p-ANCA testing may be useful, as this autoantibody is rare in chronic hepatitis C, but relatively common in AIH. Liver biopsy in hepatitis C often shows less interface hepatitis (Figure 3.4.3) and lobular activity (Figure 3.4.4) than in AIH, although the histologic findings can be indistinguishable.
References
FIGURE 3. 4. 3 Portal lymphocytic inflammatory infiltrate in chronic
hepatitis C, with reactive changes in bile ducts. Note minimal interface hepatitis.
1. McFarlane IG. Autoimmune hepatitis: diagnostic criteria, subclassifications, and clinical features. Clin Liver Dis. 2002;6(3):605–621. 2. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31(5):929–938. 3. Marceau G, Lapierre P, Beland K, Soudeyns H, Alvarez F. LKM1 autoantibodies in chronic hepatitis C infection: a case of molecular mimicry? Hepatology. 2005;42:675–682.
Case 3.5
Syncytial Giant Cell Hepatitis KAY WASHINGTON
C L I N I C AL I N F OR M AT I ON
A 20-year-old man developed progressive fatigue over a 2-month span and sought medical attention when he noticed scleral icterus. There was no history of alcohol or drug use, and he was taking no medications. Serum ALT and AST were 10 times normal. Serum total bilirubin was 3 times normal. Serologic studies for hepatitis A and B, as well as molecular studies for hepatitis C were negative. ANA test was positive at 1:160; anti-SMA was negative. R E A S ON F OR R E F E R R A L
The liver biopsy shows active hepatitis with numerous syncytial giant cells. What is the etiology of the giant cell hepatitis in this adult patient? PAT H OL OG I C F E AT U R E S
F I G U R E 3 . 5 . 2 Multinucleated giant cells in zone 3.
The biopsy shows active hepatitis, with numerous apoptotic hepatocytes and spotty hepatocyte necrosis. The portal tracts contain a mononuclear inflammatory infiltrate with scattered plasma cells, and circumferential interface hepatitis is present (Figure 3.5.1). Areas of bridging necrosis are present, and some portal tracts show early fibrosis and bile ductular reaction. The most striking feature is the presence of numerous multinucleated hepatocytes, more prominent in this case in zone 3 of the lobule. The hepatocyte giant cells have a fused or syncytial appearance, and contain from 5 to more than 20 nuclei (Figure 3.5.2). Mild hepatocellular cholestasis is noted.
DIAGNO SIS
Syncytial giant cell hepatitis, probably autoimmune in etiology, with bridging necrosis.
DISCUSSIO N
Giant cell transformation of hepatocytes is a nonspecific tissue reaction in neonates that is rarely seen outside of infancy. In children it is particularly striking in cholestatic disorders and is prominent in neonatal hepatitis, but syncytial hepatocyte giant cells are also seen to a lesser extent in extrahepatic biliary atresia, paucity of intrahepatic bile ducts, alpha-1-antitrypsin deficiency, and many other disorders. In older patients, the presence of numerous hepatocyte giant cells is termed adult or postinfantile giant cell hepatitis or syncytial giant cell hepatitis. This pattern of injury is seen in autoimmune liver disease, drug reactions, and is occasionally reported in human immunodeficiency virus (HIV), hepatitis C (1), and hepatitis B infections. Some cases of adult giant cell hepatitis do not have a clearly established etiology, however, and are regarded as idiopathic. Adult giant cell hepatitis has the same range of histologic features seen in viral or autoimmune hepatitis (AIH), with the additional finding of multinucleated hepatocyte giant cells. The number of multinucleated giant cells, defined as hepatocytes with more than 4 nuclei per cell, is variable, but these cells should be more than a rare isolated occurrence.
FIGURE 3. 5. 1 Interface hepatitis with ballooning degeneration of
hepatocytes.
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SYNCYTIAL
GIANT
The giant cells may be located anywhere within the lobule and sometimes contain Mallory’s hyaline. A 1991 report of paramyxovirus-like particles in biopsies from 8 of 10 patients with adult syncytial giant cell hepatitis stimulated intense interest in an infectious case among idiopathic cases. However, most investigators have been unable to confirm this finding, and the nature of the ultrastructural findings has been questioned. In one series, 40% of patients (2) had evidence of autoimmune disease such as positive ANA or SMA. About 25% of reported patients with postinfantile giant cell hepatitis remain stable or have gradual resolution of the disease. Corticosteroid treatment results in improvement in some but not all patients, and in the setting of autoimmune hepatitis the clinical course may be severe, with most patients progressing to cirrhosis (3). One-third of patients die of liver
CELL
H E PAT I T I S
37
disease, and the remainder progress to cirrhosis or liver failure. Disease recurrence after liver transplantation has been reported and may require retransplantation (4).
References 1. Moreno A, Moreno A, Perez-Elias MJ, et al. Syncytial giant cell hepatitis in human immunodeficiency virus-infected patients with chronic hepatitis C: 2 cases and review of the literature. Hum Pathol. 2006;37(10):1344–1349. 2. Devaney K, Goodman ZD, Ishak KG. Post-infantile giant-cell transformation in hepatitis. Hepatol. 1992;16:327–333. 3. Estradas J, Pascual-Ramos V, Martinez B, Uribe M, Torre A. Autoimmune hepatitis with giant-cell transformation. Ann Hepatol. 2009;8(1):68–70. 4. Pappo O, Yunis E, Jordan JA, et al. Recurrent and de novo giant cell hepatitis after orthotopic liver transplantation. Am J Surg Pathol. 1994;18(8):804–813.
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4 Fatty Liver Disease MATTHEW M. YEH AND ELIZABETH M. BRUNT
I N T ROD U C T I ON
Nonalcoholic steatohepatitis (NASH) is nearly universally associated with metabolic syndrome, which includes central obesity, hypertension, type 2 diabetes or glucose intolerance (insulin resistance), dyslipidemia (hypertriglyceridemia, low high-density triglycerides, and elevated low-density triglycerides), and systemic hypertension. Metabolic syndrome has become an emerging epidemic in the 21st century, not only in the Western countries, but also across the world. NASH may progress to advanced fibrosis, that is, cirrhosis, and may develop hepatocellular carcinoma; therefore, pathologists often encounter liver biopsies in their daily practice to determine the diagnosis of NASH, its differential diagnosis, and activity (grade) and fibrosis (stage) of the disease (1,2). In adults the injury pattern of NASH is zone 3 based and includes the constellation of macrovesicular steatosis, lobular inflammation, liver cell injury, particularly ballooned hepatocytes (Figure 4.1), with or without centrizonal “chicken-wire” fibrosis (Figure 4.2), as cardinal histologic features (3–6). The injury pattern in children may differ from adults. This is discussed in more detail in Chapter 4.10. Clinical evaluation, serologic and laboratory tests, and current imaging modalities, can strongly suggest the presence of hepatic steatosis, but none can distinguish steatohepatitis from uncomplicated steatosis; likewise, these evaluations can generally detect advanced liver disease (ie, portal hypertension), but none can truly assess the degree of liver necroinflammatory injury, lesser stages of fibrosis,
F I G U R E 4 . 2 Masson’s Trichrome stain demonstrates chicken-
wire fibrosis with collagen fibers within the sinusoidal spaces and surrounding the hepatocytes.
and architectural remodeling. Liver biopsy evaluation, therefore, remains the “gold standard” to unequivocally diagnose steatohepatitis and to document the severity of hepatic injury and fibrosis (3,4,7). Of importance, biopsy assessment has also shown that not all individuals with unexplained liver test elevations have fatty liver (8), not all phenotypic “NASH” patients have steatosis (9), and that the full spectrum of fatty liver disease may be present when laboratory values are normal (10). In addition, examination of liver biopsy is useful for detecting possible concomitant or alternative processes (11–13). In fact, studies have reported the observation of histologic features of NASH in biopsies from patients with other serologically and/or clinically defined chronic liver diseases (14,15). Finally, it needs to be emphasized that pathologists can make the diagnosis of steatohepatitis but cannot make the diagnosis of nonalcoholic steatohepatitis as that diagnosis requires the clinical exclusion of alcohol use.
References 1. Bugianesi E, Leone N, Vanni E, et al. Expanding the natural history of nonalcoholic steatohepatitis: from cryptogenic cirrhosis to hepatocellular carcinoma. Gastroenterology. 2002;134–140. 2. Ratziu V, Bonyhay L, Di Martino V, et al. Survival, liver failure, and hepatocellular carcinoma in obesity-related cryptogenic cirrhosis. Hepatology. 2002;35:1485–1493. 3. Brunt EM, Janney CG, Di Bisceglie AM, Neuschwander-Tetri BA, Bacon BR. Nonalcoholic steatohepatitis: a proposal for grading and staging the histological lesions. Am J Gastroenterol. 1999;94:2467–2474.
FIGURE 4. 1 Features of NASH including macrovesicular steatosis,
lobular inflammation, and ballooned hepatocytes.
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4. Kleiner DE, Brunt EM, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41:1313–1321. 5. Ludwig J, Viggiano TR, McGill DB, Oh BJ. Nonalcoholic steatohepatitis: Mayo Clinic experiences with a hitherto unnamed disease. Mayo Clin Proc. 1980;55:434–438. 6. Matteoni CA, Younossi ZM, Gramlich T, Boparai N, Liu YC, McCullough AJ. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology. 1999;116:1413–1419. 7. Farrell GC, Larter CZ. Nonalcoholic fatty liver disease: from steatosis to cirrhosis. Hepatology. 2006;43:S99–S112. 8. Skelly MM, James PD, Ryder SD. Findings on liver biopsy to investigate abnormal liver function tests in the absence of diagnostic serology. J Hepatol. 2001;35:195–199. 9. Merriman RB, Ferrell LD, Patti MG, et al. Correlation of paired liver biopsies in morbidly obese patients with suspected nonalcoholic fatty liver disease. Hepatology. 2006;44:874–880.
LIVER
DISEASE
10. Mofrad P, Contos MJ, Haque M, et al. Clinical and histologic spectrum of nonalcoholic fatty liver disease associated with normal ALT values. Hepatology. 2003;37:1286–1292. 11. Brunt EM. Grading and staging the histopathological lesions of chronic hepatitis: the Knodell histology activity index and beyond. Hepatology. 2000;31:241–246. 12. Brunt EM. Liver biopsy interpretation for the gastroenterologist. Curr Gastroenterol Rep. 2000;2:27–32. 13. Ishak KG. Chronic hepatitis: morphology and nomenclature. Mod Pathol. 1994;7:690–713. 14. Brunt EM, Ramrakhiani S, Cordes BG, et al. Concurrence of histologic features of steatohepatitis with other forms of chronic liver disease. Mod Pathol. 2003;16:49–56. 15. Sanyal AJ, Contos MJ, Sterling RK, et al. Nonalcoholic fatty liver disease in patients with hepatitis C is associated with features of the metabolic syndrome. Am J Gastroenterol. 2003;98:2064–2071.
Case 4.1
Steatosis With Inflammation Versus Steatohepatitis MATTHEW M. YEH AND ELIZABETH M. BRUNT
C L I N IC AL I N F OR M AT I ON
A 40-year-old man underwent gastric bypass because of morbid obesity. He had not had routine checkup for his liver tests. As the liver was mildly enlarged at surgery, a liver biopsy was performed by the surgeon during the gastric bypass surgery. R E A SON F OR R E F E R R AL
There is steatosis and inflammation in the liver biopsy. The referring pathologist’s specific question is whether a diagnosis of steatohepatitis can be established. PAT H OL OG I C F E AT U R E S
The liver biopsy shows a moderate amount of macrovesicular steatosis in zone 3 (Figure 4.1.1). There are also scattered inflammatory foci in the lobules, composed predominantly of lymphocytes and Kupffer cells (Figure 4.1.2). Ballooned hepatocytes are not identified, and a Masson’s Trichrome stain shows no significant fibrosis.
F I G U R E 4 . 1 . 2 The biopsy also shows inflammatory foci in the hepatic lobules, composed predominantly of lymphocytes, Kupffer cells, and pigmented macrophages. Ballooned hepatocytes are not identified.
D I AG N OS I S DISCUSSIO N
Moderate steatosis and lobular inflammation, no evidence of steatohepatitis, history of morbid obesity.
The diagnosis of steatohepatitis may not be as straightforward as the diagnosis of chronic viral hepatitis such as hepatitis B or C, as the latter depends on the combination of clinical, laboratory, and histologic findings. In particular, serology and virology play very critical roles in the clinical evaluation of these diseases; therefore, if virologic and serologic data are compatible, a diagnosis of chronic viral hepatitis is relatively easily reached, and biopsy is largely done for evaluation of activity and fibrosis (1). The diagnosis of steatohepatitis, on the other hand, is not analogous to that of viral hepatitis, as it has been generally conceptualized that steatosis is a necessary but not sufficient component to constitute a diagnosis of steatohepatitis, and inflammation and features of liver cell injury, in particular, a rather specific liver cell injury form, that is, ballooning degeneration (Figure 4.1.3), not typically seen in other liver diseases, are also required features for a confident diagnosis of steatohepatitis to be established. In fact, it has become clearer that steatosis, ballooning, and lobular inflammation are considered the common constellation of minimal criteria for the diagnosis of NASH in adults (2,3). Although it is well known that significant liver disease may exist with liver enzymes in the normal range among nonalcoholic fatty liver disease (NAFLD) patients, it is generally recognized that patients with NASH typically present with mild elevation of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (4).
FIGURE 4.1.1 Moderate macrovesicular steatosis in zone 3
distribution pattern.
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References 1. Brunt EM. Grading and staging the histopathological lesions of chronic hepatitis: the Knodell histology activity index and beyond. Hepatology. 2000;31:241–246. 2. Brunt EM. Nonalcoholic steatohepatitis. Semin Liver Dis. 2004;24:3–20. 3. Yeh MM, Brunt EM. Pathology of fatty liver: differential diagnosis of nonalcoholic fatty liver disease. Diagn Path. 2008;14:586–597. 4. Neuschwander-Tetri BA, Caldwell SH. Nonalcoholic steatohepatitis: summary of an AASLD single topic conference. Hepatology. 2003;37:1202–1219.
FIGURE 4. 1. 3 Several ballooned and swollen hepatocytes with rarefied and clumped cytoplasm.
Case 4.2
Steatohepatitis With Minimal Ballooning MATTHEW M. YEH AND ELIZABETH M. BRUNT
C L I N IC AL I N F OR M AT I ON
DISCUSSIO N
A 55-year-old woman was evaluated for persistent mildly elevated liver tests. She has a medical history of type 2 diabetes. All viral and autoimmune serologic tests were negative. A liver biopsy was performed for further evaluation of her abnormal liver tests.
Hepatocytic ballooning is characterized by cytoplasmic alterations, swelling, and enlargement of hepatocytes, which result in loss of normal hexagonal shape (Figure 4.2.2). The cytoplasm is rarefied or finely reticulated, suggesting accumulation of intracellular fluid; at the ultrastructural level, minute vacuoles of steatosis, and/or other acute or chronic toxic cell injuries have been reported (1,2). Microvesicular steatosis may resemble ballooning degeneration as the hepatocytes may also be enlarged; nonetheless, the nuclei remain centrally located and may appear to be indented by the small fat droplets in microvesicular steatosis (Figure 4.2.3). The presence of larger and hyperchromatic nuclei in the ballooned hepatocytes may also be a subtle difference in distinguishing those with microvesicular steatosis. Predominant microvesicular steatosis is a histologic manifestation of severe liver disease caused by massive mitochondrial dysfunction and should not be seen as the primary type of steatosis in individuals with NAFLD (1,2,3). The enlarged and swollen, glycogen-rich hepatocytes of glycogenosis may occur in glycogen storage diseases or in glycogenic hepatopathy (Figure 4.2.4), which may also mimic ballooned hepatocytes. Glycogenic hepatopathy is a well-characterized entity commonly associated with type 1 diabetics with poor glycemic control (4). Typically, biopsies from patients with glycogenic hepatopathy show diffuse involvement of all hepatocytes, lack zonal and significant steatosis, lobular or portal inflammation, lobular spotty necrosis, and the characteristic perisinusoidal fibrosis of NASH. Megamitochondria can be seen in affected hepatocytes. The clinical setting is also very different (see Chapter 17).
R E A SON F OR R E F E R R AL
There is a moderate amount of macrovesicular steatosis as well as foci of lobular inflammation in the liver biopsy. Only 1 to 2 hepatocytes with possible ballooning are identified. The question from the referring pathologist is whether the findings in the liver biopsy are sufficient for the diagnosis of steatohepatitis. PAT H OL OG I C F E AT U R E S
The liver biopsy shows liver parenchyma with moderate macrovesicular steatosis, in a zone 3 distribution. There are scattered foci of inflammatory infiltrates in the hepatic lobules, composed predominantly of lymphocytes and Kupffer cells. Rare ballooned hepatocytes are identified, located in zone 3 (Figure 4.2.1). Masson’s Trichrome stain shows focal perivenular/pericellular fibrosis.
D I AG N OS I S
Steatohepatitis, with type 2 diabetes.
FIGURE 4. 2. 1 The liver biopsy shows moderate macrovesicular
F I G U R E 4 . 2 . 2 Ballooned hepatocytes are characterized by swelling and enlargement of hepatocytes, loss of the normal hexagonal shape, and rarefied or finely reticulated cytoplasm.
steatosis, foci of mononuclear inflammatory infiltrates in the lobule, and adjacent two ballooned hepatocytes.
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FIGURE 4. 2. 3 The hepatocytes in microvesicular steatosis are enlarged, with centrally located nuclei.
LIVER
DISEASE
Hepatocellular cholestasis may result in swollen and enlarged hepatocytes with flocculent cytoplasm, so-called feathery degeneration in the perivenular region in processes that result in acute cholestasis; in many ways, these may also mimic ballooned hepatocytes. However, the clinical setting of biliary obstruction or drug/toxin injury, the absence of the typical perisinusoidal/pericellular fibrosis, and the presence of canalicular cholestasis differentiates this from the ballooning degeneration of NASH. Cholate stasis, the morphologic alteration in periportal hepatocytes in chronic cholestasis, is also manifested by cellular swelling and cytoplasmic material clumped around the nucleus and large lucent peripheral areas of the cell. Sometimes Mallory-Denk bodies (Mallory’s hyaline) may also be present (5). These changes are noted, however, in the periportal or periseptal regions. Although these findings may be discerned from ballooning degeneration in NASH by the clinical setting and zonal location in the noncirrhotic liver, it is difficult to differentiate these, in advanced fibrosis, as the remodeled parenchyma usually no longer has a distinctly zonal architecture. A copper stain may be able to highlight cholate stasis in this setting. A recent study using immunohistochemistry shows that loss of keratin 8/18 immunostaining can serve as an objective marker of ballooning degeneration (6). Although not widely used, it may be useful in equivocal cases.
References
FIGURE 4. 2. 4 Enlarged and swollen, glycogen-rich hepatocytes in glycogenic hepatopathy. Note that there is no significant steatosis or inflammation.
1. Burt AD, Mutton A, Day CP. Diagnosis and interpretation of steatosis and steatohepatitis. Semin Diagn Pathol. 1998;15:246–258. 2. Fujii H, Ikura Y, Arimoto J, et al. Expression of perilipin and adipophilin in nonalcoholic fatty liver disease; relevance to oxidative injury and hepatocyte ballooning. J Atheroscler Thromb. 2009;16:893–901. 3. Pessayre D, Berson A, Fromenty B, Mansouri A. Mitochondria in steatohepatitis. Semin Liver Dis. 2001;21:57–69. 4. Torbenson M, Chen YY, Brunt E, et al. Glycogenic hepatopathy: an underrecognized hepatic complication of diabetes mellitus. Am J Surg Pathol. 2006;30:508–513. 5. Li MK, Crawford JM. The pathology of cholestasis. Semin Liver Dis. 2004;24:21–42. 6. Lackner C, Gogg-Kamerer M, Zatloukal K, Stumptner C, Brunt EM, Denk H. Ballooned hepatocytes in steatohepatitis: the value of keratin immunohistochemistry for diagnosis. J Hepatol. 2008;48:821–828.
Case 4.3
Steatohepatitis Without Activity MATTHEW M. YEH AND ELIZABETH M. BRUNT
C L I N IC AL I N F OR M AT I ON DIAGNO SIS
A 65-year-old diabetic and overweight man had evidence of portal hypertension, but no known underlying etiology on clinical testing. The patient denied past or current alcohol use; medications included antidiabetic, antihyperlipidemic, and antihypertensive agents.
Cirrhosis, etiology not known, clinical history of overweight, and diabetes.
DISCUSSIO N R E A SON F OR R E F E R R AL
Cryptogenic cirrhosis is the clinical term applied to cases such as this. The findings represent “burned-out” liver disease. This process may occur with a variety of liver diseases in which not only the serologic findings, but also the histopathologic features of the active disease are no longer evident. The common diseases that may result in this process include alcoholic and NASH, autoimmune hepatitis (AIH), and, less commonly, drug-induced liver disease and viral hepatitides. The biliary and metabolic diseases (alpha-1-antitrypsin deficiency and hemochromatosis) would not be in the differential, as histopathologic features of these entities can be documented with careful evaluation. Wilson disease is diagnosed or excluded by tissue copper quantitation. There is a large volume of literature that supports a linkage of biopsy-proven NASH with subsequent “cryptogenic” cirrhosis (1–4). A semantic problem arises with the concept of “cryptogenic”: if the underlying cause of burned-out cirrhosis is known, then, by definition, the cirrhosis is no longer “cryptogenic.” If active features remain, the potential etiology of NAFLD/NASH may be suggested (Figures 4.3.2 and 4.3.3). This, however, is not a small concern; many articles refer to “cryptogenic cirrhosis” as an identified outcome of,
The liver biopsy shows cirrhosis; the referring physician wonders whether the cause can be determined. PAT H OL OG I C F E AT U R E S
Low power evaluation shows that the liver is cirrhotic, and mild to moderate septal inflammatory mixed mononuclear infiltrates admixed with ductular reaction are noted. Occasional lipogranulomas are noted in the septa. On higher power evaluation, no steatosis, ballooning, or Mallory-Denk bodies are seen (Figure 4.3.1). Features of acute cholestasis and chronic cholestasis (cholate stasis) are not appreciated. Lobular inflammation is absent or only focal. Trichrome stain highlights the cirrhotic remodeling; focal perisinusoidal fibrosis is present. Periodic acid–Schiff diastase (PASd) is negative for globules, and iron stain shows varying amounts of periseptal hepatocellular granular reactivity among the nodules.
FIGURE 4. 3. 1 There is obvious cirrhosis with almost no inflammation or hepatocellular alterations to suggest an underlying etiology. The differential diagnosis of “cryptogenic cirrhosis” is broad and includes, but is not limited to, alcoholic and nonalcoholic fatty liver diseases as well as “burned-out” autoimmune liver disease.
F I G U R E 4 . 3 . 2 Same patient as in Figure 4.3.1, but 12 years prior. There is active liver disease noted on this low power evaluation.
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cirrhosis due to ALD. A distinguishing feature of cirrhosis due to ALD is micronodular cirrhosis; however, ALD may also result in mixed micro- and macronodular cirrhosis, and thus, if not present uniformly, micronodularity should not be relied upon for characterization. In summary, cirrhosis secondary to either alcoholic or NAFLD may result in features of inactive liver disease; focal perisinusoidal fibrosis, when present, may strongly support either of these as an underlying etiology. Accurate and astute clinical history may be the only avenue of arriving at the correct diagnosis. Cryptogenic cirrhosis is a term that should only be applied with truly unknown etiology.
References FIGURE 4. 3. 3 On higher power evaluation of the cirrhotic biopsy, there is evidence of hepatocellular ballooning and Mallory-Denk bodies. These features would suggest the possibility of “steatohepatitis” as the initiating cause of cirrhosis. However, they cannot distinguish alcoholic from nonalcoholic fatty liver.
or synonymously with, NASH, which completely ignores the possibility that cirrhosis of “unknown etiology” could be due to the various other processes discussed. In fact, some investigators have utilized the presence of features of NAFLD in an allograft liver as evidence for NASH as the underlying cause of the original disease in the native liver (2,5–8). For pathologists, it is important to keep the differential diagnostic possibilities in mind and to maintain the usage of the term “cryptogenic” for liver disease of truly unknown etiology. Cirrhosis due to burned-out steatohepatitis, whether of alcoholic or nonalcoholic etiology, may, or may not, have residual foci of perisinusoidal fibrosis by histologic evaluation. Steatosis is most commonly absent, as it is recognized that with progression, the active lesions of steatohepatitis may abate (9–12). Hepatocellular ballooning may be present rarely; affected hepatocytes may contain Mallory-Denk bodies. Lipogranulomas in the septa are described as a feature of prior alcoholic steatohepatitis (13), but they may also occur in NAFLD. Either process may result in cholestasis if there is decompensated liver disease and/or sepsis, but features of chronic cholestasis such as copper deposition, have only been described in alcoholic liver disease (ALD) (14). Iron deposition may also occur in cirrhosis and likely is a result of the diminution of hepcidin production due to decreased liver cell mass. Alcohol is also a direct suppressant of hepcidin production by hepatocytes and, thus, iron deposition is common in
1. Browning JD, Kumar KS, Saboorian MH, Thiele DL. Ethnic differences in the prevalence of cryptogenic cirrhosis. Am J Gastroenterol. 2004;99:292–298. 2. Caldwell SH, Oelsner DH, Iezzoni JC, Hespenheide EE, Battle EH, Driscoll CJ. Cryptogenic cirrhosis: clinical characterization and risk factors for underlying disease. Hepatology. 1999;29:664–669. 3. Poonawala A, Nair SP, Thuluvath PJ. Prevalence of obesity and diabetes in patients with cryptogenic cirrhosis: a case-control study. Hepatology. 2000;32:689–692. 4. Struben VM, Hespenheide EE, Caldwell SH. Nonalcoholic steatohepatitis and cryptogenic cirrhosis within kindreds. Am J Med. 2000;108:9–13. 5. Charlton MR, Kondo M, Roberts SK, Steers JL, Krom RA, Wiesner RH. Liver transplantation for cryptogenic cirrhosis. Liver Transpl Surg. 1997;3:359–364. 6. Contos MJ, Cales W, Sterling RK, et al. Development of nonalcoholic fatty liver disease after orthotopic liver transplantation for cryptogenic cirrhosis. Liver Transpl. 2001;7:363–373. 7. Maor-Kendler Y, Batts KP, Burgart LJ, et al. Comparative allograft histology after liver transplantation for cryptogenic cirrhosis, alcohol, hepatitis C, and cholestatic liver diseases. Transplantation. 2000;70:292–297. 8. Ong J, Younossi ZM, Reddy V, et al. Cryptogenic cirrhosis and posttransplantation nonalcoholic fatty liver disease. Liver Transpl. 2001; 7: 797–801. 9. Abdelmalek M, Ludwig J, Lindor KD. Two cases from the spectrum of nonalcoholic steatohepatitis. J Clin Gastroenterol. 1995;20:127–130. 10. Brunt EM. Nonalcoholic steatohepatitis: definition and pathology. Semin Liver Dis. 2001;21:3–16. 11. Brunt EM. Nonalcoholic steatohepatitis: pathologic features and differential diagnosis. Semin Diagn Pathol. 2005;22:330–338. 12. Brunt EM, Tiniakos DG. Alcoholic and nonalcoholic fatty liver disease. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract and Pancreas. 2nd ed. Philadelphia, PA: Elsevier; 2009:1007–1014. 13. Yip WW, Burt AD. Alcoholic liver disease. Semin Diagn Pathol. 2007;23:149–160. 14. Hall PDLM. Alcoholic liver disease. In: MacSween RNM, Burt AD, Portmann BC, Ishak KG, Scheuer PJ, Anthony PP, eds. Pathology of the Liver. 4th ed. London, UK: Churchill Livingstone; 2002:273–311.
Case 4.4
Nonalcoholic Steatohepatitis With Moderate/Marked Portal Inflammation MATTHEW M. YEH AND ELIZABETH M. BRUNT
C L I N IC AL I N F OR M AT I ON
A 45-year-old woman with phenotypic metabolic syndrome (increased waist to hip ratio, hypertension, elevated fasting glucose, and high high-density lipoprotein (HDL) levels) and elevated ALT had been biopsied for confirmation of clinical diagnosis of fatty liver and evaluation of severity of injury (grade and stage). The clinical workup was negative for viral hepatitis markers; ceruloplasmin and alpha-1-antitrypsin levels were normal. Antinuclear antibody (ANA) was positive but in low titer. Globulin levels were normal. Platelets were slightly depressed, but other hematologic values were normal. R E A SON F OR R E F E R R AL
The liver biopsy, otherwise suggestive of steatohepatitis, showed bridging fibrosis with prominent portal inflammation. The clinical concern was for AIH or AIH-overlap with steatohepatitis.
F I G U R E 4 . 4 . 2 Higher power evaluation of the same biopsy as in
Figure 4.4.1 shows ballooned hepatocytes, pigmented Kupffer cells, and a suggestion of perisinusoidal fibrosis. Mononuclear lobular inflammation is also present.
PAT H OL OG I C F E AT U R E S
The liver architecture is altered by bridging fibrosis and nodularity (Figure 4.4.1). There is evidence of hepatitis and hepatocellular injury including mixed small- and large droplet macrovesicular steatosis in an azonal distribution, hepatocyte ballooning, scattered inflammatory foci of mononuclear cells, single droplet lipogranulomas surrounded by Kupffer cells and an occasional eosinophil, and microgranulomas (Figure 4.4.2). Masson’s Trichrome stain highlights enlarged
F I G U R E 4 . 4 . 3 Trichrome stain highlights the dense portal chronic inflammation of a residual portal tract and zone 3 perisinusoidal fibrosis.
portal areas, septal fibrosis, and residual foci of perisinusoidal fibrosis (Figures 4.4.3 and 4.4.4). On higher magnification, expansion of septa by chronic inflammation with mixed mononuclear cells and focal “interface hepatitis” are noted (Figure 4.4.5). Plasma cells were not dominant in either portal or lobular infiltrates. Hepatitic rosettes were not present. No evidence of confluent or bridging necroses was seen.
FIGURE 4. 4. 1 On low power evaluation, there is evidence of fatty liver, bridging fibrosis, and nodularity. Portal/septal chronic inflammation is brisk, and interface activity can be seen.
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FIGURE 4. 4. 4 On trichrome stain the perisinusoidal fibrosis is evi-
dent and “dense.”
FIGURE 4. 4. 5 Interface hepatitis can be appreciated on this high
power view.
D I AG N OS I S
Nonalcoholic steatohepatitis with moderate activity and bridging fibrosis.
LIVER
DISEASE
with notable polymorphonuclear leukocytes is most likely indicative of alcoholic rather than nonalcoholic origin. The finding is common in association with ductular reaction and may represent cholangiolitis due to pancreatitis. In this setting, the portal areas take on a somewhat “holly-leaf” configuration; the proliferated ductular structures are intimately admixed with the spikes. The most common infiltrates in steatohepatitis, however, are “chronic” mixed mononuclear cells and occasionally, eosinophils. An important consideration in any liver biopsy with steatosis or steatohepatitis with or without notable portal chronic inflammation is Wilson disease (see Chapter 21). This disease has unknown prevalence, but studies have shown that Wilson disease is not restricted to the pediatric age group and may be diagnosed in individuals in middle age or older age groups (1). The key to the diagnosis is a high index of suspicion; this may first come from the pathologist. The primary clinical finding is often otherwise unexplained elevated liver tests. Histopathologic features can be as variable as the clinical features; none are absolutely diagnostic or required, and they may be present in varying combinations (1,2). Macrovesicular steatosis and portal chronic inflammation, swollen hepatocytes with or without Mallory-Denk bodies, “atypical lipofuscin” characterized by either non–zone 3 restriction or by large chunky granules, canalicular bile stasis, and megamitochondria are described. There may be portal expansion and portalbased fibrosis, or cirrhosis may be present. It is not uncommon for clinical evidence of either fulminant or submassive necrosis to show histologic features of cirrhotic remodeling with marked lobular activity. Copper staining itself is not the diagnostic standard for this disease. Although very high hepatic copper is present, histochemical stains for copper or copperbinding protein may not be able to detect it. Thus, the standard for diagnosis is copper quantitation from liver tissue; this can be obtained from the paraffin block (1). Explant livers from treated patients commonly show cirrhosis without activity and copper deposition extensively throughout the nodules. Portal accentuation (inflammation, fibrosis) is a common finding in pediatric NAFLD (3) (Figure 4.4.6). Portal chronic inflammation has also been noted as a feature of resolution of NASH in treatment trials (3,4) (Figure 4.4.7). Portal inflammation may also be a component of the injury in NASH (5) and has recently been shown to correlate with both increased fibrosis as well as more severe clinical features of NASH in adults and children (5,6). Finally, portal inflammation that is “disproportionate” to the lobular injury may be an indication of concurrent liver disease such as chronic viral hepatitis, AIH, and other forms of chronic liver disease (7,8). NASH and Other Concurrent Disease(s)
D I SC U SSI ON Significance of Portal Inflammation in NASH
Portal infiltrates can be characterized as either “chronic inflammation” dominant or polymorphonuclear leukocyte dominant. In the setting of steatohepatitis, portal expansion
The concept that more than one disease process could occur and could be detectable by liver biopsy evaluation was proposed and initially published by 2 groups (9–11) and subsequently confirmed by others. Two strong arguments allowed this concept to be accepted: (1) NAFLD was increasingly recognized as a widespread entity in the United States, and (2)
CASE
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NONALCOHOLIC
S T E AT O H E PAT I T I S
49
Diagnostic Criteria of Concurrent Disease
FIGUR E 4. 4. 6 Liver biopsy from a pediatric NAFLD patient high-
lights portal accentuation and portal chronic inflammation.
Investigators’ criteria for diagnosing both steatohepatitis and another liver disease differ. The authors’ criteria are more “strict” than for otherwise uncomplicated steatohepatitis so that this condition is not overdiagnosed (15). Thus, in addition to steatosis, ballooning may or may not be seen, Mallory-Denk bodies may or may not be present; but in noncirrhotic livers, zone 3 perisinusoidal fibrosis is required (see Figure 4.4.4). Lobular inflammation is a nondiscriminatory finding of most forms of chronic hepatitis and thus is not a required feature. Zone 3 accentuation of the necroinflammatory lesions may be lost with progression of fibrosis and architectural remodeling. Other groups have utilized less stringent criteria and discuss steatosis, lobular inflammation, and ballooning as features to characterize concurrent steatohepatitis (13,16). Suggesting that another form of chronic liver disease is present in a clinical and histologic setting of steatohepatitis can be characterized by finding the diagnostic lesions of the entity, such as periportal globules to suggest alpha-1antitrypsin deficiency, or markedly increased hepatocellular iron to suggest possible iron overload. Other, more common processes are discussed below. Hepatitis C Virus With Steatosis: Concurrent or Synonymous?
Steatosis alone has been recognized as a cofactor of progression in most liver diseases, including viral hepatitides, AIH, primary biliary cirrhosis, hereditary hemochromatosis (15). Steatosis can be found in the majority of hepatitis C virus (HCV) cases; the incidence of steatohepatitis, however, is significantly less (16) (Figures 4.4.8 and 4.4.9). Steatosis is thought to be related to “host” effects of weight, insulin resistance (IR), and diabetes mellitus (DM) in genotypes non-3 HCV, whereas genotype 3 HCV commonly results in hepatic steatosis due to viral
FIGUR E 4. 4. 7 Relative increase of portal inflammation compared
with the decrease in lobular inflammation and other features of active steatohepatitis has been reported in responders in treatment trials. This was demonstrated in the case of a patient who had clinical and histologic response to rosiglitazone.
chronic hepatitis C patients who lost weight showed improved liver tests and histologic findings in spite of lack of viral load alterations (10). Although exact figures are virtually impossible to discern, published work from referral centers has shown that around 5% of subjects with other diagnosed forms of chronic liver disease also have NAFLD or NASH (11-13). It is now currently accepted that even alcoholic liver disease can be concurrent with NAFLD/NASH, as proposed in the 1990s (14), although distinguishing the 2 typically relies on clinical findings.
F I G U R E 4 . 4 . 8 This biopsy is from a patient with HCV; it was done for grading and staging of HCV. The biopsy clearly shows the lesions of active steatohepatitis: zone 3 steatosis, ballooning, and perisinusoidal fibrosis. This is, therefore, a case of concurrent HCV and steatohepatitis.
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LIVER
DISEASE
F I G U R E 4 . 4 . 1 0 The trichrome stain demonstrates the diagnosis of
steatohepatitis in this case; zone 3 perisinusoidal fibrosis. The patient, however, is ANA positive. FIGURE 4. 4. 9 The trichrome stain of the same case highlights the
zone 3 perisinusoidal fibrosis.
promotion of hyperlipidemia but not the metabolic effects of IR. Whether steatosis promotes fibrosis, lack of response to treatment, and hepatocellular carcinoma in HCV-infected subjects are ongoing discussions recently reviewed (17). In a prospective study of biopsies and demographics in 278 hepatitis C patients (16), steatosis was noted in 34% and concurrent steatohepatitis in 9%. Two retrospective series documented steatohepatitis and HCV in 5% of cases (11,12). Bedossa et al showed that nongenotype 3 biopsies with steatohepatitis had greater fibrosis as well as elevated liver tests and serum triglycerides compared with controls. The study used ballooning and perisinusoidal fibrosis as features of concurrent steatohepatitis. The impact of concurrent underlying IR and/or DM on response to treatment for HCV has been reviewed (18,19). In brief, treatment of either has a potentially positive effect on both; whereas the presence of IR and/or DM negatively impacts response to HCV therapy and is related to progression of fibrosis. ANA/ASMA/AMA Pos NAFLD/NASH: What Does This Mean to the Pathologist?
Up to 5% of biopsies with features of other forms of chronic liver disease may have histopathologic features of concurrent steatohepatitis (11). This number may actually have increased since the original studies were published, as the prevalence of obesity has not abated. However, studies have also shown a range of non–organ-specific autoantibody positive cases of NAFLD. Typically, the autoantibody is ANA and/or anti–smooth muscle antibody (ASMA), but less commonly, antimitochondrial antibodies (AMA) or protoplasmic antineutrophil cytoplasmic antibodies (p-ANCA) have been noted (Figure 4.4.10). The prevalence has varied but may be as high as 30% overall (20,21). For a pathologist, the presence of a positive serologic test should initiate care in evaluation of liver biopsies in order to either document or exclude a concurrent disease. In a case
F I G U R E 4 . 4 . 1 1 This is an example of AMA positive primary biliary
cirrhosis (PBC) and steatohepatitis concurrent disease. The photomicrograph illustrates a florid duct lesion and shows some of the steatosis present elsewhere in the biopsy. The biopsy also had zone 3 perisinusoidal fibrosis.
with positive AMA, florid duct lesion and other features of chronic cholestasis (such as the presence of periportal copper in a noncirrhotic liver) that suggest primary biliary cirrhosis should be noted (Figure 4.4.11). A positive ANA with or without positive ASMA, however, is more common than AMA, and potentially raises considerable difficulties. Just as the presence of ANA cannot be considered diagnostic of AIH, simply the presence of plasma cells in portal inflammation cannot be considered sufficient criteria; in overlap of AIH and NASH, portal inflammation is marked and plasma cells are abundant, are present at the interface, and are present in the lobules. In addition, hepatitic rosettes and/or confluent necroses may be noted. A final finding for consideration of overlap with AIH is the presence of elevated globulins, particularly immunoglobulin G (IgG), in the serum. Without this, the diagnosis may be suggested but not unequivocally made. Alternatively, patients
CASE
4.4:
NONALCOHOLIC
with AIH may be receiving steroid therapy and may have steatosis (but not steatohepatitis with zone 3 perisinusoidal fibrosis) due to the medications. At the current time, the meaning of ANA-positive steatohepatitis is not clear; some authors have found increased severity of steatohepatitis (22–24), but this is not necessarily the case (25).
References 1. Ferenci P, Caca K, Loudianos G, et al. Diagnosis and phenotypic classification of Wilson disease. Liver Int. 2003;23:139–142. 2. Ishak KG. Inherited metabolic diseases of the liver. Clin Liver Dis. 2002;6:455–479, viii. 3. Schwimmer JB, Behling C, Newbury R, et al. Histopathology of pediatric nonalcoholic fatty liver disease. Hepatology. 2005;42:641–649. 4. Brunt EM. Pathology of nonalcoholic fatty liver disease. Nat Rev Gastroenterol Hepatol. 2010;7:195–203. 5. Brunt EM, Janney CG, Di Bisceglie AM, Neuschwander-Tetri BA, Bacon BR. Nonalcoholic steatohepatitis: a proposal for grading and staging the histological lesions. Am J Gastroenterol. 1999;94:2467–2474. 6. Brunt EM, Kleiner DE, Wilson LA, et al. Portal chronic inflammation in nonalcoholic fatty liver disease (NAFLD): a histologic marker of advanced NAFLD-clinicopathologic correlations from the nonalcoholic steatohepatitis clinical research network. Hepatology. 2009;49:809–820. 7. Brunt EM. Nonalcoholic steatohepatitis. Semin Liver Dis. 2004;24:3–20. 8. Brunt EM, Clouston AD. Histologic features of fatty liver disease. In: Bataller R, Caballeria J, eds. Nonalcoholic Steatohepatitis (NASH). Barcelona: Permanyer; 2007:95–110. 9. Clouston AD, Powell EE. Interaction of non-alcoholic fatty liver disease with other liver diseases. Best Pract Res Clin Gastroenterol. 2002;16: 767–781. 10. Hickman IJ, Clouston AD, Macdonald GA, et al. Effect of weight reduction on liver histology and biochemistry in patients with chronic hepatitis C. Gut. 2002;51:89–94. 11. Brunt EM, Ramrakhiani S, Cordes BG, et al. Concurrence of histologic features of steatohepatitis with other forms of chronic liver disease. Mod Pathol. 2003;16:49–56.
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12. Ramesh S, Sanyal AJ. Hepatitis C and nonalcoholic fatty liver disease. Semin Liver Dis. 2004;24:399–413. 13. Ong JP, Younossi ZM, Speer C, Olano A, Gramlich T, Boparai N. Chronic hepatitis C and superimposed nonalcoholic fatty liver disease. Liver. 2001;21:266–271. 14. Naveau S, Giraud V, Borotto E, Aubert A, Capron F, Chaput JC. Excess weight risk factor for alcoholic liver disease. Hepatology. 1997;25: 108–111. 15. Yeh MM, Brunt EM. Pathology of nonalcoholic fatty liver disease. Am J Clin Pathol. 2007;128:837–847. 16. Bedossa P, Moucari R, Chelbi E, et al. Evidence for a role of nonalcoholic steatohepatitis in hepatitis C: a prospective study. Hepatology. 2007;46:380–387. 17. Powell EE, Jonsson JR, Clouston AD. Steatosis: co-factor in other liver diseases. Hepatology. 2005;42:5–13. 18. Cross TS, Rashid MM, Berry PA, Harrison PM. The importance of steatosis in chronic hepatitis C infection and its management: a review. Hepatology Research. 2010;40:237–247. 19. Blonsky JJ, Harrison SA. Review article: nonalcoholic fatty liver disease and hepatitis C virus—partners in crime. Aliment Pharmacol Ther. 2008;27:855–865. 20. Loria P, Lonardo A, Leonardi F, et al. Non-organ-specific autoantibodies in nonalcoholic fatty liver disease: prevalence and correlates. Dig Dis Sci. 2003;48:2173–2181. 21. Loria P, Carulli L, Lonardo A. The prevalence of autoantibodies and autoimmune hepatitis in patients with nonalcoholic fatty liver disease. Am J Gastroenterol. 2005;100:1200–1201. 22. Adams LA, Lindor KD, Angulo P. The prevalence of autoantibodies and autoimmune hepatitis in patients with nonalcoholic fatty liver disease. Am J Gastroenterol. 2004;99:1316–1320. 23. Niwa H, Sasaki M, Haratake J, et al. Clinicopathological significance of antinuclear antibodies in non-alcoholic steatohepatitis. Hepatol Res. 2007;37:923–931. 24. Bacon BR, Farahvash MJ, Janney CG, Neuschwander-Tetri BA. Nonalcoholic steatohepatitis: an expanded clinical entity. Gastroenterology. 1994;107:1103–1109. 25. Brunt EM. Pathology of hepatic iron overload. Semin Liver Dis. 2005;25:392–401.
Case 4.5
Steatohepatitis With Elevated Serum Iron Indices and Siderosis MATTHEW M.YEH AND ELIZABETH M. BRUNT
C L I N I C AL I N F OR M AT I ON DIAGNO SIS
A 48-year-old man presented with abnormal liver tests. He had metabolic syndrome including type 2 diabetes, obesity, and hyperlipidemia. Laboratory data also showed elevated serum iron indices, including increased transferrin saturation and ferritin. There was no family history of liver diseases. Physical examination did not reveal abnormal skin pigmentation and he had no joint pain. A liver biopsy was performed while results for genetic testing were awaited.
Steatohepatitis with mild iron deposition in the hepatocytes and sinusoidal lining cells.
DISCUSSIO N
Similar to alcoholic liver disease, iron deposition in NAFLD is not uncommon, especially in end-stage liver cirrhosis. Previous studies examining liver explants found increased iron in a significant number of nonbiliary cirrhosis cases, including NAFLD, with hepatic iron indices or 1.9 (the value commonly associated with hereditary hemochromatosis), indicating that nonbiliary cirrhosis may result in abnormal iron accumulation (1,2). The current explanation is that endstage liver disease leads to decreased expression of hepcidin, a negative regulator of iron homeostasis. Loss of hepcidin results in promoting excess release of iron from the reticuloendothelial cells, enhancing duodenal iron absorption and increasing iron uptake by the hepatocytes. Therefore overinterpretation of iron overload in biopsies from NAFLD-induced cirrhosis needs to be cautioned against. Iron deposition in NAFLD may be hepatocellular (Figure 4.5.1), reticuloendothelial (Figure 4.5.2), or both.
R E A S ON F OR R E F E R R A L
The liver biopsy shows features of steatohepatitis. In addition, there is significant hepatocyte iron deposition on using Perls’ iron stain. The specific question from the referring pathologist and hepatologist is whether the patient has hemochromatosis. PAT H OL OG I C F E AT U R E S
Besides the features of steatohepatitis, the liver biopsy also shows a mild degree of (grade 2 of 4) iron granules deposition within the hepatocytes and sinusoidal lining cells on using Perls’ iron stain (Figure 4.5.1).
FIGURE 4. 5. 1 Perls’ iron stain shows mild iron deposition in the hepatocytes and Kupffer cells.
F I G U R E 4 . 5 . 2 Perls’ iron stain demonstrates deposition in Kupffer
cells in an NAFLD case.
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NASH
WITH
E L E VAT E D
The pattern of iron deposition in the hepatocytes may inhomogenously involve zone 1, or may be similar to hereditary hemochromatosis, with a decreasing gradient from zone 1 to zone 3. Iron deposition in the reticuloendothelial cells, is typically punctuate and may be panacinar. NAFLD has been reported to be associated with increased serum iron indices including transferrin saturation and ferritin independent of genetic hemochromatosis. However, other studies showed the C282Y HFE gene mutation was enriched in NAFLD patients (3,4) and there was a significant correlation among the mutation, hepatic iron concentration or tissue iron stain, and degree of fibrosis (3). Thus liver biopsy in NAFLD patients may also provide prognostic implication in assessing hepatic iron stores, in addition to confirming the diagnosis. Although elevated serum ferritin may be a manifestation of aberrant HFE genetics (4), it has to be noted that elevated serum ferritin levels do not necessarily reflect increased hepatic iron stores, as ferritin is a known acute phase reactant protein and may be nonspecifically elevated in NAFLD alone or in insulin resistance (5,6). Whether
SERUM
IRON
INDICES
53
aberrant genetics, iron deposition, and localization of increased iron in NAFLD relate to progression of disease are areas of active investigation.
References 1. Ludwig J, Hashimoto E, Porayko MK, Moyer TP, Baldus WP. Hemosiderosis in cirrhosis: a study of 447 native livers. Gastroenterology. 1997;112:882–888. 2. Deugnier Y, Turlin B, le Quilleuc D, et al. A reappraisal of hepatic siderosis in patients with end-stage cirrhosis: practical implications for the diagnosis of hemochromatosis. Am J Surg Pathol. 1997;21:669–675. 3. George DK, Goldwurm S, MacDonald GA, et al. Increased hepatic iron concentration in nonalcoholic steatohepatitis is associated with increased fibrosis. Gastroenterology. 1998;114:311–318. 4. Bonkovsky HL, Jawaid Q, Tortorelli K, et al. Non-alcoholic steatohepatitis and iron: increased prevalence of mutations of the HFE gene in nonalcoholic steatohepatitis. J Hepatol. 1999;31:421–429. 5. Bugianesi E, Manzini P, D’Antico S, et al. Relative contribution of iron burden, HFE mutations, and insulin resistance to fibrosis in nonalcoholic fatty liver. Hepatology. 2004;39:179–187. 6. Zelber-Sagi S, Nitzan-Kaluski D, Halpern Z, Oren R. NAFLD and hyperinsulinemia are major determinants of serum ferritin levels. J Hepatol. 2007;46:700–707.
Case 4.6
Alcoholic Steatohepatitis MATTHEW M.YEH AND ELIZABETH M. BRUNT
As can be recalled, the term “nonalcoholic steatohepatitis,” credited to Ludwig et al from the 1980 publication (1) derived from the initial consideration of liver biopsy findings identical to ALD in patients who did not consume alcohol. These findings included macrosteatosis, ballooning, the presence of Mallory’s hyaline, now referred to as Mallory-Denk bodies (2), lipogranulomas, and varying degrees of fibrosis, including perisinusoidal, “chicken-wire” fibrosis. The clinical features included female gender, overweight, diabetes, and hyperlipidemia. These same clinical and histologic findings had been previously or concurrently reported in the similar setting of overweight and/or diabetes by others in the United States (3,4), Europe (5), and Japan (6) and were subsequently confirmed from studies around the world. Unfortunately, both the negative nomenclature (“non” alcoholic) and the concept of inseparability from “alcoholic histologic features” are embedded in the literature. Currently, there is discussion in the literature as to the amount of alcohol intake required for consideration of ALD (7). However, as pointed out, more than simply an amount may be causative; in fact, types of alcohol consumed and patterns are also important considerations (8). Most NAFLD literature lists consumption of 20g/d for men and 10g/d for women as the upper limit for “exclusion of ALD” as a contributor to liver disease.
F I G U R E 4 . 6 . 1 Active steatohepatitis with perisinusoidal fibrosis. Whether the lesions are caused by the patient’s diabetes or “mild alcohol” use, or both, cannot be discerned by histology.
DIAGNO SIS
Steatohepatitis, history of obesity, diabetes, and alcohol use.
DISCUSSIO N
The overlapping and often inseparable features of ALD and NAFLD are likely a reflection of the overlapping underlying pathophysiology of these 2 processes. The features in common include steatosis, that is, macrovesicular steatosis with or without lobular inflammation and with or without foci of microvesicular steatosis, with or without megamitochondria; and steatohepatitis, that is, steatosis with hepatocyte ballooning, with or without Mallory-Denk bodies, lobular inflammation, varying degrees of portal inflammation, and with or without varying amounts of perisinusoidal fibrosis. Cirrhosis, with or without the features above, may also occur in both processes. It is for these reasons, as illustrated in the case, pathologists cannot always assign an etiology, and it is recommended that the report simply state what is present, that is, steatohepatitis, and what is known clinically, that is obesity, diabetes, alcohol use. However, there are features of ALD that, to date, have not been reported in NAFLD. First, alcoholic hepatitis or cirrhosis due to alcohol may have a veno-occlusive lesion of subendothelial fibrosis or obliteration (9). Secondly, alcoholic hepatitis may or may not have steatosis but is characterized by numerous hepatocytes with Mallory-Denk bodies and satellitosis (polymorphonuclear leukocytes surrounding the affected cells). The affected hepatocytes may be ballooned or undergoing apoptosis and are eosinophilic and shrunken.
C L I N I C AL I N F OR M AT I ON
The patient is a 58-year-old obese, diabetic man with elevated liver tests: alanine aminotransferase (ALT) 59 IU/L, aspartate transaminase (AST) 76 IU/L, and hemoglobin A1C (HbA1C) 7.7. The patient’s history includes “mild” alcohol use. R E A S ON F OR R E F E R R A L
The question in this liver biopsy is one of attribution of cause of elevated liver tests: specifically, are they due to alcoholic steatohepatitis or nonalcoholic steatohepatitis? PAT H OL OG I C F E AT U R E S
The histologic features of the biopsy are those of markedly active steatohepatitis with grade 1 (5%–33%) macrovesicular steatosis in a nonzonal distribution, marked ballooning and evidence of Mallory-Denk bodies, moderate lobular and portal chronic inflammation. Perisinusoidal and periportal fibrosis can be discerned even on the hematoxylin and eosin (HE)–stained slides (Figure 4.6.1).
54
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ALCOHOLIC
Thirdly, canalicular cholestasis has yet to be reported in NAFLD. Finally, alcoholic foamy degeneration has also not been reported in NAFLD. This is an uncommon form of ALD; the hepatocytes appear uniformly foamy and there is little to no portal and/or lobular inflammation (10).
References 1. Ludwig J, Viggiano TR, McGill DB, Oh BJ. Nonalcoholic steatohepatitis: Mayo Clinic experiences with a hitherto unnamed disease. Mayo Clin Proc 1980 Jul;55(7);434–438. 2. Zatloukal K, French SW, Denk H, et al. From Mallory to MalloryDenk inclusion bodies: what, how and why? Exp Cell Res. 2007;313: 2033–2049. 3. Miller DJ, Ishimaru H, Klatskin GGA. Nonalcoholic liver disease mimicking alcoholic hepatitis and cirrhosis. Gastroenterology. 1979;77:27A.
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4. Schaffner F, Thaler H. Nonalcoholic fatty liver disease. Progr Liver Dis. 1986;8:283–298. 5. Thaler H. Die fettleber und ihre pathogenetische Beziehung zur Leberzirrhose. Virchows Arch. 1962;335:180–188. 6. Itoh S, Tsukada N, Motomura Y, Ichinoe A. Five patients with nonalcoholic diabetic cirrhosis. Acta Hepato-Gastroenterol. 1979;26:90–97. 7. Falck-Ytter Y, Younossi ZM, Marchesini G, McCullough AJ. Clinical features and natural history of nonalcoholic steatosis syndromes. Semin Liver Dis. 2001;21:17–26. 8. Day CP. Who gets alcoholic liver disease: nature or nurture? J R Coll Physicians Lond. 2000;34:557–562. 9. Goodman ZD, Ishak KG. Occlusive venous lesions in alcoholic liver disease. A study of 200 cases. Gastroenterology. 1982;83:786–796. 10. Hall P. Alcoholic liver disease. In: MacSween RNM BA, Burt AD, Portmann BC, et al. eds. Pathology of the Liver. 4th ed. London, UK: Churchill Livingstone; 2002; 273–311.
Case 4.7
Drugs and NAFLD MATTHEW M.YEH AND ELIZABETH M. BRUNT
The associations of medications with NAFLD continues to expand. As noted by authorities in the field, it is important to consider that the patient may have NAFLD and may be on a particular medication, but the disease may be related to the patient’s underlying metabolic condition rather than to the medication (1). Two drugs deserve specific comment: methotrexate and amiodarone. The injury of both may be exacerbated by the presence of underlying steatohepatitis due to insulin resistance; however, there are clues to distinguish the injuries. Methotrexate use may result in hepatocellular anisonucleosis and focal necrosis, nonzonally distributed macrovesicular steatosis that is commonly ”mild” (<33%), mild to moderate portal inflammation, and portal-based fibrosis (2). Zone 3 perisinusoidal fibrosis is not a characteristic of uncomplicated methotrexate, but excess alcohol use is known to result in progression of fibrosis with use of methotrexate (2). Injury to the Canals of Hering is speculated (3). Amiodarone toxicity is somewhat more challenging, as hepatic manifestations of this medication include not only the well-known phospholipidosis, but also Mallory-Denk bodies and steatosis. Amiodarone may also, however, result in cholestasis, “acute hepatitis,” and features of Reyes syndrome (ie, microvesicular steatosis) (4). The most common
feature of amiodarone use and/or toxicity is phospholipidosis, with little or no steatosis. Alternatively, less frequently, biopsies with “alcoholic steatonecrosis”-like features, including Mallory-Denk bodies, occur; it has been noted that these biopsies commonly also show cirrhosis. These 2 injury patterns reflect separate reactivity patterns to metabolic mechanisms of the drug in hepatocytes (5). As with all liver biopsies, careful attention to all clinical details of the patient, as well as all histologic features can be quite useful in biopsy interpretation.
References 1. Farrell GC. Drugs and steatohepatitis. Sem Liv Dis. 2002;22:185–194. 2. Roenigk HH, Auerback R, Maibach H, Weinstein G, Lebwoh M. Methotrexate in psoriasis: consensus conference. J Am Acad Dermatol. 1998;38:478–485. 3. Hytiroglou P, Tobias H, Saxena R, Abramidou M, Papadimitriou CS, Theise ND. The Canals of Hering might represent a target of methotrexate hepatic toxicity. Am J Clin Pathol. 2004;121:324–329. 4. Lewis JH, Ranard RC, Caruso A, et al. Amiodarone hepatotoxicity: prevalence and clinicopathologic correlations among 104 patients. Hepatology. 1989;9:679–685. 5. Zimmerman HJ. Drugs used in cardiovascular disease. In: Zimmerman HJ, ed. Hepatoxicity: The Adverse Effects of Drugs and Other Chemicals on the Liver. 2nd ed. Philadelphia, PA: Lippincott Williams and Wilkins;1999:639–672.
56
Case 4.8
Microvesicular Steatosis MATTHEW M.YEH AND ELIZABETH M. BRUNT
C L I N IC AL I N F OR M AT I ON
The patient is a 33-year-old woman who suffers from epilepsy. She has taken valproic acid regularly. She is noted to have abnormal liver tests. A liver biopsy was performed. R E A SON F OR R E F E R R AL
There is no significant steatosis in the liver biopsy; however, many hepatocytes are swollen and enlarged. The referring pathologist’s specific question is whether these cells represent ballooned hepatocytes in steatohepatitis. PAT H OL OG I C F E AT U R E S
The liver biopsy shows hepatic parenchyma with no significant macrovesicular steatosis. However, there are patches of swollen and flocculent hepatocytes (Figure 4.8.1). High power magnification of these hepatocytes reveal centrally located nuclei with microvesicular steatosis showing very fine lipid droplets within the cytoplasm (Figure 4.8.2).
F I G U R E 4 . 8 . 1 Significant macrovesicular steatosis is not present in the liver biopsy; however, there are patches of hepatocytes with microvesicular steatosis showing swollen and flocculent hepatocytes.
D I AG N OS I S
Microvesicular steatosis associated with valproic acid use.
D I S C U S S I ON
It is important to recognize the significance of classifying steatosis into macrovesicular and microvesicular because of the different clinical implications, and therefore pathologists should be familiar with their exact definitions when interpreting liver biopsies. Not only is purely microvesicular steatosis not common, but it also suggests very specific conditions that typically warrant clinically urgent awareness such as Reyes syndrome, alcoholic foamy degeneration, acute fatty liver of pregnancy, and certain drug toxicities, including valproic acid. Severe mitochondrial dysfunction underlies this type of steatosis, which is typically associated with markedly elevated liver tests, with or without hepatic encephalopathy. Nonzonal aggregates of hepatocytes may contain microvesicular steatosis in a minority of cases of NAFLD, and the significance is yet to be elucidated. True microvesicular steatosis is characterized by enlargement of the hepatocytes and flocculent alteration of the cytoplasm with centrally located nuclei (Figures 4.8.1 and 4.8.2). As the morphology may resemble ballooned hepatocytes in which the hepatocytes are swollen in both lesions, the distinction is important and the clinical implications are very different. Clinical presentations likewise differ. In general, the nuclei in
F I G U R E 4 . 8 . 2 Higher magnification of Figure 4.8.1 reveals centrally
located nuclei with very fine lipid droplets within the cytoplasm.
ballooned hepatocytes are hyperchromatic and may be located at the periphery of the cytoplasm, whereas the nuclei in hepatocytes with microvesicular steatosis are located at the center of the cells. There is also a finite difference in the cytoplasmic contents, in which the cytoplasm in ballooned hepatocytes is rarefied or finely reticulated; this suggests accumulation of intracellular fluid within injured cells, whereas the visualization of droplets of steatosis in microvesicular steatosis can be quite variable, and the confirmation often requires the use of Oil red O on a frozen section of a liver biopsy. 57
Case 4.9
Pediatric Fatty Liver Disease CYNTHIA BEHLING
C L I N I C AL I N F OR M AT I ON DIAGNO SIS
A 13-year-old obese boy was noted to have elevated serum transaminases but no stigmata of liver disease. Further clinical testing demonstrated negative viral markers for hepatitis B and C (including viral RNA studies for HCV), normal levels of serum ceruloplasmin, and negative autoimmune markers. The astute pediatrician ordered an ultrasound which demonstrated fatty liver. The patient and his parents agreed to be part of a clinical trial and a liver biopsy was performed.
Severe fatty change with periportal fibrosis consistent with steatohepatitis (Type 2 pattern, stage 1c by Kleiner methodology for staging nonalcoholic steatohepatitis).
DISCUSSIO N
Shortly after the first descriptions of a nonalcoholic fatty liver disease similar to that in adults, Moran et al reported steatohepatitis in a group of obese children (1). Pediatric fatty liver was little studied until more than a decade later when the rapidly increasing incidence of obesity in children drew attention to diseases associated with obesity, including fatty liver. Pediatric fatty liver disease is now considered the most common liver disease in children and adolescents (2). Estimates of the prevalence of fatty liver disease have been made from epidemiologic studies with various direct and surrogate measures of liver steatosis, such as elevated serum ALT and AST or imaging studies, since liver biopsy of otherwise healthy children is considered an unacceptable risk. A population-based autopsy study that reported histologic findings in a series of 742 children showed fatty liver present in 13% of children aged 2 to 19 (3). In addition, the magnitude of the problem in the United States can be estimated in the following manner. In 2006, there were 73.7 million
R E A S ON F OR R E F E R R A L
The patient was referred to a pediatric gastroenterology clinic for evaluation of possible fatty liver disease and treatment. PAT H OL OG I C F E AT U R E S
The liver biopsy demonstrated severe fatty change (grade 3, for . 66% of hepatocytes with fat) and periportal fibrosis (Figure 4.9.1). The fat consisted of both large and small droplet type of macrovesicular steatosis (Figure 4.9.2). In addition, the degree of lobular inflammation was only mild and no ballooned hepatocytes were noted. The portal zone also contained somewhat prominent lymphoid infiltrate in the form of an aggregate of lymphocytes, but no prominent plasma cell infiltrate was present. The trichrome stain confirmed the presence of periportal fibrosis, but no centrizonal fibrosis was noted (Figure 4.9.1).
B
A
FIGURE 4. 9. 1 (A) Low power examination of the trichrome-stained sections of the liver biopsy showed severe steatosis involving 80%–90%
of hepatocytes. A portal tract on the left is expanded by inflammation and periportal as well as septal fibrosis. Two normal central (terminal hepatic) veins are noted, with relative lack of fatty change in hepatocytes in Zone 3 near the central veins. (B) At higher magnification, portal and lobular inflammation are noted, with distortion of the portal architecture and periportal fibrosis.
58
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DISEASE
59
B
A
FIGURE 4. 9. 2 Other examples of the Type 2 pediatric fatty liver pattern demonstrate typical portal inflammation and fibrosis, (A) and
relative sparing of zone 3 by fat and fibrosis, (B) No ballooned hepatocytes are noted in either example.
children, and of these, 17.1% are obese (12.6 million). Of the obese children, 3% to 10% could have fatty liver (378 000–1.26 million), and a small percentage could also have steatohepatitis and possible progression of disease. Further details about calculating the prevalence of fatty liver can be found in the reviews by Patton (2) and Loomba, et al (4). Risk Factors
The risk factors for fatty liver disease in children are primarily associated with obesity and certain ethnicities, including groups such as Hispanic children (5). Genetic factors likely contribute to risk as well, with several family studies suggesting increase in the proportion of family members with fatty liver. Fatty liver has been identified in about two-thirds of the siblings and three-fourths of the parents of children with fatty liver (6). Prognosis
One of the more significant early observations of pediatric fatty liver disease related to prognosis was the presence of fibrosis. Although it is now recognized that fibrosis may be dynamic, its presence implies a degree of liver injury that may be more difficult to repair and that may be more likely to progress. Advanced fibrosis and cirrhosis have been reported in pediatric fatty liver disease (7). Spectrum of Histologic Changes in Pediatric Steatohepatitis
One of the first descriptions of fatty liver in children was a study in 1995 reporting biopsy findings from 14 patients with “idiopathic” steatohepatitis. These biopsies showed a variable amount of hepatic fat, mixed portal inflammation, and portal fibrosis present in all of the biopsy samples. More advanced
fibrosis including bridging (portal-portal and/or centralportal) and zone 3, and perisinusoidal fibrosis was present in all but one of the cases (8). Further systematic investigation of the histologic features of pediatric fatty liver disease has been published in several major studies to date (9–11). In the first, liver biopsies from 100 children with fatty liver were grouped according to clustered histologic features. Three distinct groups were identified. Of the biopsies 17% showed a classic (termed Type 1) pattern of steatohepatitis in which there was zone 3 predominant injury with perisinusoidal fibrosis and ballooned hepatocytes previously described in Chapter 4. Half of the cases were grouped into a portal-based pattern (termed Type 2), with portal inflammation and fibrosis but little or no ballooning degeneration. The remainder showed a hybrid pattern with features of both. Subsequent studies have also noted the portal-based pattern of liver injury that accounts for a varying number of cases of pediatric NASH (10,11). At this time it is unknown whether the portal-based inflammation represents a phase in the evolution of the fatty liver disease or a possible different pathophysiologic mechanism. Of practical importance is the recognition that some cases of pediatric, and rare cases of adult, NASH have a different “look.” Liver injury may occur even in a case with no ballooned hepatocytes or apparent zone 3 injury. Biopsy reports for these patients should mention the possibility of an alternate pattern of injury, which may include cases with less ballooning and a more zone 1 portal-predominant pattern, cases with marked steatosis but relatively little inflammation or fibrosis, and cases which have similar features and distribution of features as NASH in adults. It is not clear why there are different patterns of fatty liver disease. Various factors may influence the accumulation of fat in different zones of the liver, including hormones (as suggested by gender differences in the prevalence of fatty
60
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liver and adolescent age of onset), differences in insulin resistance, dietary factors and interaction with gut flora, and metabolic correlates of visceral versus subcutaneous fat. Role of Liver Biopsy
Imaging studies can reveal steatosis and advanced fibrosis. However, liver biopsy allows refinement of the degree of steatosis, even if minor, and also allows grading of fat as well as staging of fibrosis and the exclusion of the presence of other liver diseases. The staging system developed by the NAFLD consortium pathology group as described by Kleiner et al (10) includes a Stage 1c for the periportal pattern of injury in early-stage disease when no pericentral fibrosis is present; so this methodology is recommended for usage in cases of pediatric NASH. Differential Diagnosis
The etiology of many of the other diseases that cause fatty liver in childhood can be distinguished on the basis of clinical history and/or age at presentation. Metabolic and mitochondrial diseases typically present in infancy or very early childhood, whereas the incidence of NAFLD is estimated at only 0.7% for children aged 2 to 4 (3). Fatty liver related to intestinal abnormalities (short gut, intestinal bypass, or total parenteral nutrition) is also discernable based on clinical history. The predominant histologic mimic of NAFLD is Wilson disease, which can be more definitively diagnosed by serum and urine testing for copper as well as genetic testing.
LIVER
DISEASE
References 1. Moran JR, Ghishan FK, Halter SA, Greene HL. Steatohepatitis in obese children: a cause of chronic liver dysfunction. Am J Gastroenterol. 1983;78:374–377. 2. Patton HM, Sirlin C, Behling C, Middleton M, Schwimmer JB, Lavine JE. Pediatric nonalcoholic fatty liver disease: a critical appraisal of current data and implications for future research. J Pediatr Gastroenterol Nutr. 2006;43(4):413–427. 3. Schwimmer JB, Deutsch R, Kahen T, Lavine JE, Stanley C, Behling C. Prevalence of fatty liver in children and adolescents. Pediatrics. 2006; 118(4):1388–1393. 4. Loomba R, Sirlin CB, Schwimmer JB, Lavine JE. Advances in pediatric nonalcoholic fatty liver disease. Hepatology. 2009;50(4):1282–1293. 5. Schwimmer JB, Deutsch R, Rauch JB, Behling C, Newbury R, Lavine JE. Obesity, insulin resistance and other clinicopathological correlates of pediatric nonalcoholic fatty liver disease. J Pediatr. 2003;143:500–505. 6. Schwimmer JB, Celedon MA, Lavine JE, et al. Heritability of nonalcoholic fatty liver disease. Gastroenterology. 2009;136(5):1585–1592. 7. Molleston JP, White F, Teckman J, Fitzgerald JF. Obese children with steatohepatitis can develop cirrhosis in childhood. Am J Gastroenterol. 2002;97:2460–2462. 8. Baldridge AD, Perez-Atayde AR, Graeme-Cook F, Higgins L, Lavine JE. Idiopathic steatohepatits in childhood: a multicenter retrospective study. J Pediatr. 1995;127(5):700–704. 9. Schwimmer JB, Behling C, Newbury R, et al. Histopathology of pediatric nonalcoholic fatty liver disease. Hepatology. 2005;42(3):641–649. 10. Kleiner DE, Brunt EM, Van Natta M, et al. Nonalcoholic steatohepatitis clinical research network. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005; 41(6):1313–1321. 11. Carter-Kent C, Yerian LM, Brunt EM, et al. Nonalcoholic steatohepatitis in children: a multicenter clinicopathological study. Hepatology. 2009;50(4):1113–1120.
Case 4.10
Chemotherapy-Associated Steatohepatitis Due to Irinotecan VIKRAM DESHPANDE AND GREGORY Y. LAUWERS
C L I N IC AL I N F OR M AT I ON
A 56-year-old male had a prior history of pT3N1 adenocarcinoma of the sigmoid colon. Three years following this resection, an imaging study detected 3 foci of metastasis in the left lobe of the liver. Preoperative chemotherapy with 5-fluorouracil plus irinotecan was instituted and a hemihepatectomy was performed 6 weeks after the end of chemotherapy.
R E A SON F OR R E F E R R AL
Intraoperatively, in addition to the 3 foci of metastatic disease, the liver was noted to be yellow. A frozen section was evaluated to assess the status of the background liver.
PAT H OL OG I C F E AT U R E S
The specimen as well as the frozen and paraffin sections showed striking hepatic steatosis (Figures 4.10.1, 4.10.2). The change was most prominent in zone 3 and zone 2 (Figure 4.10.3). In addition to steatosis (Figure 4.10.4), ballooned hepatocytes, some containing “soft” Mallory’s hyaline, were also noted (Figure 4.10.5). Spotty foci of hepatocellular dropout were present as was a sparse lobular lymphocytic infiltrate. The portal tracts were essentially unremarkable.
F I G U R E 4 . 1 0 . 2 Metastatic colonic adenocarcinoma (arrow) with
steatosis in the adjacent nonneoplastic liver.
F I G U R E 4 . 1 0 . 3 The steatosis predominantly involves zones 2 and 3.
DIAGNO SIS
Chemotherapy-associated steatohepatitis due to irinotecan.
FIGURE 4. 10. 1 Fatty liver associated with irinotecan associated
steatohepatitis.
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LIVER
DISEASE
is a higher risk of postoperative morbidity and mortality in patients with marked hepatic steatosis (3). Broadly 2 forms of liver injury are recognized: steatosis/steatohepatitis and hepatic sinusoidal pattern of injury. The former pattern of injury is associated predominantly with 5-FU and irinotecan, whereas sinusoidal injury as evidenced by sinusoidal dilatation has been predominantly seen with oxaliplatin. Chemotherapy and Steatosis
FIGURE 4. 10. 4 Diffuse steatosis associated with irinotecan.
The backbone of first-line chemotherapy regimens is 5-FU, and modern chemotherapy regimens combine 5-FU/leucovorin with irinotecan (FOLFIRI) or oxaliplatin (FOLFOX). An association between steatosis and chemotherapy was first discovered by several pathological and radiological studies. Computed tomography scan screening before and after chemotherapy showed 47% of patients treated with 6 to 12 cycles of 5-FU develop evidence of steatosis (4). Irinotecan and Steatohepatitis
FIGURE 4. 10. 5 Irinotecan associated steatohepatitis. Note the
ballooned hepatocytes (arrow) and Mallory’s hyaline (arrow head).
Steatohepatitis was first noted in a small series that observed an increased rate of steatohepatitis in 14 patients treated with irinotecan or oxaliplatin (5). The association of irinotecan and steatohepatitis was further clearly demonstrated in a larger series treated with FOLFIRI (5-FU/leucovorin with irinotecan) with 20% of these patients developing steatohepatitis (3). The increased rate of steatohepatitis caused by irinotecan has clinically relevant consequences, since these patients have a significantly increased 90-day mortality rate compared with patients without steatohepatitis (14.7% vs 1.6%) (3). However, others did not confirm an increase in morbidity or mortality in patients treated preoperatively with irinotecan-containing regimens (6-8), although this may reflect the variability in diagnosing and grading steatosis and steatohepatitis. Furthermore, in a recent study, steatosis and steatohepatitis correlated with body mass index (BMI) and not chemotherapy (8). However, the delayed surgical resections (12.4 weeks vs 6.4 weeks) in this series may have been a confounding factor (3,8).
D I S C U S S I ON
About one-third of patients with colorectal cancer will present with liver metastasis, either at the time of diagnosis or during the course of the disease. Surgical resection of the metastases is frequently coupled with systemic neoadjuvant chemotherapy. The drugs with efficacy in the neoadjuvant setting include 5-fluorouracil (5-FU), irinotecan, and oxaliplatin; the latter 2 are frequently infused in conjunction with 5-FU. A major goal of this therapy is to decrease the tumor size and burden sufficiently so that unresectable patients can become candidates for surgery, and this is successfully achieved in about 12.5% of patients (1). In addition, there is evidence that this form of therapy may improve overall survival of individuals with metastatic liver disease (2). This neoadjuvant approach damages the adjacent liver parenchyma. This is an important clinical issue, since there
Oxaliplatin
Oxaliplatin has been specifically associated with sinusoidal dilatation and hemorrhage (Figure 4.10.6) (9). Furthermore, centrizonal perisinusoidal and veno-occlusive fibrosis, peliosis, and nodular regenerative hyperplasia have developed following use of this drug (9,10). Other morphological lesions associated with oxaliplatin include small vessel loss, hepatocyte plate disruption, and parenchymal extinction lesions (8). Preoperative Assessment of Risk for Hepatic Toxicity
Novel methods are needed to identify patients at high risk for postoperative complications. Abdominal ultrasound, CT
CASE
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C H E M O T H E R A P Y- A S S O C I AT E D
S T E AT O H E PAT I T I S
63
References
FIGURE 4. 10. 6 Oxaliplatin associated sinusoidal congestion.
scans, and magnetic resonance imaging (MRI) have limited utility since they can detect steatosis but not steatohepatitis. Chemical-shift imaging MRI may be more efficacious in predicting chemotherapy-induced liver injury (11). Preoperative liver biopsies are also proposed for patient selection, but opinions are mixed about whether these biopsies can be helpful. Others have advocated performing laparoscopy prior to doing the hepatectomy (3).
C ON C L U S I ON S
Irinotecan may result in steatohepatitis and significant liver injury. New strategies to minimize the postoperative morbidity caused by irinotecan such as the use of atorvastatin (lipitor) may decrease the severity of steatohepatitis (12). Great caution should be used in considering hepatectomy in obese, diabetic, and alcoholic patients who have received neoadjuvant chemotherapy.
1. Adam R, Delvart V, Pascal G, et al. Rescue surgery for unresectable colorectal liver metastases downstaged by chemotherapy: a model to predict long-term survival. Ann Surg. 2004;240:644-657, discussion 57–58. 2. Kopetz S, Chang GJ, Overman MJ, et al. Improved survival in metastatic colorectal cancer is associated with adoption of hepatic resection and improved chemotherapy. J Clin Oncol. 2009;27:3677–3683. 3. Vauthey JN, Pawlik TM, Ribero D, et al. Chemotherapy regimen predicts steatohepatitis and an increase in 90-day mortality after surgery for hepatic colorectal metastases. J Clin Oncol. 2006;24:2065–2072. 4. Peppercorn PD, Reznek RH, Wilson P, Slevin ML, Gupta RK. Demonstration of hepatic steatosis by computerized tomography in patients receiving 5-fluorouracil-based therapy for advanced colorectal cancer. Br J Cancer. 1998;77:2008–2011. 5. Fernandez FG, Ritter J, Goodwin JW, Linehan DC, Hawkins WG, Strasberg SM. Effect of steatohepatitis associated with irinotecan or oxaliplatin pretreatment on resectability of hepatic colorectal metastases. J Am Coll Surg. 2005;200:845–853. 6. Pawlik TM, Olino K, Gleisner AL, Torbenson M, Schulick R, Choti MA. Preoperative chemotherapy for colorectal liver metastases: impact on hepatic histology and postoperative outcome. J Gastrointest Surg. 2007;11:860–868. 7. Sahajpal A, Vollmer CM Jr, Dixon E, et al. Chemotherapy for colorectal cancer prior to liver resection for colorectal cancer hepatic metastases does not adversely affect peri-operative outcomes. J Surg Oncol. 2007;95:22–27. 8. Ryan P, Nanji S, Pollett A, et al. Chemotherapy-induced liver injury in metastatic colorectal cancer: semiquantitative histologic analysis of 334 resected liver specimens shows that vascular injury but not steatohepatitis is associated with preoperative chemotherapy. Am J Surg Pathol. 2010;34:784–791. 9. Rubbia-Brandt L, Audard V, Sartoretti P, et al. Severe hepatic sinusoidal obstruction associated with oxaliplatin-based chemotherapy in patients with metastatic colorectal cancer. Ann Oncol. 2004;15:460–466. 10. Rubbia-Brandt L, Lauwers GY, Wang H, et al. Sinusoidal obstruction syndrome and nodular regenerative hyperplasia are frequent oxaliplatinassociated liver lesions and partially prevented by bevacizumab in patients with hepatic colorectal metastasis. Histopathology. 2010;56:430–439. 11. O’Rourke TR, Welsh FK, Tekkis PP, et al. Accuracy of liver-specific magnetic resonance imaging as a predictor of chemotherapy-associated hepatic cellular injury prior to liver resection. Eur J Surg Oncol. 2009;35:1085–1091. 12. Hyogo H, Tazuma S, Arihiro K, et al. Efficacy of atorvastatin for the treatment of nonalcoholic steatohepatitis with dyslipidemia. Metabolism. 2008;57:1711–1718.
Case 4.11
Subacute Steatohepatitis LINDA D. FERRELL
5 months from an early stage 1 fibrosis with focal pericentral fibrosis to extensive centrizonal sinusoidal fibrosis, as well as periportal and bridging fibrosis, indicative of a stage 3 fibrosis by both Brunt (1) and Kleiner methodologies (2). There was marked fatty change and large numbers of ballooned hepatocytes, many with well-formed Mallory-Denk bodies, were present in centrizonal areas (Figure 4.11.1–4.11.3). The
C L I N I C AL I N F OR M AT I ON
A 33-year-old, morbidly obese woman was admitted for abdominal pain of 2-weeks’ duration. Past history was significant for “long-limb” Roux-en-Y gastric bypass surgery 5 months prior to this admission, a procedure that resulted in an anastomosis of jejunum to the distal ileum. She had a BMI of 45.3 at that time, and had lost 40 pounds after her surgery. She had complications from the surgery that resulted in a return to the operating room at that institution for anastomotic leak and stricture. A liver biopsy done at the referring institution at the time of the bypass showed severe fatty change with minimal lobular inflammation associated with focal sinusoidal fibrosis on trichrome stain consistent with stage 1 fibrosis by the Brunt methodology (1), or stage 1a by the Kleiner methodology (2). No ballooned hepatocytes were present. Past medical history was unremarkable, with no evidence for diabetes, hyperlipidemia, alcohol, or other substance abuse. At the time or referral for abdominal pain, the patient had stable vital signs, and was noted to have a height of 5 ft 1 in, and weight of 211 pounds, with BMI 39.9. Abnormal laboratory tests included AST of 80 and ALT of 143. Ultrasound showed hepatic steatosis. The patient was immediately taken to the operating room due to concerns for small bowel obstruction or perforation, but these complications were not found. The long-limb Roux-en-Y was revised to the conventional Roux-en-Y. However, the surgeon was unable to close the abdomen due to marked swelling of the liver, which appeared to be grossly fatty. Liver biopsy at this time (5 months after the first biopsy, see above) demonstrated extensive fibrosis with many ballooned hepatocytes and abundant Mallory-Denk bodies, consistent with a rapidly progressive steatohepatitis. Postoperatively, the patient required blood transfusions, and she became septic due to fungemia, developed respiratory distress syndrome, and renal failure, and died 20 days post-op. An autopsy was performed that demonstrated similar changes of advanced damage to the liver as was seen in the biopsy, with the addition of ischemic necrosis as an additional finding.
F I G U R E 4 . 1 1 . 1 Centrizonal region demonstrates extensive pericellular fibrosis. Hepatocytes contain mostly large droplets of fat, but some small droplets is also present. There are several ballooned hepatocytes containing prominent Mallory-Denk bodies but inflammation is sparse.
R E A S ON F OR R E F E R R A L
The patient was referred to UCSF with the clinical diagnosis of possible small bowel ischemia or perforation and a diagnosis of fatty liver disease with no evidence of active steatohepatitis on the previous liver biopsy. PAT H OL OG I C F E AT U R E S
4 . 1 1 . 2 Centrizonal region demonstrates severe fatty change, congestion, ductular reaction, and extensive pericellular fibrosis. Numerous swollen hepatocytes are present.
FIGURE
Both the biopsy at the time of the second surgery and the autopsy showed a marked progression of fibrosis within only 64
CASE
4.11:
SUBACUTE
FIGURE 4.11.3 Centrizonal region (higher magnification of previous
figure) highlights the Mallory-Denk bodies in swollen hepatocytes. Inflammatory infiltrate is scant.
scarring was most prevalent in the centrizonal areas, and centrizonal veins were difficult to identify. Bile stasis was seen in canaliculi. In addition, in the autopsy sample, zones of ischemic necrosis of hepatic parenchyma were also present.
D I AG N OS I S
Steatohepatitis, active and chronic, with extensive fibrosis.
D I S C U S S I ON
This case demonstrates an unusual variant of nonalcoholic steatohepatitis with an aggressive subacute course, leading
S T E AT O H E PAT I T I S
65
to extensive fibrosis within 5 to 6 months after an unusual, long-limb Roux-en-Y procedure. This procedure likely resulted in abnormal hepatic-enteric interactions mimicking those seen in the jejunal-ileal bypass procedure (3), which in turn was discovered to cause severe liver damage as well. This pattern of rapidly progressive fibrosis is rare in the setting of NASH but can be seen associated with alcoholic liver injury. In fact, many of the features are more typical of alcoholic steatohepatitis, including the abundant ballooned hepatocytes with Mallory-Denk bodies, cholestasis, and sclerosis of hepatic veins. Another unusual feature is the extensive sinusoidal and pericellular fibrosis without as much evidence of nodularity, a finding that can also be seen in chronic alcoholic liver disease where regeneration is limited. Caldwell and Hespenheide (4) has described subacute liver failure in obese women as a rare clinical entity but did not describe the pathologic features in his series. Other rare settings with histologic findings showing similar extensive pericellular fibrosis have been noted and include rapid weight loss due to conventional gastric bypass as well as weight loss while on the high protein Atkin’s diet (5).
References 1. Brunt EM, Janney CG, Di Bisceglie AM, Neuschwander-Tetri BA, Bacon BR. Nonalcoholic steatohepatitis: a proposal for grading and staging the histological lesions. Am J Gastroentroenterol. 1999;94: 2467–2474. 2. Kleiner D, Brunt E, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41:1313–1321. 3. Shibata H, Mackenzie J, Huang S. Morphologic changes of the liver following small intestinal bypass for obesity. Arch Surg. 1971;103:229–237. 4. Caldwell SH, Hespenheide EE. Subacute liver failure in obese women. Am J Gastroenterol. 2002;97(8):2058–2062. 5. Tan V, Jimenez C, Merriman R, Ferrell L. Variants of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) with rapidly progressive course. Mod Path. 2008;21(suppl 1):317A.
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5 Hepatic Granulomas and Granulomatous Hepatitis LAURA W. LAMPS
granulomas/granulomatous inflammation may be divided into the following morphologic categories.
I N T ROD U C T I ON
Granulomas are aggregates of macrophages, often admixed with other inflammatory cells, which usually result from chronic antigen presentation. The liver is involved in many granulomatous diseases, some of which are intrinsic hepatic diseases, whereas others are disseminated systemic diseases that involve the liver in addition to other organs. Hepatic granulomas are reportedly present in 2% to 10% of all liver biopsy specimens examined in general pathology practice, and of those supposedly 13% to 36% have no discoverable etiology even after extensive evaluation (1–4). There are several classification schemes that address types of granulomas/granulomatous inflammation. Regardless of the classification used, the morphology of the granulomas may provide clues to the diagnosis (2–4) (Table 5.1). Hepatic
Epithelioid Granulomas With or Without Necrosis
Epithelioid granulomas are discrete lesions with distinct edges. Necrotizing epithelioid granulomas frequently have an infectious etiology, although no specific organism is detected in some circumstances. Necrotizing granulomas in infectious disease processes often do not respect the architecture of the liver and destroy adjacent structures. Infections that cause epithelioid granulomas include, but are not limited to, Mycobacterium tuberculosis (see Chapter 5.1), tuberculoid leprosy, schistosomiasis (see Chapter 5.4), and brucellosis. Liver involvement is seen in
TA B LE 5. 1 Classification of granulomatous inflammation in the liver by histologic pattern
Fibrin Ring Granuloma
Microgranulomas
Lipogranulomas
Stellate Abscess With Granulomatous Inflammation
Infectious Q-fever
Infectious
Mineral oil
Bartonella
Rhodococcus equi
Tularemia
M. tuberculosis
Drug reaction
Toxoplasmosis
Listeria (rare)
Tularemia
Whipple disease
Listeriosis
Brucellosis
Foreign body reaction
Salmonella
Other Nonspecific reaction to liver injury
Fungi, esp. Candida
MAI (immunocompromised patients)
Melioidosis
MAI (immunocompetent patients)
Sarcoidosis
CMV
Actinomycosis
Lepromatous leprosy
Tuberculoid leprosy
Autoimmune diseases
EBV
Nocardia
Histoplasmosis
Tertiary syphilis
Primary biliary cirrhosis
Leishmaniasis
Other Chronic granulomatous disease
Leishmaniasis
Chlamydia
CVID
Whipple disease (rare)
Hodgkin disease
Schistosomiasis
Other paraneoplastic conditions
Fungal infections
Chronic granulomatous disease of childhood
Foamy Macrophage Aggregates
Other Drug reaction
Predominantly Suppurative, ±Granulomatous Inflammation
Epithelioid Granuloma, Infectious Causes
Epithelioid Granulomas, Other Causes
Viral infections (rare) Abbreviations: CMV, cytomegalovirus; CVID, common variable immunodeficiency; EBV, Epstein-Barr virus; MAI, Mycobacterium avium-intracellulare.
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almost all cases of miliary tuberculosis, and is common in both localized extrapulmonary and pulmonary tuberculosis (2,5–6). The hallmark of hepatic tuberculosis is necrotizing granuloma, and confluent granulomas can lead to masses (tuberculomas). Periportal lymphadenopathy is common (6). There is often an accompanying reactive hepatitis. It may be difficult to detect mycobacteria on special stains; thus, culture and polymerase chain reaction (PCR) assays may be of value. The lesion typical of tuberculoid leprosy is a discrete, tuberculoid granuloma with associated giant cells. Bacilli are often rare and difficult to detect in this variant (7–9). Other atypical mycobacteria that occasionally cause liver disease include M. kansasii and BCG (Bacillus Calmette-Guerin). Brucellosis occurs primarily in domestic and barnyard animals, and humans contract infection through occupational exposure and by ingesting contaminated food. Hepatic involvement is seen in approximately half of the cases (10–12). Liver biopsies often (although not always) show noncaseating granulomatous inflammation, sometimes with giant cells. Granulomas may be discrete and epithelioid or small and poorly formed. Organisms are difficult to culture and are rarely seen on special stains; thus, serologic studies and exposure history are helpful in making the diagnosis (13–15). Sarcoidosis involves the liver in 50% to 100% of cases. Autopsy studies have shown that the liver is secondary only to the lungs and lymph nodes in frequency of involvement by granulomas (2). Sarcoid granulomas are noncaseating, epithelioid with variable giant cells, and severe lesions may be confluent. Sarcoid granulomas are often accompanied by fibrosis, which may lead to cirrhosis (2,13–15). Noncaseating granulomas are also reported in 18% to 64% of cases of primary biliary cirrhosis (see Chapter 5.2). They may be portal or lobular but are often associated with bile duct lesions. Granulomas are seen in a minority of cases of primary sclerosing cholangitis, in which they are usually well-formed, nonnecrotizing, and epithelioid (2–4). Lipogranulomas
These contain lipid and are associated with mineral oils in foods and medications (16–17). Whether or not they are directly associated with fatty liver disease remains controversial. Microgranulomas
Microgranulomas have been defined as 3 to 7 macrophages in cross-section, often admixed with other inflammatory cells and/or apoptotic hepatocytes. This pattern is very nonspecific and does not carry any special diagnostic significance; it has been associated with a number of infections and drugs (3). Fibrin Ring Granulomas
This distinctive form of hepatic granuloma consists of an epithelioid granuloma with a central lipid vacuole surrounded by a fibrin ring. Although classically described in association with
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Q fever, these lesions are nonspecific and have been observed in the context of numerous diseases including leishmaniasis, Boutonneuse fever, Hodgkin disease, allopurinol reaction, toxoplasmosis, cytomegalovirus (CMV) infection, mononucleosis, Mycobacterium avium-intracellulare (MAI) infection, and typhoid fever (2–4,18) (see Chapter 5.3). Foamy Macrophage Aggregates
This pattern of granulomatous inflammation is usually due to infection and is frequently seen in immunocompromised patients. There may be very little associated additional inflammatory response. MAI is most commonly associated with this pattern; usually, but not always, in the setting of AIDS. The liver is involved in over 50% of disseminated cases (19–20). Organisms are usually abundant on acid-fast staining in immunocompromised patients. Other causes of foamy macrophage aggregates include Rhodococcus equi, lepromatous leprosy, visceral leishmaniasis (kala-azar), and Whipple disease. In addition, hepatic histoplasmosis frequently features portal lymphohistiocytic inflammation and sinusoidal Kupffer cell hyperplasia rather than discrete granulomas, and organisms are present in portal macrophages and Kupffer cells (21). Granulomatous Inflammation With or Without Admixed Suppurative Inflammation
Although the term “granulomatous inflammation” is often used to describe any type of granuloma in a biopsy, strictly speaking this term implies poorly formed granulomas with indistinct edges, often with admixed inflammatory cells of other types. Granulomatous inflammation with associated hepatocellular and/or duct damage is often associated with drug-induced liver injury. When suppurative inflammation predominates, certain infectious etiologies should be suspected (Table 5.1). Francisella tularensis, which causes tularemia, is a Gramnegative coccobacillus endemic in many areas of North America. It is transmitted to humans from rodents and rabbits. Hepatic involvement is often a component of disseminated infection (22,23). Histologically, there are suppurative microabscesses with occasional surrounding macrophages; as the lesions evolve they may become more granulomatous (23). Periportal lymph nodes may show discrete, well-delineated areas of cortical necrosis (23). Organisms are rarely seen on special stains; thus cultures, serologic tests, and molecular testing are useful diagnostic modalities. Hepatic listeriosis is also usually seen in the context of disseminated infection in immunocompromised patients and diabetics. Histologically, scattered microabscesses are seen, often with small granulomas (24). Sometimes an exclusively microgranulomatous pattern, and rarely true epithelioid granulomas, may be present. Occasionally short pleomorphic Gram-positive rods may be identified, but blood culture is the most important diagnostic test. Many fungal infections also cause a mixed suppurative and granulomatous pattern, including aspergillus, mucormycosis and related zygomycetes, and Cryptococcus (25–28).
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Stellate Abscesses With Associated Granulomatous Inflammation
This pattern is also usually associated with infectious etiologies and is most commonly associated with cat scratch disease (CSD). Bartonella henselae is the most common cause of cat scratch disease. A small percentage of patients (1%–2%) develop disseminated CSD, and these patients usually lack the characteristic skin papule and superficial adenopathy (29,30) (see Chapter 5.5). Liver lesions are often multiple and have associated abdominal lymphadenopathy. Hepatic CSD patients are usually not immunocompromised (30). The characteristic histologic lesion of hepatic CSD consists of irregular, stellate microabscesses surrounded by an inner layer of palisading histiocytes, a surrounding rim of lymphocytes, and an outermost thick layer of fibrous tissue. This outer fibrous zone is very pronounced in the liver. Diagnostic aids include patient history with specific questions pertaining to cat exposure, silver impregnation stains (Warthin-Starry or Steiner), molecular assays, and enzymelinked immunosorbent assay (ELISA). Other entities that can produce similar lesions include tularemia, tuberculosis, and hepatic candidiasis (31). In addition to the morphology of the granulomas, the pathologist should evaluate the location, presence or absence of necrosis, nature of accompanying inflammatory infiltrate, organisms or foreign material, and other morphologic changes in the liver biopsy. Special stains for microorganisms are invaluable in evaluating granulomatous processes in the liver. It is also important to decide whether or not the granuloma is incidental to some other chronic disease process (such as hepatitis C infection) or represents a second true pathologic process; in some cases, it is impossible to make this distinction on morphologic grounds alone.
References 1. Harrington PT, Gutierrez JJ, Ramirez-Ronda CH, Quiñones-Soto R, Bermúdez RH, Chaffey J. Granulomatous hepatitis. Rev Infect Dis. 1982;4:638–655. 2. Ishak KG. Granulomas of the liver. In: Ioachim HL, ed. Pathology of Granulomas. New York, NY: Raven Press; 1983. 3. Kleiner DE. Granulomas in the liver. Sem Diagn Pathol. 2006;23: 161–169. 4. Gaya DR, Thorburn D, Oien KA, Morris AJ, Stanley AJ. Hepatic granulomas: a 10 year single centre experience. J Clin Pathol. 2003;56: 850–853. 5. Essop AR, Posen JA, Hodkinson JH, Segal I. Tuberculosis hepatitis: a clinical review of 96 cases. Q J Med. 1984;53:465–477. 6. Oliva A, Duarte B, Jonasson O, Nadimpalli V. The nodular form of local hepatic tuberculosis: a review. J Clin Gastroenterol. 1990;12:166–173. 7. Karat AB, Job CK, Rao PS. Liver in leprosy: histological and biochemical findings. Br Med J. 1971;1:307–310.
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8. Chen TS, Drutz DJ, Whelan GE. Hepatic granulomas in leprosy: their relation to bacteremia. Arch Pathol Lab Med. 1976;100:182–185. 9. Sehgal VN, Tyagi SP, Kumar S, Gupta MC, Hameed S. Microscopic pathology of the liver in leprosy patients. Int J Dermatol. 1972;11:168–172. 10. Williams RK, Crossley K. Acute and chronic hepatic involvement of brucellosis. Gastroenterology. 1982;83:455–458. 11. Ablin J, Mevorach D, Eliakim R. Brucellosis and the gastrointestinal tract: the odd couple. J Clin Gastroenterol. 1997;24:25–29. 12. Cervantes F, Bruguera M, Carbonell J, Force L, Webb S. Liver disease in brucellosis: a clinical and pathological study of 40 cases. Postgrad Med J. 1982;58(680):346–350. 13. Valla DC, Benhamou JP. Hepatic granulomas and hepatic sarcoidosis. Clin Liver Dis. 2000;4:269–285. 14. Ishak KG. Sarcoidosis of the liver and bile ducts. Mayo Clin Proc. 1998;73:467–472. 15. Devaney K, Goodman ZD, Epstein MS, Zimmerman HJ, Ishak KG. Hepatic sarcoidosis. Clinicopathologic features in 100 patients. Am J Surg Pathol. 1993;17:1272–1280. 16. Delladetsima JK, Horn T, Poulsen H. Portal tract lipogranulomas in liver biopsies. Liver. 1987;7(1):9–17. 17. Petersen P, Christoffersen P. Ultrastructure of lipogranulomas in human fatty liver. Acta Pathol Microbiol Scand A. 1979;87(1):45–49. 18. Marazuela M, Moreno A, Yebra M, Cerezo E, Gómez-Gesto C, Vargas JA. Hepatic fibrin-ring granulomas: a clinicopathologic study of 23 patients. Hum Pathol. 1991;22:607–613. 19. Farhi DC, Mason UG III, Horsburgh CR Jr. Pathologic findings in disseminated mycobacterium avium-intracellulare infection. A report of 11 cases. Am J Clin Pathol. 1986;85:67–72. 20. Klatt EC, Jensen DF, Meyer PR. Pathology of mycobacterium aviumintracellulare infection in acquired immunodeficiency syndrome. Hum Pathol. 1987;18:709–714. 21. Lamps LW, Molina CP, West AB, Haggitt RC, Scott MA. The pathologic spectrum of gastrointestinal and hepatic histoplasmosis. Am J Clin Pathol. 2000;113(1):64–72. 22. Ortega TJ, Hutchins LF, Rice J, Davis GR. Tularemic hepatitis presenting as obstructive jaundice. Gastroenterology. 1986;91:461–463. 23. Lamps LW, Havens JM, Sjostedt A, Page DL, Scott MA. Histologic and molecular diagnosis of tularemia: a potential bioterrorism threat endemic to North America. Mod Pathol. 2004;17:489–495. 24. Gebauer K, Hall JC, Donlon JB, Herrmann R, Rofe S, Platell C. Hepatic involvement in listeriosis. Aust N Z J Med. 1989;19:486–487. 25. Chandler FW, Watts JC. Pathologic Diagnosis of Fungal Infections. Chicago, IL: ASCP Press; 1987. 26. Bonacini M, Nussbaum J, Ahluwalia C. Gastrointestinal, hepatic, and pancreatic involvement with Cryptococcus neoformans in AIDS. J Clin Gastroenterol. 1990;12:295–297. 27. Wilkins MJ, Lindley R, Dourakis SP, Goldin RD. Surgical pathology of the liver in HIV infection. Histopathology. 1991;18:459–464. 28. Washington K, Gottfried MR, Wilson ML. Gastrointestinal cryptococcosis. Mod Pathol. 1991;4;707–711. 29. Scott MA, McCurley TL, Vnencak-Jones CL, et al. Cat scratch disease: detection of Bartonella henselae DNA in archival biopsies from patients with clinically, serologically, and histologically defined disease. Am J Pathol. 1996;149:2161–2167. 30. Lamps LW, Gray GF, Scott MA. The histologic spectrum of hepatic cat scratch disease. A series of six cases with confirmed Bartonella henselae infection. Am J Surg Pathol. 1996;20:1253–1259. 31. Johnson TL, Barnett JL, Appelman HD, Nostrant T. Candida hepatitis: histopathologic diagnosis. Am J Surg Pathol. 1988;12:716–720.
Case 5.1
Necrotizing Epithelioid Granulomas LAURA W. LAMPS
C L I N I C AL I N F OR M AT I ON
A 50-year-old woman presented with fever and right upper quadrant pain. Physical examination revealed mild hepatosplenomegaly, and computed tomography (CT) scan of the abdomen revealed multiple liver lesions as well as portal adenopathy. Transaminases and alkaline phosphatase were mildly elevated. Hepatitis viral panel and autoimmune serologies were negative. R E A S ON F OR R E F E R R A L
Necrotizing epithelioid granulomas of uncertain etiology. PAT H OL OG I C F E AT U R E S
The liver biopsy shows numerous caseating epithelioid granulomas with admixed lymphocytes and scattered giant cells (Figure 5.1.1). The granulomas are both portal and lobular and have destroyed the normal architecture of the liver. Some of the granulomas are confluent and associated with fibrosis (Figure 5.1.2). There is a background of reactive hepatocellular changes and a nonspecific lobular hepatitis. A portal lymph node was also biopsied, which showed similar granulomatous inflammation with abundant necrosis (Figure 5.1.3). Multiple sets of special stains revealed rare foci with organisms (Figure 5.1.4). PCR testing was positive for M. tuberculosis.
A
D I AG N OS I S
M. tuberculosis infection involving the liver. B D I S C U S S I ON
F I G U R E 5 . 1 . 1 Hepatic tuberculosis featuring confluent epithelioid
Signs and symptoms of liver disease may be the dominant or presenting features of tuberculosis. Liver involvement is seen in almost all cases of miliary tuberculosis and is common in both localized extrapulmonary tuberculosis and in association with pulmonary tuberculosis (1–4). Patients may present with fever, hepatomegaly, and right upper quadrant pain or they may be asymptomatic. Bilirubin and transaminases may be elevated, along with a disproportionately high alkaline phosphatase (1–4). The histologic hallmark of hepatic tuberculosis is the epithelioid granuloma, often with associated caseous necrosis and giant cells. There may be a surrounding ring of lymphocytes and histiocytes. Granulomas are usually small but may
granulomas with admixed lymphocytes and numerous giant cells, (A). Other granulomas show caseating necrosis, (B).
coalesce to form nodules with central liquefactive necrosis. Older lesions may show fibrosis and calcification (1). Confluent granulomas can lead to masses (tuberculomas) (4). Similar lesions are often found in periportal lymph nodes. There is often an accompanying reactive hepatitis. It may be difficult to detect mycobacteria on special stains; thus, culture and PCR assays may be of value. The differential diagnosis focuses on other causes of necrotizing epithelioid granulomas, which are most often 70
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FIGURE 5. 1. 2 Confluent granulomas with fibrosis and residual giant
cells. Note that the lesion effaces the normal liver architecture.
F I G U R E 5 . 1 . 4 Ziehl-Neelsen stain shows clusters of acid-fast organisms consistent with M. tuberculosis.
infectious (see Table 5.1, Introduction). Schistosomiasis commonly produces epithelioid granulomas, but they are usually associated with eggs or parts of eggs (see Chapter 5.4). Many fungal infections can produce granulomatous inflammation, but it is often mixed with neutrophils. In addition, Gömöri methenamine silver (GMS) stains should highlight fungi, whereas acid-fast bacilli (AFB) stains should be negative. Tuberculoid leprosy may involve the liver and closely mimic M. tuberculosis infection (Figure 5.1.5), and molecular studies A
B FIGURE 5.1.3 A periportal lymph node with confluent granulomas and prominent giant cells, (A). Higher power view shows central caseation, (B).
F I G U R E 5 . 1 . 5 Scattered discrete, epithelioid granulomas in the liver
in a case of tuberculoid leprosy.
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(see Chapter 5.2). Prominent among them are sarcoidosis, primary biliary cirrhosis, and adverse drug reaction. Unfortunately, special stains for AFB, as well as molecular assays, may be negative even in patients who have an infection. Sampling bias in small biopsy specimens, technical limitations of stains and molecular assays, and the fact that organisms are often rare in immunocompetent patients all affect our ability to demonstrate organisms in tissue. Therefore, our clinical colleagues should be advised that the pattern of necrotizing granulomas is most seen in infections even if stains are negative, and that infectious entities should be rigorously excluded clinically even when special studies are negative.
References
FIGURE 5. 1. 6 A minority of patients with hepatitis C show portal
epithelioid granulomas that are not attributable to other causes.
and/or microbiological cultures may be required to distinguish between the two. More rare infectious causes of epithelioid granulomas include brucellosis, which may cause either discrete, epithelioid noncaseating granulomatous or small, poorly formed granulomas (3,4); MAI, which may rarely cause epithelioid granulomas in immunocompetent persons; tertiary syphilis (1,2); Chlamydia (1,2,5); Whipple disease (1,2,6); Rickettsia conorii (the causative agent of Boutonneuse fever and South African tick bite fever) (7); and viral infections, including EBV and CMV (1,2,8). Furthermore, granulomas that are not attributable to any other underlying etiology have been reported in a minority of hepatitis C biopsies (Figure 5.1.6) (9) and rarely in cases of hepatitis B (10). Noninfectious causes of epithelioid granulomas, which are rarely necrotizing, are discussed in more detail below
1. Ishak KG. Granulomas of the liver. In: Ioachim HL, ed. Pathology of Granulomas. New York, NY: Raven Press; 1983. 2. Kleiner DE. Granulomas in the liver. Semin Diagn Pathol. 2006;23: 161–169. 3. Essop AR, Posen JA, Hodkinson JH, Segal I. Tuberculosis hepatitis: a clinical review of 96 cases. Q J Med. 1984;53:465–477. 4. Oliva A, Duarte B, Jonasson O, Nadimpalli V. The nodular form of local hepatic tuberculosis: a review. J Clin Gastroenterol. 1990;12:166–173. 5. Ragnaud JM, Dupon M, Echinard E, Lacut JY, Aubertin J. Hepatic manifestations of psittacosis. Gastroenterol Clin Biol. 1986;10(3):234–237. 6. Cho C, Linscheer WG, Hirschkorn, MA, Ashutosh K. Sarcoidlike granulomas as an early manifestation of Whipple’s disease. Gastroenterology. 1984;87:941–947. 7. Walker DH, Gear JH. Correlation of the distribution of Rickettsia conorii, microscopic lesions, and clinical features in South African tick bite fever. Am J Trop Med Hyg. 1985;34:361–371. 8. Clarke J, Craig RM, Saffro R, Murphy P, Yokoo H. Cytomegalovirus granulomatous hepatitis. Am J Med. 1979;66:264–269. 9. Harada K, Minato H, Hiramatsu K, Nakanuma Y. Epithelioid cell granulomas in chronic hepatitis C: immunohistochemical character and histological marker of favourable response to interferon-alpha therapy. Histopathology. 1998;33:216–221. 10. Tahan V, Ozaras R, Lacevic N, et al. Prevalence of hepatic granulomas in chronic hepatitis B. Dig Dis Sci. 2004;49:1575–1577.
Case 5.2
Sarcoidosis LAURA W. LAMPS
C L I N IC AL I N F OR M AT I ON
PAT H O LO GIC FEAT UR ES
A 45-year-old African American woman went for a preoperative screening prior to hysterectomy for uterine leiomyomas. She was found to have elevated transaminases as well as an abnormal chest x-ray. Subsequent CT scan revealed hilar lymphadenopathy. Other pertinent medical history included obesity and hypertension.
Sections of a wedge liver biopsy showed numerous well-developed epithelioid granulomas with associated lymphocytes and scattered giant cells (Figure 5.2.1). The granulomas were often confluent, and there was associated fibrosis. The granulomas were predominantly based in portal tracts, but bile ducts were intact and free of inflammation. The background liver showed steatosis. Special stains for AFB and fungi were negative, and no polarizable material was detected.
R E A SON F OR R E F E R R AL
Granulomas of unknown etiology; clinician expected nonalchoholic steatohepatitis (NASH) based on the history.
A
B
C
D
FIGURE 5. 2. 1 Confluent, noncaseating epithelioid granulomas with associated fibrosis and admixed lymphocytes in sarcoidosis, (A,B).
Trichrome stain highlights the associated fibrosis, (C; courtesy of Dr. Joseph Misdraji). Asteroid bodies are seen within giant cells, (D).
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Sarcoidosis. D I SC U SSI ON
The incidence of hepatic granulomas in sarcoidosis varies from 50% to 100%, but autopsy studies have shown that the liver is secondary only to the lungs and lymph nodes in frequency of involvement by granulomas (1). In many patients, involvement is subclinical. Sarcoid granulomas are compact and epithelioid with variably present giant cells (Figure 5.2.2) (2–5). A surrounding rim of lymphocytes is common, and eosinophils may be present. Severe lesions may be confluent. Caseation is usually absent, but there may be central fibrinoid necrosis (Figure 5.2.3). They are often located in portal tracts, and there
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may be associated spotty lobular inflammation and portal lymphocytic inflammation. Many types of inclusions have been described, most commonly the asteroid body (Figure 5.2.1). Sarcoid granulomas are often accompanied by fibrosis (2,3–5). Some patients with hepatic sarcoidosis develop progressive liver disease with portal hypertension and ascites (1,5,6). Although some patients develop cirrhosis, portal hypertension in the absence of cirrhosis has been well documented in sarcoidosis. This appears to be a result of a pressure effect due to portal granulomas and fibrosis rather than fully developed cirrhosis. A subset of sarcoid patients develops a chronic cholestatic process that resembles primary biliary cirrhosis (PBC), with progressive destruction of bile ducts (Figure 5.2.4) (2,5,7,8). This has been referred to as chronic cholestasis of sarcoidosis and may progress to biliary cirrhosis. Histologically, there is progressive bile duct loss and often lymphocytic cholangitis. Rare cases of cholestasis in sarcoidosis are a result of a “mass effect” due to granulomas at the hilum of the liver that compress large bile ducts (4,9).
A FIGURE 5. 2. 2 The classic sarcoid granuloma is epithelioid, noncaseating, and has admixed lymphocytes.
B F I G U R E 5 . 2 . 4 A subset of sarcoidosis patients have a chronic choles-
FIGURE 5. 2. 3 Sarcoid granulomas occasionally contain fibrinoid
necrosis but should not contain caseous necrosis.
tatic disorder that can mimic primary biliary cirrhosis. Note the granulomatous and lymphocytic inflammation in this portal tract, with an atrophic bile duct to the left, (A). A high power view highlights the bile duct damage and infiltration by lymphocytes, (B).
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75
A C FIGURE 5. 2. 4 The duct has almost disappeared in this portal
tract, (C).
The differential diagnosis includes other causes of noncaseating epithelioid granulomas, both infectious (see above, Chapter 5.1) and noninfectious. A list of noninfectious causes is summarized in Table 5.2.1. Sarcoidosis and PBC (Figure 5.2.5) may have significant overlap in a minority of patients. Antimitochondrial antibodies (AMA) should be negative in sarcoidosis patients, and they should have other signs of their disease, particularly pulmonary, that should help distinguish between sarcoidosis and PBC. Granulomas may be rare and poorly formed in PBC and are occasionally absent altogether. Although some patients with sarcoidosis have been reported to have hepatic vein phlebitis (10), patients with granulomas secondary to vasculitis should have detectable vasculitic lesions, usually with fibrinoid necrosis that are
B F I G U R E 5 . 2 . 5 The classic “florid duct lesion” in primary biliary cir-
rhosis features an epithelioid granuloma with associated lymphocytes and plasma cells adjacent to a damaged bile duct, (A). Adjacent portal tract shows well-developed lymphocytic cholangitis, (B).
TA B LE 5. 2. 1 Selected noninfectious causes of hepatic granulomas Cause
Examples
Primary cholestatic disorders
Primary biliary cirrhosis, primary sclerosing cholangitis (rare)
Vasculitides
Polyarteritis nodosa, lupus
Drug-induced injury
Isoniazid, quinidine, allopurinol
Metal toxicity
Beryllium, copper toxicity
Foreign material
Talc, starch
Inherited diseases
Chronic granulomatous disease
Neoplasms
Hodgkin’s lymphoma, primary hepatic tumors, metastases
Idiopathic
Sarcoidosis
absent in sarcoidosis. Drug-induced granulomatous inflammation usually features a background of hepatitis and hepatocellular injury. A search for polarizable material helps to rule out granulomas secondary to foreign material, although the granulomas of sarcoidosis may contain polarizable calcium oxalate crystals. A complete discussion of granulomatous lesions caused by drugs and toxins is beyond the scope of this chapter. The morphologic features of the granulomas associated with adverse drug reactions are very variable, and the granulomas may be well or poorly formed. Associated necrosis is very rare. Giant cells may be present, and there is a variable associated inflammatory infiltrate that may include lymphocytes, plasma cells, and eosinophils (Figure 5.2.6). There may be associated bile duct and/or vascular injury. The combination of
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References
FIGURE 5. 2. 6 Epithelioid granuloma with numerous admixed eosi-
nophils and a giant cell in a case of granulomatous hepatitis after ingestion of Echinacea tea.
granulomatous inflammation with significant hepatocellular injury should strongly suggest drug associated liver injury. A few notable drug culprits include allopurinol, nitrofurantoin, isoniazid, phenytoin, quinidine, and hydralazine (1–5,11).
1. Harrington PT, Gutierrez JJ, Ramirez-Ronda CH, Quiñones-Soto R, Bermúdez RH, Chaffey J. Granulomatous hepatitis. Rev Infect Dis. 1982;4:638–655. 2. Ishak KG. Granulomas of the liver. In: Ioachim HL, ed. Pathology of Granulomas. New York, NY: Raven Press; 1983. 3. Valla DC, Benhamou JP. Hepatic granulomas and hepatic sarcoidosis. Clin Liver Dis. 2000;4:269–285. 4. Ishak KG. Sarcoidosis of the liver and bile ducts. Mayo Clin Proc. 1998;73:467–472. 5. Devaney K, Goodman ZD, Epstein MS, Zimmerman HJ, Ishak KG. Hepatic sarcoidosis. Clinicopathologic features in 100 patients. Am J Surg Pathol. 1993;17:1272–1280. 6. Maddrey WC, Johns CJ, Boitnott JK, Iber FL. Sarcoidosis and chronic hepatic disease: a clinical and pathologic study of 20 patients. Medicine. 1970;49:375–395. 7. Valla D, Pessegueiro-Miranda H, Degot C, Lebrec D, Rueff B, Benhamou JP. Hepatic sarcoidosis with portal hypertension. A report of seven cases with a review of the literature. Q J Med. 1987;63:531–544. 8. Kim WR, Ludwig J, Lindor KD. Variant forms of cholestatic diseases involving small bile ducts in adults. Am J Gastroenterol. 2000;95: 1130–1138. 9. Bass NM, Burroughs AK, Scheuer PJ, et al. Chronic intrahepatic cholestasis due to sarcoidosis. Gut. 1982;23:417–421. 10. Reteigm MA, Fashir BM. Biliary tract obstruction due to sarcoidosis: a case report. Am J Gastroenterol. 1997;92:527–528. 11. Russi EW, Bansky G, Pfaltz M, Spinas G, Hammer B, Senning A. BuddChiari syndrome in sarcoidosis. Am J Gastroenterol. 1986;81:71–75.
Case 5.3
Fibrin Ring Granulomas LAURA W. LAMPS
were numerous small granulomas throughout the biopsy, as well as fibrin ring granulomas (Figure 5.3.1). AFB stain revealed scattered acid-fast bacteria, and subsequent PCR confirmed MAI.
C L I N IC AL I N F OR M AT I ON
The patient was a 30-year-old African American woman with human immunodeficiency virus (HIV) and AIDS who presented with a fever of unknown origin, malaise, and weight loss. She was found to have elevated transaminases.
DIAGNO SIS
R E A SON F OR R E F E R R AL
Mycobacterium avium-intracellulare infection.
To determine the etiology of granulomas in the HIV-positive patient. PAT H OL OG I C F E AT U R E S
DISCUSSIO N
The needle biopsy showed a lobular hepatitis with lobular disarray and a predominantly lymphocytic infiltrate. There
Fibrin ring granulomas are a distinctive form of granuloma consisting of an epithelioid granuloma with a central lipid vacuole surrounded by a fibrin ring (Figure 5.3.2) (1,2). The fibrin ring stains with fibrin stains and may not form a distinctive ring (2). These lesions were classically described in association with Coxiella burnetii, the causative agent of Q-fever (2–3). However, these lesions are now known to be quite nonspecific and have been observed in the context of numerous diseases including leishmaniasis (4), Boutonneuse fever (5), toxoplasmosis (5), CMV (6,7), EBV (6,5), MAI (8), typhoid (5), Hodgkin disease (5), and adverse drug reaction (allopurinol) (6,9). When fibrin ring granulomas are seen on liver biopsy, infection should be suspected, although they are also associated with drugs and rarely Hodgkin’s lymphoma. A combination of special stains, serologic studies, and molecular studies may be required to detect the infectious agent.
A
C F I G U R E 5 . 3 . 1 Lobular hepatitis with hepatocyte disarray and reactive
hepatocellular changes in a case of MAI infection, (A). Higher power view shows both small epithelioid and fibrin ring granulomas, (B,C).
B
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References 1. Ishak KG. Granulomas of the liver. In: Ioachim HL, ed. Pathology of Granulomas. New York: NY: Raven Press; 1983. 2. Pellegrin M, Delsol G, Auvergnat JC, et al. Granulomatous hepatitis in Q fever. Hum Pathol. 1980;11:51–57. 3. Srigley JR, Vellend H, Palmer N, et al. Q-fever: the liver and bone marrow pathology. Am J Surg Path. 1985;9:752–758. 4. Moreno A, Marazuela M, Yebra M, et al. Hepatic fibrin-ring granulomas in visceral leishmaniasis. Gastroenterol. 1988;95:1123–1126. 5. Marazuela M, Moreno A, Yebra M, Cerezo E, Gómez-Gesto C, Vargas JA. Hepatic fibrin-ring granulomas: a clinicopathologic study of 23 patients. Hum Pathol. 1991;22:607–613. 6. Kleiner DE. Granulomas in the liver. Semin Diagn Pathol. 2006;23: 161–169. 7. Lobdell DH. “Ring” granulomas in cytomegalovirus hepatitis. Arch Pathol Lab Med. 1987;111:881–882. 8. Lamps LW. Hepatic granulomas, with an emphasis on infectious causes. Adv Anat Pathol. 2008;15:309–318. 9. Stricker BH, Blok AP, Babany G, Benhamou JP. Fibrin ring granulomas and allopurinol. Gastroenterology. 1989;96:1199–1203.
FIGURE 5. 3. 2 The classic fibrin ring granuloma contains a lipid
vacuole surrounded by histiocytes and a fibrin ring.
Case 5.4
Schistosomiasis LAURA W. LAMPS
C L I N IC AL I N F OR M AT I ON
A 67-year-old Filipino man presented with vague abdominal pain. Transaminases were found to be minimally elevated. Hepatitis and autoimmune serologies were negative. R E A SON F OR R E F E R R AL
To determine the nature of calcified structures in liver biopsy. PAT H OL OG I C F E AT U R E S
The liver biopsy shows numerous ovoid calcified structures consistent with the calcified eggs of schistosomiasis (Figure 5.4.1). The eggs are present within remote hyalinized granulomas, with virtually no remaining active inflammatory response. The background liver shows steatosis.
A
D I AG N OS I S
Remote hepatic schistosomiasis.
D I S C U S S I ON
Schistosomiasis is one of the most common diseases in the world and is the most common worldwide cause of portal hypertension (1–3). It is also known as bilharziasis, after its discovery by Sir Theodore Bilharz in Egypt in 1851. These trematodes are endemic in Africa, Asia, and parts of the Americas. In the United States, infected patients are often immigrants, travelers, or persons who have worked abroad. Humans become infected by exposure to contaminated water. Most hepatobiliary disease is caused by S. mansoni, S. japonicum, or S. mekongi, as these prefer mesenteric and portal veins. Once settled in their vein of choice, adult worms copulate and produce thousands of eggs in their lifetimes; approximately 50% of the eggs remain within the body. The severity of the disease and the likelihood of significant sequelae are related to the intensity and duration of the infection. In addition, egg deposition is seemingly random and nonuniform. Acute symptomatic infection most often occurs in immunologically naïve adults infected for the first time; this is rarely seen in inhabitants of endemic areas. Most patients in endemic areas have chronic schistosomiasis and are asymptomatic or have only mild chronic complaints. Hypersensitivity to the eggs themselves is the underlying cause of disease, and the resultant inflammation leads to fibrosis and obstructive hepatobiliary disease. Symptomatic patients present with splenomegaly and signs of portal hypertension, particularly bleeding; hepatic function is usually preserved (1–8).
B
C F I G U R E 5 . 4 . 1 Scattered calcified ovoid structures consistent with
ova in a patient with remote schistosomiasis, (A). A higher power view shows eggs within a hyalinized granuloma. There is no residual active inflammation, (B). At high power, the calcified eggs are blueblack and refractile, (C).
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A
F I G U R E 5 . 4 . 3 Hematoidin pigment is a common feature in hepatic
schistosomiasis.
B FIGURE 5. 4. 2 Granulomatous inflammation in schistosomiasis,
with several epithelioid granulomas surrounding ova, and associated fibrosis, (A). An egg with an embryo is seen within a granuloma, (B; courtesy of Dr. Joseph Misdraji).
Grossly, livers are enlarged and nodular. On cut surface, the typical portal fibrosis known as pipestem or Symmers’ fibrosis may be seen (1). The histologic features of schistosomiasis vary with duration of disease and result from inflammation and fibrosis in reaction to the eggs deposited in tissue; the worms themselves cause little damage. In general, there is an active phase of infection, characterized by more intense inflammation and an inactive phase, characterized by decreasing inflammation and increasing fibrosis and calcification of ova. In chronic schistosomiasis there is typically a granulomatous reaction to the eggs, which are present in varying numbers both within granulomas and fibrotic areas (Figure 5.4.2). The granulomas may be rich in eosinophils, and eggs or egg parts may be detectable within granulomas (1,3,5). As lesions progress, there is increased fibrosis, as well as an increase
in macrophages and giant cells. Remote lesions may show only fibrosis and calcified eggs, with virtually no inflammatory reaction (as in the case presented here). Ultimately, portal tracts become large and densely sclerotic, and fibrous septa link portal tracts together. Sinusoidal fibrosis may also develop. As the fibrosis progresses, eggs may be increasingly difficult to find. Granulomas and fibrosis also affect portal vein branches, leading to phlebitis, sclerosis, and thrombosis. Eventually portal veins are obstructed and destroyed, with subsequent proliferation of hepatic arterial branches (3–7). Schistosomal pigment accumulation in macrophages (Figure 5.4.3) is also a helpful finding. It is finely granular, dark brown, and birefringent; it is considered to be a hemoglobin derivative, presumably released by worms after ingestion of host red blood cells (1). Schistosome eggs are variably acid fast; morphologic and staining characteristics of the eggs of the various species are given in Table 5.4.1. In hematoxylin and eosin (HE) sections, the calcified eggs are generally dark blue or black and somewhat amorphous (1,3–7). Decalcification may reveal partially preserved embryos (8). The worms themselves are slender and elongated, measuring 0.5 to 2.5 cm in length. The inflammatory reaction to the organism may mimic other infectious and noninfectious causes of hepatic granulomas. Schistosome eggs in tissue sections may be distinguished from the eggs of Enterobius, Capillaria, and trematodes by their spines and the acid-fast properties of the eggs (see Table 5.4.1). Microscopic detection of eggs in stool or urine is the most reliable, cost-effective method of diagnosis, although multiple specimens may be required. Worms are occasionally retrieved from biliary lavage. Serologic studies are also useful.
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SCHISTOSOMIASIS
TA B LE 5. 4. 1 Schistosome target organs, geographical distribution, and staining characteristics of eggs Species
Egg Shape
Staining Properties
Target Organs
Endemic Areas
S. haematobium
Terminal spine
Acid-fast spine
Bladder, ureter, pelvis
Africa Southern Europe Western Asia
S. mansoni
Lateral spine
Acid-fast shell and spine
Gut, liver, lung
Africa Brazil West Indies Puerto Rico
S. japonicum
Small lateral spine
Acid-fast shell and spine
Gut, liver, lung
China Japan Philippines
S. intercalatum
Terminal spine
Acid-fast spine
Gut, liver
West Africa
S. mekongii
Small lateral spine
Acid-fast shell and spine
Gut, liver, lung
Laos Cambodia Thailand
S. malayi
Small lateral spine
Acid-fast shell and spine
Liver
Penang peninsula (Malaysia)
References 1. Ishak KG. Granulomas of the liver. In: Ioachim HL, ed. Pathology of Granulomas. New York, NY: Raven Press; 1983. 2. Gryseels B, Polman K, Clerinx J, Kestens L. Human schistosomiasis. Lancet. 2006;368(9541):1106–1118. 3. von Lichtenberg F. Schistosomiasis. In: Connor DH, Chandler FW, et al eds. Pathology of Infectious Diseases. Stamford, CT: Appleton and Lange; 1997:1537–1551. 4. Warren KS. The pathology, pathobiology, and pathogenesis of schistosomiasis. Nature. 1978;273:609–612.
5. Grimaud JA, Borojevic R. Chronic human schistosomiasis mansoni. Pathology of the Disse’s space. Lab Invest. 1977;36:268–273. 6. Davis A. Recent advances in schistosomiasis. Q J Med. 1986; 58:95–110. 7. Elliott DE. Schistosomiasis: Pathophysiology, diagnosis, and treatment. Gastroenterol Clin North Am. 1996;25(3):599–625. 8. Cheever AW. Decalcification of schistosome eggs during staining of tissue sections: a potential source of diagnostic error. Am J Trop Med Hyg. 1986;35:959–961.
Case 5.5
Cat Scratch Disease LAURA W. LAMPS
negative, and there were no fecal leukocytes. Histoplasma urinary antigen test was negative. Purified protein derivative (PPD) skin test was nonreactive.
C L I N I C AL I N F OR M AT I ON
A previously healthy 18-year-old male presented with an 8-month history of fever and abdominal pain. His home contained several dogs and cats. CT scan showed multiple low attenuation hepatic masses in both lobes of the liver. An extensive serological workup was negative. Stool cultures were
R EA SO N FO R R EFER R A L
Stellate microabscesses and granulomatous inflammation of unknown etiology. PAT H O LO GIC FEAT UR ES
A wedge biopsy shows necrotizing granulomatous inflammation with central stellate abscess formation (Figure 5.5.1). Special stains for fungi and AFB are negative. Warthin-Starry stain shows a few pleomorphic coccobacilli in areas of necrosis (Figure 5.5.2). The paraffin block sent for PCR for Bartonella DNA, confirmed the diagnosis of hepatic cat scratch disease (CSD).
DIAGNO SIS
Hepatic cat scratch disease.
A
B FIGURE 5.5.1 A low power view of hepatic cat scratch disease shows
irregular, stellate microabscesses surrounded by granulomatous inflammation and fibrosis, (A). This high power view of the “layered” appearance of the lesions shows central necrosis, palisading histiocytes, mononuclear cells, and an outer rim of fibrosis, (B).
F I G U R E 5 . 5 . 2 Warthin-Starry silver impregnation stain shows small,
pleomorphic bacilli in areas of necrosis.
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D I S C U S S I ON
Bartonella henselae (formerly Rochalimaea henselae (1)) is the major etiologic agent of CSD. There are 4 species of Bartonella, and B. henselae and B. quintana are most frequently associated with human disease (2). Bartonella henselae is the species most commonly associated with the necrotizing granulomatous lesions of “classical” CSD, which typically occurs in immunocompetent patients. The overall incidence in the United States is estimated at 6.6/100 000 persons, but this is considered a low estimate because many patients do not seek medical attention. More than 80% of the patients are children and adolescents under the age of 21. Over 90% of patients with CSD have cat exposure, and in the majority of these cases the exposure consists of a scratch or bite, most characteristically from a young cat or kitten (3,4). Cat scratch disease most often presents as tender, regional lymphadenopathy arising approximately 2 weeks after the development of a distal inoculation site, most often on the hands, arms, or chest. A minority of patients (approximately 5%–20%) have atypical presentations that often lack superficial regional adenopathy and an obvious inoculation site. These atypical forms of CSD can present with severe constitutional symptoms that may mimic neoplasia, collagen vascular diseases, or other systemic infections. Hepatic CSD is rarely associated with either superficial adenitis or an identifiable inoculation site (5,6,7). There are typically multiple low-density lesions on CT scan that mimic metastatic tumor, and there are often accompanying constitutional symptoms including fever, weight loss, and malaise that often support the suspicion of malignancy (6,7). Both the liver and the spleen may be enlarged, and there is often associated intra-abdominal lymphadenopathy (5). Transaminases are usually normal, and an elevated serum alkaline phosphatase is often the only abnormal laboratory value (8). Despite the ominous clinical and radiographic appearances, these lesions often resolve without treatment, and, generally, there are no significant sequelae (5,6). Antibiotic use is controversial, but successful results have been obtained with numerous antibiotics (3,7). The hallmark lesion of hepatic CSD is a granuloma with a central stellate microabscess (Figure 5.5.3) surrounded by 3 distinct zones: an inner zone of palisading histiocytes, an intermediate zone of lymphocytes, and an outer rim of dense fibrosis (5). Morphologic characteristics of the lesions vary widely within the same biopsy, corresponding to the age of the lesions; granulomas with definitive zonation, resolving necrosis, and prominent fibrosis and granulation tissue suggest chronicity. The dense fibrous rind surrounding the lesions may present a problem on needle biopsy (Figure 5.5.4), particularly at frozen section, for the central, diagnostic portion of the biopsy may not be sampled. For that reason, wedge liver biopsy is often required for diagnosis. The first step in the diagnosis of hepatic CSD is a careful history with attention to patient contact with cats. Culture is generally not relied upon for the diagnosis of CSD, as the organism is very fastidious and slow-growing. Several serologic studies are now commercially available, but it has been
A
B F I G U R E 5 . 5 . 3 Hepatic cat scratch disease with characteristic zonated appearance, (A). The outer rim of fibrosis may be particularly prominent in the liver, (B).
shown that some patients never mount a detectable antibody response, and conversely patients may remain serologically positive long after exposure and recovery from their illness. In addition, there is extensive serological cross-reactivity between B. henselae and B. quintana, as well as with other intracellular bacteria such as Coxiella burnetii (4,9,10). Tissue biopsy is one of the most useful ways to diagnose CSD, as well as to exclude other etiologies. Silver impregnation stains (such as Warthin-Starry or Steiner) are the preferred histochemical stain for detection of Bartonella; however, organisms are only variably detectable, and these stains are technically challenging due to the high background of silver precipitate. Immunohistochemical antibodies to Bartonella are available (11). PCR assays are also available for both fresh
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reveal fungi, and fungal culture may also be useful in separating fungal infection from hepatic CSD. Other entities in the differential diagnosis of hepatic CSD include bacterial abscesses, which have a prominent fibrous “rind” and central suppuration but lack granulomatous features; actinomycosis, which shows filamentous Gram-positive bacteria on tissue Gram stain; and lymphogranuloma venereum (LGV), which may mimic CSD in inguinal lymph nodes but almost never involves the liver.
References
FIGURE 5. 5. 4 The diagnosis of cat scratch disease may be difficult
to make on a needle biopsy, especially if only the outer fibrous areas are sampled.
and formalin-fixed, paraffin-embedded material (9,11). PCR is both sensitive and specific, particularly when combined with Southern blotting and lacks many of the problems inherent in other diagnostic methodologies (9,12). The differential diagnosis primarily includes other infectious processes. The granulomas in M. tuberculosis infection are usually epithelioid, often with caseation, giant cells, and a surrounding ring of lymphocytes and histiocytes but lack the characteristic zonation of the CSD lesions. In addition, mycobacteria can generally be detected with special stains, microbiological techniques, and/or PCR assays. Brucellosis may cause a variety of granulomatous lesions but again lacks the characteristic zonation of CSD. Francisella tularensis typically causes suppurative microabscesses with occasional surrounding macrophages; as the lesions evolve they may become more granulomatous but also lack the zonation typically seen in hepatic CSD. Fungal infections, particularly candidiasis, may closely mimic CSD; but GMS stain should
1. Brenner DJ, O’Connor SP, Winkler HH, Steigerwalt AG. Proposals to unify the genera Bartonella and Rochalimaea, with descriptions of B. quintana comb. nov., B. vinsonii comb. nov., and B. elizabethae comb. nov., and to remove the family Bartonellaceae from the order Rickettsiales. Int J Syst Bacteriol. 1993;43:777–786. 2. Adal KA, Cockerell CJ, Petri WA Jr. Cat scratch disease, bacillary angiomatosis, and other infections due to Rochalimaea. N Engl J Med. 1994;330:1509–1515. 3. Klein JD. Cat scratch disease. Pediatr Rev. 1994;15:348–353. 4. Smith DL. Cat-scratch disease and related clinical syndromes. Am Fam Physician. 1997;55:1783–1789. 5. Lamps LW, Gray GF, Scott MA. The histologic spectrum of hepatic cat scratch disease. A series of six cases with confirmed Bartonella henselae infection. Am J Surg Pathol. 1996;20:1253–1259. 6. Port J, Leonidas JC. Granulomatous hepatitis in cat-scratch disease. Ultrasound and CT observations. Pediatr Radiol. 1991;21:598–599. 7. Larsen CE, Patrick LE. Abdominal (liver,spleen) and bone manifestations of cat scratch disease. Pediatr Radiol. 1992;22:353–355. 8. Rocco VK, Roman RJ, Eigenbrodt EH. Cat scratch disease. Report of a case with hepatic lesions and a brief review of the literature. Gastroenterology. 1985;89:1400–1406. 9. Agan BK, Dolan MJ. Laboratory diagnosis of Bartonella infections. Clin Lab Med. 2002;22:937–962. 10. Barka NE, Hadfield T, Patnaik M, et al. EIA for detection of R. henselaereactive IgG, IgM, and IgA antibodies in patients with suspected catscratch disease. J Inf Dis. 1993;167:1503–1504. 11. Caponetti GC, Pantanowitz L, Lamps LW, Marconi S, Havens JM, Otis CN. Utility of immunohistochemistry to diagnose cat scratch disease. Am J Clin Pathol. 2009;31:250–256. 12. Anderson B, Sims K, Regnery R, et al. Detection of Rochalimaea henselae DNA in specimens from cat scratch disease patients by PCR. J Clin Microbiol. 1994;32:942–948. 13. Shinall EA. Cat-scratch disease: a review of the literature. Pediatr Dermatol. 1990;7:11–18.
Case 5.6
Chronic Granulomatous Disease DAVID E. KLEINER
tissue around these abscesses is not inflamed (Figure 5.6.2). Special stains for fungi show fragments of hyphal forms within the necrotic areas. One of the wedge resections is much larger and mainly consists of hepatic parenchyma. The largest wedge shows diffusely inflamed liver parenchyma, with multiple small nonnecrotizing granulomas in a background of lobular lymphocytic inflammation (Figure 5.6.3). There is portal inflammation associated with disruption of the limiting plate and pseudoxanthomatous changes in periportal hepatocytes. Some of the larger ducts are missing and replaced by inflamed
C L I N IC AL I N F OR M AT I ON
A 23-year-old man presented with sinusitis. He had a history of recurrent pulmonary, hepatic, and bone infections since young childhood. These infections required repeated hospitalizations and chronic administration of antibacterial and antifungal medications. During the workup, he was noted to have elevated liver enzymes: alkaline phosphatase 866 IU/L, alanine aminotransferase (ALT) 52 IU/L, aspartate aminotransferase (AST) 37 IU/L, and a total bilirubin of 0.6 mg/dL. Imaging using ultrasound, CT, and magnetic resonance imaging (MRI) showed multiple hepatic lesions consistent with abscesses. A CT-guided aspirate grew Staphylococcus aureus and Streptococcus mitis. He was started on ceftriaxone, vancomycin, and rifampin and discharged but returned 1 week later with right upper quadrant pain, fatigue, and chills. He was taken to surgery where wedge resections of liver were performed. R E A SON F OR R E F E R R AL
Evaluation of abscesses and granulomatous changes in the surrounding hepatic parenchyma. PAT H OL OG I C F E AT U R E S
Eight separate wedge excisions of hepatic abscesses are available for review. All of them show liver parenchyma replaced with dense fibrous connective tissue. Multiple small wellcircumscribed necrotic abscesses bounded by a palisaded histiocytic infiltrate are present (Figure 5.6.1). The connective
F I G U R E 5 . 6 . 2 Palisaded histiocytes at the edge of the granulomatous abscess.
F I G U R E 5 . 6 . 3 Liver parenchyma distant from the abscesses showing a nonnecrotizing granuloma and numerous foci of lobular inflammation.
Well-circumscribed granulomatous abscesses embedded in dense fibrous connective tissue.
FIGURE 5. 6. 1
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FIGURE 5. 6. 4 Large portal area with periductal inflammation and
narrowing of large duct.
connective tissue, whereas others show constriction with periductal fibrosis and inflammation (Figure 5.6.4). Some of the periportal hepatocytes are positive for copper on rhodanine stain. There is portal fibrosis, but no bridging fibrosis. Collections of pigmented macrophages from individual cells to larger aggregates are present.
D I AG N OS I S
Chronic granulomatous disease with necrotizing granulomatous hepatic abscesses, positive for fungal hyphae. Nonnecrotizing granulomatous hepatitis with secondary sclerosing cholangitis-like changes.
D I SC U SSI ON
Chronic granulomatous disease (CGD) is an inherited immunodeficiency due to a defect in intracellular killing of pathogens by neutrophils (1–3). The incidence has been estimated to be about 1 in 200 000 in the United States. It is inherited through both X-linked and autosomal recessive mechanisms. The specific functional defect is in NADPH oxidase, a membranebound enzyme that catalyzes the oxidation of O2 to superoxide anion, O2. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase has 4 subunits, gp91phox, which is on the X chromosome and p22phox, p47phox and p67phox, which are on chromosomes 16, 7, and 1, respectively. About 70% of patients have the X-linked form of the disease. Because patients with CGD cannot generate superoxide, they are particularly susceptible to infections from certain catalase-positive organisms such as Staphylococcus aureus, Burkholderia sp., Serratia marcescens, Nocardia sp., and Aspergillus sp. Patients usually present with infection and granulomatous disease, with the lungs, skin, lymph nodes, and liver being the most common sites of infection. The diagnosis is established by measurement
AND
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of the defect by measurement of superoxide product, dihydrorhodamine oxidation, or other tests (4). Molecular determination of the specific genetic defects is also available and is the only type of testing useful in the prenatal setting (1). This case illustrates several aspects of the hepatic pathology of CGD. Hepatic abscess formation is the main manifestation of clinically significant liver disease and it can be life threatening. The risk of developing hepatic abscesses rises with increasing age and the total number of infections the patient has experienced. About a third of patients with CGD will develop hepatic abscesses, which are typically multiloculated and embedded in a thick cuff of fibrous tissue. The fibrous tissue may be bland and scar-like, as in this case, or it may be inflamed and highly vascular, like inflamed granulation tissue. Staphylococcus aureus is commonly cultured from these abscesses, but fungal organisms may also be found, particularly Aspergillus. Although the appearance of the abscesses is similar to granulomatous abscesses in other diseases, the presence of abundant connective tissue around the abscesses, as well as multiloculation is characteristic of CGD. This architectural peculiarity makes CGD abscesses very difficult to drain percutaneously, and surgical intervention is required when medical management cannot control the infection (5,6). Specimens of abscesses should always be sent for culture, and special stains for microorganisms should be done routinely. Aside from the dramatic development of abscesses, patients with CGD may have more subtle forms of liver disease (7,8). Biopsies of nonabscessed liver can show a wide variety of findings. At one end of the spectrum, biopsies may show only collections of pigmented macrophages. These cells accumulate at sites of inflammation and cell turnover, and they may be the only pathologic manifestation of CGD. In the liver, the larger aggregates tend to accumulate near portal or central veins. In addition, there can be varying degrees of lobular and portal lymphocyte inflammation as well as wellformed, nonnecrotizing epithelioid granulomas. About 90% of specimens will show spotty lobular inflammation and 75% will have nonnecrotizing granulomas (8). On histologic grounds, the differential diagnosis could include both chronic hepatitis and other granulomatous diseases, such as sarcoidosis or primary biliary cirrhosis. Rarely there can be granulomatous destruction of ducts or periductal sclerosis with duct obliteration as seen in this case. Correct diagnosis requires correlation with the clinical history. The chronic cholestatic disease in this patient responded to steroid therapy, which would be unlikely if primary sclerosing cholangitis was present. A recently recognized hepatic complication of CGD is the development of noncirrhotic portal hypertension (7). Patients develop splenomegaly and show a gradual decline in platelet levels over a period of several years. A drop in platelets of more than 9000/μL/year was associated with a 4.7-fold increased risk of mortality as compared with those whose platelet levels were stable. Histologically, there were a variety of findings that might have explained the noncirrhotic portal hypertension. Portal and central veins were narrowed or obliterated by the accumulation of pigmented macrophages or perivascular inflammation in 65% to 90% of cases, depending
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on the group examined. These changes are particularly pronounced near abscesses but may be seen elsewhere in the liver. This same study noted that nodular regenerative hyperplasia (NRH) was observed in 40% of patients who died as opposed to only 11% of those who were alive at the end of the follow-up period. NRH may have developed from the venopathy or from drug injury. The mechanism by which portal hypertension contributes to death in CGD is not entirely clear, as patients typically die from infection and sepsis. Portal hypertension may increase the risk of infection by increased bacterial translocation from the gut and may also be worsened by sepsis. Patients with CGD may develop other liver diseases as well, and it has been noted that drug-induced liver injury is a relatively common cause of liver enzyme elevations (8). Patients with CGD have also been reported to have concurrent viral hepatitis infection, and with the advent of bone marrow transplantation as a potentially curative therapy, hepatic graft-versus-host disease has been found. Our understanding of CGD has led to improvements in the management of these patients, enabling many patients to survive into middle age. Although hepatic abscesses remain important, it has become clear that the liver pathology of CGD is more complex than simple localized infections, and attention should be paid to the nonabscessed liver parenchyma. Granulomas in CGD vary from nondescript collections of pigmented macrophages to well-formed nonnecrotizing
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granulomas to necrotizing granulomatous abscesses. If liver disease is the first manifestation of the disease, the pathologist may be able to suggest the diagnosis by noting the more specific features of CGD, particularly the multiloculated nature of the abscesses and the numerous pigmented macrophages.
References 1. Holland SM. Chronic granulomatous disease. Clin Rev Allergy Immunol. 2010;38:3–10. 2. Segal BH, Leto TL, Gallin JI, Malech HL, Holland SM. Genetic, biochemical, and clinical features of chronic granulomatous disease. Medicine (Baltimore). 2000;79:170–200. 3. Winkelstein JA, Marino MC, Johnston RB Jr, et al. Chronic granulomatous disease. Report on a national registry of 368 patients. Medicine (Baltimore). 2000;79:155–169. 4. Elloumi HZ, Holland SM. Diagnostic assays for chronic granulomatous disease and other neutrophil disorders. Methods Mol Biol. 2007;412: 505–523. 5. Chen LE, Minkes RK, Shackelford PG, Strasberg SM, Kuo EY, Langer JC. Cut it out: Managing hepatic abscesses in patients with chronic granulomatous disease. J Pediatr Surg. 2003;38:709–713. 6. Lublin M, Bartlett DL, Danforth DN, et al. Hepatic abscess in patients with chronic granulomatous disease. Ann Surg. 2002;235:383–391. 7. Feld JJ, Hussain N, Wright EC, et al. Hepatic involvement and portal hypertension predict mortality in chronic granulomatous disease. Gastroenterology. 2008;134:1917–1926. 8. Hussain N, Feld JJ, Kleiner DE, et al. Hepatic abnormalities in patients with chronic granulomatous disease. Hepatology. 2007;45:675–683.
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6 Cholestasis JAY H. LEFKOWITCH
Histologic cholestasis is a considerable diagnostic challenge for the pathologist because of its diverse causes and the many potential anatomic sites where bile flow may be interrupted. Establishing the etiology of cholestasis requires histologic assessment of the site(s) of cholestasis, the status of the liver parenchyma, and, importantly, the appearances of the portal tracts and constituent intrahepatic bile ducts (1,2). It should also be borne in mind that disorders referable to the biliary tract may not invariably be associated with visible bile in tissue sections. Examples include liver involvement in small duct primary sclerosing cholangitis (PSC), early stages of primary biliary cirrhosis, individuals with intermittent episodes of large bile duct obstruction (eg, alcoholic pancreatitis), stricturing lesions involving specific segments of bile ducts, or large bile duct obstructive diseases which have been treated by placing biliary stents. Despite the absence of histologic bile in such instances, the diagnosis of biliary tract disease rests on recognizing the portal tract and parenchymal changes reflecting involvement of the biliary tree. Cholestasis (Figure 6.1) is most often apparent in centrilobular regions (acinar zones 3) where the products of drug metabolism and the effects of ischemia and/or hypoxia have their greatest physiologic impact. Retained bile within hepatocytes on H&E stain appears as granular yellow-brown pigment and is often present in conjunction with brown bile plugs (bile thrombi) molded within rounded intercellular bile canaliculi (or within longitudinally cut canalicular lumens). Detergent action of retained bile acids in hepatocytes may result in livercell swelling and cytoplasmic rarefaction referred to as “feathery degeneration” (Figure 6.2). Examination of a Prussian blue iron stain may be helpful in the identification of subtle cholestasis that might be hidden by overly saturated eosin on a standard H&E-stained slide, by virtue of the pale nuclear red counterstain used in the iron stain. The chief pigment with which intrahepatocellular bile is likely to be confused is lipofuscin, which shows similar color and texture to bile (Figure 6.3A). DubinJohnson pigment is coarser and more often darker brown in color and extends more deeply into the lobules to involve both centrilobular and midzonal regions or acinar zones 3 and 2 (Figure 6.3B). Both lipofuscin and Dubin-Johnson pigments stain positively on using the long Ziehl-Neelsen stain, whereas bile is negatively stained. Hall’s bile stain may be used to specifically stain bile. Identification of canalicular bile plugs is the most practical means on H&E stain of distinguishing hepatocellular cholestasis from lipofuscin. Hemosiderin pigment (granular, brown, refractile, and glassy) preferentially accumulates in periportal hepatocytes and is, therefore, an unlikely consideration in the differential of perivenular (centrilobular) hepatocellular pigment (except in the later progressive iron-loading stages of
F I G U R E 6 . 1 Cholestasis. The centrilobular region seen here shows
prominent bile within canaliculi and within hepatocytes.
F I G U R E 6 . 2 Feathery degeneration of hepatocytes in cholestasis. Bile and bile salt retention within hepatocytes has caused bile salt–related detergent damage with resultant “feathery degeneration,” including swelling, cytoplasmic rarefaction, and vacuolar degeneration.
classical hereditary HFE hemochromatosis when all 3 acinar zones of the liver show iron overload). Hepatocellular and canalicular cholestasis may also be associated with bile within sinusoidal Kupffer cells. The affected Kupffer cells show diffuse cytoplasmic tan-brown staining on H&E, are positive with diastase-digested periodic acid Schiff (DPAS) stain, and in cases of recent (but resolved) cholestasis may be the only residual evidence of a recent cholestatic
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FIGURE 6. 3 Centrilobular hepatocyte pigments. (A) Lipofuscin is finely granular, yellow-brown, and localized toward the hepatocyte membrane
in a pericanalicular distribution. (B) Dubin-Johnson pigment seen in these centrilobular hepatocytes is coarse and brown and distributed randomly throughout the liver-cell cytoplasm. The pigment often extends from centrilobular regions more deeply into the lobular periphery.
episode. Uncommonly bile is seen within periportal bile ductular structures (so-called “bile ductular cholestasis”). In pediatric liver specimens, this is one of several features seen in extrahepatic biliary atresia, whereas in adults this distribution is highly suggestive of sepsis (3). Rarely, bile is present in septal or larger caliber bile ducts. This “ductal cholestasis,” in chiefly a postmortem finding, is likely to be related to marked slowing of bile flow during the preterminal period. Cholestasis may be classified according to etiopathogenesis as primary (genetic), secondary (acquired), or due to mechanical obstruction of bile ducts. Some of the hepatobiliary disorders in these 3 categories are shown in Table 6.1. TA B LE 6. 1 Etiopathogenesis of cholestasis
Primary (Genetic) • Bile salt transporter mutations (eg, PFIC-1, BRIC) • Bile salt synthesis defects
Secondary (Acquired) • • • •
Sepsis (endotoxin-cytokine–related) Hepatitis (viral/drug-related) Paraneoplastic (eg, lymphoma cytokine secretion) Preservation injury after liver transplantation (ischemia/ reperfusion injury)
Mechanical (Bile duct disease) • • • • •
PSC Choledocholithiasis Biliary stricture Carcinoma (pancreas/bile duct/ampulla) Late primary biliary cirrhosis
Abbreviations: BRIC, benign recurrent intrahepatic cholestasis; PFIC-1, progressive familial intrahepatic cholestasis 1;PSC, primary sclerosing cholangitis.
Cholestasis may also be classified morphologically according to the histologic patterns identified in acute and chronic cholestasis as described below. H ISTO LO GIC PAT T ER NS IN ACUT E CH O LESTAS IS Cholestasis in Acute Large Bile Duct Obstruction (Pattern 1: Classical Ductular Reaction Type [ Figures 6.4 and 6.5 ])
Acute obstruction of large bile ducts (days to weeks) results in cholestasis accompanied by a triad of classical changes affecting portal tracts, including portal connective tissue edema, mild neutrophil infiltrates, and proliferation of bile ductular structures (4) (Figure 6.6). The ductular structures are characteristically arranged along the margins of the portal tract in portal/periportal regions (“marginal” bile ductular proliferation). The combination of ductular structures and stromal changes is now referred to as the ductular reaction (5,6). The ductular structures evolve from periportal Canals of Hering and/or progenitor/stem cells and are well demonstrated with cytokeratin (CK) 7 and 19 immunostains (Figures 6.7–6.9). Intraluminal and periductular neutrophils are virtually universal in the ductular reaction. Neutrophil chemotaxis into the ductular reaction is mediated by cytokine secretion by the ductular epithelium and by the rich inflammatory cytokine milieu associated with biliary obstruction (7–9). When examining H&E and CK7/CK19 immunostains, care should be given to assessing the quality and nature of the ductular reaction that may be present. This can differ considerably among the different etiologies of cholestatic liver disease. For example, an exaggerated version of the typical ductular reaction seen in acute and chronic large bile duct
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FIGURE 6. 4 Histologic pattern set of acute cholestasis. Four histologic
response patterns include, pattern 1: cholestasis with triad of portal changes including edema, ductular reaction, and neutrophils (classical ductular reaction [DR] type); pattern 2: pure (bland) cholestasis; pattern 3: intrahepatic bile duct disease (b.d.) with bile duct damage and/or loss and cholestasis; and pattern 4: cholestasis associated with hepatitis. See Figure 6.5 for key to diagrams.
FIGURE 6. 5 Key to histologic patterns of acute cholestasis.
obstruction (Figure 6.7) also characterizes fibrosing cholestatic hepatitis due to hepatitis B or C virus reinfection after liver transplantation (10,11) (Figure 6.8) (a progenitor/stem cell activation response due to the severity of the hepatocellular injury and inadequate hepatocyte regeneration). In contrast, the ductular reaction is absent, extremely limited, or consists of only linear arrays of periportal intermediate hepatobiliary cells (“biliary hepatocytes”) in certain cholestatic disorders such as chronic ductopenic rejection and neonatal cholestasis with bile duct paucity (Figure 6.9). Loss of CD10 immunoreactivity on bile canaliculi may be a helpful diagnostic feature in such cases (12) (Figure 6.9C). With complete large bile duct obstruction, parenchymal bile is seen within hepatocytes, bile canaliculi, and sometimes in Kupffer cells. Hepatocellular cholestasis occasionally
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F I G U R E 6 . 6 Portal tract in acute large bile duct obstruction. The triad of edema, inflammation, and ductular reaction is present. Note the normal-appearing native bile duct at upper left. Although the portal tract features are indicative of acute large duct obstruction in general, the specific anatomic site of obstruction is histologically uncertain and requires further clinical evaluation.
F I G U R E 6 . 7 The ductular reaction in large bile duct obstruction. In this case of primary sclerosing cholangitis, the proliferation of bile ductular structures are highlighted on CK7 immunostain (CK7 immunoperoxidase).
induces a ground-glass–like cytoplasmic appearance due to induction of smooth endoplasmic reticulum (13). Reorganization of hepatic plates into cholestatic liver-cell rosettes may be prominent. Bile infarcts, bile extravasates, and bile lakes accompanying type 1 “ductular reaction” pattern portal lesions are virtually pathognomonic of large duct obstruction. Examples of the type 1 pattern of acute cholestasis include gallstone impaction within the common bile duct (choledocholithiasis), common bile duct obstruction within the swollen and inflamed pancreas in acute pancreatitis, and biliary anastomotic obstruction after liver transplantation due to stricture, kinking, or bile extravasation (biloma).
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TA BL E 6 . 2 Causes of intrahepatic “pure” cholestasis Sepsis Drug hepatotoxicity Early large bile duct obstruction Extrahepatic lymphoma Bile salt transporter protein mutations Mitochondriopathies Ischemia/reperfusion injury after transplantation (“functional bile flow impairment”)
FIGURE 6. 8 Marked ductular reaction in fibrosing cholestatic hepatitis C following liver transplantation (CK 7 immunostain). The extensive periportal ductular reaction resembles that seen in large bile duct obstruction, often necessitating radiologic studies to exclude large bile duct disease (CK7 immunoperoxidase).
(acinar zones 3) are primarily affected owing to a number of features specific to this region, including the constitutive localization of drug metabolizing enzymes to perivenular hepatocytes, susceptibility of bile canalicular bile transport systems in zone 3 to ischemia, hypoxia and the effects of circulating cytokines and endotoxins, and slower functional rates of bile flow when compared with periportal regions. The examples shown in Table 6.2 range from mutations of bile salt transport proteins (14–16) (eg, progressive familial intrahepatic cholestasis type 1 or PFIC-1, benign recurrent intrahepatic cholestasis) to endotoxin-related inhibition of BSEP (bile salt export pump) in sepsis.
Cholestasis Associated With Intrahepatic Bile Duct Disease (Pattern 3)
FIGURE 6. 9 Neonatal giant cell hepatitis with cholestasis and bile duct paucity. (A) Liver biopsy from this neonate with jaundice shows centrilobular cholestasis and multinucleated giant hepatocytes (top). The portal tract below shows an unpaired artery (a) without an accompanying interlobular bile duct; there is no apparent periportal ductular reaction. (B) Cytokeratin 7 immunostain shows an array of periportal intermediate hepatobiliary cells, but no well-formed ductular structures. (C) CD10 immunostain shows loss of bile canalicular endopeptidase staining except for focal periportal positivity below and upper left.
Pure (Bland) Cholestasis (Pattern 2)
The presence of cholestasis alone, without accompanying portal tract or parenchymal changes, may result from a variety of intrahepatic disorders or may be the earliest manifestation of large bile duct obstruction (Table 6.2). Centrilobular regions
The importance of the structural and functional integrity of intrahepatic bile ducts to bile secretion is emphasized by cholestatic disorders associated with damage to the smaller caliber bile ducts (usually interlobular bile ducts) within the liver. For histologic cholestasis to be present there must be substantial diffuse damage to intrahepatic bile ducts, potentially including bile duct loss (ductopenia). Idiosyncratic drug hepatotoxicity (Figure 6.10), later stages of primary biliary cirrhosis, and severe liver transplant rejection are examples. The affected duct epithelium may be infiltrated by immune cells (lymphocytes, eosinophils, neutrophils) and may show a variety of reactive features including nuclear pleomorphism and dyspolarity, occasional mitotic figures, cytoplasmic attenuation or vacuolization and disruption of the surrounding basement membrane by inflammatory cells.
Cholestasis Associated With Hepatitis (Pattern 4)
Viral, drug, and autoimmune hepatitis (AIH) are sometimes accompanied by cholestasis. Certain cases of acute hepatitis A may be particularly cholestatic (17). In the author’s experience, of the several causes of chronic hepatitis (eg, hepatitis B virus [HBV] or hepatitis C virus [HCV] infection), it is usually autoimmune hepatitis (in either its acute presentation or in its acute exacerbations) in which cholestasis is identifiable within swollen hepatocytes and/or in bile canaliculi (Figure 6.11). Unusually severe hepatitis with confluent necrosis may
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FIGURE 6. 10 Drug-induced bile duct damage and cholestasis (methimazole
hepatitis). There is centrilobular cholestasis with bile pigment visible within hepatocytes. Sparse lymphocytes are present within the lobule. Hepatocyte nuclei appear atypical, with prominent chromatin and nucleoli, features related to cholestasis rather than true dysplasia. Inset: The bile duct (arrow) is surrounded by lymphocytes and scattered eosinophils and shows pleomorphic and dysmorphic epithelium. The presence of cholestasis and bile duct damage with scattered eosinophils suggested drug hepatotoxicity (in this case related to methimazole).
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FIGURE 6.12 Marked hepatitis with severe cholestasis. The extensive hepatocellular necrosis, lobular and portal inflammation, and cholestasis in this case were ascribed to drug toxicity. Severe panlobular cholestasis is evident on low magnification. Inset: Striking bile canalicular and Kupffer cell (KC) cholestasis are present.
F I G U R E 6 . 1 3 Chronic large bile duct obstruction. (A) Portal tracts are expanded by fibrous tissue with bile ductular structures (ductular reaction) arranged marginally along the edges of the portal tracts. (B) Periportal hepatocytes are swollen and pale (pseudoxanthomatous change or cholate stasis). (C) Rhodanine stain for copper shows orange granules in periportal hepatocytes. (D) Extensive periportal copper-binding protein is evident on Victoria blue stain. FIGURE 6. 11 Autoimmune hepatitis with cholestasis. There are portal
and lobular infiltrates of plasma cells and lymphocytes. Mild cholestasis is evident within hepatocytes (long arrow) and bile canaliculi (short arrow). Inset: Intracellular bile (long arrow) and canalicular bile (short arrow) are present.
also be the background for substantial histologic cholestasis (Figure 6.12). The parenchymal changes of hepatitis (disarray of liver-cell plates, hepatocyte ballooning and apoptosis, portal and lobular inflammation) should make clear the cause of the cholestasis in such cases.
HISTOLOGIC CHANGES IN CHRONIC CHOLESTASIS
Prolonged cholestasis of many weeks, months, or longer period leads to common histologic endpoints, including the development of portal and periportal fibrosis (usually, although not invariably, associated with a ductular reaction), ongoing parenchymal cholestasis, which may now extend to the lobular periphery (periportal regions) where periportal fibrosis further blocks bile egress, and changes in periportal hepatocytes due to chronic retention of bile salts (“pseudoxanthomatous change”) (1,2) (Figure 6.13). Retained copper
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FIGURE 6. 14 Architectural variations in chronic biliary obstruction. (A) The 2 cores in this needle biopsy sample show differences in architecture, with more extensive portal-to-portal bridging fibrosis and developing nodularity (arrow) in the core at left compared with the core at right which shows only mild periportal fibrosis. Such regional variations in close proximity of one another are a recognized feature of the progression of chronic biliary tract disease. This patient had a chronic biliary stricture that was treated with intermittent endoscopic dilatation. (B) The features of chronic biliary tract obstruction consist of a prominent ductular reaction (arrows) and periportal fibrosis. Note preservation of the native bile duct (white arrow). (A&B, hematoxylin, phloxine saffron stain).
and copper-binding protein within periportal hepatocytes is demonstrable on rhodanine and Victoria blue stains, respectively (Figure 6.13). Periportal Mallory-Denk bodies are also a sequelae of intracellular copper retention and hepatocellular oxidative stress (18). The progression toward a “biliary” type of cirrhosis often shows considerable architectural variations across the entire liver such that areas of mild periportal fibrosis may coexist with adjacent regions of more advanced portal-to-portal bridging fibrosis or even fully formed cirrhotic nodules (Figure 6.14). Regenerative hyperplasia of periportal hepatocytes is often evident near fibrotic portal tracts as twinned (or thicker) liver-cell plates. Bridging fibrous septa progressively link portal tracts but may spare terminal venules which can be seen preserved in their normal centrilobular positions well into the developed stage of biliary cirrhosis. The fibrous septa of biliary cirrhosis are characteristically uniform and thick; ductular reaction is often evident. The thick fibrous septa surrounding islands of regenerative liver tissue in the form of nodules renders a low-power “geographic” appearance (Figure 6.15). The “halo effect” that is often visible at the nodule periphery in biliary cirrhosis (Figure 6.15) is due to the combination of periportal edema and pseudoxanthomatous change of periseptal hepatocytes. Depending on the etiology of the biliary cirrhosis, bile ducts may be surrounded by concentric periductal fibrosis and thickened basement
FIGURE 6.15 Biliary cirrhosis. The cirrhotic nodules are intensely cholestatic and are surrounded by regular, thick fibrous septa. A peripheral “halo effect” is present.
membranes, may appear simplified (dystrophic) and lined by only a few epithelial cells, or may be replaced by fibroobliterative scars, collections of chronic inflammatory cells (Figures 6.16 and 6.17), or by lymphoid aggregates and follicles with germinal centers.
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FIGURE 6.16 Chronic large bile duct obstruction (primary sclerosing cholangitis). (A) Periductal, concentric “onion-skin” fibrosis is present. (B) Periductal fibrosis surrounds several interlobular bile duct branches. (C) Basement membrane thickening of small intrahepatic bile ducts may be present in chronic biliary obstruction (Diastase-resistant periodic acid Schiff [DPAS] stain).
References 1. Li MK, Crawford JM. The pathology of cholestasis. Semin Liver Dis 2004;24:21–42. 2. Lefkowitch JH. Scheuer’s Liver Biopsy Interpretation. 8th ed. Edinburgh: Elsevier, 2010:47–74. 3. Lefkowitch JH. Bile ductular cholestasis: an ominous histopathologic sign related to sepsis and “cholangitis lenta.” Hum Pathol. 1982;13:19–24. 4. Christoffersen P, Poulsen H. Histological changes in human liver biopsies following extrahepatic biliary obstruction. Acta Pathol Microbiol Scand. 1970;212:150–157. 5. Roskams T, Desmet V. Ductular reaction and its diagnostic significance. Semin Diagnos Pathol 1998;15:259–269. 6. Roskams TA, Theise ND, Balabaud C, et al. Nomenclature of the finer branches of the biliary tree: canals, ductules, and ductular reactions in human livers. Hepatology. 2004;39:1739–1745. 7. Crawford JM, Boyer JL. Clinicopathology conferences: inflammationinduced cholestasis. Hepatology. 1998;28:253–260. 8. Kosters A, Karpen SJ. The role of inflammation in cholestasis: clinical and basic aspects. Semin Liver Dis. 2010;30:186–194. 9. Copple BL, Jaeschke H, Klaassen CD. Oxidative stress and the pathogenesis of cholestasis. Semin Liver Dis. 2010;30:195–204. 10. Delladetsima JK, Boletis JN, Makris F, et al. Fibrosing cholestatic hepatitis in renal transplant recipients with hepatitis C virus infection. Liver Transplant Surg. 1999;5:294–300.
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FIGURE 6.17 Intrahepatic bile duct disease. Interlobular bile ducts in biliary tract disease may show dystrophy and simplification, (A) as well as basement membrane thickening in (B) and (C). (C, trichrome stain).
11. Davies SE, Portmann BC, O’Grady JG, et al. Hepatic histological findings after transplantation for chronic hepatitis B virus infection, including a unique pattern of fibrosing cholestatic hepatitis. Hepatology. 1991;13:150–157. 12. Byrne JA, Meara NJ, Rayner AC, Thompson RJ, Knisely AS. Lack of hepatocellular CD10 along bile canaliculi is physiologic in early childhood and persistent in Alagille syndrome. Lab Invest. 2007;87: 1138–1148. 13. Popper H, Schaffner F. Pathophysiology of cholestasis. Hum Pathol. 1970;1:1–24. 14. Paulusma CC, Elferink RPJO, Jansen PLM. Progressive familial intrahepatic cholestasis type 1. Semin Liver Dis. 2010;30:117–124. 15. Stapelbroek JM, van Erpecum KJ, Klomp LW, Houwen RH, et al. Liver disease associated with canalicular transport defects: current and future therapies. J Hepatol. 2010;52:258–271. 16. Wagner M, Zollner G, Trauner M. New molecular insights into the mechanisms of cholestasis. J Hepatol. 2009;51:565–580. 17. Teixeira MR Jr, Weller IVD, Murray AM, et al. The pathology of hepatitis A in man. Liver 1982;2:53–60. 18. Müller T, Langner C, Fuchsbichler A, et al. Immunohistochemical analysis of Mallory bodies in Wilsonian and non-Wilsonian hepatic copper toxicosis. Hepatology. 2004;39:963–969.
Case 6.1
Drug-Induced Pure Cholestasis JAY H. LEFKOWITCH
organized into rosette-like structures rather than the usual radiating liver-cell plate pattern (Figure 6.1.2). Some of the cholestatic rosettes do not contain bile, but the alteration in plate architecture in midzonal and centrilobular regions (in contrast to periportal regions, the common site for regenerative liver-cell rosettes in chronic hepatitis) should prompt consideration of cholestatic disease. Bile thrombi are present within centrilobular bile canaliculi and within hepatocytes (Figure 6.1.1).
C L I N I C AL I N F OR M AT I ON
A 55-year-old woman was admitted to an outside hospital for painless jaundice. She was known to have systemic hypertension and had been taking lisinopril for an unspecified length of time. On admission she was jaundiced but had no significant findings on abdominal exam. Her white blood cell count was normal and showed no increase in eosinophils. Serum liver tests showed aspartate aminotransferase (AST) 5 57 (normal Ó40 U/L), alanine aminotransferase (ALT) 5 26 (normal 40 U/L), alkaline phosphatase (ALP) 5 857 (normal 110 U/L), total bilirubin 5 35.1 (normal 1.0 mg/dL), conjugated bilirubin 5 23.5, and normal total protein and albumin. A liver biopsy was obtained and was reported as showing “cholestasis,” without further comment. Because of concern for malignancy (cholangiocarcinoma), she was transferred to our center for further evaluation. During the workup at our institution, MRCP (magnetic resonance cholangiopancreatography) was performed and showed no bile duct dilatation, mass, or defect.
DIAGNO SIS
Marked cholestasis hepatotoxicity.
compatible
with
lisinopril
DISCUSSIO N
The chief biopsy change is cholestasis predominating in centrilobular regions, without portal tract inflammation, bile duct damage or loss, or fibrosis. The liver test results further point to a primary cholestatic injury, with major elevations of bilirubin and ALP. The virtually normal aminotransferases indicate little hepatocellular component to the liver injury (a consideration in certain forms of drug-induced liver injury where the agent causes both hepatocellular injury and canalicular injury—so-called hepatocanalicular drug toxicity). The majority of conditions in the differential diagnosis of pure
R E A S ON F OR R E F E R R A L
Review the liver biopsy to determine the cause of the patient’s persistent jaundice. PAT H OL OG I C F E AT U R E S
There is striking cholestasis in centrilobular regions (Figure 6.1.1). Portal tracts do not show inflammation, bile duct changes, or fibrosis. The lobular parenchyma appears
FIGURE 6. 1. 1 Drug-induced pure cholestasis. (A) The centrilobular region shows striking cholestasis. (B) Bile thrombi are prominent within
bile canaliculi and there is also intrahepatocellular bile (small arrows).
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FIGURE 6. 1. 2 Cholestatic rosettes in drug-induced cholestasis. Cholestasis is prominent (bottom right) and has resulted in the transformation of liver-cell plates into cholestatic rosettes (between arrows). Many rosettes show no obvious bile.
(bland) cholestasis (see Table 6.2, page 92) were clinically excluded or not relevant in this 55-year-old woman. Although pure cholestasis without significant portal tract pathology may be seen in the early days of large bile duct obstruction, MRCP excluded biliary obstruction. Drug hepatotoxicity must always be considered in evaluating this type of cholestasis. Even if there is no previously published report on a specific agent being administered, there is always the potential for a “first time” idiosyncratic liver injury. In this case, lisinopril is thought to be the cause of the cholestasis and clinical jaundice. Lisinopril, along with captopril, enalapril, ramipril, and fosinopril, belongs to the class of angiotension converting enzyme (ACE) inhibitors for which there is a substantial literature regarding cholestatic liver injury (1). In 20 published reports of ACE inhibitor– related liver injury discussed by Yeung et al (1), cholestasis was prominent in 14, hepatocellular injury was dominant in 4, and mixed hepatocellular-cholestatic features were seen in 2 cases. In the present case, the duration of lisinopril administration was not specified, but ACE inhibitor hepatotoxicity shows a wide range of onset, from as early as 5 days to as late as 3 years (1). In 1 report of lisinopril-induced chronic liver disease, initial cholestasis was accompanied on biopsy by prominent portal inflammation (plasma cells, neutrophils) and ductular reaction, and progressed 9 months later to portal fibrosis and developing cirrhosis, without cholestasis (2). Fulminant hepatitis after lisinopril use is also described (3). Lisinopril-induced cholestasis in our case is likely an idiosyncratic drug hepatotoxic injury. There were no indications of a typical hypersensitivity reaction (eg, fever, peripheral or tissue eosinophilia). Other mechanisms of ACE inhibitor liver injury have been postulated to be related to metabolic idiosyncracy (ie, the terminal proline ring present in common among captopril, lisinopril, and enalapril) and to prostaglandin-induced decreased bile flow (ACE inhibitors
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F I G U R E 6 . 1 . 3 Cholestasis due to bile salt transporter mutation
(ATP8B1). Pure canalicular cholestasis is evident in this needle biopsy from an infant with progressive familial intrahepatic cholestasis type 1. Two cholestatic rosettes have formed around bile thrombi (arrows). Similarly, bland cholestasis is also evident in benign recurrent intrahepatic cholestasis (BRIC).
favor conversion of arachidonic acid to prostaglandins) (2). In our case lisinopril was discontinued, but follow-up information was not available. Brief mention should be made of BRIC which is among the causes of pure cholestasis (see Table 6.2, page 92), although the patient had suffered no prior sporadic episodes of jaundice, pruritus, or cholestatic liver tests punctuated by long periods (months to years) of normalcy characteristic of BRIC (4–6). The liver in BRIC shows bland canalicular and hepatocellular cholestasis, sometimes with accompanying Kupffer cell bile (5,6) (Figure 6.1.3). A few patients with BRIC show mild portal lymphocytic infiltrates or lobular necroinflammation along with cholestasis; rarely there are portal eosinophils or a ductular reaction (5). The parenchymal cholestasis of BRIC resembles that seen in PFIC-1 (see Chapter 10), and both conditions result from mutations in ATP8B1 which encodes the phosphatidylserine flippase FIC-1 protein. The spectrum of severity of cholestasis in PFIC-1 and BRIC is related to the existence of many heterogeneous ATP8B1 mutations. Folmer et al recently demonstrated complete absence of canalicular ATP8B1 mutant expression in PFIC-1 subjects due to reduced protein stability and its failure to interact with CDC50A (which is required for appropriate endoplasmic reticulumto-canaliculus translocation) (7). In BRIC, ATP8B1 mutant protein stability was not altered and residual expression on canaliculi was present. Folmer et al postulate that stressors such as fever, inflammation, and cytokine release, in tandem with effects on other bile salt transporters, mediate the episodic cholestasis of BRIC (7). Immunohistochemical staining for bile salt transport protein expression on bile canaliculi including bile salt export pump (BSEP), multidrug resistance protein 3 (MDR3), and others, therefore now provides important diagnostic information when applied to cases of unexplained pure intrahepatic cholestasis (6).
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References 1. Yeung E, Wong FS, Wanless IR, et al. Ramipril-associated hepatotoxicity. Arch Pathol Lab Med. 2003;127:1493–1497. 2. Droste HT, de Vries RA. Chronic hepatitis caused by lisinopril. Netherlands J Med. 1995;46:95–98. 3. Larrey D, Babany G, Bernuau J, et al. Fulminant hepatitis after lisinopril administration. Gastroenterology. 1990;99:1832–1833. 4. Beaudoin M, Feldmann G, Erlinger S, et al. Benign recurrent cholestasis. Digestion. 1973;9:49–65.
C H O L E S TA S I S
5. Brenard R, Geubel AP, Benhamou JP. Benign recurrent cholestasis. A report of 26 cases. J Clin Gastroenterol. 1989;11:546–551. 6. Liu LU, Qin L, Knisely AS. A patient with persistent pruritus. Semin Liver Dis. 2010;30:205–209. 7. Folmer DE, van der Mark VA, Ho-Mok KS, et al. Differential effects of progressive familial intrahepatic cholestasis type 1 and benign recurrent intrahepatic cholestasis type 1 mutations on canalicular localization of ATP8B1. Hepatology. 2009;50:1597–1605.
Case 6.2
Bile Ductular Cholestasis Associated With Sepsis JAY H. LEFKOWITCH
C L I N IC AL I N F OR M AT I ON
A 70-year-old man with hypertension, type 2 diabetes, coronary artery disease with prior myocardial infarction, and status/ post 2 prior-deceased donor renal transplants with current graft rejection (on hemodialysis) was admitted to the medical intensive care unit because of a major drop in hematocrit following a retroperitoneal hemorrhage. Shortly after admission, he underwent interventional radiologic embolization of L3/L4 arteries with cessation of bleeding. One month prior to this admission, he was diagnosed with tuberculous spinal L5-S1 osteomyelitis (Pott disease) for which he was undergoing multidrug therapy including pyrazinamide and rifampin, and culture of a later spinal biopsy disclosed moraxella osteomyelitis. The latter was treated with a course of levofloxacin. Other medications at the time of admission included cyclosporin and vancomycin. During the first week of admission he had altered mental status and poor respiratory effort and was placed on a ventilator. He was persistently febrile and had bilateral infiltrates on chest X-ray, an elevated white blood cell count of 29 700/mm3, and a tracheal culture was positive for vancomycin-resistant enterococci. Blood cultures were negative. He was jaundiced, but an abdominal ultrasound showed only tiny shadowing gallstones without evidence of bile duct dilatation or acute cholecystitis. Serum liver tests included normal ALT and mildly elevated AST, total bilirubin 5 25.6 with direct bilirubin 5 11.3, and alkaline phosphatase approximately twice normal (254 U/L). Rifampin was discontinued because of jaundice, and a liver biopsy was obtained.
F I G U R E 6 . 2 . 1 Bile ductular cholestasis associated with sepsis. Periportal regions diffusely show dilated bile ductular structures with inspissated bile concretions (“bile ductular cholestasis”). Inset: Centrilobular cholestasis is present within hepatocytes and bile canaliculi.
R E A SON F OR R E F E R R AL
To determine whether jaundice is due to drug toxicity or retroperitoneal hemorrhage. PAT H OL OG I C F E AT U R E S
The liver biopsy shows a striking pattern of cholestasis consisting of markedly dilated periportal bile ductular structures containing inspissated bile concretions affecting all portal and periportal regions (Figures 6.2.1 and 6.2.2). This is accompanied by diffuse centrilobular cholestasis, with bile evident within hepatocyte cytoplasm and in bile canaliculi (Figure 6.2.1, Inset). The portal tracts show mild edema and mixed neutrophil-lymphocyte infiltrates. The native bile ducts appear normal, without intraluminal bile (Figure 6.2.2), whereas the periportal ductular structures are surrounded by neutrophils and are lined by attenuated and flattened low cuboidal epithelium (Figure 6.2.2, Inset). The lobular parenchyma shows no inflammation or significant hepatocellular damage. No eosinophils are evident within the portal tracts or lobules.
F I G U R E 6 . 2 . 2 Bile ductular cholestasis associated with sepsis. The
dilated periportal bile ductular structures contain bile concretions and are surrounded by inflammatory cells. Note the preserved native bile duct (without intraluminal cholestasis) paired with an arteriole at bottom center. Inset: The epithelium of the bile ductular structures ranges from low cuboidal to tapering and attenuated. The surrounding mixed inflammatory cell infiltrate includes numerous neutrophils and scattered lymphocytes.
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DISCUSSIO N D I AG N OS I S
Bile ductular and parenchymal cholestasis consistent with sepsis.
FIGURE 6. 2. 3 Pure centrilobular cholestasis associated with sepsis.
This is the most common cholestatic response to sepsis, featuring centrilobular bile canalicular and hepatocellular cholestasis without significant changes in portal tracts. (A) Low power demonstrates cholestasis and no significant changes in the portal tract at left. (B) Prominent centrilobular cholestasis.
The liver biopsy in this case was especially helpful in pointing to sepsis as the likely cause of his liver dysfunction, rather than the clinical diagnoses of drug toxicity or recent retroperitoneal hemorrhage. Although blood cultures were negative, the patient had pulmonary infiltrates consistent with pneumonia and an elevated peripheral white blood cell count. D-dimer and lactic dehydrogenase elevations suggested low-grade disseminated intravascular coagulation. The unusual distribution of cholestasis in this case (“bile ductular cholestasis”) is virtually pathognomonic of sepsis (1), although this pattern is uncommon among individuals with sepsis who undergo liver biopsy. Identification of this pattern of cholestasis always warrants immediate discussion with the clinical team, since exclusion and treatment of sepsis have urgency. Elevated serum total bilirubin disproportionate to aminotransferases and alkaline phosphatase is an important clinical feature associated with this picture (2). The liver in sepsis more typically shows pure (bland) cholestasis within bile canaliculi and hepatocytes with a perivenular predilection, without significant portal tract changes (Figure 6.2.3). Gram-negative endotoxin (lipopolysaccharide or LPS) and inflammatory cytokines are the circulating factors that cause this type of cholestasis which appears to be mediated in part through inhibition of canalicular BSEP (3–6). In addition to pure cholestasis and bile ductular cholestasis, a third distinctive histologic picture is seen in postmortem liver tissue from individuals with preterminal sepsis (Figure 6.2.4). The tissue sections appear to have accelerated autolysis with poor staining of all cell nuclei throughout
FIGURE 6. 2. 4 Postmortem hepatic changes in sepsis-related cholestasis. (A) Preterminal fever and accelerated lysosome release result in excessive
autolysis and lysosomal enzyme release with breakdown of endothelial/sinusoidal borders. Hepatocytes show unusually wide separation. (B) Cholestasis is apparent with bile canaliculi and hepatocytes show marked separation with a “jigsaw puzzle”–like appearance.
CASE
6.2:
BILE
DUCTULAR
C H O L E S TA S I S
A S S O C I AT E D
WITH
SEPSIS
101
ghosts of endothelial cells with elongated lining are evident (Figure 6.2.5). Bile thrombi in cross-sectional or longitudinal casts between hepatocytes are seen. In such cases, usually with temperatures exceeding 101°F prior to death, it is likely that as death ensues there is accelerated lysosomal rupture and release from hepatocytes, endothelial cells, and Kupffer cells, which results in degeneration and necrosis of sinusoidal endothelial barriers, with widening of intercellular spaces. Such changes are likely to proceed relatively unabated until postmortem examination and tissue procurement and fixation occur.
References
FIGURE 6. 2. 5 Chronic large bile duct obstruction. The portal tract is expanded by fibrosis, ductular reaction, and chronic inflammation. A septal bile duct (arrow) shows periductal inflammation and fibrosis. Inset: Trichrome stain shows 1 duct with periductal fibrosis compatible with primary sclerosing cholangitis.
the section and a mosaic- or jigsaw puzzle–like separation of hepatocytes and widening of intercellular spaces (Figure 6.2.5). The remnants of sinusoidal architecture are visible, but only
1. Lefkowitch JH. Bile ductular cholestasis: an ominous histopathologic sign related to sepsis and “cholangitis lenta.” Hum Pathol 1982;13:19–24. 2. Riely CA, Dean PJ, Park AL, et al. A distinct syndrome of liver disease with multisystem organ failure associated with bile ductular cholestasis. Hepatology. 1989;10:739A. 3. Crawford JM, Boyer JL. Clinicopathology conferences: inflammationinduced cholestasis. Hepatology. 1998;28:253–260. 4. Kosters A, Karpen SJ. The role of inflammation in cholestasis: clinical and basic aspects. Semin Liver Dis. 2010;30:186–194. 5. Stapelbroek JM, van Erpecum KJ, Klomp LW, Houwen RH. Liver disease associated with canalicular transport defects: current and future therapies. J Hepatol. 2010;52:258–271. 6. Wagner M, Zollner G, Trauner M. New molecular insights into the mechanisms of cholestasis. J Hepatol. 2009;51:565–580.
Case 6.3
Crohn Disease With Primary Sclerosing Cholangitis JAY H. LEFKOWITCH
C L I N I C AL I N F OR M AT I ON
A 37-year-old man with a history of Crohn disease since age 14 and resection of the small- and large-bowel because of obstruction, abscess, and fistula formation 18 years earlier (with a primary anastomosis) was referred to our institution for further clinical management. Two years earlier he had developed a bowel perforation and underwent further bowel resection resulting in the need for total parenteral nutrition (TPN). He had received TPN for the past 2 years but suddenly became jaundiced due to a liver biopsy performed elsewhere 3 months before being seen at our center. The outside endoscopic retrograde cholangiopancreatography (ERCP) report was unavailable to our clinical team. On physical exam the liver was enlarged and palpable, firm but not nodular, without ascites. Serum liver tests showed AST 5 138, ALT 5 99, alkaline phosphatase 5 274, total bilirubin 5 23.2 (conjugated 5 10.2), with normal total protein and albumin. His current medications in addition to TPN therapy included asacol, hydromorphone, trazadone, and fentanyl patch. R E A S ON F OR R E F E R R A L
F I G U R E 6 . 3 . 1 Periportal cholestasis and cholate stasis (pseudoxanthomatous change). The portal tract shown in Figure 6.2.5, Chapter 6.2 is shown at higher magnification. Periportal hepatocytes are swollen and contain bile (arrow). Ductular reaction and chronic inflammatory cells are also apparent.
To determine whether there is fibrosis on the liver biopsy, and if present, is it due to TPN and is it reversible, to be factored into consideration of the patient as a candidate for isolated intestinal transplantation. PAT H OL OG I C F E AT U R E S
Chronic liver disease is evident, with irregular expansion of all portal tracts by lymphocytes, a prominent ductular reaction and mild early periportal fibrosis on trichrome and reticulin stains (see Figure 6.2.5). Marked hepatocellular and bile canalicular cholestasis is present with focal bile in Kupffer cells. Periportal hepatocytes contain bile and appear pale and swollen, demonstrating pseudoxanthomatous change (cholate stasis) (Figure 6.3.1). Approximately two-thirds of the portal tracts show no identifiable native bile duct (Figure 6.3.2). One portal tract showed periductal fibrosis with an “onion-skin” appearance on hematoxylin and eosin (H&E) and trichrome stains (see Figure 6.2.5).
F I G U R E 6 . 3 . 2 Ductopenia. Cholestasis is seen within the lobular pa-
renchyma. The majority of portal tracts in this needle biopsy specimen showed only hepatic artery branches (arrow) without bile ducts of similar caliber. DISCUSSIO N
D I AG N OS I S
Chronic ductopenic liver disease with marked cholestasis, focal periductal and early-mild periportal fibrosis compatible with primary sclerosing cholangitis ([PSC] Crohn disease, clinical).
This biopsy presents the not uncommon diagnostic dilemma of deciphering several confounding possible causes of jaundice and chronic cholestatic liver disease, in this case the history of prolonged administration of parenteral nutrition, several concomitant medications, and underlying Crohn disease (with unavailable ERCP data). Review of published data concerning 102
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CROHN
DISEASE
WITH
PRIMARY
FIGURE 6. 3. 3 Cholestasis with bile duct obstructive features in parenteral
nutrition. Liver biopsy from a 10-week-old infant receiving parenteral nutrition since birth due to duodenal atresia. Marked cholestasis with prominent proliferation of bile ductular structures (arrows) and mild periportal fibrosis have developed: a recognized complication of prolonged administration of parenteral nutrition.
the medications administered shows no reports of cholestatic or bile duct injury. Liver injury following parenteral nutrition shows age-related differences, with cholestasis and portal tract features closely resembling those of bile duct obstruction predominating in infants and children (Figure 6.3.3) and fatty liver disease seen in adults (1–4). Loss of bile ducts and ductopenia are not reported for TPN but are a significant late feature in PSC (5–8). The biopsy further demonstrates the problem of focality in obtaining diagnostic lesions in liver biopsies PSC; in this case a single portal tract in the liver biopsy shows periductal “onion-skin” fibrosis (Figure 6.3.1). Liver biopsies in PSC can show diverse features, often indicative of biliary tract obstruction in general but sometimes also mimicking chronic hepatitis (5,6). The biopsy changes and clinical history of Crohn disease are most consistent with PSC. The typical male:female ratio in PSC is 2:1 with a mean age at diagnosis of approximately 40, so this patient’s demographics are consistent with the diagnosis, as are the cholestatic liver test results (9,10). Information regarding a pANCA (perinuclear antineutrophil cytoplasmic antibody) test was not known in this case, but it is positive in 26% to 94% of cases (9). Antinuclear and anti–smooth muscle antibodies (ANA and anti-SMA) may also be positive (11) but are thought to be nonspecific. The importance of such autoantibodies, if positive, is in excluding a possible autoimmune hepatitis (AIH)-PSC “overlap
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syndrome” (covered in Chapter 3). The present case shows no interface hepatitis or parenchymal hepatitic changes, thereby not providing support for overlap with AIH. The results of the ERCP are critical to review in this case. In PSC, both intraand extrahepatic bile ducts are usually involved (9,10), showing multifocal strictures and segmental dilatations. Single nucleotide polymorphism (SNP) markers were examined in a genome-wide association analysis in PSC and show significant associations with human leukocyte antigen (HLA) and non-HLA genes, the latter including genes involved in bile homeostasis and inflammation (12). Other causes of ductopenic disease including the recently described mutations in the bile canalicular phospholipid transporter gene ABCB4 (MDR3) (13) should be considered if cholangiogram is negative. Bile duct loss without cause in adults is termed idiopathic adulthood ductopenia (14,15).
References 1. Mullick FG, Moran CA, Ishak KG. Total parenteral nutrition: a histopathologic analysis of the liver changes in 20 children. Mod Pathol. 1994;7: 190–194. 2. Body JJ, Bleiberg H, Bron D, Maurage H, Bigirimana V, Heimann R. Total parenteral nutrition-induced cholestasis mimicking large bile duct obstruction. Histopathology. 1982;6:787–792. 3. Baker AL, Rosenberg IH. Hepatic complications of total parenteral nutrition. Am J Med. 1987;82:489–497. 4. Klein S, Nealon WH. Hepatobiliary abnormalities associated with total parenteral nutrition. Semin Liver Dis. 1988;8:237–246. 5. Lefkowitch JH. Primary sclerosing cholangitis. Arch Int Med. 1982;142:1157–1160. 6. Scheuer PJ. Pathologic features and evolution of primary biliary cirrhosis and primary sclerosing cholangitis. Mayo Clin Proc. 1998;73:179–183. 7. LaRusso NF, Shneider BL, Black D, et al. Primary sclerosing cholangitis: summary of a workshop. Hepatology. 2006;44:746–764. 8. Lefkowitch JH, Martin EC. Primary sclerosing cholangitis. Prog Liver Dis. 1986;8:557–580. 9. European Association for the Study of the Liver. EASL clinical practice guidelines: management of cholestatic liver diseases. J Hepatol. 2009;51:237–267. 10. Chapman R, Fevery J, Kalloo A, et al. Diagnosis and management of primary sclerosing cholangitis. Hepatology. 2010;51:660–678. 11. Hov JR, Boberg KM, Karlsen TH. Autoantibodies in primary sclerosing cholangitis. World J Gastroenterol. 2008;14:3781–3791. 12. Karlsen TH, Franke A, Melum E, et al. Genome-wide association analysis in primary sclerosing cholangitis. Gastroenterology. 2010;138:1102–1111. 13. Gotthardt D, Runz H, Keitel V, et al. A mutation in the canalicular phospholipid transporter gene, ABCB4, is associated with cholestasis, ductopenia, and cirrhosis in adults. Hepatology 2008; 48:1157–1166. 14. Ludwig J, Wiesner RH, La Russo NF. Idiopathic adulthood ductopenia: a cause of chronic cholestatic liver disease and biliary cirrhosis. J Hepatol 1988;7:193–199. 15. Moreno A, Carreño CA, González C. Idiopathic biliary ductopenia in adults without symptoms of liver disease. N Engl J Med. 1997;336: 835–838.
Case 6.4
Chronic Large Bile Duct Obstruction of Uncertain Cause JAY H. LEFKOWITCH
C L I N I C AL I N F OR M AT I ON
A 74-year-old woman underwent liver biopsy because she appeared to have cirrhosis at the time of cholecystectomy for cholelithiasis. R E A S ON F OR R E F E R R A L
In addition to increased fibrous tissue within the portal tracts, 1 septal bile duct is surrounded by edema and shows infiltrating neutrophils lifting off its epithelium from the underlying basement membrane. Centrilobular regions show enlarged and hyperchromatic hepatocyte nuclei with focal trinucleation (Figure 6.4.6). The affected cells show intracellular brown pigment compatible with bile.
The referring pathologist wished to have an explanation for the dysplasia present and the marked ductular reaction of unknown origin. PAT H OL OG I C F E AT U R E S
The liver biopsy shows moderate parenchymal cholestasis with bile in canaliculi, hepatocytes, and Kupffer cells with a centrilobular and midzonal predilection (Figure 6.4.1). Focal periportal bile is also seen. The portal tracts are expanded by fibrosis and show focal portal-to-portal bridging fibrosis, but neither parenchymal nodularity nor an established cirrhosis is present. The portal tracts are infiltrated by mixed acute and chronic inflammatory cells and there is a dramatic periportal ductular reaction broadening the periportal regions (Figures 6.4.2–6.4.5). Neutrophils are readily seen adjacent to the proliferated ductular structures, and collections of rounded, “oval cells” (progenitor cells) are particularly conspicuous in many periportal areas (Figures 6.4.4 and 6.4.5).
F I G U R E 6 . 4 . 2 Ductular reaction in chronic biliary obstruction. The duc-
tular reaction (DR) appears prominently at the edge of this fibrotic portal tract.
FIGURE 6. 4. 1 Features of chronic biliary tract obstruction with bridging
fibrosis and early nodularity. Portal tracts are broadened by fibrosis and a conspicuous ductular reaction. Bridging fibrosis links portal tracts in this field. Inset: The portal tract changes are associated with prominent hepatocellular cholestasis (arrows).
F I G U R E 6 . 4 . 3 Diffuse periportal ductular reaction in chronic biliary ob-
struction. The ductular reaction is striking throughout all periportal regions.
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LARGE
6. 4. 4 Periportal ductular reaction. Ductular structures lie parallel to the portal tract (PT) and are associated with mild surrounding neutrophil infiltrates. Collections of rounded putative “progenitor/stem cells” are seen near the ductular structures (arrows).
FIGURE
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DUCT
OBSTRUCTION
105
F I G U R E 6 . 4 . 5 “Oval-like” periportal progenitor/stem cells and the ductular reaction. The bile ductular structure at the top shows small numbers of neutrophils within the epithelium and in the surrounding connective tissue. The collections of rounded cells with little cytoplasm (between arrows) are most likely progenitor/stem cells in nature. Compare their size and cytoplasm with that of periportal hepatocytes at the bottom.
FIGURE 6. 4. 6 Hepatocellular atypia of cholestasis. (A) Centrilobular hepatocytes show tri-nucleation, coarse nuclear chromatin, and hyperchromatism. The affected cells contain bile. This atypia is reactive and should therefore not be regarded as evidence of true liver-cell dysplasia. (B) Hepatocellular nuclear atypia is related to the presence of considerable intracellular and bile canalicular cholestasis (arrows).
DISCUSSIO N D I AG N OS I S
Features of acute and chronic large bile duct obstruction with periportal and focal portal-to-portal bridging fibrosis, unknown etiology.
The liver biopsy shows features of acute and chronic large bile duct obstruction but does not demonstrate cirrhosis (the clinical impression of cirrhosis at cholecystectomy was most likely based on the abnormal capsular surface due to regions of underlying periportal and bridging fibrosis). The ductular
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reaction in this case is particularly striking, reflecting diffuse activation of periportal progenitor/stem cells (1–4). Although this reaction is a normal constituent of the changes following biliary obstruction, the reason for its unusually robust nature in this case is not entirely certain. However, it likely is related both to the chronicity of the process and to the evolution of fibrosis demonstrated in the biopsy sample; the cytokine and signaling factors involved are likely to be analogous to the close relationship observed between ductular reaction and the genesis of fibrosis in the evolution of nonalcoholic steatohepatitis (5). The groups of primitive-appearing cells near the ductular reaction (Figures 6.4.4 and 6.4.5 ) are vivid examples of the progenitor/stem cell compartment in the periportal regions of human livers resembling the “oval cells” of rodents (6). The atypical-appearing centrilobular hepatocytes in this case (Figure 6.4.6) need to be distinguished from large-cell dysplasia (7), since, instead, they represent the combination of aging polyploidy (ie, anisonucleosis) with superimposed effects of intracellular bile retention on hepatocyte nuclear morphology. Hepatocytes in cholestasis sometimes demonstrate coarsened nuclear chromatin and peripheral accentuation with resulting atypia; affected cells are not always limited to perivenular areas. Although there is little data in this area, retained intracellular bile salts may potentially alter cellular pH levels with resultant effects on nuclear chromatin. This case further demonstrates the relative anatomic nonspecificity of the features of chronic large bile duct obstruction. Comments at the conclusion of our consultation biopsy report therefore suggested that the patency of the biliary tree
C H O L E S TA S I S
required clinical evaluation in order to exclude several possible causes of chronic large duct obstruction. This differential diagnosis is that of “secondary sclerosing cholangitis” (8), which includes chronically impacted gallstones with choledocholithiasis, chronic pancreatitis or occult pancreatic carcinoma, benign biliary stricture, and cholangiocarcinoma. In this patient’s age group, primary sclerosing cholangitis is a less likely diagnosis. We have not received further clinical follow-up on this patient.
References 1. Roskams T, Desmet V. Ductular reaction and its diagnostic significance. Semin Diagnos Pathol. 1998;15:259–269. 2. Roskams TA, Theise ND, Balabaud C, et al. Nomenclature of the finer branches of the biliary tree: canals, ductules, and ductular reactions in human livers. Hepatology. 2004;39:1739–1745. 3. Roskams T. Progenitor cell involvement in cirrhotic human liver diseases: from controversy to consensus. J Hepatol. 2003;39:431–434. 4. Zhang L, Theise N, Chua M, Reid LM. The stem cell niche of human livers: symmetry between development and regeneration. Hepatology. 2008;48:1598–1607. 5. Richardson MM, Jonsson JR, Powell EE, et al. Progressive fibrosis in nonalcoholic steatohepatitis: association with altered regeneration and a ductular reaction. Gastroenterology. 2007;133:80–90. 6. Roskams T, De Vos R, Van Eyken P, Myazaki H, Van Damme B, Desmet V. Hepatic OV-6 expression in human liver disease and rat experiments: evidence for hepatic progenitor cells in man. J Hepatol. 1998;29:455–463. 7. Natarajan S, Theise ND, Thung SN, et al. Large-cell change of hepatocytes in cirrhosis may represent a reaction to prolonged cholestasis. Am J Surg Pathol. 1997;21:312–318. 8. Ruemmele P, Hofstaedter F, Gelbmann CM. Secondary sclerosing cholangitis. Nat Rev Gastroenterol Hepatol. 2009;6:287–295.
Case 6.5
Primary Sclerosing Cholangitis, Exclude Cholangiocarcinoma JAY H. LEFKOWITCH
C L I N IC AL I N F OR M AT I ON
A 43-year-old man with liver disease for approximately 16 years presented for liver transplantation evaluation. At age 27 he had liver function test abnormalities that were initially attributed to alcohol use, but an ERCP done 10 years ago showed some bile duct narrowing that was thought to be congenital. There was no history of inflammatory bowel disease. A year before coming for transplant evaluation he suffered a massive gastrointestinal hemorrhage and was found to have varices which were banded. ERCP was repeated elsewhere with a diagnosis of PSC, with brushings reported as negative. He had ascites, intermittent jaundice, and pruritus. Over the 3 months prior to the current evaluation he had a weight loss of 16 kg. At our center, he underwent a computed tomography (CT) scan without contrast, which showed focal intrahepatic bile duct dilatation without involvement of large ducts. On physical examination the patient was thin with moderate muscle wasting and trace icteric sclerae. Cardiac and pulmonary examinations were normal. On abdominal examination the liver was markedly enlarged, hard, and had a palpable nodular edge 3 fingerbreadths below the right costal margin. Marked splenomegaly was present, but there was no clinical ascites or caput medusae. Peripheral edema and asterixis were absent. Serum liver tests showed mild total bilirubin elevation of 3.7 mg/dL (direct bilirubin 1.7), AST 5 74, ALT 5 63, alkaline phosphatase (ALP) 5 181, total protein 5 6.8, and albumin 5 3.4. Several weeks after evaluation he underwent liver transplantation.
6 . 5 . 1 Developing biliary cirrhosis in small-duct PSC. (A) This field shows a cirrhotic nodule surrounded by thick fibrous septa containing chronic inflammation and ductular reaction. Native bile ducts appear to be missing (arrow). (B) The fibrous septa are chronically inflamed and show a prominent ductular reaction with mild periportal edema. Unpaired hepatic arterioles are seen (arrows).
FIGURE
R E A SON F OR R E F E R R AL
Exclude malignancy in the explant liver and establish a diagnosis of primary sclerosing cholangitis. PAT H OL OG I C F E AT U R E S
The explant liver was green, micronodular, and showed no evidence of tumor in the slices that were cut at 0.5 cm intervals. Histologic sections showed varying architecture in most sections, with regions of mild periportal fibrosis or portal-to-portal bridging fibrosis with developing parenchymal nodularity directly adjacent to areas of already developed cirrhotic nodules (Figure 6.5.1). Most portal tracts showed ductular reaction and chronic inflammation, but few native bile ducts could be identified (Figure 6.5.1B). Periportal hepatocytes were often markedly swollen and pale due to pseudoxanthomatous change and contained large Mallory-Denk bodies (Figure 6.5.2). Copper-binding protein in periportal hepatocytes was present on Victoria
F I G U R E 6 . 5 . 2 Periseptal pseudoxanthomatous change and MalloryDenk bodies. Two adjacent cirrhotic nodules are separated by a thick fibrous septum with chronic inflammation. Periportal hepatocytes are swollen and pale and contain aggregates of Mallory bodies. Inset: Pseudoxanthomatous change and intracellular Mallory-Denk bodies at higher magnification.
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blue and diastase-resistant periodic acid Schiff (DPAS) stains. Numerous portal tracts showed fibro-obliterative scars replacing bile ducts (Figure 6.5.3). Neither bile duct dysplasia nor cholangiocarcinoma (CCA) was identified histologically in the multiple sections examined. Sections from the liver hilum showed dense periductal lymphoplasmacytic infiltrates and lymphoid structures, the latter including lymphoid aggregates and follicles with germinal centers (Figure 6.5.4). Immunoglobulin G4 (IgG4) immunostain was performed and showed no significant positivity.
FIGURE 6. 5. 3 Fibro-obliterative sclerosing cholangitis. Many portal
tracts in this explant liver showed round-to-ovoid fibro-obliterative scars (arrow). Inset: The native bile duct has been replaced by a discrete scar. The surrounding portal tract connective tissue shows irregular fibrosis, chronic inflammation, and a mild ductular reaction.
FIGURE 6. 5. 4 Primary sclerosing cholangitis involvement of hilar bile
ducts. Larger ducts of the hilum demonstrate an onion-skin pattern of periductal edema, fibrosis, and inflammation. There are dense lymphoplasmacytic infiltrates within the surrounding hilar connective tissue, and a periductal lymphoid follicle with germinal center has formed.
C H O L E S TA S I S
DIAGNO SIS
Fibro-obliterative primary sclerosing cholangitis with developing biliary cirrhosis.
DISCUSSIO N
This case raised several important diagnostic issues in PSC including the risk of development of CCA and histologic surveillance for precursor lesions (ie, dysplasia), histologic features suggesting primary involvement of small ducts (“small duct PSC”), and changes suggesting the possibility of IgG4-associated cholangitis (IAC). Since CCA was not identified, the patient’s weight loss was attributed to his underlying liver disease and liver failure. Lewis et al recently addressed the proposed hyperplasiadysplasia-carcinoma sequence in the context of PSC and CCA (1). Approximately 7% to 30% of PSC patients develop CCA (1–3). In the study by Lewis et al (1), submission of 10 additional tissue cassettes randomly sampled from hilar and large septal ducts in PSC explants, the authors found dysplasia in 83% of PSC explants with CCA and in 36% of PSC explants without CCA (1). Their study highlights the importance of adequate tissue sampling in the identification of bile duct dysplasia. In liver biopsy specimens from individuals with PSC and concomitant or subsequent CCA, Fleming et al found dysplasia in only 19% (4). In our case, cholangiographic evidence of only intrahepatic bile duct disease and the presence of generalized small bile duct loss and/or fibro-obliterative lesions suggest that the patient’s liver disease was primarily small duct PSC, in which there appears to be no risk of developing CCA until there is transition to involvement of large bile ducts (5). Björnsson et al found that 22.9% of their 83 small duct PSC patients progressed to large duct PSC in a median of 7.4 years (5). The inflammatory changes involving hilar ducts in our explant (Figure 6.5.4) suggest that a transition to large bile duct involvement had already occurred, the recent CT results notwithstanding. Among the epithelial changes which can be recognized with adequate sampling of large bile ducts in PSC are mucinous, pyloric, and intestinal metaplasia, and both low- and high-grade dysplasia in the form of flat and/or micropapillary lesions (1) (Figures 6.5.5 and 6.5.6). Intestinal metaplasia appears to be the most significant predictor of bile duct dysplasia in PSC (1). Histologic surveillance for dysplasia in liver biopsy and explant specimens should encompass the spectrum of bile duct epithelial changes described in the conditions “biliary intraepithelial neoplasia” (BilIN) (6) and intraductal papillary mucinous tumors of pancreas and bile ducts (7). The chronic periductal inflammation with lymphoid follicle formation also raised the diagnostic question of IAC (8–10). IgG4-positive plasma cells were found in nearly 25% of explants with PSC in a recent study (11). The PSC patients with tissue IgG4 positivity had a more clinically aggressive course leading to liver transplantation and greater risk of recurrence, compared with IgG4-negative PSC cases. However,
CASE
6.5:
PRIMARY
SCLEROSING
F I G U R E 6 . 5 . 5 Biliary intraepithelial neoplasia (BilIN) involving large
intrahepatic bile duct. A micropapillary lesion has replaced the normal simple cuboidal duct epithelium. This individual underwent partial hepatectomy and large bile duct resection because of previously diagnosed intraepithelial neoplasia. Similar changes constitute part of the spectrum of epithelial dysplastic changes that may be identified in large septal and hilar bile ducts in primary sclerosing cholangitis. The 3 bile ducts at the bottom and the duct at far right center show normal epithelium.
despite the presence of IgG4-positive plasma cells amid the lymphoplasmacytic infiltrates in their explants, the histologic features of IAC were absent. IAC is covered further in the following chapter.
References 1. Lewis JT, Talwalkar JA, Rosen CB, Smyrk TC, Abraham SC. Precancerous bile duct pathology in end-stage primary sclerosing cholangitis, with and without cholangiocarcinoma. Am J Surg Pathol. 2010;34:27–34. 2. Tischendorf JJ, Hecker H, Krüger M, Manns MP, Meier PN. Characterization, outcome, and prognosis in 273 patients with primary sclerosing cholangitis: a single center study. Am J Gastroenterol. 2007;102:107–114. 3. Maggs JRL, Chapman RW. An update on primary sclerosing cholangitis. Curr Op Gastroenterol. 2008;24:377–393. 4. Fleming KA, Boberg KM, Glaumann H, Bergquist A, Smith D, Clausen OP. Biliary dysplasia as a marker of cholangiocarcinoma in primary sclerosing cholangitis. J Hepatol. 2001;34:360–365.
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F I G U R E 6 . 5 . 6 Comparison of normal bile duct epithelium to intestinal metaplasia and dysplasia. (A) This large conducting bile duct shows normal low-cuboidal epithelium. (B) and (C) Micropapillary lesion showing intestinal metaplasia (many goblet cells are evident) and low-grade dysplasia (BilIN2) reflected in the mild nuclear dyspolarity and atypia.
5. Björnsson E, Olsson R, Bergquist A, et al. The natural history of smallduct primary sclerosing cholangitis. Gastroenterology. 2008;134:975–980. 6. Zen Y, Adsay NV, Bardadin K, et al. Biliary intraepithelial neoplasia: an international interobserver agreement study and proposal for diagnostic criteria. Mod Pathol. 2007;20:701–709. 7. Zen Y, Fujii T, Itatsu K, et al. Biliary papillary tumors share pathological features with intraductal papillary mucinous neoplasm of the pancreas. Hepatology. 2006;44:1333–1343. 8. Björnsson E, Chari ST, Smyrk TC, Lindor K. Immunoglobulin G4 associated cholangitis: description of an emerging clinical entity based on review of the literature. Hepatology. 2007;45:1547–1554. 9. Webster GJM, Pereira SP, Chapman RW. Autoimmune pancreatitis/ IgG4-associated cholangitis and primary sclerosing cholangitis— overlapping or separate diseases? J Hepatol. 2009;51:398–402. 10. Chung H, Watanabe T, Kudo M, et al. Identification and characterization of IgG4-associated autoimmune hepatitis. Liver Int. 2010;30:222–231. 11. Zhang L, Lewis JT, Abraham SC, et al. IgG4+ plasma cell infiltrates in liver explants with primary sclerosing cholangitis. Am J Surg Pathol. 2010;34:88–94.
Case 6.6
Immunoglobin G4–Associated Cholangitis Versus Primary Sclerosing Cholangitis VIKRAM DESHPANDE
C L I N I C AL I N F OR M AT I ON
A 58-year-old male presented with obstructive jaundice and a 4-cm unresectable pancreatic tumor on CT scan. A palliative gastric/biliary bypass was planned. Intraoperatively, a firm liver was identified, and a wedge biopsy was performed. The alkaline phosphatase was 4 times normal. A subsequent ERCP showed multiple strictures in the intrahepatic bile ducts and pancreatic duct (Figure 6.6.1).
and 6.6.4). On immunohistochemistry 115 IgG4-positive plasma cells were identified per high power field (HPF) (Figure 6.6.5). The IgG4 to IgG ratio was 50% (Table 6.6.1).
DIAGNO SIS
IgG4-associated cholangitis in the setting of autoimmune pancreatitis.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows a dense but patchy portal-based lymphoplasmacytic infiltrate. An acellular zone was noted around the bile ducts (Figure 6.6.2). Occasional bile ducts showed periductal onion-skin–type fibrosis. There was no evidence of bile duct loss. The inflammation was accentuated around the portal venules. Mild lobular inflammation composed of scattered lymphocytes and plasma cells was present as well. In addition, a large portal tract showed an expansive nodule composed of lymphocytes, plasma cells, and eosinophils (Figures 6.6.3
F I G U R E 6 . 6 . 2 Smaller portal tracts may show sparse inflammation.
Note the inflammation is centered around the portal venule.
FIGURE 6. 6. 1 IgG4-associated cholangitis. There is narrowing and irregularity of the distal left and right main hepatic ducts at the confluence with the common hepatic duct. In addition, there is irregularity of the intrahepatic bile ducts.
F I G U R E 6 . 6 . 3 High power view of the inflammatory nodule with
lymphocytes, plasma cells, and numerous eosinophils. Fibroblasts are present in the background.
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TA BL E 6 . 6 . 1 Clinical, imaging, and pathologic features of primary
sclerosing cholangitis and IgG4-associated cholangitis IgG4-Associated Cholangitis
Primary Sclerosing Cholangitis
Age
Older (mean age, 63)
Young (mean age, 39)
Sex
Male predominance
Male predominance
ERCP
Intrahepatic and extrahepatic biliary strictures; irregularly narrow pancreatic duct with strictures
Intrahepatic and extrahepatic biliary strictures
Histology and immunohistochemistry
Inflammatory portalbased nodules and IgG4+ plasma cells
Variable portal-based inflammation, periductal fibrosis. IgG4+ plasma cells typically rare to absent in biopsy
Therapy
Steroids, rituximab
Ursodeoxycholic acid
FIGURE 6. 6. 4 Portal-based inflammatory nodule with inflammatory cells embedded in a myxoid stroma.
Abbreviation: ERCP, endoscopic retrograde cholangiopancreatography.
FIGURE 6. 6. 5 Immunohistochemistry for immunoglobin G4 show-
ing numerous IgG4-positive plasma cells. D I S C U S S I ON
The clinical and radiologic appearance suggests a diagnosis of pancreatic cancer. However, this tumorous pancreatic mass responded to steroids. Steroid response, in conjunction with strictures of the pancreatic duct is characteristic of autoimmune pancreatitis (AIP) (1). Autoimmune pancreatitis is associated with an elevated number of IgG4-positive plasma cells in tissue as well as elevated levels of serum IgG4 (2,3). It is a systemic disease that can involve virtually every organ including the hepatobiliary system (4–7); this disease is now categorized as IgG4-associated systemic disease and hepatic involvement is 1 facet of this systemic disease. Two patterns of hepatic involvement are seen in Ig4-associated systemic disease. The first is a mass-forming lesion involving the hilar region of the liver, mimicking cholangiocarcinoma (5–7). The second form of this disease,
termed IgG4-associated cholangitis (IAC), mimics primary sclerosing cholangitis (PSC). In most instances the disease is identified following a diagnosis of AIP and rarely may precede clinically inapparent pancreatic involvement. Hepatic disease without pancreatic involvement has been reported, albeit rarely (6). Most patients present with obstructive jaundice. On cholangiogram both intra- and extrahepatic strictures are present. This appearance mimics PSC. It is important, therefore, to distinguish this disease from PSC. Unlike PSC, IAC is a steroid responsive disease (6). Furthermore, though PSC is associated with an increased risk of malignancy, there have been no documented cases of IAC-associated malignancy. The presence of pancreatic disease that is compatible with AIP strongly supports IAC. A liver biopsy may assist in making this distinction, although the characteristic features may not always be apparent on a biopsy. The presence of portal-based inflammatory nodules is highly characteristic of IAC (5). The inflammatory nodules are composed of lymphocytes, plasma cells, eosinophils, and are admixed with fibroblasts. Although obliterative phlebitis, an obligate feature of AIP, is not seen in peripheral liver biopsies, a perivascular accentuation in portal tracts is present. The bile ducts may show histological evidence of injury, but accentuation of the inflammation around the duct is rarely seen. However, sections from the hilar region of the liver show both obliterative phlebitis and inflammatory destruction of large-caliber bile ducts (Figure 6.6.6). The key to arriving at a correct diagnosis is a tissue stain for IgG4 (5). Liver biopsy in IAC shows elevated numbers of IgG4-positive plasma cells. In 1 series, 70% of biopsies from IAC cases showed less than 5 IgG4-positive plasma cells per HPF, whereas IgG4-positive plasma cells were either
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patients cannot be weaned off steroids. More recently, excellent response to Rituximab has been documented (11,12). In contrast, the vast majority of cases of PSC do not respond to steroids.
References
FIGURE 6. 6. 6 Large-caliber portal vein with lymphoplasmacytic
phlebitis.
absent or fewer than 5 per HPF in PSC. However, in another series, 23% of explants from individuals with PSC showed IgG4-positive plasma cells (8). Compared with cases without IgG4-positive plasma cells, these cases had a more aggressive clinical course and a higher likelihood of recurrence (8). Thus, without the appropriate morphological features (ie, inflammatory nodules), the significance of occasional IgG4positive cells remains uncertain. IgG4 to IgG ratio may help improve the specificity of these markers; however, a cut-off for this variable has not been established. IgG4-positive plasma cells have also been identified in a subset of cases of AIH (9). Although only a relatively small number of cases have been evaluated, IgG4-positive plasma cells have not been observed in liver biopsies from patients with chronic viral hepatitis and primary biliary cirrhosis (10). The mainstay of treatment remains steroids (6). A dramatic normalization of the cholangiogram is typically seen within weeks of starting steroid therapy. However, many
1. Finkelberg DL, Sahani D, Deshpande V, Brugge WR. Autoimmune pancreatitis. N Engl J Med. 2006;355:2670–2676. 2. Deshpande V, Chicano S, Finkelberg D, et al. Autoimmune pancreatitis: a systemic immune complex mediated disease. Am J Surg Pathol. 2006;30:1537–1545. 3. Hamano H, Kawa S, Horiuchi A, et al. High serum IgG4 concentrations in patients with sclerosing pancreatitis. N Engl J Med. 2001;344: 732–738. 4. Bjornsson E, Chari ST, Smyrk TC, Lindor K. Immunoglobulin G4 associated cholangitis: description of an emerging clinical entity based on review of the literature. Hepatology. 2007;45:1547–1554. 5. Deshpande V, Sainani NI, Chung RT, et al. IgG4-associated cholangitis: a comparative histological and immunophenotypic study with primary sclerosing cholangitis on liver biopsy material. Mod Pathol. 2009; 22:1287–1295. 6. Ghazale A, Chari ST, Zhang L, et al. Immunoglobulin G4-associated cholangitis: clinical profile and response to therapy. Gastroenterology. 2008;134:706–715. 7. Zen Y, Harada K, Sasaki M, et al. IgG4-related sclerosing cholangitis with and without hepatic inflammatory pseudotumor, and sclerosing pancreatitis-associated sclerosing cholangitis: do they belong to a spectrum of sclerosing pancreatitis? Am J Surg Pathol. 2004;28:1193–1203. 8. Zhang L, Lewis JT, Abraham SC, et al. IgG4+ plasma cell infiltrates in liver explants with primary sclerosing cholangitis. Am J Surg Pathol. 2010;34:88–94. 9. Chung H, Watanabe T, Kudo M, Maenishi O, Wakatsuki Y, Chiba T. Identification and characterization of IgG4-associated autoimmune hepatitis. Liver Int. 2009;30:221–231. 10. Umemura T, Zen Y, Hamano H, et al. Immunoglobin G4-hepatopathy: association of immunoglobin G4-bearing plasma cells in liver with autoimmune pancreatitis. Hepatology. 2007;46:463–471. 11. Khosroshahi A, Bloch DB, Deshpande V, Stone JH. Rituximab therapy leads to rapid decline of serum IgG4 levels and prompt clinical improvement in IgG4-related systemic disease. Arthritis Rheum. 2010;62:1755–1762. 12. Khosroshahi A, Stone JR, Pratt DS, Deshpande V, Stone JH. Painless jaundice with serial multi-organ dysfunction. Lancet. 2009;373:1494.
Case 6.7
Hepatolithiasis POLLY W. Y. LAM AND WILSON M. S. TSUI
C L I N IC AL I N F OR M AT I ON
A 52-year-old Chinese female, who claimed previous good health, presented with epigastric pain, tea-colored urine, and vomiting. She had clinical jaundice. Laboratory tests revealed raised white cell count. Serum bilirubin was 3 times normal, ALP level 4 times normal, and ALT 14 times normal. Her condition improved soon after biliary stent insertion through ERCP, with normalization of serum bilirubin level and white cell count. Her ALT level also gradually returned to normal, whereas the ALP level remained slightly raised. The endoscopic cholangiogram revealed a hilar stricture. CT of the abdomen revealed markedly dilated left intrahepatic duct with multiple intraductal stones. The left lobe of the liver was atrophic, whereas the right lobe appeared normal. There was no mass lesion. Microscopic examination of her bile revealed clonorchis ova. Bile culture also yielded Klebsiella species and Escherichia coli. In view of the presence of left lobar atrophy, left hepatectomy was performed.
are filled with yellowish brown to black stones ranging from 0.5 to 1 cm in size. There is no annular stricture or web. The background liver tissue is atrophic, with more pronounced atrophy of the lateral segment than the quadrate lobe. Microscopic examination revealed bilirubinate stones in the ectatic bile ducts, lymphoplasmacytic infiltration of the duct mucosa, mural fibrosis, and hyperplasia of the peribiliary glands (Figures 6.7.2 and 6.7.3). Occasional portal veins show fibrous obliteration. Occasional ducts show suppurative
R E A SON F OR R E F E R R AL
The case was referred in order to establish the etiology of cholestasis in this patient. PAT H OL OG I C F E AT U R E S
The specimen consists of the left lobe of the liver, measuring 11 6 4 cm (Figure 6.7.1). The left hepatic duct and major branches are markedly dilated and have thickened walls. They
FIGURE 6. 7. 1 Gross specimen showing dilated bile ducts with pig-
mented stones. Noted atrophic fibrotic background liver parenchyma and less severe atrophy in the adjacent segment.
F I G U R E 6 . 7 . 2 Stone-bearing large duct with hyperplasia of peribil-
iary glands.
F I G U R E 6 . 7 . 3 Large bile duct showing lymphoplasmacytic infiltration and fibrosis of wall. Note the superficial location of the inflammatory infiltrate.
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FIGURE 6. 7. 4 Medium-sized bile duct showing concentric fibrous
F I G U R E 6 . 7 . 6 Orcein stain of a small portal area showing accumu-
thickening.
lation of copper-associated protein in periportal hepatocytes. DISCUSSIO N
FIGURE 6. 7. 5 A portal area with fibrous replacement of interlobular
bile ducts.
inflammation. Some of the medium-sized and small portal areas show marked concentric fibrous thickening of the interlobular bile ducts, with narrowed lumens (Figure 6.7.4). Some portal areas show replacement of the interlobular bile ducts by a dense fibrous scar (Figure 6.7.5). Orcein stain reveals copper-associated protein, indicating chronic cholestasis (Figure 6.7.6). The associated liver parenchyma shows nodularity and fibrosis.
The epigastric pain, clinical jaundice, and laboratory findings indicate an attack of cholangitis. The positive bile culture is in keeping with such a diagnosis (1–16). The most obvious causative factor in this case is the presence of multiplepigmented calcium bilirubinate stones in her intrahepatic bile ducts, but biliary calculi can also arise in bile stasis, so conditions associated with secondary HL should therefore be considered as well (Table 6.7.1). In this case, the previous good health and lack of other diagnostic radiologic abnormality rule out underlying developmental or iatrogenic bile duct abnormalities. Among the various conditions in Table 6.7.1, PSC is a major differential in this case, especially as cholangiectasis and secondary stone formation have been observed in PSC. Although PSC typically has a more insidious onset, cholangitis can be a presenting sign. Many of the microscopic features found in PSC are also found in our case. In fact, changes of sclerosing cholangitis affect the interlobular bile ducts in all cases of primary HL; this is particularly prominent in the chronic and advanced stages. As many as 85% of the medium-sized septal TA BL E 6 . 7 . 1 Conditions resulting in the formation of stones
in intrahepatic bile ducts (secondary HL) Congenital bile duct malformation such as extrahepatic biliary atresia, Caroli disease Bile duct ischemia Previous bile duct surgery
D I AG N OS I S
Primary hepatolithiasis (HL).
Inflammatory condition such as primary sclerosing cholangitis Biliary abscess From Refs. 7.11.
CASE
6.7:
H E PAT O L I T H I A S I S
bile ducts exhibit periductal fibrosis, whereas duct loss (20%), ductal atrophy (10%), and fibro-obliterative scars (7%) are observed in the small interlobular bile ducts (1). The degree of ductopenia is never as significant as PSC and ductular proliferation is only rarely observed. The portal tracts show variable fibrous expansion and only patchy chronic inflammatory infiltrate. The inflammation is not as diffuse and chronic hepatitis-like with interface hepatitis as in PSC. There is no chronic cholestasis nor progression to biliary cirrhosis as long as biliary obstruction can be relieved. There are other aspects in our case which favor primary HL over PSC (Table 6.7.2), including the ethnic group, selective left lobar atrophy, presence of clonorchis in bile, lack of inflammatory bowel disease, and presence of peribiliary gland hyperplasia. The radiologic finding of disproportionate dilatation of an intrahepatic duct, instead of a beaded appearance, also speaks for HL over PSC. Caroli disease should be distinguished because of presence of cholangiectasis and similar clinical presentation in both diseases. In HL, there is predominant involvement of the left lobe and no evidence of ductal plate malformation.
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Bilirubinate stones and chronic proliferative cholangitis are not observed in uncomplicated Caroli disease. The histologic picture of lymphoplasmacytic infiltration in thickened bile duct walls may raise some suspicion for IAC. Distinction from this condition is important since it is steroid responsive. IAC frequently involves the extrahepatic ducts and presents in the middle to elderly age group with obstructive jaundice. Histologic features include lymphoplasmacytic infiltration, fibrosis (often with a storiform arrangement), and obliterative phlebitis. The inflammatory process is often more dense at the periphery of the duct and extends into periductal soft tissue. The inflammatory cell infiltrate in this case is superficial and the fibrosis does not show a storiform pattern. Even though venous thrombosis is present in this case, the characteristic obliterative phlebitis found in IAC is not seen. Immunohistochemical staining also helps in diagnosis, since IAC is characterized by the presence of large numbers of IgG4-positive plasma cells in the inflammatory cell infiltrate. Another condition to consider is cholangiocarcinoma, since the initial ERCP revealed hilar stricture. Indeed,
TA B LE 6. 7. 2 Comparison between primary sclerosing cholangitis and hepatolithiasis
Primary Sclerosing Cholangitis
Hepatolithiasis
Ethnic group
Much more common in Europe and the United States
Common in East Asia, rare in Western countries except among immigrants of East Asian origin (9)
Age
Wide range but most present between 25 and 40 years (12)
Peaks between 50 and 60 years, range from 20 to beyond 80 years (7)
Gender
Male preponderance of 2–3 to 1
Slight male predominance
Presenting symptoms and signs
Fatigue, vague upper abdominal pain, intermittent jaundice. Cholangitis is less common
Epigastric pain, backache, fever, jaundice. A significant proportion is asymptomatic (4,7)
Laboratory investigations
Raised serum ALP, GGT levels. Bilirubin is raised as disease progresses
During attacks, raised ALP, bilirubin, and ALT levels. WBCs may also be raised
Radiologic findings
Typically “beaded” appearance involving both intra- and extrahepatic bile ducts, strictures, diverticula (13)
Dilatation of first and second divisions of intrahepatic ducts, abrupt nonvisualization of peripheral divisions, calculi, pneumobilia (8,14) Lobar atrophy
Associated disease
Idiopathic inflammatory bowel disease, including ulcerative colitis and Crohn disease
Parasitic infestation, including clonorchiasis and ascariasis
Typical clinical course
Progressive, overall 12–18 years from diagnosis to death or transplantation May be complicated by cholangiocarcinoma
Recurrent attacks of cholangitis may cause death due to sepsis (5) May be complicated by cholangiocarcinoma.
Microscopic findings
Lymphoplasmacytic infiltrates around large intrahepatic ducts, ± acute inflammatory infiltrates Onion-skin type of periductal fibrosis around medium-sized large bile ducts Obliteration of bile ducts which are replaced by fibrous whorls; extensive duct loss May have portal tract inflammation and ductular reaction (11,12)
Bilirubinate stones, fibrous thickening of large ducts, with lymphoplasmacytic infiltration, 6 suppurative cholangitis Periductal lamellar fibrosis of septal and small interlobular ducts Small bile ducts may show duct atrophy, fibrous obliteration, and duct loss Hyperplasia of peribiliary glands (7)
Abbreviations: ALP, alkaline phosphatase; ALT, alanine aminotransferase; GGT, gamma glutamyl transpeptidase; WBC, white blood cell.
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cholangitis can be the presenting symptoms in cholangiocarcinoma. Even if we have a firm diagnosis of HL, cholangiocarcinoma should still be excluded, since it is also a known complication of HL (2–4). The hyperplastic peribiliary glands may look alarming to those less familiar with the full spectrum of pathologic changes of HL. Features indicating a benign nature include a lobular arrangement, lack of infiltrating cords, and lack of nuclear pleomorphism. Western pathologists often have the misconception that HL results from parasitic infestation and consider peribiliary glandular proliferation as a feature indicating clonorchiasis, another oriental liver disease. Intrahepatic stones are not regular features in pure clonorchis infestation. The intrahepatic bile ducts are slightly enlarged with thickened wall and do not show marked dilatations and stenoses. The wall thickening is due to florid intramural mucinous glandular hyperplasia (so-called adenomatous hyperplasia) and tissue eosinophilia, quite different from the chronic proliferative cholangitis in HL. Indeed in the olden days, evidence of Clonorchis sinensis infestation could be detected in 30% to 40% of the HL livers (5). Nowadays, the clonorchis worms are seldom found in HL cases. Nonetheless the present case has concomitant clonorchiasis, which may be responsible for the severe recurrent bouts of cholangitis. The term recurrent pyogenic cholangitis (RPC), which is frequently used by Chinese clinicians, also describes a condition characterized by intrahepatic, pigmented stones, although the name emphasizes the clinical presentation of recurrent bouts of cholangitis rather than the stones. This condition, also known as oriental cholangiohepatitis and intrahepatic, pigmented stone disease, shares many clinical and pathologic features with primary pigmented HL (5–9). The 2 terms just describe different aspects of the same disease with HL emphasizing the pathological changes and RPC emphasizing the clinical presentation of the disease (10,15,16). Other than the much more commonly encountered calcium bilirubinate stones, pure cholesterol stones are also recognized in primary HL.
C H O L E S TA S I S
References 1. Tsui WMS, Lam PWY, Mak CK, Ng CS, Tse CCH. Features of sclerosing cholangitis in recurrent pyogenic cholangitis [Abstract]. Int J Surg Pathol. 1995;2S:323. 2. Al-sukhni W, Gallinger S, Pratzer A, et al. Recurrent pyogenic cholangitis with hepatolithiasis—the role of surgical therapy in North America. J Gastrointest Surg. 2008;12:496–503. 3. Zhou YM, Yin ZF, Yang JM, et al. Risk factor for intrahepatic cholangiocarcinoma: a case-control study in China. World J Gastroenterol. 2008;28:632–635. 4. Kusano T, Isa T, Ohtsubo M, Yasaka T, Furukawa M. Natural progression of untreated hepatolithiasis that shows no clinical signs at its initial presentation. J Clin Gastroenterol. 2001;33:114–117. 5. Chou ST, Chan CW. Recurrent pyogenic cholangitis: a necropsy study. Pathology. 1980;12;415–428. 6. Carmona RH, Crass RA, Lim RC Jr, Trunkey DD. Oriental cholangitis. Am J Surg. 1984;148:117–124. 7. Nakanuma Y, Yamaguchi K, Ohta G, Terada T. Pathologic features of hepatolithiasis in Japan. Hum Pathol. 1988;19:1181–1186. 8. Lim JH. Oriental cholangiohepatitis: pathologic, clinical, and radiologic features. AJR Am J Roentgenol. 1991;157:1–8. 9. Harris HW, Kumwenda ZL, Sheen-Chen SM, Shah A, Schecter WP. Recurrent pyogenic cholangitis. Am J Surg. 1998;176:34–37. 10. Chan FL, Chan JK, Leong LL. Modern imaging in the evaluation of hepatolithiasis. Hepatogastroenterology. 1997;44:358–369. 11. Portmann BC, Nakanuma. Y. Disease of the Bile Ducts in Macsween’s Pathology of the Liver. 5th ed. Chapter 11, Churchill Livingstone Elsevier; 2007. 12. Chapman RW, Arborgh BA, Rhodes JM, et al. Primary sclerosing cholangitis: a review of its clinical features, cholangiography, and hepatic histology. Gut. 1980;21:870–877. 13. MacCarty RL, LaRusso NF, Wiener RH, Ludwig J. Primary sclerosing cholangitis: findings on cholangiography & pancreatography. Radiology. 1983;149:39–44. 14. Chan FL, Man SW, Leong LLY, Fan ST. Evaluation of recurrent pyogenic cholangitis with CT: analysis of 50 patients. Radiology. 1989;170: 165–169. 15. Tsui WM, Chan YK, Wong CT, Lo YF, Yeung YW. Hepatolithiasis and the syndrome of recurrent pyogenic cholangitis-clinical, radiologic and pathologic features. Semin Liver Dis. 2011 (in press). 16. Tsui WM, Lam PW, Lee WK, Chan YK. Primary hepatolithiasis, recurrent pyogenic cholangitis, and oriental cholangiohepatitis—a tale of three countries. Adv Anat Pathol. 2011 (in press).
7 Bile Duct Damage and Ductopenia KAY WASHINGTON
I N T ROD U C T I ON Bile Duct Damage and Ductopenia
Injury to and loss of interlobular bile ducts occur in a number of inflammatory disorders in adults (Table 7.1); in children, congenital disorders, such as Alagille syndrome, must also be considered. Infiltration of bile duct epithelium by mononuclear inflammatory cells is common in conditions in which there is a dense portal inflammatory infiltrate, such as hepatitis B, hepatitis C (1), and autoimmune hepatitis, but the bile duct is not the primary target of the immune response and biliary injury. In such conditions, bile duct involvement is usually modest and infrequently results in bile duct loss. In other immune-mediated diseases, such as primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), graft-versushost disease, hepatic allograft rejection, and some cholestatic drug reactions, the bile duct is a primary target of the immune attack and may be destroyed consequently. Duct loss is generally patchy at first, but if progressive, changes of chronic cholestasis ensue when a critical number of ducts have been destroyed. The portal tracts should be systematically evaluated in liver biopsies from adults to assess for bile duct loss to avoid underdiagnosis of liver diseases leading to ductopenia, most commonly PBC and PSC. The threshold for ductopenia has been set at absence of bile ducts in 50% of portal tracts in an adequate sample and was largely based on work on Alagille syndrome (2) and primary biliary cirrhosis (3). Early work recommended evaluation of up to 20 portal tracts for an accurate assessment of ductopenia (4). More lenient recommendations include at least 10 portal tracts (5,6) or at least 5 complete portal tracts (7). As needle biopsies have become smaller in recent years, the difficulties in assessing ductopenia have become more problematic, because many of
TA B LE 7. 1 Differential diagnosis of ductopenia in adults Primary biliary cirrhosis Primary sclerosing cholangitis Chronic hepatic allograft rejection
the portal tracts represented in the biopsy are incomplete or tangentially sectioned. To overcome these limitations, it has been proposed that ductopenia be defined based on the percentage or number of portal tracts containing hepatic arteries without paired bile ducts (8). This method, in which ductopenia is defined as unpaired hepatic artery branches in 10% of portal tracts, or in at least 2 portal tracts regardless of the number of portal tracts present, appears to be more sensitive than bile duct loss in 50% of portal tracts, but further validation studies are needed. P R IMA RY BILIA RY CIR R H O SIS Definition of Primary Biliary Cirrhosis
Primary biliary cirrhosis is a chronic cholestatic liver disease of unknown etiology in which the intrahepatic bile ducts are progressively destroyed by a nonsuppurative inflammatory process. Large intra- and extrahepatic bile ducts are not affected. The serologic hallmark of the disease is the presence of antimitochondrial antibodies (AMA), which are highly specific for the disorder. PBC affects primarily middle aged women and is probably autoimmune in etiology, judging by its association with other autoimmune disorders such as Sjögren syndrome and keratoconjuctivitis sicca, and may in some patients represent a generalized disorder of lacrimal, salivary, and pancreaticobiliary small duct epithelia. Diagnostic criteria for primary biliary cirrhosis
Diagnosis of PBC rests upon a combination of clinical, serologic, and histologic features, including cholestatic serum enzyme pattern, serum AMA, and compatible histology. A probable diagnosis of PBC requires 2 of the following 3 criteria, and a definite diagnosis requires 3: • 1AMA • elevated liver enzymes, usually alkaline phosphatase, for over 6 months • Compatible liver biopsy A more detailed scoring system similar to that used for AIH has been proposed, but not well validated (9); a number of weighted parameters are assessed, including: 1. Cholestatic serum enzyme pattern, as evidenced by alkaline phosphatase/alanine aminotransferase (ALT) ratio 2. Elevated serum IgM 3. AMA titer greater than 1:40, detected by immunofluorescence or PBC-specific AMA-M2 detected by ELISA or immunoblot 4. Florid bile duct lesion
Hepatic graft-versus-host disease Drug reaction Ischemic cholangiopathy Sarcoidosis Idiopathic adulthood ductopenia
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Histologic features
The characteristic lesion of primary biliary cirrhosis is the so-called florid duct lesion, sometimes also called chronic nonsuppurative destructive cholangitis (10). Interlobular bile ducts 40 to 80 microns in diameter are typically involved (Figure 7.1). In early-stage PBC, the diagnostic lesions may be focal and may not be sampled on needle biopsy. The 3 components of the florid duct lesion are inflammation, injury to bile duct epithelial cells, and disruption of the bile duct basement membrane. The inflammatory infiltrate is composed of lymphocytes, scattered eosinophils, macrophages, and a variable number of plasma cells, and is intimately associated with the bile duct. The macrophages may be dispersed throughout the portal inflammatory infiltrate or may be aggregated into loose clusters or occasionally into well-formed granulomas. Granulomas and Kupffer cell aggregates may be present in the lobule. In early stages, the inflammatory infiltrate is largely confined to the portal tract. The biliary epithelial cells of injured bile ducts are swollen, focally stratified, and may be vacuolated. Lymphocytes commonly infiltrate bile duct epithelium. The basement membrane becomes disrupted and fragmented, best visualized on PAS stain. In small portal tracts, bile ducts are often absent and seem to have vanished without a trace (Figure 7.2), although aggregates of lymphocytes or PAS-positive basement membrane material may mark their former location. Canalicular cholestasis is not a feature of early-stage PBC.
F I G U R E 7 . 1 Florid duct lesion in primary biliary cirrhosis, with
granulomatous injury to small interlobular bile duct.
Treatment and Natural History of Primary Biliary Cirrhosis
Most patients with PBC are asymptomatic at diagnosis (11) and identified after screening tests show elevation of serum alkaline phosphatase. Overt symptoms develop in most within 2 to 4 years, although some are asymptomatic for years. The most common presenting symptoms are fatigue (21%) and pruritis (19%), the latter due to the accumulation of bile salts. The mainstay of treatment of early PBC is ursodeoxycholic acid (UDCA), which appears to alter the natural history of the disease by delaying clinical and histologic progression. At least 25% of patients with early PBC (stage I or II) treated with UDCA will have no histologic progression over 4 years, and 25% to 30% will have a complete response (12) characterized by normalization of liver enzyme tests and improvement or stabilization of liver biopsy. With treatment, the survival rate for patients with stage 1 or 2 disease appears to be similar to a healthy control population (13). Without treatment, the mean time to progression from stage 1 or 2 disease to cirrhosis is 4 to 6 years. In contrast to autoimmune hepatitis, corticosteroids are not effective in PBC. Survival is variable in untreated or advanced stage patients, but is generally from 6 to 12 years after presentation for symptomatic patients who do not undergo liver transplantation. Factors decreasing survival are jaundice, loss of bile ducts, cirrhosis, and the presence of other autoimmune disorders. Liver transplantation is the only effective therapy
F I G U R E 7 . 2 Portal tract without bile duct; inflammation and
ductular reaction are minimal, PBC.
for late-stage disease; although histologic disease recurrence is reported in up to 30% of patients, clinically significant and progressive recurrent disease is uncommon (14).
References 1. Souza P, Prihoda TJ, Hoyumpa AM, Sharkey FE. Morphologic features resembling transplant rejection in core biopsies of native livers from patients with hepatitis C. Hum Pathol. 2009;40(1):92–97. 2. Alagille D, Odievre M, Gautier M, Dommergues JP. Hepatic ductular hypoplasia associated with characteristic facies, vertebral malformations, retarded physical, mental, and sexual development, and cardiac murmur. J Pediatr. 1975;86(1):63–71. 3. Nakanuma Y, Ohta G. Histometric and serial section observations of the intrahepatic bile ducts in primary biliary cirrhosis. Gastroenterology. 1979;76(6):1326–1332. 4. Witzleben CL. Bile duct paucity (“intrahepatic atresia”). Perspect Pediatr Pathol. 1982;7:185–201.
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5. Ludwig J, Wiesner RH, LaRusso NF. Idiopathic adulthood ductopenia: a cause of chronic cholestatic liver disease and biliary cirrhosis. J Hepatol. 1988;7(2):193–199. 6. Nakanuma Y, Tsuneyama K, Harada K. Pathology and pathogenesis of intrahepatic bile duct loss. J Hepatobiliary Pancreat Surg. 2003;8(4): 303–315. 7. Sinha J, Magid MS, VanHuse C, Thung SN, Suchy F, Kerkar N. Bile duct paucity in infancy. Semin Liver Dis. 2007;27(3):319–323. 8. Moreira RK, Chopp W, Washington MK. The concept of hepatic artery-bile duct parallelism in the diagnosis of ductopenia in liver biopsy samples. Modern Pathol. 2010;23S1:366A. 9. Yamamoto K, Terada R, Okamoto R, et al. A scoring system for primary biliary cirrhosis and its application for variant forms of autoimmune liver disease. J Gastroenterol. 2003;38(1):52–59. 10. Weisner RH, LaRusso NF, Ludwig J, Dickson ER. Comparison of the clinicopathologic features of primary sclerosing cholangitis and primary biliary cirrhosis. Gastroenterology. 1985;88:108–114.
AND
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11. Prince M, Chetwynd A, Newman W, Metcalf JV, James OF. Survival and symptom progression in a geographically based cohort of patients with primary biliary cirrhosis: follow-up for up to 28 years. Gastroenterology. 2002;123:1044–1051. 12. Leuschner M, Dietrich CF, You T, et al. Characterisation of patients with primary biliary cirrhosis responding to long term ursodeoxycholic acid treatment. Gut. 2000;46(1):121–126. 13. Corpechot C, Carrat F, Bahr A, Chretien Y, Poupon R-E, Poupon R. The effect of ursodeoxycholic acid therapy on the natural course of primary biliary cirrhosis. Gastroenterology. 2005;128:297–303. 14. Khettry U, Anand N, Faul PN, et al. Liver transplantation for primary biliary cirrhosis: a long-term pathologic study. Liver Transpl. 2003;9(1):87–96.
Case 7.1
Primary Biliary Cirrhosis With Nonspecific Changes and Positive Antimitochondrial Antibody KAY WASHINGTON
C L I N I C A L I N F OR M AT I ON
A 52-year-old asymptomatic woman was discovered to have elevated serum alkaline phosphatase (3 times normal), with normal serum total bilirubin and normal transaminase levels. There was no history of drug or alcohol use. Serologic testing was positive for antimitochondrial antibodies (1:640) and negative for antinuclear antibodies and anti–smooth muscle antibodies. Serum IgM was slightly elevated (1.5 times normal).
R E A S ON F OR R E F E R R A L
The liver biopsy shows minimal bile duct injury; are the findings indicative of primary biliary cirrhosis? FIGURE 7.1.2 Portal tract with mild nonspecific chronic inflammatory
infiltrate, minimal interface inflammation, and intact bile duct.
PAT H OL OG I C F E AT U R E S
The overall hepatic architecture is preserved. Most portal tracts are normal (Figure 7.1.1) or contain only a modest lymphocytic infiltrate, with minimal interface inflammation (Figure 7.1.2). A few interlobular bile ducts show mild reactive change and focal infiltration by lymphocytes, and 1 bile duct is surrounded by a cuff of plasma cells (Figure 7.1.3). No granulomas are seen. There is no steatosis.
F I G U R E 7 . 1 . 3 Bile duct surrounded by plasma cells and showing
focal epithelial disruption and infiltration by lymphocytes.
DIAGNO SIS
FIGURE 7. 1. 1 Portal tract with minimal inflammation, normal bile
duct, and no ductular reaction.
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Nonspecific portal chronic inflammation with minimal bile duct injury and no fibrosis, compatible with primary biliary cirrhosis (PBC), stage 1, in the setting of AMA positivity.
CASE
7.1:
PRIMARY
BILIARY
CIRRHOSIS
D I S C U S S I ON
WITH
Histopathology of Early-Stage PBC
Although interlobular bile duct injury and destruction are the central histologic features of PBC, changes may be patchy and not evident on needle biopsy early in the course of disease. Bile duct destruction is segmental in distribution and may sometimes be revealed through deeper sectioning of the biopsy block. In some cases, the only histologic evidence of the disease is a mononuclear inflammatory infiltrate in portal tracts, with or without interface inflammation, and the differential diagnosis is very broad. Such cases with a nonspecific inflammation warrant careful assessment of the portal tracts for bile duct damage or loss. Bile ducts may show infiltration by lymphocytes and degenerative changes such as vacuolization of epithelial cells, but such changes may also be seen in autoimmune hepatitis (4) and chronic viral hepatitis (Table 7.1.1). If other causes of a mild hepatitis pattern of injury are excluded, a diagnosis of probable PBC may be rendered in the setting of AMA seropositivity. Other nonspecific histologic features seen in some cases of early-stage PBC include small nonnecrotizing granulomas in portal tracts and lobules and aggregates of Kupffer cells in hepatic sinusoids. Hepatocyte injury and apoptosis are usually
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121
TA BL E 7 . 1 . 1 Comparison of histologic features of PBC, AIH,
and chronic viral hepatitis
Clinical and Immunologic Features
PBC has a distinctive clinical profile, occurring primarily in women (90% of patients), mostly in the fifth to eighth decades. The disease almost never occurs in children. Other coexisting autoimmune disorders are common and include hypothyroidism, Sjögren syndrome, scleroderma, interstitial lung disease, celiac disease, hemolytic anemia, and autoimmune thrombocytopenia. Most patients are asymptomatic at diagnosis. Portal hypertension, osteopenia, hyperlipidemia, and other complications related to chronic cholestasis, such as malabsorption, deficiencies of fat-soluble vitamins, and steatorrhea, may be seen in advanced disease. The risk of hepatocellular carcinoma, although lower than that in many causes of cirrhosis, is increased in cirrhotic patients with PBC (1). The most specific feature of PBC is the presence of antimitochondrial antibodies in the serum of 90% of patients affected. These antibodies directed to the PDC-E2 antigen, a component of the pyruvate dehydrogenase enzyme complex present on the inner mitochondrial membrane, are highly specific (96%) for PBC. The presence of serum AMA indicates a specific B-cell response to this mitochondrial antigen, but specific T cell responses are seen as well (2). Other circulating autoantibodies such as anti–smooth muscle and antinuclear antibodies and rheumatoid factor are often present, and hypergammaglobulinemia with a selective elevation of IgM is common. Other disease-specific antibodies that may be detected in PBC include the nuclear core protein gp210, which appears to be highly specific (99%) for PBC and may portend a more severe course. This autoantibody is found in 10% to 40% of AMA-positive patients and up to 50% of AMA-negative patients (3).
NONSPECIFIC
Chronic Viral Hepatitis
Feature
PBC
AIH
Chronic cholestasis
Prominent, late
Mild, late stages only
Trace, late stages only
Copper storage
Variable
Minimal
Minimal
Duct loss
Extensive
Rare
Rare
Granulomas
Variable
Absent
Rare
Interface hepatitis
Variable
Key feature; variable
Key feature
Lobular hepatitis
Mild
Variable
Variable
Perivenular necroinflammatory activity
Not seen
Variable, often in early disease
Minimal
Abbreviations: AIH, autoimmune hepatitis; PBC, primary biliary cirrhosis.
TA BL E 7 . 1 . 2 Useful stains in evaluation of bile duct lesions Stain
Shows
Disease
PAS with diastase
Basement membrane
Bile duct injury; PBC
Trichrome
Type I collagen
Useful for identification of bile ducts
Shikata stain (orcein, aldehyde fuchsin)
Increased copper-binding protein in chronic cholestasis
PBC, PSC
Rubeanic acid or rhodanine
Copper deposition in periportal hepatocytes in chronic cholestasis
PBC, PSC
Cytokeratin (AE1/ AE3, CK7, CK19)
Biliary epithelium (bile ducts express CK 7, 8, 18, 19)
Ductopenia
EMA
Biliary epithelium
Ductopenia
Abbreviations: EMA, epithelial membrane antigen PAS, periodic acid–Schiff; PBC, primary biliary cirrhosis; PSC, primary sclerosing cholangitis.
minimal, and active cholestasis and bile plugs are only seen in advanced stage disease. Accumulation of copper within periportal hepatocytes is a feature of chronic cholestasis that may be helpful in diagnosis of PBC. This copper storage can be demonstrated with rhodanine or rubeanic acid stains. Orcein or aldehyde fuchsin stains will highlight increased copper-binding protein (Table 7.1.2). Positive staining for copper or copper-binding protein is seen as granular deposition in periportal hepatocytes. This copper accumulation is not specific, but when found in a precirrhotic liver biopsy is highly suggestive of chronic cholestasis, if rare entities
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such as Wilson disease have been excluded. Mallory’s hyaline may also be found in periportal hepatocytes in chronic cholestasis in advanced disease but is not seen in early-stage PBC.
References 1. Cavazza A, Caballeria L, Floreani A, et al. Incidence, risk factors, and survival of hepatocellular carcinoma in primary biliary cirrhosis: comparative analysis from two centers. Hepatology. 2009;50(4):1162–1168.
AND
DUCTOPENIA
2. Kita H, Naidenko OV, Kronenberg M, et al. Quantitation and phenotypic analysis of natural killer T cells in primary biliary cirrhosis using a human CD1d tetramer. Gastroenterology. 2002;123(4):1031–1043. 3. Itoh S, Ichida T, Yoshida T, et al. Autoantibodies against a 210 kDa glycoprotein of the nuclear pore complex as a prognostic marker in patients with primary biliary cirrhosis. J Gastroenterol Hepatol. 1998;13(3): 257–265. 4. Zen Y, Harada K, Sasaki M, et al. Are bile duct lesions of primary biliary cirrhosis distinguishable from those of autoimmune hepatitis? Interobserver histological agreement on trimmed bile ducts. J Gastroenterol. 2005;40:164–170.
Case 7.2
Antimitochondrial Antibody-Negative Primary Biliary Cirrhosis KAY WASHINGTON
C L I N I C A L I N F OR M AT I ON
A 36-year-old woman was referred for evaluation of cholestatic liver disease. She had been followed for 5 years with progressive elevation of alkaline phosphatase to 5 times normal, despite treatment with ursodeoxycholic acid (UDCA). Serum transaminase levels were 2 to 3 times normal, and total bilirubin was 1.5 times the upper limit of normal. Further laboratory testing revealed high titer antinuclear antibodies and negative AMA and SMA. A family history of primary biliary cirrhosis was noted. R E A SON F OR R E F E R R AL
The liver biopsy shows destruction of interlobular bile ducts in the setting of negative antimitochondrial antibodies. Do the findings represent primary biliary cirrhosis? F I G U R E 7 . 2 . 2 Non-necrotizing granuloma in portal tract.
PAT H OL OG I C F E AT U R E S
Portal tracts are expanded by a lymphoplasmacytic infiltrate with interface hepatitis and numerous plasma cells. Interlobular bile ducts are focally disrupted by lymphocytes (Figure 7.2.1), and nonnecrotizing granulomas are present in some portal tracts (Figure 7.2.2). Other portal tracts lack bile ducts (Figure 7.2.3). There is mild macrovesicular steatosis and scattered foci of spotty hepatocyte necrosis (Figure 7.2.4), without centrilobular pericellular fibrosis.
F I G U R E 7 . 2 . 3 No interlobular bile duct is identified in this portal tract, which is expanded by a mononuclear inflammatory infiltrate.
DIAGNO SIS
FIGURE 7. 2. 1 Portal tract with lymphoplasmacytic infiltrate; note
focally disrupted bile duct (arrow).
123
Antimitochondrial antibody-negative primary biliary cirrhosis (autoimmune cholangitis).
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FIGURE 7. 2. 4 Mild macrovesicular steatosis and spotty hepatocyte
necrosis.
AND
DUCTOPENIA
F I G U R E 7 . 2 . 5 Cirrhosis in PBC, with chronic cholestasis and neartotal destruction of interlobular bile ducts. Note lack of ductular reaction.
D I SC U SSI ON
The term “AMA-negative PBC” or “autoimmune cholangitis” has been applied to cases that are clinically, histologically, and biochemically compatible with PBC except for the lack of identifiable antimitochondrial antibodies; serum ANA and anti–smooth muscle antibodies may be present in high titers but are not required for the diagnosis. More sensitive testing using cloned mitochondrial antigens such as a triple hybrid recombinant molecule may identify AMA in some patients previously thought to be seronegative. In retrospective studies, no significant differences between patients with PBC and these AMA-negative patients have been described (1–4), although a prospective study describing 20 patients with autoimmune cholangitis reports that these patients have higher serum levels of aspartate aminotransferase (AST) and bilirubin and lower serum IgM than patients with classic PBC (5). Of the 15 patients with autoimmune cholangitis with biopsies reported in 1 study, 6 had a PBC-like and 7 had a PSC-like pattern of injury, suggesting that “autoimmune cholangitis” may represent a mixed group of autoimmune disorders at varying stages or possibly a transition state (5). AMA-negative patients were slightly younger in 1 study (50 vs. 55 years) but were otherwise indistinguishable (1). Although data are largely lacking, it is thought that the response to UDCA therapy in these patients is the same as for those who are AMA-positive, and there are accordingly no differences in the treatments prescribed for these 2 groups at the present time.
In this case, the mild large droplet steatosis and spotty hepatocyte necrosis are nonspecific findings and are not considered to represent nonalcoholic steatohepatitis. Treatment with UDCA was ineffective, and the patient developed progressive liver disease with cirrhosis and portal hypertension. Liver transplantation was performed 5 years after the biopsy was obtained; the explanted liver showed established biliary cirrhosis with loss of interlobular bile ducts typical of stage 4 PBC (Figure 7.2.5).
References 1. Goodman ZD, McNally PR, Davis DR, Ishak KG. Autoimmune cholangitis: a variant of primary biliary cirrhosis. Clinicopathologic and serologic correlations in 200 cases. Dig Dis Sci. 1995;40(6): 1232–1242. 2. Lacerda MA, Ludwig J, Dickson ER, Jorgensen RA, Lindor KD. Antimitochondrial antibody-negative primary biliary cirrhosis. Am J Gastroenterol. 1995;90(2):247–249. 3. Michieletti P, Wanless IR, Katz A, et al. Antimitochondrial antibody negative primary biliary cirrhosis: a distinct syndrome of autoimmune cholangitis. Gut. 1994;35(2):260–265. 4. Taylor SL, Dean PJ, Riely CA. Primary autoimmune cholangitis: an alternative to antimitochondrial antibody-negative primary biliary cirrhosis. Am J Surg Pathol. 1994;18:91–99. 5. Invernizzi P, Crosignani A, Battezzati PM, et al. Comparison of the clinical features and clinical course of antimitochondrial antibody-positive and -negative primary biliary cirrhosis. Hepatology. 1997;25(5): 1090–1095.
Case 7.3
Primary Biliary Cirrhosis With Ductopenia KAY WASHINGTON
C L I N IC AL I N F OR M AT I ON
A 48-year-old woman presented with pruritis, worse at night. She had been treated recently with a course of amoxicillin clavulanate (Augmentin) for acute sinusitis, but otherwise, her past medical history was unremarkable. Review of systems was notable for dry mouth and eyes. Laboratory testing revealed elevated alkaline phosphatase (3.5 times normal), elevated IgM (1.5 times normal), normal serum transaminase levels, positive antimitochondrial antibodies, negative antinuclear antibodies, smooth muscle antibodies, and slightly elevated serum total bilirubin. R E A SON F OR R E F E R R AL
The liver biopsy shows ductopenia with relatively mild portal inflammation and no florid duct lesions. Given the history of treatment with amoxicillin clavulanate, do the findings represent drug reaction or PBC?
F I G U R E 7 . 3 . 2 Minimal lobular inflammation and no cholestasis.
Note area of regenerating hepatocytes (arrow) bounded by atrophic hepatocytes, suggestive of nodular regenerative hyperplasia.
PAT H OL OG I C F E AT U R E S
Interlobular bile ducts are absent from most portal tracts. There is a modest portal chronic inflammatory infiltrate with minimal bile ductular reaction and no significant interface hepatitis (Figure 7.3.1). Focally, portal-portal bridging fibrosis is noted. Centrilobular areas show no canalicular cholestasis (Figure 7.3.2). Alternating areas of hepatocyte regeneration and atrophy are present, suggestive of an element of nodular regenerative hyperplasia.
FIGURE 7. 3. 1 Portal tract with modest chronic inflammatory infil-
trate and no identifiable interlobular bile duct.
DIAGNO SIS
Primary biliary cirrhosis with ductopenia.
DISCUSSIO N
Whereas this case exhibits classic clinical and serologic features of primary biliary cirrhosis, including the not-uncommon finding of nodular regenerative hyperplasia, the histologic finding of ductopenia should prompt consideration of other possible causes of bile duct loss in adults (see Table 7.3.1, Chapter 7). PBC and PSC are usually distinguished easily by their characteristic clinical and pathologic profiles. PBC is overwhelmingly a disorder of middle aged women and affects only small- and medium-sized intrahepatic ducts, whereas PSC is seen in all age groups, is associated with inflammatory bowel disease, and affects large intrahepatic and extrahepatic bile ducts with variable involvement of the smaller biliary radicles. The diagnosis of small duct PSC can be difficult to establish with certainty and is made most confidently in the patient with inflammatory bowel disease. Diagnosis of graftversus-host disease and chronic ductopenic hepatic allograft rejection may be challenging, but these disorders enter the differential diagnosis only in the appropriate clinical setting. Similarly, ischemic cholangiopathy is rarely encountered and is seen primarily in the setting of hepatic artery infusion of 5-FU–based chemotherapy.
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Drug reaction should be considered in the differential diagnosis of any pattern of liver injury, and many different drugs, most commonly neuroleptics, anticonvulsants, and antibiotics; specific examples which include ibuprofen, carbamazepine, chlorpromazine, trimethoprim-sulfamethoxazole, and tetracycline have been associated with a cholestatic hepatitis pattern of injury with injury to interlobular bile ducts. Correlation with clinical findings is essential, and a high index of suspicion must often be maintained to arrive at a correct diagnosis. Drug-induced prolonged cholestasis is diagnosed when jaundice persists for more than 6 months or liver tests indicate continued cholestasis for more than 1 year after withdrawal of the offending agent. Acute onset of disease, appropriate drug history, and a period of jaundice suggest a drug-induced lesion. The bile duct injury in drug-induced prolonged cholestasis (Figure 7.3.3) may be relatively subtle, consisting of reactive changes, focal degenerative changes in bile duct epithelium, or overt loss of bile ducts resulting in ductopenia. Infiltration of bile ducts by inflammatory cells, generally lymphocytes, is variable but may be prominent. In early stages of drug-induced bile duct injury, bile duct epithelial cells are swollen and vacuolated. Pyknotic nuclei and mitotic figures may be seen; some bile ducts may appear atrophic, and ductopenia has been reported as early as 10 days following onset of jaundice. Marked canalicular cholestasis is generally present in zone 3 (Figure 7.3.4), and a mild lobular inflammation with occasional eosinophils may be seen. The portal inflammatory infiltrate is variable in density but often contains eosinophils. In the chronic phase, some degree of portal inflammation and bile ductular reaction is found, although canalicular bile plugs, lobular inflammation, and hepatocyte necrosis have generally resolved in biopsies taken late (24 months) after the inciting agent has been discontinued (1). In some patients, liver biopsies show changes similar to primary biliary cirrhosis. In time, most patients recover,
AND
DUCTOPENIA
although it may take several years for liver tests to return to normal, and in some patients, the disease is irreversible and results in biliary cirrhosis (Figure 7.3.5). Fibrosis in the liver biopsy and failure to withdraw the offending drug are factors associated with persistent liver damage (2). The pathogenesis of drug-induced bile duct injury is unclear. Most of the drugs associated with drug-related bile duct paucity undergo biotransformation to toxic intermediates, which may result in direct cellular injury. More likely, immune response targeting bile duct epithelial cells may be responsible, as prolonged cholestasis has been most often seen with drugs considered to induce acute hepatitis or cholestatic hepatitis through a hypersensitivity mechanism. Genetic predisposition probably also plays a role in pathogenesis. In rare instances, careful clinicopathologic correlation may fail to reveal an etiology for ductopenia in the adult
F I G U R E 7 . 3 . 4 Zone 3 cholestasis and canalicular bile plugs
(arrow) in cholestatic hepatitis due to drug reaction to amoxicillin clavulanate.
FIGURE 7. 3. 3 Bile duct.injury due to drug reaction to amoxicillin
clavulanate. The bile duct (arrow) is distorted with loss of individual epithelial cells. Portal inflammation is modest.
F I G U R E 7 . 3 . 5 Ductopenia with canalicular bile plugs in prolonged cholestasis due to drug reaction.
CASE
7.3:
PRIMARY
BILIARY
patient. The term idiopathic adulthood ductopenia has been applied to such cases of chronic cholestasis of unknown etiology associated with loss of intrahepatic bile ducts. This disorder usually affects young to middle-aged adults and is more common in males (3); familial cases are described (4). Reported cases probably represent a heterogeneous group of related disorders, with some representing late onset of paucity of intrahepatic bile ducts, primary sclerosing cholangitis involving small ducts without large duct involvement, and autoimmune-mediated cholangitis. The criteria generally used for idiopathic adulthood ductopenia are onset of cholestasis in late adolescence or adulthood, ductopenia defined as lack of bile ducts in more than 50% of portal tracts, normal cholangiogram, and no known etiology. The liver often shows empty portal tracts with no inflammation. The patient with ulcerative colitis, ductopenia, or other biopsy features consistent
CIRRHOSIS
WITH
DUCTOPENIA
127
with PSC, but a normal cholangiogram, is considered to have isolated small duct PSC. This disorder probably represents less than 5% of cases of chronic cholestasis in adulthood.
References 1. Degott C, Feldmann G, Larrey D, et al. Drug-induced prolonged cholestasis in adults: a histological semiquantitative study demonstrating progressive ductopenia. Hepatology. 1992;15:244–251. 2. Aithal PG, Day CP. The natural history of histologically proved drug induced liver disease. Gut. 1999;44:731–735. 3. Kim WR, Ludwig J, Lindor KD. Variant forms of cholestatic diseases involving small bile ducts in adults. Am J Gastroenterol. 2000;95(5): 1130–1138. 4. Burak KW, Pearson DC, Swain MG, Kelly J, Urbanski SJ, Bridges RJ. Familial idiopathic adulthood ductopenia: a report of five cases in three generations. J Hepatobiliary Pancreat Surg. 2000;32:159–163.
Case 7.4
Primary Biliary Cirrhosis With Cirrhosis KAY WASHINGTON
C L I N I C AL I N F OR M AT I ON
A 61-year-old woman with known long-standing primary biliary cirrhosis unresponsive biochemically to ursodeoxycholic acid therapy is referred for evaluation for possible liver transplantation. She complains of debilitating fatigue. Review of laboratory tests reveals high titer positive antimitochondrial antibodies. The most recent liver tests reveal total bilirubin twice normal, AST and ALT 1.5 times normal, and alkaline phosphatase twice normal. A liver biopsy is performed for staging purposes. R E A S ON F OR R E F E R R A L
The liver biopsy shows cirrhosis with loss of interlobular bile ducts. Are the findings consistent with primary biliary cirrhosis? F I G U R E 7 . 4 . 2 Ductopenia with minimal bile ductular reaction.
PAT H OL OG I C F E AT U R E S
The biopsy shows irregular regenerating nodules of hepatocytes separated by fibrous bands (Figure 7.4.1). The fibrous septa contain no recognizable interlobular bile ducts, and there is minimal bile ductular reaction (Figure 7.4.2). Only mild necroinflammatory activity is seen. No canalicular cholestasis is identified.
D I AG N OS I S
Cirrhosis secondary to primary biliary cirrhosis (stage 4).
FIGURE 7. 4. 1 Biliary-type cirrhosis with irregular elongated nodules.
DISCUSSIO N
In advanced primary biliary cirrhosis (PBC), changes of chronic cholestasis begin to appear, with swollen and rarefied periportal hepatocytes and accumulation of copper. As periportal fibrosis progresses, portal-portal fibrous bridges are formed. Bile ductular proliferation often subsides in late-stage PBC, and in the cirrhotic stage little ductular or ductal epithelium can be identified. The cirrhosis has a typical biliary pattern, in which the nodules have an irregularly shaped “jigsaw puzzle piece” profile. The value of histologic staging in assessing prognosis in PBC is somewhat controversial, given the lack of uniformity of duct loss and fibrosis in the liver in this disease. However, the presence of portal-portal bridging fibrosis on biopsy has been shown to be a poor prognostic sign. Several staging schemes have been described, and there is little practical difference between the 2 that are most commonly employed, those described by Scheuer (1) and Ludwig (2) (Table 7.4.1). In stage 1 disease, damage to interlobular bile ducts is seen in the form of the florid duct lesion. In stage 2, the effects of duct injury result in extension of the process to involve the periportal areas, and ductular reaction, probably representing a compensatory reaction to bile duct loss, is prominent (Figure 7.4.3). Stage 3 is characterized as a scarring or precirrhotic stage, with bridging fibrosis (Figure 7.4.4). Stage 4 is cirrhosis (see Figure 7.4.5).
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BILIARY
CIRRHOSIS
WITH
CIRRHOSIS
129
TA B LE 7. 4. 1 Histologic staging of primary biliary cirrhosis Scheuer (1)
Ludwig (2)
Stage 1
Florid duct lesion (bile duct damage and portal inflammation)
Portal stage (portal inflammation)
Stage 2
Ductular proliferation (portal tracts expanded by fibrosis, with bile ductular reaction; interface hepatitis)
Periportal stage (periportal inflammation and interface hepatitis)
Stage 3
Scarring (fibrosis and loss of bile ducts)
Septal stage (fibrous septa link portal tracts)
Stage 4
Nodular cirrhosis
Cirrhosis
F I G U R E 7 . 4 . 4 Stage 3 primary biliary cirrhosis with bridging fibrosis.
References 1. Scheuer P. Primary biliary cirrhosis. Proc R Soc Med. 1967;60: 1257–1260. 2. Ludwig J, Dickson ER, McDonald GS. Staging of chronic nonsuppurative cholangitis (syndrome of primary biliary cirrhosis). Virchows Arch A Pathol Anat Histol. 1978;379:103–112.
FIGURE 7. 4. 3 Stage 2 primary biliary cirrhosis, with periportal bile ductular reaction and loss of interlobular bile duct.
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8 Ductal Plate Malformations and Cystic Diseases of the Liver BARTON KENNEY AND DHANPAT JAIN
I N T ROD U C T I ON The Ductal Plate
The development of the embryologic and fetal liver occurs in an organized sequence, beginning with the formation of hepatic anlagen and accrual of liver mass, with subsequent formation and remodeling of the biliary tree (1,2). There is no intrahepatic bile duct (IHBD) system until the first 7 weeks of embryonic development (3). At this time, the portal vein enters the liver at the hepatic hilum and begins branching. As the vein grows inward with its accompanying mesenchyme, a layer of epithelial cells surrounds the portal branches like a cylindrical sleeve (3). This layer of cells is known as the “ductal plate” and eventually forms the intrahepatic biliary tree. The ductal plate can be thought of as a temporary scaffolding constructed by the embryologic liver for building of the mature intrahepatic biliary system (1). The ductal plate cells originate from multipotent progenitor cells that are capable of differentiating into either hepatocytes or cholangiocytes (2). These cells develop CK19 positivity by the 9th to 10th embryonic week (Figure 8.1). The cells that form the liver parenchyma go on to express CK8 and CK18, while losing expression of CK19 (2,3). This binary cell
differentiation is induced by the presence of a periportal gradient of activin/TGF- signaling, the extent of which is modulated by inhibitory influences of hepatocyte nuclear factor 6 (HNF6) and one-cut factor (OC-2). The NOTCH signaling pathway is also believed to play a role in repression of hepatocyte differentiation in future IHBD cells (2,3). The ductal plate develops 2 layers of epithelium, and after 12 weeks undergoes progressive remodeling, starting at the hepatic hilum. Subsequently, this double-layered plate forms slit-like lumina, undergoing the so-called “tubulardilatation” (3). The portal tracts continue to develop with the appearance of hepatic artery branches in the periportal mesenchyme (1). The tubular components of the ductal plate then get incorporated into the mesenchyme by the in-growth of mesenchyme between the plate and the surrounding hepatic progenitor cells. This process forms primitive portal tracts containing the early interlobular bile ducts. The excess epithelium of the plate gradually regresses by apoptosis, leaving only the bile ducts behind, which begin to express CK7 by 20 weeks (Figures 8.2 and 8.3) (1,3). At birth, most peripheral branches of the IHBD system are still immature, and portal vein radicals at this level are still surrounded by ductal plates. Not until 4 weeks postpartum do these structures mature into well-developed portal tracts.
FIGURE 8. 1 (A) Ductal plate in fetal liver showing irregularly shaped and spaced bile ducts embedded in fibrous stoma surrounding a central portal venule. At this stage, the mesenchyme of the portal tract has grown in between the limiting plate of hepatocytes and the ductal plate, and the developing bile ducts can be easily distinguished. (B) CK19 immunostain highlighting the ductal plate epithelium at an earlier stage. The separation of the ductal plate from the hepatocytes has just begun, and a few lumina of developing bile ducts are barely evident. Note that the hepatocytes are also staining for CK19, although less strongly than the ductal plate epithelium.
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FIGURE 8. 2 Evolution of the ductal plate. Initially a double layer of
epithelium forms, surrounding a portal vein branch. The cell plates fuse to form small ductules. Intervening cell plates involute, leaving separate interlobular bile ducts (bottom left). In DPM, the process goes awry, leading to fibrosis and formation of ectatic bile ducts. Ductal Plate Malformation
The development and remodeling of the ductal plate requires precisely coordinated biologic function and highly regulated epithelial-mesenchymal interaction (3). Aberrant remodeling or a lack of remodeling altogether can lead to persistence of the embryonic bile duct structures, which may retain their primitive ductal plate–like configuration (1,3), an event that is generically referred to as “ductal plate malformation (DPM)” (Figure 8.2). This defect represents the basic underpinning of most variants of fibrocystic liver disease (1). The etiology and pathophysiology of DPM are not well understood but likely represent a defect in the complex epithelial-mesenchymal interaction necessary for proper development of the IHBD system. Abnormalities in cell-cell signaling or adhesion and intracellular cation handling have been implicated, but the precise mechanisms have not been elucidated (2). Some specific signaling defects have been shown to result in biliary abnormalities in animal models, namely deletion of various HNFs. Tissue-specific selection of HNF1 leads to gallbladder abnormalities and inadequate IHBD formation, and whole-body knockout of HNF6 leads to agenesis of the gallbladder, replacement of the cystic duct with a choledochocele, and abnormalities in IHBD formation (2,4–6). Histologically, DPM is represented by the persistence of the ductal plate beyond fetal life. This is represented by
FIGURE 8.3 Histologic evolution of the ductal plate in fetal liver. The ductal plate epithelium stains more intensely with CK19 compared to hepatocytes and can be easily distinguished. (A) Early stage with a single layer of epithelium. (B) Later stage with 2-layered epithelium of the ductal plate. (C) Early formation of ductules (red arrow) with separation of the ducts from the limiting plate of hepatocytes by in-growth of mesenchyme.
CHAPTER
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DISEASE
circumferentially oriented bile ducts at the margin of portal tracts, which are not separated from the hepatocytes by connective tissue. This is frequently accompanied by increased numbers of ectatic bile ducts with irregular contours and a lack of mature bile ducts or portal venules within the portal tracts (2,7) (Figure 8.4). The IHBD system shows increased numbers of immature ducts with irregular geometric shapes, but with well-differentiated ductal epithelium. The presence of increased bile ductular structures can be highlighted by staining for CK19. There may be canalicular and ductal cholestasis. Staining for CD34 reveals increased capillary density within portal tracts, and staining for smooth muscle actin may show a zone of condensed myofibroblasts around biliary structures (8). The hepatic arterioles often show hypertrophy and/or hyperplasia, with increased hepatic artery branches around biliary structures. The portal connective tissue may show moderate to severe fibrosis with variable inflammation. The hepatic lobule is typically normal, unless damaged secondarily by chronic infection or other injury (7).
OF
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133
LIVER
CYST IC DISEA SES O F T H E LIV ER
Cystic liver disease can be divided into 3 broad categories: hereditary (DPM-related and non-DPM related), infectious, and neoplastic. The majority of cystic liver disease in the developed world is hereditary and is most commonly associated with polycystic kidney disease (Table 8.1). Other rare conditions are also responsible for a minority of cystic liver disease cases (Table 8.2). Infectious cystic disease is more common in the developing world. Cystic neoplasms are represented by lesions that are either primarily cystic in nature or result from cystic degeneration/necrosis in otherwise solid tumors. Overall, cystic neoplasms are relatively uncommon in clinical practice. Hereditary DPM-Related Cystic Diseases of the Liver
Autosomal recessive polycystic kidney disease (ARPKD) affects between 1:6000 and 1:40 000 live births (9) and is generally a severe and lifelong disease (9,10). ARPKD may present,
FIGURE 8. 4 Comparison of a normal portal tract with persistence of ductal plate–like abnormality. (A) Normal portal tract with a well-
defined interlobular bile duct, portal venule, and hepatic arteriole. (B) DPM in a patient with CHF with ectatic and irregular bile ducts, prominent at the periphery of the portal tract, embedded in fibrous stroma similar to the developing ductal plate in Figure 8.1A. TA B LE 8. 1 Most common fibrocystic liver diseases May Be Associated With Other Condition
Specific Genetic Test Commercially Available
Gene
Protein
Age of Onset
ARPKD
PKHD1 (6p21.1-p12)
Fibrocystin
Young
Yes (CHF)
Yes
ADPKD
PKD1 (16p13.3-p13.12) PKD2 (4q21-q23)
Polycystin 1 and 2
Adult
Yes (CHF)
Yes
PLD
PRKSCH 19p13.2-p13.1 and SEC63 6p21-p23
Hepatocystin
Adult
No
No (research setting)
Caroli disease
None (but syndrome yes. . .PKHD1)
—
Young
Yes (PKD)
No
CHF
PKHD1
—
Young
Yes (PKD)
No
Abbreviations: CHF-congenital hepatic fibrosis, PKD-polycystic kidney disease, ARPKD-autosomal recessive polycystic kidney disease, ADPKD-autosomal dominant polycystic kidney disease, PLD-polycystic liver disease.
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TA B LE 8. 2 Less common syndromes associated with cystic
liver disease Syndrome
Gene
Medullary cystic kidney disease 1
MCKD1 (1q21)
Medullary cystic kidney disease 2
UMOD (16p12)
Nephronophthisis
NPHP1 (multiple)
Meckel syndrome
MKS1, 2, 3 (multiple)
Asplenia with cystic liver, kidney and pancreas
Unknown
Ellis–van Creveld syndrome or chondroectodermal dysplasia
EVC2 (4p16)
Asphyxiating thoracic dystrophy (Jeune syndrome)
Unknown
Congenital disorder or glycosylation, type Ib (phosphomannose isomerase deficiency)
MPI (15q22-qter)
Joubert syndrome
JBTS1 (9q34.3)
Vaginal atresia syndrome
Unknown
Ivermark syndrome
CX43 (possible)
Tuberous sclerosis
TSC1 (9q34), TSC2 (16p13)
Acrocephalopolydactylous dysplasia
Unknown
Bardet-Beidl syndrome
BBS1-5 (many)
COACH syndrome
Unknown
Short rib-polydactyly syndrome, type 1
Unknown
Short rib-polydactyly syndrome, type II
Unknown
Short rib-polydactyly syndrome, type III
Unknown
Short rib-polydactyly syndrome, type IV
Unknown
in its perinatal form, with bilaterally enlarged kidneys and severe renal failure (10). Individuals who survive the initial neonatal complications develop progressive renal, and often hepatic, cyst formation with variable progression to chronic renal failure and portal hypertension with increasing age (11). Approximately 199 different mutations have been recognized in patients with ARPKD. Fundamentally, these mutations affect the PKHD1 gene locus on chromosome 6p21.1 (9). This gene codes for fibrocystin, a 450-kDa hepatocyte growth factor receptor–like protein, which functions on the primary cilia of renal and biliary epithelial cells (11,12). Dysfunction of fibrocystin results in abnormal ciliary signaling, which is fundamental to proliferation and differentiation of renal and biliary epithelium. The fibrocystic disorders associated with ARPKD vary and represent a range of conditions. One end of the spectrum is exemplified by the formation of extensive fibrous septae and nodularity, generally termed as “congenital hepatic fibrosis (CHF).” The other end of the spectrum is represented by the formation of multiple bilary cysts, referred to as “Caroli disease.” There is significant overlap in presentation of these forms, and their separation into distinct entities is not always possible.
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Hepatic cysts in ARPKD result from dilation of the bile ducts and are in continuity with the remainder of the biliary system (9), although true biliary cysts that are completely isolated may also be present. As DPM underlies this condition, histologic changes include an increase in biliary channels with irregular extension into the parenchyma and extensive branching or anastomosis. There may be an absence of normal interlobular bile ducts (10). Depending on the degree of hepatic and renal involvement, liver and/or kidney transplant may be necessary. Occasionally, cyst fenestration or partial hepatectomy may be indicated if there is mass effect on surrounding structures due to cyst enlargement. In less severe cases, medical management of hypertension with ACE inhibitor or angiotensin-receptor blocker therapy may suffice. CHF is typically associated with ARPKD, with less severe renal involvement and a generally more favorable survival profile (1). The mode of inheritance is autosomal recessive (1). Several clinical forms are recognized: portal hypertensive, cholangitic, mixed portal hypertensive-cholangitic, and latent (13). Most cases are present in childhood, whether in the neonatal, infantile, or juvenile period. In general, baseline liver function tests are within the normal range, although alkaline phosphatase may be slightly elevated. Patients may come to clinical attention as a result of cholangitis, or variceal bleed and/or hepatosplenomegaly due to portal hypertension. The pathology of CHF is best described as DPM of the interlobular bile ducts with superimposed destructive and sclerosing cholangitis (1). The histologic hallmark of CHF is broad and dense fibrous septa with numerous embedded irregularly shaped bile duct structures (13). In the so-called focal form, fibrous enlargement is predominantly relegated to the portal tracts, whereas in the so-called diffuse form, adjacent portal tracts are linked by broad fibrous septa (13). The fibrosis may result in cirrhosis-like nodularity of the liver, although the septa tend to take on a “jigsaw puzzle”–like appearance, cutting out hepatocyte nodules that have geographic shapes rather than the rounded profiles that are more often seen in hepatitic cirrhosis (Figure 8.5). Fibrosis, rather than cyst formation, is the hallmark of this DPM; hence, the nomenclature. Although bridging fibrosis may be present, the hepatocyte lobules are generally normal in architecture and function. The central venules are still identifiable, although they may not remain centrally located in the nodules, and the hepatic cords remain mostly single cell thick; these features can be helpful in differentiation from typical cirrhosis. It should be remembered that hepatic architecture may resemble cirrhosis in the presence of another concomitant liver disorder, for example, alcoholic liver disease or chronic viral hepatitis. When superimposed abnormal bile ducts with cystic changes are present, the disease process is referred to as Caroli syndrome (see below). Caroli disease also occurs as a component of ARPKD; however, it may also occur without associated renal abnormalities. Patients present with recurrent abdominal pain and fever or occasionally with jaundice if the common bile duct becomes obstructed. Liver function tests are typically normal, outside of episodes of biliary obstruction. Complications
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FIGURE 8. 5 ARPKD and Caroli disease. (A) Typical appearance of the kidney in a newborn with ARPKD; numerous small cysts distributed
evenly throughout the parenchyma. (B) Segment of liver with Caroli disease with numerous heterogeneous cysts involving the biliary tree. Note that there is no bridging fibrosis or nodularity of the liver.
include recurrent cholangitis, intrahepatic and subphrenic abscesses, sepsis, and lithiasis (10). There is an increased risk of developing adenocarcinoma, with the incidence estimated to be about 7%. Caroli disease generally involves the entire liver, although it may be segmental. The condition is defined by saccular or fusiform dilation of the large IHBDs, generally the right and left hepatic ducts and their corresponding segmental larger ducts (1,14) (Figure 8.6). Intraluminal protrusion of duct wall and the presence of intraductal vascular tracts are common findings (14). Dilated ducts may be associated with marked chronic inflammation, acute inflammatory infiltrates, and a variable degree of fibrosis. Inspissated bile and purulent material may be present within duct lumens. As in ARPKD, the cysts are in continuity with the remainder of the biliary system, rather than being isolated. The cysts correspond to incompletely remodeled DP remnants with a variable degree of dilation (1). Caroli syndrome is defined by the presence of Caroli disease–type changes superimposed with CHF (11,14,15). It is more common than pure Caroli disease without other hepatic abnormalities (1,16). Caroli syndrome involves the entire intrahepatic biliary tree. Histologic findings are defined by overlapping features of CHF and Caroli disease. Overlap of diseases: As discussed above, there is considerable (and often confusing) overlap between many forms of liver involvement with ARPKD. Although significant advances have been made with regard to defining the underlying molecular abnormalities in these disorders, molecular tests for clinical application are currently available for only a few conditions, and even then only at a few centers (Table 8.1). Thus, in practice, clinicopathologic correlation is necessary to make the correct diagnosis. Some key points to remember are as follows: 1. Essentially all ARPKD cases have some degree of associated CHF (9,11). 2. Many ARPKD cases have associated Caroli disease.
3. CHF is often accompanied by cystic biliary changes (Caroli disease), which then warrants classification as Caroli syndrome. 4. Caroli disease can occur independently of ARPKD. The presence of a significant CHF component may necessitate clinical attention due to the potential for development of portal hypertension. A significant Caroli disease component puts the patient at risk for recurrent cholangitis and cholangiocarcinoma. Autosomal dominant polycystic kidney disease (ADPKD) affects between 1:400 and 1:1000 live births and accounts for approximately 5% of cases of end-stage renal disease in the United States and Europe (17). Associated hepatic cysts are a near-universal occurrence. Additional associated conditions include intracranial aneurysm formation (6%–21%) and mitral valve prolapse (26%) (9). Two genes have been implicated in the development of ADPKD. PKD1, located on chromosome 16p13, is the more common culprit and is responsible for a more severe disease phenotype (9,12). PKD1 encodes an integral membrane protein known as polycystin1, which is implicated in cell-cell and cell-matrix interactions (12). A less common mutation event occurs in PKD2, located on chromosome 4q21-q23, which codes for the protein product polycystin2. It appears that polycystin1 and 2 join to form a heterodimeric plasma membrane ion channel involved in the regulation of tubular morphology and function (12). Hepatic cysts in ADPKD arise from dilatation of von Meyenberg complexes (VMCs) (1). Generally, a large number of VMCs are present in the liver, and many show varying degrees of dilation and cystic change. In contrast to the cysts of ARPKD, which maintain their connection to the biliary tree, the cysts of ADPKD may lose connection, grow in size and impinge on the hepatic parenchyma (9) (Figure 8.7). Although Caroli disease is mainly associated with ARPKD, several case reports have described its occurrence with ADPKD as well (15,18).
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FIGURE 8. 6 The liver in an autopsy case of CHF. (A) Irregular bridging fibrosis and nodularity mimicking cirrhosis. The fibrous septa are very dense, bland, and lack inflammation. Prominent ductular reaction is seen. (B, C) “Jigsaw”-type irregular bridging fibrosis. (D) The nodules lack the rounded profile of cirrhotic nodules, and the hepatic cords are largely single cell thick. Preservation of central veins can be seen in many of the nodules (arrow). (E) Marked bile ductular reaction in a ductal plate–type configuration (H&E, 10 ). (F) Gross specimen of the liver from the same patient showing features indistinguishable from cirrhosis on cut surface and capsular surface (inset).
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FIGURE 8. 7 (A) Coronal MRI image showing massive bilateral kidney enlargement by innumerable cysts typical of ADPKD. (B) Nephrectomy
specimen showing obliteration of the renal parenchyma by cysts of varying sizes with marked enlargement and distortion of the kidney. (C) Axial MRI image showing multiple cysts scattered throughout the hepatic parenchyma. (D) Hepatectomy specimen from the same patient with multiple smooth-walled cysts. (E) Liver cyst lined by simple cuboidal epithelium, which is partly denuded. (F) Low power view of multiple variable-sized cysts surrounded by fibrosis.
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Many patients are managed medically with ACE inhibitor or angiotensin-receptor blocker therapy and dialysis for renal dysfunction. Cyst fenestration or partial hepatectomy may be indicated if there is mass effect on surrounding structures due to cyst enlargement. Bilateral nephrectomy and transplant may be performed due to massive kidney enlargement. Polycystic liver disease (PLD) was initially considered a component of ADPKD, as described above; however, it has now been shown that PLD may occur in a pure form without renal involvement (9,18). PLD is an autosomal dominant condition resulting from mutations in the gene coding for the protein hepatocystin. Two loci have been identified, specifically PRKSCH on chromosome 19p13.2-p13.1 and SEC63 on chromosome 6p21-p23 (1,9,18). PLD is a relatively rare condition, with an incidence below 0.01% based on autopsy data (18,19). The liver disease is less severe than ADPKD, and there is, by definition, no associated renal cystic disease. Most often, patients are asymptomatic with normal liver function tests, and the disease is often discovered incidentally (18). When present, symptoms are caused by cyst enlargement, usually manifesting as right upper quadrant discomfort/pain with associated nausea or early satiety (9,18). Cyst rupture and/or hemorrhage may occur, and infection poses a serious complication. Clinical diagnostic criteria are not well defined, but, in general, the finding of 5 or more cysts in the liver should prompt further investigation for PLD (18). The cysts of PLD generally involve the liver diffusely, and the histologic changes are identical to those seen in ADPKD (Figure 8.8). The cysts appear to arise from VMCs, and they may become completely separated from the biliary system. Fibrosis is not a common finding, and the hepatic lobular architecture is generally intact (18). Most cases of PLD are asymptomatic and do not require any treatment. However, if cyst enlargement causes significant symptoms, cyst aspiration with sclerotherapy or laproscopic fenestration can be useful. In general, a conservative clinical approach is appropriate (18).
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VMCs, or biliary microhamartomas, are typically small, often multiple, and are almost invariably asymptomatic (1,20). They may be seen in otherwise normal liver, or in association with many of the conditions described above, including ADPKD, CHF, and Caroli syndrome (1). VMCs can be interpreted as DPM of the most peripheral IHBDs (1). The incidence of VMCs increases with age, reaching a peak around the 6th to 7th decade, irrespective of gender (20). VMCs consist of dilated, irregular small ducts lined by biliary epithelium, which are embedded in a fibrous and often hyalinized stroma (1) (Figure 8.8). The lining epithelium can be columnar, but tends to become cuboidal or flat as the ducts become more dilated. VMCs may be present throughout the liver; however, they are most easily recognized on the capsular surface as 1- to 5-mm whitish nodules. Inspissated bile within dilated lumina is common. VMCs are most commonly encountered during laparotomy and are frequently sent for frozen section to rule out metastasis. They are also discovered incidentally in liver biopsies, resections, or at autopsy. No therapy is required; however, the presence of multiple VMCs may prompt one to look for cystic renal disease. It has been suggested recently that VMCs may be precursors for bile duct adenomas and sporadic cholangiocarcinomas (see Chapter 25). Non–DPM-Related Cystic Diseases of the Liver
Simple hepatic cyst: Imaging studies have shown that roughly 18% of individuals in the general population have simple hepatic cysts, often referred to as solitary nonparasitic cysts (21). The prevalence of cysts increases with advancing age; in 1 study reaching 52.3% of patients more than 60 years of age, whereas seen in only 0.16% of those under 20 years of age (9,21). Simple cysts are more common in the right liver lobe and have a female predominance. Most simple hepatic cysts are asymptomatic and detected incidentally (21). However, large cysts may present with abdominal pain or as a mass lesion. The pathogenesis of
FIGURE 8. 8 (A) Liver cut surface with minute punctate whitish lesions representing numerous von Meyenberg complexes (VMCs). (B) VMCs are more readily identified on the capsular surface of the liver. (C) VMCs showing irregular dilated bile ducts, inspissated bile, and surrounding fibrosis.
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simple cysts is not entirely clear, and could be developmental or degenerative. These cysts are not connected to the biliary tree (in contrast with biliary cysts—see below). Histologically, simple hepatic cysts demonstrate an inner epithelial lining consisting of a simple cuboidal layer surrounded by a rim of fibrous tissue. The lining is frequently denuded and may not be demonstrable on microscopic sections. There is no documented risk of malignancy. Most simple cysts do not require any treatment and can be radiologically monitored to ensure stability. Symptomatic simple cysts can be treated with needle aspiration and sclerotherapy, internal drainage with cystojejunostomy, cyst unroofing, or partial hepatectomy. Recurrence rates are high with aspiration, and laparoscopic unroofing is often preferable. Biliary cysts, in contrast to simple hepatic cysts, are by definition in continuity with the biliary tree. These appear to be congenital in nature and, as such, often present in early life. They likely represent aberrant bile ducts, which become dilated with age due to bile stasis, forming isolated cysts (21). The nomenclature of these lesions is somewhat obtuse, and these cysts were originally grouped under the heading of “choledochal cysts.” However, the classification has been expanded to include intrahepatic biliary cysts as well (Table 8.3). Biliary cysts frequently present with conjugated hyperbilirubinemia in infancy. Older patients tend to present with abdominal pain, with or without a detectable mass. These are usually unilocular cysts, but some are multiloculated. Grossly, the wall is typically thin, and the lining is smooth and free of papillary projections or solid nodules. Histologically, the cyst cavity is often filled with clear serous fluid, and the lining is composed of a single layer of cuboidal biliary-type epithelium, which maintains positivity for CK7 and CK19. The cyst lining is often denuded, leaving a layer of fibrous tissue abutting the surrounding liver parenchyma. Besides choledochal cysts (see later), risk of malignancy, if any, in the other types of biliary cysts remains unknown. In practice, the distinction between simple hepatic cyst and a solitary biliary cyst is often difficult, but is of no clinical significance. Biliary cysts may be surgically resected if they result in cholestasis or repeated episodes of ascending cholangitis. Cilliated foregut cyst is a rare entity, which presents as a solitary cyst within the hepatic parenchyma. It occurs more TA B LE 8. 3 Classification of choledochal cysts Appearance
IHBD
Type I
Saccular/fusiform dilation of segment of entire CBD
No
Type II
Isolated diverticulum of CBD wall, often pedunculated
No
Type III
Dilation of intraduodenal portion of CBD (choledochocele)
No
Type IV
Multiple dilations of intra- and extrahepatic bile ducts
Yes
Type V
Multiple dilations of IHBDs (Caroli disease)
Yes
Abbreviations: IHBD-intrahepatic bile duct, CBD-common bile duct.
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often in men and in the left liver lobe. Foregut cysts are lined by a layer of pseudostratified ciliated columnar epithelium. There is often a surrounding smooth muscle layer and an outer fibrous capsule. No risk of malignancy has been recognized so far. Treatment guidelines are not clear, but the logical approach is to manage these cysts in a similar fashion to simple hepatic cysts. Infectious Hepatic Cysts
Hydatid cyst is caused by the parasite Echinococcus granulosus. The infection is caused by ingestion of Echinococcal eggs, which hatch in the duodenum and invade through the bowel wall to infect mainly the liver and lung. Humans are an accidental intermediate host, a role usually played by sheep. Dogs represent the definitive host. Echinococcal cysts are initially microscopic, but progressively enlarge in size over a number of years. Cysts larger than 10 cm have been described. Histologically, the cyst wall is characterized by an inner, nucleated germinative layer surrounded by an outer anucleated layer with a multilaminated appearance (Figure 8.9). Nonruptured cysts typically lack any fibro-inflammatory response and can be easily shelled out of the liver. With time, many cysts show an inflammatory reaction and fibrosis around the cyst wall that may be rich in eosinophils. The lumen is filled with gelatinous fluid, in which daughter cysts develop over time. As worms develop, the scolices detach and form sand-like sediment within the cyst fluid. Echinococcal cysts must be dealt with carefully due to the risk of anaphylaxis if cyst contents are released into the peritoneal space. Surgical excision is often performed, although sclerotherapy has been utilized in some centers. Concurrent antimicrobial therapy is often used. The cysts are delicate and tend to rupture due to handling during gross examination. One way to avoid this is to aspirate the fluid, which can then be centrifuged to prepare smears from the sediments that show scolices. The cyst membranes can then be submitted as a “swiss-roll” for histologic examination. Other infectious cysts: Pyogenic and amebic liver abscesses are the other common causes of infectious hepatic cysts. Many types of bacteria, including common pyogenic bacteria, have been implicated in the formation of hepatic abscesses. The protozoan parasite Entamoeba histolytica primarily infects the colon, leading to intestinal amebiasis. In up to 40% of these patients, the protozoa gain access to the splanchnic circulation to reach the liver, forming abscesses. These are often solitary, but occasionally can be multiple (Figure 8.10). Amoebic liver abscesses are characteristically hemorrhagic, containing a thick paste-like material referred to as “anchovy-sauce pus.” This is due to liquefactive necrosis of liver tissue admixed with blood secondary to the proteolytic enzyme released by the protozoa. These cysts tend to display an eroded lining with adherent fibrinous material. The protozoa are often located at the edges of the abscess and are very difficult to demonstrate on histologic sections. The diagnosis often rests on a typical histologic appearance combined with serologic evidence of amebiasis. Characteristically, there is minimal
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FIGURE 8. 9 (A) Bisected hydatid cyst showing a thick wall with multiple daughter cysts. (B) Multiple daughter cysts extruding from a large hydatid cyst showing a thick, white translucent membrane. (C) Hydatid cyst that was easily shelled out of the liver due to the lack of any inflammatory response. (D) Typical lamellated membrane that appears very pale on H&E stain. The surrounding liver shows fibrosis and dense inflammation. (E) Lamellae of cyst wall are highlighted with a silver stain. (F) Smear made from the centrifuged cyst contents showing numerous worm scolices (hydatid sand).
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FIGURE 8. 10 (A) Multiple amebic liver abscesses showing irregular outlines and necrotic debris. The “anchovy-sauce” content is best seen
in fresh specimens and usually drains upon slicing the liver. (B) The abscess is composed mainly of necrotic debris and inflammatory cells. (C) Higher magnification from the abscess to show many macrophage-like structures that represent amebic trophozoites. It is difficult to demonstrate the protozoa in these lesions. (D) Higher magnification from the edge of abscess with PAS stain highlighting amebic trophozoites. The organisms can also be highlighted with trichrome and iron-hematoxylin stain.
host fibro-inflammatory response at the periphery, unless the lesions become secondarily infected with pyogenic bacteria. Pyogenic abscesses in the liver are generally similar in appearance to those seen in other anatomic locations and consist of a purulent exudate composed of neutrophils and fibrin. This gets “walled-off” by a host fibrotic response with time. Pyogenic and amoebic abscesses are managed with specific antimicrobial therapy, percutaneous drainage, or rarely by surgical resection. Cystic Neoplasms of the Liver
Several hepatobiliary neoplasms may present with a cystic appearance. Lesions that are typically cystic include hepatobiliary cystadenoma and cystadenocarcinoma. Lesions like
hemangioma, although multicystic, rarely enter this differential diagnosis due to their characteristic gross and imaging features. Malignant lesions that can become cystic include cholangiocarcinoma and metastatic carcinoma that may be mucinous or undergo extensive necrosis/cystic degeneration (see Chapter 24). Rarely intrabiliary cholangiocarcinomas may present as a multicystic lesion. Among metastatic tumors, well-differentiated neuroendocrine carcinoma (carcinoid) can present as a cystic lesion.
References 1. Desmet V. Pathogenesis of ductal plate malformation. J Gastroenterol Hepatol. 2004;19:S356–S360. 2. Knisely AS. Biliary tract malformations. Am J Med Genet A. 2003; 122A(4):343–350.
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3. Roskams T, Desmet V. Embryology of extra- and intrahepatic bile ducts, the ductal plate. Anat Rec (Hoboken). 2008;291(6):628–635. 4. Clotman F, Lannoy VJ, Reber M, et al. The onecut transcription factor HNF6 is required for normal development of the biliary tract. Development. 2002;129(8):1819–1828. 5. Clotman F, Jacquemin P, Plumb-Rudewiez N, Pierreux CE, Van der Smissen P, Dietz HC, et al. Control of liver cell fate decision by a gradient of TGF beta signaling modulated by onecut transcription factors. Genes Dev. 2005;19(16):1849–1854. 6. Coffinier C, Gresh L, Fiette L, et al. Bile system morphogenesis defects and liver dysfunction upon targeted deletion of HNF1beta. Development. 2002;129(8):1829–1838. 7. Awasthi A, Das A, Srinivasan R, Joshi K. Morphological and immunohistochemical analysis of ductal plate malformation: correlation with fetal liver. Histopathology. 2004;45(3):260–267. 8. Villeneuve J, Pelluard-Nehme F, Combe C, et al. Immunohistochemical study of the phenotypic change of the mesenchymal cells during portal tract maturation in normal and fibrous (ductal plate malformation) fetal liver. Comp Hepatol. 2009;8:5. 9. Tahvanainen E, Tahvanainen P, Kaariainen H, Hockerstedt K. Polycystic liver and kidney diseases. Ann Med. 2005;37(8):546–555. 10. Madjov R, Chervenkov P, Madjova V, Balev B. Caroli’s disease. Report of 5 cases and review of literature. Hepatogastroenterology. 2005;52(62): 606–609. 11. Turkbey B, Ocak I, Daryanani K, Font-Montgomery E, Lukose L, Bryant J, et al. Autosomal recessive polycystic kidney disease and congenital hepatic fibrosis (ARPKD/CHF). Pediatr Radiol. 2009;39(2):100–111.
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12. Johnson CA, Gissen P, Sergi C. Molecular pathology and genetics of congenital hepatorenal fibrocystic syndromes. J Med Genet. 2003;40(5): 311–319. 13. Desmet VJ. What is congenital hepatic fibrosis? Histopathology. 1992;20(6):465–477. 14. Yonem O, Bayraktar Y. Clinical characteristics of Caroli’s disease. World J Gastroenterol. 2007;13(13):1930–1933. 15. Shedda S, Robertson A. Caroli’s syndrome and adult polycystic kidney disease. ANZ J Surg. 2007;77(4):292–294. 16. Gupta AK, Gupta A, Bhardwaj VK, Chansoria M. Caroli’s disease. Indian J Pediatr. 2006;73(3):233–235. 17. Davies F, Coles GA, Harper PS, Williams AJ, Evans C, Cochlin D. Polycystic kidney disease re-evaluated: a population-based study. Q J Med. 1991;79(290):477–485. 18. Arnold HL, Harrison SA. New advances in evaluation and management of patients with polycystic liver disease. Am J Gastroenterol. 2005;100(11):2569–2582. 19. Kwok MK, Lewin KJ. Massive hepatomegaly in adult polycystic liver disease. Am J Surg Pathol. 1988;12(4):321–324. 20. Redston MS, Wanless IR. The hepatic von Meyenburg complex: prevalence and association with hepatic and renal cysts among 2843 autopsies [corrected]. Mod Pathol. 1996;9(3):233–237. 21. Carrim ZI, Murchison JT. The prevalence of simple renal and hepatic cysts detected by spiral computed tomography. Clin Radiol. 2003;58(8): 626–629.
Case 8.1
Congenital Hepatic Fibrosis Versus Cirrhosis BARTON KENNEY AND DHANPAT JAIN
C L I N IC AL I N F OR M AT I ON
A 26-year-old male presented with severe upper gastrointestinal hemorrhage and was found to have grade 3 esophageal varices, requiring banding. The patient’s grandfather had a renal transplant at the age of 45. Physical examination revealed mild jaundice, caput medusa, and spider telangiectasias on the abdomen. Laboratory studies showed minimal elevation of alkaline phosphatase and normal alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Serologic tests for hepatitis B and C were negative.
best demonstrated on a reticulin stain. There is patchy mild neutrophilic cholangitis and pericholangitis, but the chronic inflammatory infiltrate and interface/lobular activity typical of chronic viral/autoimmune hepatitis is lacking. Features typical of steatohepatitis are not evident.
DIAGNO SIS
Congenital hepatic fibrosis.
R E A SON F OR R E F E R R AL
DISCUSSIO N
Clinical diagnosis is cirrhosis. Do the biopsy findings confirm this impression and point toward an etiology?
The histologic features suggest congenital hepatic fibrosis (CHF), even though the jigsaw-like pattern fibrosis and geographic shape of the nodules cannot be appreciated in a biopsy. Further investigation revealed that several family members had renal disease. Review of abdominal CT scan revealed multiple minute renal cysts. Genetic testing showed a mutation in the PKHD1 gene confirming autosomal recessive polycystic kidney disease (ARPKD). CHF can present at an early age with cholangitis, which may lead to clinical work-up and diagnosis. However, some patients with minimal symptoms progress quietly to severe fibrosis and portal hypertension. At this stage, distinction from other causes of cirrhosis is clinically and histologically difficult, especially on needle biopsy. Family history of renal
PAT H OL OG I C F E AT U R E S
The liver biopsy shows diffuse fibrous expansion of the portal tracts with porto-portal bridging (Figure 8.1.1). Many irregularly shaped bile duct structures are embedded in very bland-appearing broad fibrous septa. The hepatocytic nodules resemble cirrhotic nodules on cursory examination, although many unusual features are evident on a closer look. The nodules have preserved central veins, albeit located at the periphery. The hepatic plates are mostly single cell thick and lack the regenerative activity of cirrhotic nodules, which is
FIGURE 8. 1. 1 (A) Biopsy showing bridging fibrosis, bile ductular reaction, and nodule formation indistinguishable from cirrhosis. Closer examination shows that the fibrous septa are very dense and bland, with many ectatic ducts reminiscent of ductal plate malformation. The central venules can be seen in some of the nodules. The hepatic cords are comprised of 1-cell thick plates. (B) Klatskin trichrome stain highlighting fibrosis.
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disease or presence of renal cysts in the patient is helpful in supporting the diagnosis, although the renal cysts may not be typical of ARPKD as seen in this patient. Liver synthetic function and transaminases are generally within normal limits in CHF despite severe portal hypertension. The histologic findings of CHF may overlap with cirrhosis on biopsies, but some features are helpful to distinguish the two. At low power, the fibrous septa in CHF often appear very bland and dense, with numerous irregularly shaped bile ducts suggestive of ductal plate malformation. The irregular shape of the nodules and jigsaw puzzle–like fibrosis may be difficult to appreciate on needle biopsies. CHF may resemble sclerosing cholangitis, which can be excluded clinically by correlation with lack of associated inflammatory bowel disease and endoscopic retrograde cholangio-pancreatography/magnetic resonance cholangiopancreatography findings.
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The situation can be more complicated in some patients with CHF who also have clinical evidence of concomitant liver disease, most commonly chronic hepatitis C or alcohol use. This situation can be further complicated if the patient has a milder variant of CHF, lacks significant renal disease, and presents at an older age (5–6th decade) (1,2). Even in these situations, the bile ductular reaction maintains a ductal plate-type pattern and remains the most important clue to the diagnosis. Most of these cases have been recognized either at resection or autopsy, and recognition on biopsies can be challenging.
References 1. Averback P. Congenital hepatic fibrosis: asymptomatic adults without renal anomaly. Arch Pathol Lab Med. 1977;101(5):260–261. 2. Zeitoun D, Brancatelli G, Colombat M, et al. Congenital hepatic fibrosis: CT findings in 18 adults. Radiology. 2004;231(1):109–116.
Case 8.2
Caroli Disease/Syndrome Versus Other Cystic Disease BARTON KENNEY AND DHANPAT JAIN
C L I N IC AL I N F OR M AT I ON
A 12-year-old female presented to the emergency department with high fever and abdominal pain. Physical examination revealed mild jaundice, a tender right upper quadrant, and mildly increased liver span. Laboratory findings included leukocytosis with 88% neutrophils, AST 400 U/L, ALT 450 U/L, and alkaline phosphatase 1900 U/L. Urinalysis was normal, and a chest x-ray showed no infiltrates. A liver ultrasound demonstrated multiple cysts.
periductal lymphocytic inflammatory infiltrate and inspissated bile. The hepatic lobules were relatively unremarkable, with no significant inflammation or fibrosis.
DIAGNO SIS
Caroli disease presenting with acute cholangitis.
R E A SON F OR R E F E R R AL
DISCUSSIO N
Intrahepatic biliary dilation and cystic disease in a young patient with systemic symptoms, raising concern for multiple hepatic abscesses. The patient responded to aggressive antibiotic therapy, but the lesions persisted on imaging studies, leading to partial hepatectomy.
The histologic findings prompted a more detailed work-up for cystic liver and kidney disease. Abdominal MRI showed several cystic structures associated with the large intrahepatic bile ducts in the remaining liver, as well as fusiform dilatation of the right and left hepatic ducts. There was no evidence of renal cystic disease. Caroli disease often comes to clinical attention due to recurrent episodes of cholangitis, frequently after a clinical diagnosis of hepatic abscesses. A biopsy is seldom performed, but persistent liver disease or imaging abnormalities may lead to work-up of underlying liver disease and warrant a tissue diagnosis. Caroli disease affects the larger intrahepatic bile ducts, typically the immediate branches of the right and left hepatic ducts. Although Caroli disease may be associated with autosomal recessive polycystic kidney disease (ARPKD),
PAT H OL OG I C F E AT U R E S
The liver grossly showed multiple cystic spaces with denuded lining containing neutrophilic exudate suggestive of abscess formation (Figure 8.2.1). However, a partially preserved biliary-type lining was evident in some cystic spaces, and many dilated bile ducts without any inflammation were present in the background liver. Several of these dilated bile ducts had a fusiform cystic appearance and some showed a moderate
FIGURE 8. 2. 1 (A) Gross liver resection in a case of Caroli disease showing varying sized cysts affecting the large intrahepatic ducts. One of large cysts has yellowish pus sticking to the wall. (B) Whereas many of the cysts looked like abscesses full of neutrophils, others as shown here appear to be markedly dilated bile ducts with irregular outlines and lined by benign cuboidal to columnar cells. There is periductal fibrosis limited to the portal areas; bridging fibrosis and nodularity suggestive of congenital hepatic fibrosis are not seen.
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it often presents as an isolated disease process without renal manifestations. Biopsy is of limited use in establishing a diagnosis of Caroli disease, but may help in excluding other liver disorders. Thus, correlation with imaging findings and exclusion of other cystic liver diseases is important. Histology reveals saccular or fusiform dilation of larger ducts, with an associated chronic inflammatory infiltrate and variable fibrosis. A characteristic finding, though not always seen, is protrusion of the duct wall
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into the lumen, sometimes containing vascular structures. Similar to ARPKD, and in contrast to autosomal dominant polycystic kidney disease and polycystic liver disease, the cysts are dilations of the ducts themselves, rather than isolated structures. A key factor is showing that the cystic change is most prominent in the proximal ductal system. These findings are often difficult to appreciate in limited tissue samples and are best seen in resections or explants.
Case 8.3
Adult Polycystic Liver Disease Versus Caroli Disease BARTON KENNEY AND DHANPAT JAIN
C L I N IC AL I N F OR M AT I ON
R EA SO N FO R R EFER R A L
A 45-year-old male underwent MRI for chronic lower back pain. Multiple liver cysts (>30) were noted as an incidental finding. Repeat imaging confirmed multiple 1- to 4-cm liver cysts with no solid component or contrast enhancement. The cysts were not connected to the biliary system. The kidneys were normal. Laboratory findings included normal creatinine and liver function tests. Persistent abdominal pain and an increase in the size of one cyst led to partial hepatectomy.
Multiple liver cysts of unclear nature. PAT H O LO GIC FEAT UR ES
The gross examination revealed multiple cysts with scant normal hepatic parenchyma. The cysts showed a denuded or partly preserved lining consisting of low columnar to cuboidal bland-appearing epithelium (Figure 8.3.1). Several small von
FIGURE 8. 3. 1 (A) Partial hepatectomy from a patient with adult polycystic liver disease showing numerous cysts. (B) Cut surface shows
multiple smooth-walled cysts. (C) Noncystic areas of the liver show von Meyenburg complexes. (D) Liver cysts are similar to the cysts in autosomal dominant polycystic kidney disease.
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Meyenburg complexes were present in the adjacent liver. The cysts were not associated with bile ducts, but one appeared to arise from a dilated ductule at the edge of a von Meyenburg complex. The hepatic parenchyma at the periphery of the cyst showed nonspecific fibrosis without typical features of congenital hepatic fibrosis.
D I AG N OS I S
Autosomal dominant polycystic liver disease.
D I SC U SSI ON
The differential diagnosis in this case included autosomal recessive polycystic kidney disease (ARPKD), autosomal dominant polycystic kidney disease (ADPKD), autosomal dominant polycystic liver disease (ADPLD), and Caroli syndrome, all of which can present with liver cysts that can be indistinguishable on imaging studies and histology. Detailed family history revealed cystic liver disease without renal impairment in two family members. Presence of isolated cystic liver disease without any renal involvement after careful imaging analysis makes ADPLD the most likely diagnosis. Recent confirmation of unique mutations in the PRKSCH and SEC63 genes has confirmed that ADPLD is distinct from its kidney-related counterparts. Genetic sequencing in a research lab within the institution was undertaken, and the patient was found to have
DISEASE
OF
THE
LIVER
a germline mutation in the SEC63 gene on chromosome 6p, consistent with ADPLD. Many ADPLD patients are asymptomatic. In some cases, abdominal pain or fullness prompts clinical work-up. The finding of at least 5 liver cysts on imaging is enough to warrant further investigation for ADPLD. Due to autosomal dominant inheritance, other family members may have cystic liver disease as well, but may be asymptomatic. Of crucial importance is the lack of renal cystic disease, both in the patient and in family members. Typically, liver synthetic function is well preserved, and liver function tests do not show significant abnormalities. Biopsy of the cysts is generally not indicated, and the pathologist is involved either when cysts are resected/unroofed, or if the patient undergoes transplantation. Following partial excision of the cysts or unroofing procedure, often only a very limited amount of adjacent liver parenchyma is present, precluding proper assessment. The histology of the cysts is similar to those seen in ADPKD. In particular, von-Meyenburg complexes may be prominent, and cysts may be seen to emanate from them. Cysts are completely separate from bile ducts, as opposed to ARPKD, although this may be difficult to assess on histology. A combination of family history, detailed imaging findings, exclusion of associated renal disease, and genetic tests help in establishing a final diagnosis in such cases. Often a diagnosis is established without tissue confirmation in the appropriate clinical setting. Genetic testing for ADPLD remains in its infancy but may become commercially available in the near future.
Case 8.4
Choledochal Cyst BARTON KENNEY AND DHANPAT JAIN
C L I N IC AL I N F OR M AT I ON
R EA SO N FO R R EFER R A L
A 12-week-old female infant presented with jaundice. The child was not breast-fed and had no history of neonatal jaundice. Physical examination revealed fullness in the right upper quadrant. Laboratory findings included elevated total (2.4 mg/dL) and direct (1.8 mg/dL) bilirubin. Alkaline phosphatase was markedly elevated (2418 U/L); AST and ALT were normal. Ultrasound revealed a 4.5-cm extrahepatic cyst involving the common bile duct (CBD). The gallbladder and liver appeared normal, and no stones were visualized. The patient underwent resection of the cyst and hepaticojejunostomy.
Classification of extrahepatic cyst involving the CBD. The differential diagnosis included foregut cyst, abscess, and choledochal cyst. PAT H O LO GIC FEAT UR ES
The resection specimen revealed a fusiform cystic dilation involving most of the CBD (Figure 8.4.1). On sectioning, the lumen contained thick dark-green biliary sludge. The wall was smooth and without masses or excrescences. On histologic examination, the wall was thickened and fibrotic, with an
FIGURE 8. 4. 1 (A) Choledochocystectomy specimen with saccular dilation of the common bile duct suggestive of a choledochal cyst. (B) Cholangiogram showing the same finding. (C) Cyst wall consisting of fibrosis and a single layer of biliary type lining epithelium. (D) Higher magnification showing benign columnar biliary epithelium overlying fibrous tissue.
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associated lymphocytic infiltrate. The lining epithelium was mostly denuded, but what remained was cuboidal to columnar biliary epithelium with reactive atypia. There was no evidence of malignancy.
D I AG N OS I S
Choledochal cyst.
D I SC U SSI ON
The differential diagnosis of solitary cysts near the hepatic hilum in children includes enterogenous type foregut cysts/duplication cysts, choledochal cysts, and abscess. The gross pathology of choledochal cysts is characteristic, and microscopic examination typically reveals a fibrotic wall lined in places by biliary epithelium. Enterogenous foregut or duplication cysts are lined by squamous, ciliated columnar or gastric type mucosa and may be separate from the biliary tree. The diagnosis of choledocal cyst is often easily established clinically due to the location of the cyst and its biliary connection. These cysts should be resected followed by subsequent hepaticojejunostomy or biliary reconstruction, both due to obstructive symptoms and to a potential risk of malignancy. The incidence of choledochal cysts (biliary cysts) in the West varies from 1:100 000 to 150 000 live births. The frequency is much higher in Asia, where some locations show incidence rates as high as 1:1000 live births (1). There is a female predominance. Most cases present in infancy or childhood, and the majority of the cases are diagnosed in the first
DISEASE
OF
THE
LIVER
decade of life (2). Young children may present with the classic triad of abdominal pain, jaundice, and a palpable mass in approximately 20% of cases, but at least 2 of these 3 findings are present in the majority of patients (2). Older children, and rarely adults, may present with recurrent pancreatitis, fever, abdominal pain, and jaundice. Once suspected, the cysts are usually readily characterized on abdominal imaging as saccular or fusiform dilations of the extrahepatic bile duct(s). Several types of choledochal cysts are recognized (see Table 8.1.3, Case 8.1) (1,3). Type I cysts are by far the most common, representing 80% to 90% of all choledochal cysts. These involve dilation of a segment of the CBD or of the entire CBD. Types IV and V include intrahepatic duct dilation and overlap with, and can be indistinguishable from Caroli disease. In addition to cholangitis and pancreatitis, these cysts are associated with a significant risk of cholangiocarcinoma ranging from 9% to 28% (4,5).
References 1. Singham J, Yoshida EM, Scudamore CH. Choledochal cysts: part 1 of 3: classification and pathogenesis. Can J Surg. 2009;52(5):434–440. 2. Singham J, Yoshida EM, Scudamore CH. Choledochal cysts: part 2 of 3: Diagnosis. Can J Surg. 2009;52(6):506–511. 3. Todani T, Watanabe Y, Narusue M, Tabuchi K, Okajima K. Congenital bile duct cysts: classification, operative procedures, and review of thirtyseven cases including cancer arising from choledochal cyst. Am J Surg. 1977;134(2):263–269. 4. Chaturvedi A, Singh J, Rastogi V. Case report: cholangiocarcinoma in a choledochal cyst. Indian J Radiol Imaging. 2008;18(3):236–238. 5. Franko J, Nussbaum ML, Morris JB. Choledochal cyst cholangiocarcinoma arising from adenoma: case report and a review of the literature. Curr Surg. 2006;63(4):281–284.
Case 8.5
Solitary Hepatic Cyst Versus Hydatid Cyst BARTON KENNEY AND DHANPAT JAIN
C L I N IC AL I N F OR M AT I ON
A 32-year-old male presented with abdominal fullness. Physical examination showed mild right upper quadrant tenderness. Laboratory findings showed leukocytosis with 15% eosinophils. Liver transaminases were normal, whereas total bilirubin and alkaline phosphatase were mildly elevated. CT scan showed an 8-cm irregular cyst with water attenuation. There was focal pericystic calcification, with focal cystwithin-cyst pattern.
R E A SON F OR R E F E R R AL
Hepatic cyst of presumed infectious etiology. The differential diagnosis includes simple hepatic cyst, pyogenic abscess, amoebic abscess, or hydatid cyst. After consultation with the infectious disease team, the patient’s serum was sent for Echinococcus serological testing, which was negative.
PAT H OL OG I C F E AT U R E S
At resection, the right hepatic lobe was sectioned to reveal a single large cyst containing serous fluid and a thick fibrous wall, but without an identifiable lining (Figure 8.5.1). A scant amount of adjacent preserved liver parenchyma was present that appeared unremarkable.
DIAGNO SIS
Simple hepatic cyst.
DISCUSSIO N
The lack of any specific histologic features and the presence of normal adjacent liver parenchyma suggests the diagnosis of simple hepatic cyst. The characteristic laminated wall of hydatid cyst is not seen. Typical features of hepatobiliary cystadenoma/carcinoma such as columnar or mucinous lining epithelium and ovarian-type stroma are not present. Simple cysts are typically solitary, and there is usually no familial history of liver cysts. The cysts tend to grow at a slow rate and can remain asymptomatic for many years. Larger cysts come to clinical attention due to mass effect or incidental detection on imaging studies. The cyst fluid may re-accumulate soon after needle aspiration, which is best avoided as a definitive therapeutic intervention. Due to the risk of anaphylaxis, needle aspiration is contraindicated if hydatid cyst is a consideration. Imaging studies are often nonspecific. Simple hepatic cysts are uniloculated, and the remaining liver generally appears normal. Pathologic examination is important for excluding an infectious cyst or cystic neoplasm. Classification into a hepatic or biliary-type cyst is often not possible and is not clinically relevant.
FIGURE 8. 5. 1 (A) Simple hepatic cyst opened to reveal luminal hemorrhage. (B) Simple hepatic cyst with a thin fibrous cyst wall and smooth inner surface. (C) Histology of the cyst wall showing denuded epithelium, fibrous wall, and mural hemorrhage.
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9 Hereditary Hyperbilirubinemias SARANGARAJAN RANGANATHAN
I N T ROD U C T I ON
Elevation of bilirubin is a physiological phenomenon in the first week of life. This is controlled by the complex system of bilirubin conjugation and excretion and is the result of interplay of several enzymes and factors responsible for the uptake of bilirubin by the hepatocyte, its conjugation, release into bile, reabsorption in the enterohepatic circulation, and its ultimate excretion into placenta or urine. Neonatal hyperbilirubinemias are a group of genetic disorders that are characterized by disorder and defects at various steps in this process resulting in pathological elevations of unconjugated or conjugated bilirubins in the neonatal period (1). They need to be differentiated as a group from physiologic hyperbilirubinemia of the newborn that is the result of increased bilirubin production and delayed maturation resulting in decreased excretion by the neonatal liver.
due to a defect in the 39 end of the gene results in the severe form (Type I CJS), and a defect in the variable region results in partial defect in the isoforms causing the less severe Type II CJS (3,4). CJS Type I
This is the more severe form of the disease manifesting in infancy with serum bilirubin levels ranging from 20 to 25 mg dL and may exceed 50 mg/dL. Almost all the bilirubin
U N C O N J U G AT E D H Y P E R B I L I RU B I N E M I A Gilbert Syndrome
Gilbert syndrome (GS) is a familial, autosomal-dominant or recessive disease that is characterized by a mild, chronic unconjugated hyperbilirubinemia. There is a strong male predominance and most patients are diagnosed as young adults. The serum bilirubin level is usually less than 3 mg/dL but can fluctuate and rise during intercurrent illnesses. The remaining liver function tests and liver biopsy are normal with only some lipofuscin accumulation. Association with other genetic defects such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, b-thalassemia, or hereditary spherocytosis can result in neonatal hyperbilirubinemia. It is now known to be caused by mutations or polymorphisms in the bilirubin UDPglucuronosyltransferase (UGT1A1) gene (2,3). Insertion of TA dinucleotide in the TATA box of the UGT1A1 promoter is the underlying abnormality in most Caucasians, with most affected individuals being homozygous. Heterozygosity can also result in higher bilirubin levels compared with normal. GS is not associated with any significant morbidity or mortality.
A
C R I G L E R -N AJ J A R S Y N D ROM E
The Crigler-Najjar syndrome (CJS) was first described by Crigler and Najjar in 1952 as a form of severe congenital unconjugated hyperbilirubinemia that presents in the first few days of life and is fatal due to kernicterus developing as a complication. There are 2 types: CJS Type I and CJS Type II. Both types are associated with the same UGT1A1 gene wherein a complete mutation of all isoforms of bilirubin-UGT cDNA
B F I G U R E 9 . 1 (A) Explanted liver in CJS type I showing a glistening smooth surface with minimal discoloration and no evidence of cirrhosis. (B) Canalicular bile plugs with preserved liver parenchyma and no hepatocellular pigment (H&E 400).
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is unconjugated due to the inability to conjugate bilirubin with uridine diphosphoglucuronic acid. Unlike GS, there is no response of bilirubin to phenobarbital administration. Phototherapy is the treatment of choice together with plasmapheresis and liver transplantation in older children (5). Liver biopsy is normal except for bile plugs in canaliculi. The explanted liver is normal in color and architecture with
HYPERBILIRUBINEMIAS
no evidence of cirrhosis (Figure 9.1). There is canalicular cholestasis with normal hepatocytes and no significant fibrosis (Figure 9.2). CJS Type II
Also known as Arias syndrome, it commonly affects patients in later life. It is associated with marked unconjugated hyperbilirubinemia with a dominance of bilirubin monoglucuronide in the bile, as opposed to CJS Type I that has diglucoronide as the dominant component. Although it is less severe than Type I disease, it can cause kernicterus and lead to death. CO NJUGAT ED H Y P ER BILIRUBINEMIA S Rotor Syndrome
FIGURE 9. 2 DJS with the characteristic pigment accumulation in the
cytoplasm of hepatocytes in the centrilobular region (H&E 400).
This is a rare, familial hyperbilirubinemia that is characterized by a chronic conjugated hyperbilirubinemia without hemolysis. It was originally thought to be related to Dubin-Johnson syndrome (DJS), but its genetic defect is unknown (6). Laboratory tests show a delay in excretion of all forms of organic anions including bromosulphthalein (BSP) and indocyanine green (ICG). The increase in BSP excretion is usually at 45 minutes, but the secondary increase at 90 minutes noted in DJS is not seen in Rotor syndrome due to the absence of reflux of conjugated BSP. Urinary coproporphyrin levels are also markedly increased in Rotor syndrome as compared with other hereditary hyperbilirubinemias and may be 25% to 50% higher
TA B LE 9. 1 Salient laboratory and genetic features of hereditary hyperbilirubinemias Gilbert Syndrome (GS)
Crigler-Najjar Syndrome (CJS)
Rotor Syndrome (RS)
Dubin-Johnson Syndrome (DJS)
Inheritance
Autosomal dominant
Autosomal recessive or dominant
Autosomal recessive
Autosomal recessive
Prevalence
3%
Rare
Rare
1:1300 Iranian Jews
Serum bilirubin
3–10 Unconjugated
20–50 unconjugated
Up to 20 conjugated
Up to 20 conjugated
Serum bilirubin decrease with phenobarbitol
70%
0%—CJS I 77%—CJS II
Not seen
Not seen
BUGT activity
5–53% controls
Severe ↓—CJS I 2–23%—CJS II
Normal
Normal
BSP clearance
Normal
Normal
Delayed
Normal early; delayed 90–120 min
ICG clearance test
Normal
Normal
Delayed
Normal
Urine coproporphyrin
Normal
Normal
Up to 5 × ↑ Isomer 1 < 80%
Normal Isomer I > 80%
Cholecystogram
Visualized biliary tree
Visualized biliary tree
Gallbladder visualized
Gallbladder not visualized
Other LFT
Normal
Normal
Normal
Normal
Genetics
UGT1A1 gene
UGT1A1 gene
Unknown
cMOAT/MRP2/ABCC2 gene
Prognosis
Benign
Mortality due to kernicterus
Benign
Benign
Abbreviations: BSP, bromosulphthalein; BUGT, bilirubin UDP glucoronyltransferase; ICG, indocyanine green; cMOAT, canalicular multispecific organic anion transporter; MRP2, multidrug resistant protein, LFT, liver function tests; UGT1A1, UDP glucuronosyltransferase; ABCC2, ATP-binding cassette, subfamily C, member 2.
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HYPERBILIRUBINEMIAS
155
than in DJS. The coproporphyrin isomer I is, however, around 65% of the total as compared with DJS. The increase in coproporphyrin is due to decreased biliary excretion with concomitant increase in filtration and excretion by the kidneys. The disease course is benign and liver histology is normal. There is no pigmentation as seen with DJS. Dubin- Johns on Synd rome
A
B
C FIGURE 9.3 (A) Preserved liver architecture with hepatocyte bal-
looning and minimal intracellular pigment (H&E 400). (B) Normal liver with cMOAT expression in canaliculi. Stain courtesy of Dr. AS Knisely, UK ( 400). (C) Absence of staining cMOAT staining in DJS ( 400).
This is an uncommon disease except in certain populations such as the Persian Jews that have a high prevalence of 1:1300. Originally described by Dubin and Johnson (7), it is characterized by conjugated hyperbilirubinemia that can present at any age with constitutional symptoms. The salient laboratory features are listed in Table 9.1. The significant laboratory abnormality in DJS is in the transport of the organic anion BSP. Following intravenous injection the initial plasma BSP concentration is normal, and at 45 minutes it is normal to elevated. The diagnostic test is at 90 minutes when BSP levels are higher than at 45 minutes in more than 90% of DJS patients. This secondary increase is due to the reflux of conjugated BSP into the plasma. The same is not true for other anions including ICG. Since the original description of elevated urinary coproporphyrin in DJS, it has been proven that although the total urinary coproporphyrin level may be normal, in DJS it is the isomer I form that constitutes over 80% of the urinary coproporphyrin rather than the normal excretion of coproporphyrin isomer III in all other patients and normal individuals. DJS has been the only hyperbilirubinemia that is characterized by coproporphyrin isomer I elevation, and hence this test is diagnostic of DJS. Recent molecular studies have demonstrated a defect in the transport of non–bile salt organic anions at the apical canalicular membranes by the ATP-binding cassette (ABC) transport system that is regulated by a single gene on chromosome 10q24. This gene has been variably called as cMOAT (canalicular multispecific organic anion transporter) or MRP2 (multidrug resistant protein 2), or ABCC2 (8–10). The classic pathologic finding is a black liver that is characterized by accumulation of brown-black pigment in the hepatocytes in a pericentral location (Figure 9.3). This pigment stains variably with Oil red O, PAS with diastase, and Fontana-Masson stain. The exact nature of the pigment is still unknown and debate continues on whether it is related to melanin, metabolites of epinephrine, or other compounds that are not excreted from the hepatocytes due to the defect (7,11). Unusual presentations include neonatal presentation, absence of pigment especially in younger children (12), and simultaneous occurrence of GS and DJS (13).
References 1. Gourley GR. Neonatal jaundice and disorders of bilirubin metabolism. In: Suchy FJ, Sokoi RJ, Balisteri WF, eds. Liver Disease in Children. 3rd ed. New York, NY: Cambridge University Press;2007:270–309. 2. Bosma PJ, Chowdhury JR, Bakker C, et al. The genetic basis of the reduced expression of bilirubin UDP-glucoronyltransferase 1 in Gilbert’s syndrome. N Engl J Med. 1995;333:1171–1175.
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3. Kadakol A, Ghosh SS, Sappal BS, et al. Genetic lesions of bilirubin uridine-diphosphoglucuronate glucuronosyltransferase (UGT1A1) causing Crigler-Najjar and Gilbert syndromes: correlation of genotype to phenotype. Hum Mutat. 2000;16(4):297–306. 4. Sneitz N, Bakker CT, de Knegt RJ, Halley DJ, Finel M, Bosma PJ. Crigler-Najjar syndrome in The Netherlands: identification of four novel UGT1A1 alleles, genotype-phenotype correlation, and functional analysis of 10 missense mutants. Hum Mutat. 2009;30:1–8. 5. Kaufman SS, Wood RP, Shaw BW Jr, et al. Orthotopic liver transplantation for Type I Crigler-Najjar syndrome. Hepatology. 1986;6:1259–1262. 6. Hrebicek M, Jirasek T, Hartmannova H, et al. Rotor-type hyperbilirubinemia has no defect in the canalicular bilirubin export pump. Liver In. 2007;27:485–491. 7. Dubin IN, Johnson FB. Chronic idiopathic jaundice with unidentified pigment in liver cells; a new clinicopathologic entity with a report of 12 cases. Medicine (Baltimore). 1954;33:155–198. 8. Paulusma CC, Kool M, Bosma PJ, et al. A mutation in the human canalicular multispecific organic anion transporter gene causes the Dubin-Johnson syndrome. Hepatology. 1997;25:1539–1542.
HYPERBILIRUBINEMIAS
9. Keppler D, Konig J. Hepatic canalicular membrane 5: Expression and localization of the conjugate export pump encoded by MRP2 (cMRP/ cMOAT) gene in liver. FASEB J. 1997;11:509–516. 10. Kanda D, Takagi H, Kawahara Y, et al. Novel large-scale deletion (whole exon 7) in the ABCC2 gene in a patient with the Dubin-Johnson syndrome. Drug Metab Pharmacokinet. 2009;24:464–468. 11. Rastogi A, Krishnani N, Pandey R. Dubin-Johnson syndrome— a clinicopathologic study of 20 cases. Indian J Pathol Microbiol. 2006;49:500–504. 12. Lee JH, Chen HL, Chen HL, Ni YH, Hsu HY, Chang MH. Neonatal Dubin-Johnson syndrome: long term follow-up and MRP2 mutations study. Pediatr Res. 2006,59:584–589. 13. Cebecauerova D, Jirasek T, Budisova L, et al. Dual hereditary jaundice: simultaneous occurrence of mutations causing Gilbert’s and Dubin-Johnson syndromes. Gastroenterology. 2005,129:315–320.
Case 9.1
Dubin-Johnson Syndrome SARANGARAJAN RANGANATHAN
C L I N IC AL I N F OR M AT I ON
A 6-week-old child presented with hyperbilirubinemia since birth with a total bilirubin of 6.1 mg/dL and a direct component of 3.1 mg/dL. She did not have any constitutional symptoms, but there was elevation of gamma glutamyl transpeptidase (GGT) that was decreasing on its own but had not normalized. There was some elevation of urinary coproporphyrin. A liver biopsy was done. R E A SON F OR R E F E R R AL
To evaluate for causes of hyperbilirubinemia and to exclude other causes of neonatal cholestasis M I C ROSC OP I C F E AT U R E S
The liver biopsy shows a core of parenchyma with preserved architecture. There is no portal fibrosis or ductular proliferation to suggest biliary obstruction. There is ballooning of hepatocytes without significant steatosis or dropout. There is scant pigment within hepatocytes representing iron and minimal steatosis. No dark-brown pigment of DJS is noted, and a Fontana-Masson stain was negative with only staining of the iron pigment. An immunohistochemical stain was performed for cMOAT and showed complete loss of expression of this antigen in the apical canalicular membrane (see Chapter 9, Figure 9.3). The control showed appropriate staining. A diagnosis of DJS was made. D I S C U S S I ON
Although the classic picture is to identify the black pigment of DJS, neonates may not show this pigment, and hence immunohistochemistry and molecular studies may be needed to make this diagnosis. Other causes of conjugated hyperbilirubinemia such as obstruction, alpha-1-antitrypsin deficiency, total parenteral nutrition (TPN), and familial cholestasis may need to be excluded in some cases. The classic features of obstruction are portal expansion with bile ductular proliferation and ductular and canalicular cholestasis: features that are usually not present in DJS other than the canalicular cholestasis. Fibrosis is not an integral part of the histology of DJS. Familial cholestasis may also present with canalicular cholestasis, but the Byler type (ATP8B1 disease) and PFIC-2 (ABCB11 disease) are both characterized by a low GGT in
view of the persistent cholestasis. Byler disease is characterized by canalicular bile plugs with pale staining bile. Electron microscopy shows the characteristic granular, “coarse” bile in the canaliculus. Immunohistochemical staining frequently shows aberrant staining for cytokeratin 7 (CK7), a bile duct marker within hepatocytes within the lobules, either singly or in clusters. There is preserved immunoreactivity for GGT in the apical portions of cholangiocytes along canaliculi, usually at the periphery of the lobule. Some bile may also be seen in the hepatocytes and Kupffer cells, but again no bile plugs are noted. Progressive familial intrahepatic cholestasis-2 (PFIC2), on the other hand, shows a striking inflammatory background with the appearance of a giant cell hepatitis with prominent giant cell change in hepatocytes, foci of necrosis with inflammation, and portal fibrosis besides the canalicular cholestasis. Hepatocytes may express CK7, while GGT staining is preserved in the canaliculus. There is, however, loss of bile salt export pump (BSEP) protein expression in many cases. The third important subtype of PFIC that is most likely to mimic DJS is the ABCB4 disease that is usually a high-GGT conjugated hyperbilirubinemia of infancy and is the result of failure of activity of the ABCB4/MDR3 protein. The children present with neonatal hepatitis that rapidly progresses to cirrhosis unlike the clinical picture of DJS. Histology may show giant cell change, disarray of hepatocytes, portal fibrosis, inflammation, and biliary proliferation with subsequent bridging fibrosis and cirrhosis (1). TPN-induced liver damage shows abundant inflammation with portal expansion, cholestasis, both ductular and canalicular and prominent ballooning, and fatty change in hepatocytes. There is ductular reaction with pericholangitis with evolving bridging fibrosis and centrilobular fibrosis. In conclusion, liver biopsy is not warranted for diagnosis of DJS and is done only when there is clinical overlap with other conditions or if coproporphyrin excretion studies are not available (2). A biopsy diagnostic of DJS with or without the pigment is now possible by performing cMOAT staining. Genetic testing is now the preferred modality for diagnosis.
References
157
1. Knisely AS. Hepatocellular and familial cholestasis. In: Russo P, Ruchelli E, Piccoli DA, eds. Pathology of pediatric gastrointestinal and liver disease. 1st ed. New York, NY: Springer-Verlag;2004:237–250. 2. Frank M, Doss MO. Relevance of urinary coproporphyrin isomers in hereditary hyperbilirubinemias. Clin Biochem. 1989;22:221–222.
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10 Neonatal Cholestatic Liver Disease GRACE E. KIM AND LINDA D. FERRELL
I N T ROD U C T I ON
TA BL E 1 0 . 2 Neonatal hepatitis—associated etiologies
The differential diagnosis of neonatal jaundice is lengthy. Many normal-term newborns have transient neonatal jaundice with elevated unconjugated bilirubin. The unconjugated hyperbilirubinemia in some neonates results from an immature hepatic enzyme glucuronosyl transferase activity or can be associated with breast-feeding. Other etiologies include hemolysis, sepsis, hypothyroidism, or pyloric stenosis, and inherited disorders such as Crigler-Najjar and Gilbert syndromes (see Chapter 9). In contrast, conjugated hyperbilirubinemia nearly always reflects hepatic dysfunction. The current practice is to investigate jaundice in any infant who is more than 14 days old to determine whether the hyperbilirubinemia is unconjugated or conjugated. Unfortunately, jaundiced infants often escape clinical attention until the first well-baby examination at 6 to 8 weeks of age. For neonatal jaundice that represents hepatic dysfunction, one of the most frequent entities that presents within the first 2 months of life with conjugated hyperbilirubinemia is biliary atresia (BA), which typically causes an obstructive pattern of injury with a prominent portal-based fibrosis and ductular reaction in addition to bile stasis. This pattern is not specific for BA, and many of the other lesions with this pattern are listed in Table 10.1. The other most common pattern of injury in this age group is neonatal hepatitis (NH), which in contrast has a more lobular prominence of injury, with proportionately less portal-based injury and ductular reaction. As with the obstructive pattern, the neonatal hepatitic pattern also can be caused by a long list of entities (Table 10.2). The obstructive and hepatitic patterns can have overlapping features, and liver biopsy is often performed to establish the TA B LE 10. 1 Obstructive-type pattern of ductular reaction—
associated etiologies Biliary atresia Total parenteral nutrition effect Cholestasis-associated sepsis Inspissated bile syndrome, as in cystic fibrosis, prematurity, congenital heart disease, starvation, dehydration, diuretic therapy, congenital anomalies of the biliary tract, gut dysfunction or ileal resection, ABO incompatibility/hemolytic anemia, idiopathic (3,4) Infections, including CMV Alpha-1-antitrypsin deficiency Paucity of bile ducts, some nonsyndromatic types, and rarely in Alagille syndrome Abbreviation: CMV, cytomegalovirus.
Idiopathic forms (most common) Hypopituitarism, including septo-optic dysplasia Infectious Hepatotropic viruses: A, B, C Herpes viruses: CMV, HSV, varicella Other viruses: rubella, reovirus-3, ECHO, Coxsackie, adenovirus, parvovirus B19, HIV Bacteria: Listeria monocytogene, Mycobacterium tuberculosis,Treponema pallidum Protozoa: Toxoplasma gondii Metabolic Progressive familial intrahepatic cholestasis Alpha-1-antitrypsin deficiency Niemann-Pick disease type-C Cystic fibrosis Bile acid synthesis defects Zellweger syndrome Tyrosinemia Immunologic Autoimmune hepatitis Severe combined immunodeficiency Abbreviations: CMV, cytomegalovirus; ECHO, enteric cytopathic human orphan; HSV, herpes simplex virus; HIV, human immunodeficiency virus.
diagnosis. This distinction is important since early surgical intervention is required in BA (1). Neonatal hemochromatosis, one of the most common causes of liver failure at birth, is discussed with iron overload in Case 20.6. BILIA RY AT R ESIA
BA is an idiopathic, necroinflammatory process of the bile ducts that leads to periductal fibrosis and obliteration and secondary biliary cirrhosis. This entity typically presents within the first 2 months of life, but earlier and later presentations can occur. Numerous etiologic factors, including congenital, infectious, immunologic, vascular, and toxic have been proposed; however, the cause of BA remains unknown, and multiple factors resulting in the same outcome may be involved. About 20% of the cases are associated with other congenital anomalies, such as polysplenia, situs inversus, genetic trisomies, vascular anomalies, and perhaps maternal diabetes (2). In addition, numerous other entities can mimic the obstructive pattern of injury seen in BA (see Table 10.1) (3,4). Thus, correlating the biopsy findings with clinical setting, laboratory studies, intraoperative cholangiogram, and other biliary tree imaging results is needed. The reported accuracy of the liver 159
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biopsy to determine an obstructive form of neonatal cholestasis approaches 95% when 5 to 7 portal tracts are present. Histology
Typically, the liver shows morphologic signs of biliary obstruction with cholestasis, ductular reaction, and portal edema or fibrosis. Greater than 90% of the cases involve obliteration of the hilar ducts at the porta hepatis. The remaining cases show patency of the large ducts to the levels of the common hepatic duct or common bile duct (2). BA is a dynamic process, and the histology transforms with the time course of the disease. During the neonate’s first 4 to 6 weeks of life, nonspecific features of cholestasis including swollen hepatocytes are present. Ductular reaction, the most reliable criterion for diagnosing biliary obstruction, develops around 6 to 8 weeks of age (Figure 10.1). During this time, the portal tracts may show a variable density of lymphocytes and neutrophils, damaged interlobular duct epithelium, similar to that observed in the extrahepatic ducts, and portal edema or early portalbased fibrosis. At about 8 weeks of age, the periportal fibrosis begins or may have progressed into portal-to-portal bridging fibrosis. The amount of portal inflammation may decrease and damaged interlobular ducts can have concentric fibrosis. Cholestasis persists in the parenchyma with pigment-laden Kupffer cells. Eventually, secondary biliary cirrhosis, the socalled jigsaw pattern of cirrhosis, forms at 1 to 6 months of age with a subset developing loss of interlobular ducts. The suggested timeline can be quite variable, and at least some cases described as perinatal, or neonatal sclerosing cholangitis may represent late onset BA. At the time of hepatoportoenterostomy, a segment of the porta hepatis and gallbladder, if present, is removed. Previously, a bile duct diameter of more than 150 μm within the ductal remnant within the portal hepatis was critical in
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determining postoperative bile flow. Subsequent studies have refuted this criterion, and, hence, surgeons no longer request frozen sections on bile duct remnant. The ductular structures in the portal hepatitis typically demonstrate a destructive fibro-obliterative process, often with intraductal inflammatory or cholestatic changes. The periductal fibrotic reaction typically has increased fibroblastic changes. NEO NATA L H EPAT IT IS
The other major pattern of liver injury in the newborn period is NH, which is an intrahepatic cholestatic disease, typically diagnosed within 2 months after birth. Most NH cases are idiopathic, but some cases have been linked to hypopituitarism (5), including the entity of septo-optic dysplasia, a syndrome with congenital hypoplasia of the optic nerve, absent septum pellucidum, and hypopituitarism. Other associated lesions are noted in Table 10.2 (6). Histologic features are not thought to distinguish the various possible etiologies of NH but can often differentiate NH from BA (Table 10.3). Rarely, BA and Alagille syndrome can also present with this pattern of injury. However, typical features like portal-based ductular reaction and ductopenia respectively predominate as histologic findings later in the clinical course. The clinical outcome in NH is often dependant on the etiology. Most idiopathic or infectious forms resolve without significant liver injury with appropriate therapy and supportive care. Histology
NH is also known as neonatal giant cell hepatitis because of the frequent finding of giant cell transformation in the lobular hepatocytes (Figures 10.1 and 10.2). These “giant cells” usually have greater than 4 nuclei that are often centrally clustered. Another almost universal feature is the presence of extramedullary hematopoiesis (EMH) in portal and lobular areas. Lobular hepatocyte necrosis, evidence of previous TA BL E 1 0 . 3 Comparison of histologic features of biliary atresia
and neonatal hepatitis
FIGURE 10. 1 Biliary atresia pattern of portal ductular reaction with fibrosis. A few giant multinucleate hepatocytes are present, but these are not a prominent pattern in most cases.
Histologic Features Biliary Atresia
Neonatal Hepatitis
Giant cell change
Focal
Diffuse
Lobular inflammation
Absent
Variable, can be absent
Hepatocyte loss
Rare
Present as focal necrosis, dropout, or intraparenchymal pericellular fibrosis
Fibrosis pattern
Portal-based, early feature
Intraparenchymal pericellular, variable periportal fibrosis
Ductular reaction
Present, becomes more prominent over time
Rare
Extramedullary hematopoiesis
Present in variable degrees
Typically present and often prominent
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TA BL E 1 0 . 4 Paucity of bile ducts in the neonatal period—
associated disorders Inheritable disorders Alagille syndrome Alpha-1-antitrypsin deficiency Zellweger syndrome (lack of peroxisomes) Progressive familial intrahepatic cholestatic defects type 1 and/or 2 Chromosomal defects including Turner syndrome, Trisomy 17-18, 21 Infections Congenital rubella Congenital CMV Abbreviation: CMV, cytomegalovirus.
FIGURE 10.2 Neonatal hepatitis with giant cell change, mild lobular
inflammation, and no significant ductular reaction. Focal cholestasis is present. Some hepatocytes are smaller than normal, and plates are wider than 2 cells thick, consistent with regenerative change.
FIGURE 10. 3 Neonatal hepatitis—follow-up biopsy 12 weeks later at age 5 months (after resolution of symptoms and enzymatic changes) demonstrates a few residual multinucleate hepatocytes.
hepatocyte dropout, or presence of pericellular fibrosis as a sign of lobular injury is also typically present. The degree of inflammatory infiltrates other than EMH can be variable and is scant in many cases. Hepatocanalicular bile stasis is common. Portal tracts have bile ducts, but these may be smaller than expected (hypoplastic) and difficult to identify on routine staining. Cytokeratin (CK)7 or CK19 immunostaining may be helpful to identify the ducts in order to differentiate NH from diseases related to paucity of bile ducts. Mild ductular reaction can be present. The giant multinucleate hepatocytes can persist for some months after symptoms have resolved (Figure 10.3). PAU C I T Y OF B I L E D U C T S
In the pediatric neonatal setting, paucity of bile ducts can be typically divided into 2 types: the syndromatic type (Alagille
syndrome, also known as arteriohepatic dyplasia), or nonsyndromatic types, associated with a long list of entities, some of which are noted in Table 10.4 (7,8). Paucity of ducts is defined by evaluation of the ratio of bile ducts per portal tract, with normal range from 0.9 to 1.8 per portal tract, and paucity as less than 0.5 ducts per portal tract with at least 10 portal tracts for evaluation. Values between 0.5 and 0.8 are considered borderline or nondiagnostic. Alagille syndrome is a variably penetrant, autosomal dominant disorder that typically has 5 major components. These consist of the paucity of ducts as the liver manifestation, associated with other extrahepatic abnormalities including peripheral pulmonary artery stenosis as the cardiac component, typical facial appearances, butterfly-shaped vertebral arch defects, and ocular defects; the latter 2 entities having no functional significance (9). This disorder is caused by a mutation in JAG 1 (JAGGED 1), resulting in overexpression of human growth factor (HGF), which in turn may have an effect on hepatic stem cells, pushing them toward hepatocytic rather than biliary differentiation (10). In addition to paucity of bile ducts, there may be hypoplasia of the gallbladder, common bile duct, and portal vein. Destructive lesions of the bile ducts, bile stasis, and giant cell transformation are often seen in the early stages. Ductular reaction and periportal fibrosis are not typical features but can rarely occur. In addition, a hypoplastic common bile duct might mimic the large duct lesions of BA on imaging. Of the nonsyndromatic forms, Zellweger syndrome (11), an autosomal recessive defect characterized by lack of peroxisomes and defect in bile acid synthesis, alpha-1-antitrypsin deficiency (AATD) (see below), and cystic fibrosis are other rare genetic forms of ductopenia in early infancy (6,7). A LP H A - 1- A NT IT RY P SIN DEFICIENCY
AATD is one of the more common inheritable defects that can present in the neonatal period but may be difficult to diagnose by routine histology as the typical (periodic acid–Schiff diastase) PASd+ cytoplasmic globules are almost always not yet present in a diagnostic pattern at this young age. Fortunately, the deposits of AAT in distended endoplasmic reticulum can be usually noted on electron microscopic examination, and immunohistochemistry for AAT may demonstrate granular
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cytoplasmic positivity in hepatocytes (6). However, in this age group, the diagnosis is often more one of clinical suspicion and testing for serum AAT and phenotyping (protease inhibitor, or PI typing) for the abnormal alleles. Typically, only the patients with PiZZ phenotype would have a severe enough defect, if fully penetrant, to present in the neonatal period, as the other SZ and MZ phenotypes tend to present later in life if they are associated with high penetrance and fibrotic changes. The spectrum of changes in AATD are more fully discussed in Chapter 16, but for the purpose of this chapter on neonatal cholestasis, AAT can present with either an NH-like pattern of injury, or an obstructive pattern more like that of BA, and an element of ductopenia can occur with either pattern of injury. Progressive Familial Intrahepatic Cholestasis
Progressive familial intrahepatic cholestasis (PFIC) was initially categorized into 3 clinical diseases as PFIC1, PFIC2, and PFIC3. Recent molecular advances have added to our knowledge of these diseases. The involved inherited defects for some of the forms of PFIC are known, and this is reflected in the nomenclature. PFIC1 is due to ATP8B1 mutation encoding familial intrahepatic cholestasis 1 (FIC1), PFIC2 has mutations on ABCB11 that encodes bile salt export pump (BSEP), and PFIC3 is associated with a defect in the multidrugresistance-3 (MDR3) pathway on the encoding gene ABCB4. Hence PFIC1, PFIC2, and PFIC 3 are also termed FIC1 deficiency, BSEP deficiency, MDR3 deficiency, respectively. Based on the specific gene defect, the spectrum of these diseases can vary from mild to severe. PFIC1 and PFIC2 are characterized by normal serum gamma-glutamyl transferase (GGT) activity, which can be differentiated from the higher levels typically found in PFIC3. PFIC2 patients have been found to have a higher risk for neonatal jaundice than PFIC1 and may thus present with an NH-like pattern of injury with high serum alanine aminotransferase and elevated serum alpha-fetoprotein levels (12). A recent study identified that at presentation, serum aminotransferase and bile salt levels were higher in PFIC2, whereas serum alkaline phosphatase levels were higher and serum albumin levels were lower in PFIC1 (13). Morphologically, bland canalicular cholestasis between compact hepatocytes and small multinucleated hepatocytes with increasing portal fibrosis are characteristic features of PFIC1. Although PFIC2 can also demonstrate fibrosis, this typically begins in the pericentral regions. An NH pattern of injury with giant cell transformation can be observed. Some patients with PFIC1 or PFIC2 have paucity of ducts (14). PFIC3 displays a biliary pattern of injury depicted as expanded portal tracts with ductular reaction and mixed inflammatory infiltrate. Bile plugs can be present in ductules and eventual biliary cirrhosis can develop. Bile Acid Synthesis Defects
Bile acid synthesis defects can be due to a variety of enzymatic defects. Table 10.5 contains a short list of some of
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TA BL E 1 0 . 5 Bile acid defects: common histologic patterns Bile Acid Deficiency
Patterns of Histology
Oxysterol 7␣-hydroxylase
NH as well as ductular reaction, early progression to cirrhosis
3-OH steroid dehydrogenase
NH, progresses to cirrhosis
5-Reductase
NH, with progression to liver failure; neonatal hemochromatosis-like pattern
Mitochondrial sterol 27-hydroxylase (cerebrotendinous xanthomatosis)
NH as rare presentation, but neurologic dysfunction and xanthomas typically present later in life
C-27 peroxisomal side-chain oxidation (Zellweger syndrome)
NH, also with paucity of ducts and fibrosis EM: absence of perioxisomes
Acyl-CoA racemase (AMACR)
Similarities to Zellweger syndrome, with decreased size and number of perioxisomes
Abbreviations: EM, erythema multiforme; NH, neonatal hepatitis. From Refs. 11, 15.
the enzymatic defects and common histologic patterns that are typically present (11,15,16). A specific diagnosis for individual defects is important, as the efficacy of therapy with oral bile acid therapy is dependant on type of defect present (11,16). This chapter will not attempt to illustrate these entities, but excellent reviews by Bove et al (11), Heubi et al (15), and Sundaram et al (16) provide more detailed descriptions. Most of these lesions present in the neonatal period, with neonatal giant cell hepatitis being the most common pattern of injury. Some cases may demonstrate ductular reaction, and/or progression to cirrhosis at variable rates. Zellweger syndrome, which is characterized by absence of peroxisomes on electron microscopic examination, is one of the bile acid defects that can present in this period and progress to cirrhosis. This entity is also one of the few bile acid synthesis defects that can demonstrate duct paucity.
References 1. Mieli-Vergani G, Howard ER, Portman B, Mowat AP, et al. Late referral for biliary atresia: missed opportunities for effective surgery. Lancet. 1989;1:412–423. 2. Hartley JL, Kelly DA, Davenport M. Biliary atresia. Lancet. 2009;374:1704–1713. 3. Miloh T, Rosenberg HK, Kochin I, Kerkar N. Inspissated bile syndrome in a neonate treated with cefotaxime, sonographic aid to diagnosis, management, and follow-up. J Ultrasound Med. 2009;28:541–544. 4. Brown DM. Bile plug syndrome: successful management with a mucolytic agent. J Ped Surg. 1990;25:351–352. 5. Spray CH, McKiernan P, Waldron KE, Shaw N, Kirk J, Kelly DA. Investigation and outcome of neonatal hepatitis in infants with hypopituitarism. Acta Paediatr. 2000;89:951–954. 6. Jevon GP, Dimmick JE. Histopathologic approach to metabolic liver disease: Part 1. Pediatr Dev Pathol. 1998;1:179–199. 7. Kahn E, Daum F, Markowitz J, Teichberg S, Duffy L, Harper R, Aiges H. Nonsyndromatic paucity of interlobular bile ducts: light and electron
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11.
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microscopic evaluation of sequential liver biopsies in early childhood. Hepatology. 1986;6:890–901. Dimmick JE. Intrahepatic bile duct paucity and cytomegalovirus infection. Pediatr Pathol. 1993;13(6):847–852. Hadchouel, M. Alagille syndrome. Indian J Pediatr. 2002;69:815-818. Yuan A, Kobayashi N, Kohsaka T. Human Jagged 1 mutants cause liver defect in Alagille syndrome by overexpression of hepatocyte growth factor. J Molecular Biol. 2006;356:559–568. Bove KE, Heubi JE, Balistreri WF, Setchell KD. Bile acid synthetic defects and liver disease: a comprehensive review. Pediatr Dev Pathol. 2004;7:315–334. Davit-Spraul A, Fabre M, Branchereau S, et al. ATP8B1 and ABCB11 Analysis in 62 children with normal gamma-glutamyl transferase progressive familial intrahepatic cholestasis (PFIC): phenotypic differences
13.
14.
15. 16.
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between PFIC1 and PFIC2 and natural history. Hepatology. 2010;51(5):1645–1655. Pawlikowska L, Strautnieks S, Jankowska I, et al. Differences in presentation and progression between severe FIC1 and BSEP deficiencies. J Hepatol. 2010;13. [Epub ahead of print]) Naveh Y, Bassan L, Rosenthal E, et al. Progressive familial intrahepatic cholestasis among the Arab population in Israel. J Pediatr Gastroenterol Nutr. 1997;24:548–554. Heubi JE, Setchell KD, Bove KE. Inborn errors of bile acid metabolism. Semin Liver Dis. 2007;3(27):282–294. Sundaram SS, Bove KE, Lovell MA, Sokol RJ. Mechanisms of disease: inborn error of bile acid synthesis. Nat Clin Pract Gastroenterol Hepatol. 2008;5:456–468.
Case 10.1
Biliary Atresia GRACE E. KIM AND LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
A 5-week-old baby boy presented with pale stool, dark urine, delayed growth, and jaundice. He was a full-term infant with normal delivery. Laboratory data showed elevated alkaline phosphatase at 649 U/L (normal 110-302), gamma-glutamyl transferase of 616 U/L (normal 7-71), total bilirubin of 10.9 mg/dL with conjugated bilirubinemia of 6.2 mg/dL, and elevated transaminases at 3 to 4 times normal. Serum albumin, prothrombin time, alpha-1-antitrypsin levels, thyroidstimulating hormone (TSH), and free T4 were normal. Family history was noncontributory. Ultrasound showed a normalsized liver and spleen, with no biliary tract dilation or other anomalies, but the gallbladder was not visualized. HIDA scan (hepatobiliary [scintigraphy] imino-diacetic acid) showed no excretion of radiotracer (as a marker for bile excretion) into the duodenum. A liver biopsy was done. F I G U R E 1 0 . 1 . 1 Biliary atresia at age 6 weeks. Fibrosis around residual
R E A S ON F OR R E F E R R A L
To determine the cause of neonatal jaundice, the primary concern being biliary atresia. PAT H OL OG I C F E AT U R E S
The liver biopsy at 6 weeks of age demonstrated periportal and porto-portal bridging fibrosis. Ductular reaction was prominent in the fibrous bands, with many of the ductules closely approximating the edge of the fibrotic zone near the residual hepatic parenchyma; these ductules often contained bile (Figure 10.1) (Figures 10.1.1 and 10.1.2). The ductules also had a somewhat anastomosing appearance (Figure 10.1.2). The liver parenchyma was nodular; bile plugs were also noted. A few scattered giant, multinucleated hepatocytes were present, but this was not a prominent feature. Hepatocytic acinar change was focally noted (as a feature of chronic cholestasis), but there was no significant hepatocellular necrosis (Figure 10.1.2). Lobular and portal inflammation was scant other than some focal periductular mixed inflammatory reaction (Figure 10.1.1). A few foci of extramedullary hematopoiesis were also present. Based on these findings, the patient had an intraoperative cholangiogram, followed by a Kasai procedure. The intraoperative cholangiogram confirmed complete blockage of the ductal system and only minimal luminal patency of an atretic gallbladder. During Kasai portoenterostomy, the portal plate appeared very fibrotic with no visible bile duct. No drainage was noted into the bowel after surgery, and living-related donor liver transplantation was successfully completed at age 5 months. The porta hepatis was excised during Kasai portoenterostomy demonstrated complete obliteration of the large bile duct, confirming the findings of the intraoperative cholangiogram.
portal areas is prominent and contains a prominent ductular reaction. Note bile stasis in some of the ductules. The parenchyma shows a nodular appearance. Hepatocytes are crowded, some are smaller than normal and arranged in an acinar pattern, all of which are regenerative changes related to cholestasis. Inflammatory infiltrates are scant.
F I G U R E 1 0 . 1 . 2 Biliary atresia at age 6 weeks with fibrosis and ductu-
lar reaction (higher magnification of Figure 10.1). The parenchyma demonstrates a few multinucleate hepatocytes.
Histologically, the ducts were small, with minimal residual lumina, surrounded by a fibroblastic reaction and mild inflammatory changes. The lumina contained a few residual epithelial cells (Figure 10.1.3). At age 5 months (21 weeks), the liver explant, obtained during a living-related donor
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FIGURE 10. 1. 3 Portal hepatitis at age 7 weeks. The ducts are essentially obliterated by fibroblastic and mild inflammatory reaction.
FIGURE 10. 1. 4 Explanted liver at age 5 months demonstrates fully developed cirrhosis and very prominent ductular reaction as highlighted on cytokeratin 7 (CK7) immunoperoxidase staining.
transplantation, demonstrated cirrhosis with biliary pattern of injury (Figure 10.1.4).
D I AG N OS I S
Biliary obstructive pattern, consistent with biliary atresia.
D I S C U S S I ON
In this case, the histology was consistent with BA, demonstrating the typical portal-based fibrosis with ductular reaction. These numerous ductules with anastomosing, chain-like pattern may have a ductal plate malformation–like appearance. This feature has been proposed to be a marker of congenital
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or fetal form of biliary atresia that is frequently associated with congenital anomalies, most commonly biliary atresia splenic malformation syndrome. This has led to the suggestion that the etiology of biliary atresia dates to fetal life (1) and is an indicator of poor prognosis (2). A recent study (3) noted the challenges on what features actually constituted this ductal plate malformation–like appearance and did not conclude these features identified the fetal form of biliary atresia. This finding is not specific for BA. Thus, correlation with other clinical features, particularly the conjugated bilirubinemia, preoperative radiographic imaging to exclude other biliary tree anomalies, duct dilation, and intraoperative cholangiogram to confirm the obliterative changes of the hilar ducts, and absence of gallbladder are very important. Untreated BA is typically fatal within 2 years, typically as a result of biliary cirrhosis and hepatic failure. The first step in the treatment remains hepatoportoenterostomy (Kasai procedure) early in the course of the condition, usually before 100 days of birth, and before prolonged complete obstruction leading to extensive liver fibrosis and/or cirrhosis (4). The next step is liver transplantation; BA represents more than 50% of pediatric liver transplants. Response to the Kasai procedure (as defined by normal bilirubin levels by 6 months after surgery) can result in prolonged survival of the native liver, which can postpone liver transplantation (5–7). Approximately 25% to 35% of patients with successful hepatoportoenterostomy survive more than 10 years without liver transplantation. One-third of the patients drain bile but develop complications of cirrhosis and require transplantation before age 10. In the remaining one third of the patients, bile flow is inadequate following heptoportoenterostomy leading to progressive fibrosis. These children usually die by age 2, if liver transplantation is not performed. A common complication after the Kasai procedure is recurrent cholangitis resulting from direct biliary-enteric connection (7,8). Essentially all patients develop progressive fibrosis and cirrhosis, leading to complications of portal hypertension including esophageal varices and ascites, and increased risk for hepatocellular carcinoma, and, rarely, hepatoblastoma or cholangiocarcinoma (9,10). Hepatopulmonary syndrome, a state of hypoxia probably due to unmetabolized vasoactive substances causing the shunting of blood away from the pulmonary vasculature, can also occur (4). Another feature often seen in BA and present in this case is extramedullary hematopoeisis. This is a common finding in many forms of neonatal liver diseases (particularly in neonatal hepatitis), and is thought to be a nonspecific finding related to stress in the intrauterine and neonatal period.
References 1. Desmet VJ. Ludwig symposium on biliary disorders—Part 1. Pathogenesis of ductal plate abnormalities. Mayo Clin Proc. 1998;73:80–89. 2. Low Y, Vijayan V, Tan CE. The prognostic value of ductal plate malformation and other histologic parameters in biliary atresia: an immunohistochemical study. J Pediatr. 2001;139(2):320–322.
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3. Pacheco MC, Campbell KM, Bove KE. Ductal plate malformation-like arrays in early explants after a Kasai procedure are independent of splenic malformation complex (heterotaxy). Pediatr Dev Pathol. 2009;12(5): 355–360. 4. Hartley JL, Kelly DA, Davenport M. Biliary atresia. Lancet. 2009;374:1704–1713. 5. Lykavieris P, Chardot C, Sokhn M, Gauthier F, Valayer J, Bernard O. Outcome in adulthood of biliary atresia: a study of 63 patients who survived for over 20 years with their native liver. Hepatology. 2005;41: 366–371. 6. Shinkai M, Ohhama Y, Take H, et al. Long-term outcome of children with biliary atresia who were not transplanted after the Kasai operation: >20-year experience at a children’s hospital. J Pediatr Gastroenterol Nutr. 2009;48:443–450.
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7. Houben C, Phelan S, Davenport M. Late-presenting cholangitis and Roux loop obstruction after Kasai portoenterostomy for biliary atresia. J Pediatr Surg. 2006;41:1159–1164. 8. Wu ET, Chen HL, Ni YH, et al. Bacterial cholangitis in patients with biliary atresia: impact on short-term outcome. Pediatr Surg Int. 2001;17:390–395. 9. Tatekawa Y, Asonuma K, Uemoto S, Inomata Y, Tanaka K. Liver transplantation for biliary atresia associated with malignant hepatic tumors. J Pediatr Surg. 2001;36:436–439. 10. Kulkarni PB, Beatty E Jr. Cholangiocarcinoma associated with biliary cirrhosis due to congenital biliary atresia. Am J Dis Child. 1977;131: 442–444.
Case 10.2
Neonatal Hepatitis With Hypopituitarism GRACE E. KIM AND LINDA D. FERRELL
C L I N IC AL I N F OR M AT I ON
PAT H O LO GIC FEAT UR ES
A full-term neonate born to a 16-year-old mother had an uncomplicated prenatal course and normal vaginal delivery, other than a hypoglycemic episode that was successfully treated with dextrose infusion. The infant was readmitted at age 8 weeks with jaundice. Ultrasound demonstrated a small gallbladder, and a liver biopsy was done (first liver biopsy, see section on pathologic features), followed by Kasai hepatoportoenterostomy for probable BA. The patient was transferred to the referral center for further testing. On admission, the patient appeared to have some hypotonia and hyperreflexia. Laboratory values included anemia, thrombocytopenia, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) of 3 and 2 times normal respectively, total bilirubin 5.7 mg/dL with direct bilirubin 4.1 mg/dL. Other findings included negative markers for viral hepatitis A, B, C, as well as autoimmune hepatitis, and normal serum alpha-1-antitrypsin Pi typing. Ultrasound of the liver demonstrated a normal-sized liver with normal intrahepatic bile ducts, portal and hepatic arteries, and moderate ascites. In addition, an enlarged spleen was noted, but no gallbladder was visualized. Because of the abnormal neurologic examination, an ultrasound of the head was done and demonstrated normal ventricles with no evidence of hemorrhage, but no definitive septum pellucidum was visualized and the corpus callosum was thin. Ophthalmologic consultation revealed evidence of bilateral optic nerve hypoplasia. Magnetic resonance imaging (MRI) confirmed hypoplastic anterior pituitary, with ectopic posterior pituitary in the tuber cinereum. The optic chiasm and optic nerve appeared small. The patient had hypoglycemia, and other pituitary function hormones such as adrenocorticotropic hormone (ACTH), growth hormone, and thyroid stimulating hormone (TSH) were low. The patient was treated for hypopituitarism. Initially, the patient did well but then became increasingly jaundiced, with elevations of total and direct bilirubins. At age 7 months, ultrasound of the liver revealed dilated intrahepatic bile ducts with distal obstruction at the hepatoportoenterostomy site, and the patient was taken to surgery for revision of the anastomosis. A liver wedge biopsy was taken at that time (second biopsy, see section on Pathologic Features.). After that revision, the jaundice resolved and the patient was in a stable condition 1 year later.
Two liver biopsies were obtained, one at age 9 weeks and the other at 8 months of age. First biopsy, age 9 weeks: This liver biopsy demonstrated features of mild hepatitis with expanded portal zones, focal swollen hepatocytes as well as scattered necrotic hepatocytes in the lobules, canalicular bile stasis, and a mild increase in sinusoidal cells (Figures 10.2.1–10.2.5). The cellular infiltrates in the portal areas and lobules consisted predominantly of EMH, with a few portal areas containing prominent eosinophilic or megakaryocytic components (Figures 10.2.4 and 10.2.5). No periportal fibrosis or ductular reaction was present and ducts were intact and present (Figures 10.2.6 and 10.2.7). No prominent giant, multinucleate cell transformation of hepatocytes was present (Figure 10.2.3). No porta hepatic sample was available for review. Second biopsy, age 8 months: This liver biopsy was a wedge biopsy performed at the time of revision of the Kasai procedure deemed necessary due to poor drainage of the hepatoportoenterostomy. The liver now had extensive portalbased fibrosis with prominent ductular reaction, a pattern typical of bile duct obstruction, as could be seen in BA or other forms of mechanical obstruction (Figures 10.2.8–10.2.10). No hepatitic changes were noted, no multinucleate giant hepatocytes of any significant number were seen, and the interlobular bile ducts were intact, without evidence of ductopenia on CK7 staining (Figure 10.2.10). Cholestasis as evidenced by bile plugs was easily identified (Figure 10.2.9).
R E A SON F OR R E F E R R AL
This patient was referred with the diagnosis of neonatal hepatitis–like syndrome, status-post Kasai procedure (hepatoportoenterostomy) for possible BA.
F I G U R E 1 0 . 2 . 1 First liver needle biopsy. Two portal tracts contain a cellular infiltrate, with a duct visible in the larger portal zone. The parenchyma contains a mild cellular infiltrate and shows mild hepatocellular disarray.
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FIGURE 10.2.2 First liver biopsy. A small canalicular bile plug is noted directly below the small central vein in this figure. A couple of clusters of EMH are present in sinusoids above the vein. The hepatocytes do not show giant cell change, but have focal pale cytoplasm and swelling (just right of EMH) as well as appear to be somewhat smaller than normal, the latter a possible result of regenerative change.
FIGURE 10. 2. 3 First liver biopsy. A necrotic hepatocyte (apoptotic
body) is noted (center), and acinar change is present (lower center), the latter a feature commonly seen in cholestatic disease. A mild cellular infiltrate is present in sinusoids.
D I AG N OSI S
Liver, needle biopsy: neonatal hepatitis, mild, consistent with hypopituitarism and septo-optic dysplasia. Liver, wedge biopsy (8 months): Biliary pattern of cirrhosis, likely due to obstruction. D I SC U SSI ON
This case demonstrates a neonatal hepatitis pattern of injury but does not have the typical feature of multinucleate hepatocytes, reinforcing the idea that this feature is not necessary for
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DISEASE
F I G U R E 1 0 . 2 . 4 First liver biopsy. This portal zone is mildly expanded
by a dense cellular infiltrate, most of which is EMH, with prominent eosinophilia. An artery is present at the lower part of the portal zone, with the duct in upper right, but somewhat obscured by the infiltrate.
F I G U R E 1 0 . 2 . 5 First liver biopsy. This portal zone contains prominent megakaryocytes, and EMH is also seen in adjacent periportal sinusoids. An apoptotic body (necrotic hepatocyte) is also present (directly below megakaryocytes in lower center).
the diagnosis, and is a nonspecific manifestation of hepatocellular injury. The diagnostic features include lobular hepatocyte necrosis and swelling, canalicular cholestasis. EMH is a common finding in this setting and is prominent in this case. All 3 hematopoietic cell lines can be seen, but 1 cell line might predominate. EMH should not be confused with lymphocytes, the blasts of a leukemic infiltrate, or other malignancies. Hypopituitarism is one of the more common associated etiologies for hepatitis presenting in the neonate (1), in particular, septo-optic dysplasia spectrum of changes including optic nerve hypoplasia and absence of the septum pellucidum, but more commonly, hypoglycemia and evidence of endocrine failure, including low TSH and free T4, serum cortisol, and human growth hormone. The hepatitis is thought to be due to low
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F I G U R E 1 0 . 2 . 9 Second liver biopsy. Higher magnification demonFIGURE 10. 2. 6 First liver biopsy, higher magnification of Figure
strates cholestatic changes.
10.2.8. The portal zone contains mostly EMH, and the duct is intact. The hepatocytes show focal hepatocyte swelling and pale cytoplasm.
F I G U R E 1 0 . 2 . 1 0 Second liver biopsy. Cytokeratin 7 immunostain confirms a prominent ductular reaction and presence of an interlobular bile duct. FIGURE 10. 2. 7 First liver biopsy, trichrome stain. No periportal
fibrosis has occurred, and the bile duct is present.
cortisol and/or growth hormone levels, and appropriate hormone replacement therapy will almost always lead to resolution of the cholestasis and hepatitis if the lesion is diagnosed in early infancy. Thus, it is important to follow any hypoglycemic episodes in childhood associated with jaundice with examination for pituitary function, which is often done by monitoring serum TSH and free T4 and/or early morning serum cortisol. If the diagnosis is made at a later stage, liver fibrosis may be present. Other noninfectious causes of a mild hepatitic or a neonatal hepatitic pattern with giant cells (see Table 10.2) include alpha-1-antitrypsin deficiency (Case 10.4) and rare entities such as progressive familial intrahepatic cholestatic disorders (types 1–3) and bile salt defects, described in the introduction and in Table 10.2.
Reference FIGURE 10. 2. 8 Second liver biopsy, wedge taken at time of revision of hepatoportoenterostomy. Prominent portal-based fibrosis with ductular reaction is present.
1. Spray CH, McKiernan P, Waldron KE, Shaw N, Kirk J, Kelly DA. Investigation and outcome of neonatal hepatitis in infants with hypopituitarism. Acta Paediatr. 2000;89:951–954.
Case 10.3
Paucity of Intrahepatic Bile Ducts GRACE E. KIM AND LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
This neonate presented at 12 days of age with direct hyperbilirubinemia. Ultrasound of the abdomen revealed normal-sized liver and spleen with no bile duct dilation or other anomalies, and a normal gallbladder. HIDA scan showed no biliary excretion of radiotracer into the bowel and was interpreted as consistent with either BA or severe neonatal hepatitis. Laboratory examination showed total bilirubin of 7.1 mg/dL (direct 4.4 mg/dL), elevated alkaline phosphatase of 537 U/L, gammaglutamyl transferase of more than 1000 U/L, and mild elevation of transaminases. A liver biopsy was performed at age 8 weeks. During this time period, echocardiography revealed bilateral branch pulmonary vascular stenosis, and a bone survey showed butterfly vertebral bodies at the level of T6-8. R E A S ON F OR R E F E R R A L
The patient was referred for evaluation for persisting neonatal jaundice and concerns for biliary atresia.
F I G U R E 1 0 . 3 . 2 This smaller portal zone contains a small hepatic arteriole and portal venule, as well as mild cellular infiltrate. Acinar structures and some crowding of hepatocyte nuclei are present in adjacent liver parenchyma.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows 12 portal zones, 8 of which lacked an interlobular bile duct, confirming ductopenia. In addition, there is lobular canalicular cholestasis with acinar transformation of hepatocytes (Figures 10.3.1–10.3.4). No significant amount of giant cell transformation was present. The CK7 stain highlighted periportal hepatocyte as well as minimal ductular reaction (Figure 10.3.4) The portal zones did not show significant inflammation or fibrosis (Figures 10.3.1 and 10.3.2). EMH was present but was not prominent (Figure 10.3.3).
F I G U R E 1 0 . 3 . 3 A small central vein is present on the left. Note the
prominent small acinar formation by hepatocytes, and many hepatocytes are pale, or have a somewhat biphasic pink and pale cytoplasm. The sinusoidal infiltrate is mostly that of EMH with a cluster of erythroid precursors on the right.
DIAGNO SIS
Paucity of bile ducts, consistent with Alagille syndrome. FIGURE 10. 3. 1 The portal zone contains a mild cellular infiltrate, and the lobule also shows very mild sinusoidal cellular infiltrate. The portal zone also contains an artery but no obvious duct of corresponding caliber is noted.
DISCUSSIO N
Paucity of ducts and the identification of other features of Alagille syndrome are important to differentiate from BA in
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PAU C I T Y
OF
I N T R A H E PAT I C
FIGURE 10. 3. 4 Cytokeratin 7 immunostain: A small portal tract demonstrates some CK7 immunostaining around the edges of the portal zone but no interlobular bile duct is present, consistent with ductopenia. Some of the CK7 staining of single cells may represent periportal stem cells, and some of the lobular staining likely represents cholestatic hepatocytes. A few forms likely represent a minimal periportal ductular reaction.
the early postnatal period in order to avoid hepatoportoenterostomy (Kasai procedure). The primary histologic differentiating features in the liver of Alagille syndrome are lack of interlobular bile ducts in a significant number of portal zones (usually more than 50%) and lack of a significant portal-based fibrosis or ductular reaction at age 6 to 8 weeks. Alagille syndrome can also usually be distinguished from the neonatal hepatitic pattern of injury by the relative lack of giant multinucleate hepatocytes and/or portal/lobular mononuclear infiltrate. The presentation of jaundice and liver injury in Alagille syndrome usually occurs before 6 months of age, and intermittent jaundice is typical after the initial presentation. The other important syndromatic features that are helpful in the diagnosis of Alagille syndrome are cardiovascular,
BILE
DUCTS
171
vertebral, and ocular abnormalities. The most common cardiovascular defect is peripheral pulmonic stenosis, but aortic coarctation, stenosis of other main arteries, or more complex cardiac defects can also occur. The more complex cardiac defects may cause a significant number of deaths. The ocular and vertebral abnormalities are not significant clinically, but split lamp examination and dorsal spine radiographic examination (spinal survey) are part of the workup to exclude BA. Other associations include abnormal facies and voice, renal tubular acidosis, other renal malformations, retinal pigmentation, inner ear abnormalities, and unexplained intracranial hemorrhage. Abnormal facies are difficult to recognize in the neonate, and are not reliable for diagnosis. The prognosis for Alagille syndrome is much better than for BA, but there is no specific treatment other than fatsoluble vitamins and nutritional support. About 75% of patients reach age 20, and about 25% require liver transplant due to failure to thrive, bone fractures, end-stage liver disease, disfiguring xanthomas, or refractory pruritus. Only 25% to 30% of deaths are due to liver disease; the severity of the cardiac lesion has a major effect on prognosis. Hepatocellular carcinoma can occur in those surviving into adulthood. If the associated lesions are not seen, but the biopsy has paucity of ducts, nonsyndromatic causes for ductopenia must be considered (Table 10.4). Electron microscopic examination for absence of peroxisomes, sweat test or genetic testing for cystic fibrosis, phenotyping for alpha-1-antitrypsin deficiency (AAT), testing for progressive familial intrahepatic cholestatic disorders, chromosomal abnormalities (trisomies including chromosome 6) (1), or examination for congenital infections such as rubella or cytomegalovirus (CMV) may be helpful to determine etiology of nonsyndromatic cases.
Reference 1. Kenny AP, Crimmins NA, Mackay DJG, Hopkin RJ, Bove KE, Leonis MA. Concurrent course of transient neonatal diabetes with cholestasis and paucity of interlobular bile ducts: a case report. Pediatr Dev Pathol. 2009;12:417–420.
Case 10.4
Neonatal Hepatitis Due to Alpha-1-Antitrypsin Deficiency GRACE E. KIM AND LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
A 6-week-old boy developed upper respiratory symptoms and jaundice. On examination, the liver was palpable 1 cm below the right costal margin. Laboratory studies included total bilirubin of 6.3 mg/dL, direct bilirubin 3.7 mg/dL, gamma glutamyl transpeptidase (GGT) 719, AST 104, and ALT 84. A HIDA scan did not show excretion of bile into the duodenum. The patient was then referred for further evaluation at age 8 weeks. Physical examination at this time revealed a jaundiced infant. Further laboratory workup also revealed a low serum alpha-1-antitrypsin (AAT) level and Pi typing was then pursued, demonstrating a ZZ phenotype. A liver biopsy was done. The patient was followed for more than 2 years, gradually developing more severe jaundice and suffering from various complications of liver disease and cirrhosis including portal hypertension, ascites, and spontaneous bacterial peritonitis. Living donor liver transplantation was performed, and the patient has had a relatively unremarkable course for 2 years posttransplant.
F I G U R E 1 0 . 4 . 1 Liver biopsy at 8 weeks showed a mild lobular and
portal infiltrate, but no prominent pattern of multinucleate hepatocyte formation, consistent with a mild hepatitis.
R E A S ON F OR R E F E R R A L
To determine the etiology of the cholestasis with concern for biliary atresia. PAT H OL OG I C F E AT U R E S
Liver biopsy at age 8 weeks showed a mild hepatitis-like injury with a few giant/multinucleate hepatocytes. A mild degree of mononuclear infiltrate was present in lobules and portal zones (Figure 10.4.1). Focal apoptosis and mild fatty change was also present, and periportal hepatocytes contained iron (Figures 10.4.2 and 10.4.3 including iron stain). Canalicular cholestasis was present (Figure 10.4.3). Ductular reaction was minimal (Figure 10.4.2). Trichrome stain did not show significant fibrosis. Immunohistochemistry for CK7 confirmed the presence of 5 complete portal zones, with most containing an interlobular bile duct, but a rare small portal zone lacked a bile duct. Periodic acid–Schiff diastase (PASd) stain demonstrated rare positivity in small granules in periportal hepatocytes (Figure 10.4.4). Immunohistochemical stain for AAT demonstrated granular cytoplasmic positivity in about majority of the hepatocytes, with the most intense staining in the periportal region (zone 1) (Figure 10.4.5) and a decreasing gradient into zone 2 of the acinus. Electron microscopic examination confirmed the presence of finely granular homogeneous material in the endoplasmic reticulum, supporting the diagnosis of AAT deficiency (Figure 10.4.6).
1 0 . 4 . 2 Higher magnification of the same area as Figure 10.4.1 shows a mild, mostly mononuclear infiltrate of portal zone, mild fatty change, and periportal pigment. Only minimal ductular reaction is present.
FIGURE
The patient underwent transplant approximately 2.5 years later, and the explanted liver demonstrated wellestablished cirrhosis (Figure 10.4.7), with ductopenia.
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C A S E
1 0 . 4 :
N E O N ATA L H E PAT I T I S D U E T O A L P H A - 1 - A N T I T RY P S I N D E F I C I E N C Y
173
FIGURE 10. 4. 3 Perls’ iron stain demonstrates periportal iron deposits in hepatocytes as well as acinar change of hepatocytes in the lobule, with bile stasis present in the lumina of the acini.
F I G U R E 1 0 . 4 . 5 AAT immunostain showed focal granular zone 1 staining for AAT with most prominent staining in the periportal hepatocytes, supporting the diagnosis of AAT deficiency.
FIGURE 10. 4. 4 PASd stain demonstrated small PASd+ granules in
F I G U R E 1 0 . 4 . 6 Electron microscopic examination confirmed the presence of finely granular, amorphous, and homogenous material in the endoplasmic reticulum typical of AAT deposits.
periportal hepatocytes, but with the prominent iron staining present as seen in Figure 10.4.3, this staining might represent lysosomes with iron. In addition, the size of the granules was not diagnostic for AAT globules.
DISCUSSIO N D I AG N OS I S
Alpha-1-antitrypsin deficiency.
Alpha-1-antitrypsin deficiency (AATD) is one of the most common etiologies of neonatal jaundice (1), or neonatal hepatitis–like syndrome, especially in societies with large populations of Northern European descent (2). The pattern of
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FIGURE 10. 4. 7 The explant at age 2.5 years demonstrated cirrhosis
and ductopenia.
LIVER
DISEASE
who present earlier with jaundice (within first 10 weeks of life) are the most likely to develop cirrhosis. Those that do not develop cirrhosis typically have liver biopsies with significantly less fibrosis at presentation. Variation severity of liver disease and pulmonary symptoms is common and may in part be due to genetic modifiers/variants of the defect (2). The diagnosis can often be histologically confirmed by immunohistochemical staining for AAT globules in older patients, but this is not reliable in infants as the globules are often not present until after 3 months of age. AAT can also be positive in unaffected infants, typically as mild cytoplasmic staining without significant granularity or globules. Likewise, PASd+ globules may not be present in neonates, and care must be taken as PASd may also highlight bile and lysosomes in histiocytes. The latter may contain iron or bile in granular forms. Electron microscopic examination will be positive for deposits in the smooth endoplasmic reticulum at this age, but examination for serum phenotype is the confirmatory test of choice.
References presentation of AATD in infancy can vary and include neonatal hepatitis (with or without giant cells), biliary obstruction– like changes (mimicking biliary atresia), paucity of ducts, or a combination of these presentations either simultaneously or sequentially. Children can also present later in life with chronic hepatitis or even cirrhosis. Patients who present in the first 6 months of life with a neonatal hepatitis–like syndrome typically have fully penetrant disease with ZZ phenotype (3,4) and more than 50% progress to cirrhosis in childhood (5). Some progressive cases can be associated with SZ and MZ phenotypes (3,4). Those
1. Jevon GP, Dimmick JE. Histopathologic approach to metabolic liver disease: Part 1. Pediatr Dev Pathol. 1998;1:179–199. 2. Fregonese L. Stolk J. Hereditary alpha-1-antitrypsin deficiency and its clinical consequences. Ophanet J Rare Dis. 2008;3:16. 3. Pittschieler K, Massi G. Liver involvement in infants with PiSZ phenotype of AATD. J Pediatr Gastroenterol Nutr. 1992;15:315–318. 4. Asarian J, Archibald RW, Lieberman J. Childhood cirrhosis associated with AATD. A genetic, biochemical, and morphologic study. J Pediatr. 1975;86;844–850. 5. Nebbia G, Hadchouel M, Odievre M, Alagille D. Early assessment of evolution of liver disease associated with AATD in childhood. J Pediatr. 1983;102:661–665.
11 Sinusoidal Dilatation and Congestion SANJAY KAKAR
Dilatation and congestion of hepatic sinusoids is most commonly observed as a manifestation of vascular congestion due to obstruction of venous outflow from the liver (1,2). However, in around one-third of biopsies with sinusoidal dilatation and congestion, there is no evidence of venous outflow obstruction. The most common clinical scenarios associated with this pattern are discussed below (Table 11.1). 1. Venous outflow obstruction: Obstruction to venous outflow from the liver leads to passive venous congestion manifested as sinusoidal dilatation and congestion that is most pronounced in the zone 3 of the acinus, but can involve zones 1 and 2 in more severe cases (3–7). The increased sinusoidal pressure leads to compression and atrophy of the hepatic plates, a useful diagnostic feature. The increased pressure also leads to extravasation of red blood cell in the space of Disse, hepatocyte atrophy, and necrosis. The congestion and necrosis are most marked in zone 3 of the acinus but can involve zones 1 and 2 in more severe cases. As the disease process becomes chronic, perivenular and sinusoidal fibrosis develops, which can eventually progress to bridging fibrosis and cirrhosis. Venous outflow obstruction can occur at the 3 levels: a. Heart due to cardiac disease (right heart failure, constrictive pericarditis, tricuspid valve disease). b. Large hepatic veins or inferior vena cava (Budd-Chiari syndrome).
2.
3.
TA B LE 11. 1 Sinusoidal dilatation and congestion: differential
diagnosis
4.
Venous Outflow Obstruction Budd-Chiari syndrome
Systemic Inflammatory Diseases Crohn disease
Membranous occlusion of inferior vena cava
Castleman disease
Cardiac disease (right heart failure, tricuspid insufficiency, constrictive pericarditis) Sinusoidal obstruction syndrome (chemotherapeutic drugs, infiltrative disorders like leukemia/lymphoma, sickle cell anemia, extramedullary hematopoiesis, malaria) Other Vascular Etiologies Portal vein thrombosis
Rheumatoid arthritis/Still disease Polymyalgia rheumatica Granulomatous disorders (saroidosis, tuberculosis)
5.
Extrahepatic Neoplasms RCC
6.
Hodgkin lymphoma Carcinoma (stomach, uterus, colon)
Nodular regenerative hyperplasia Abbreviation: RCC, renal cell carcinoma.
175
c. Small hepatic veins (sinusoidal obstruction syndrome, formerly veno-occlusive disease). This most commonly results from chemotherapeutic drugs used in colorectal cancer (oxaliplatin), leukemia/lymphoma (actinomycin D, cytosine arabinoside, anti-CD33 antibody), and immunosuppressive agents like azathioprine, due to injury to sinusoidal endothelial cells and hepatic stellate cells (8,9). This manifests histologically as sinusoidal dilatation and hepatocellular necrosis. It can lead to centrilobular fibrosis, resulting in occlusion of the central veins. Infiltrative disorders that block the sinusoids like sickle cell anemia, leukemia, malaria, and extramedullary hematopoiesis can also lead to dilatation and congestion of sinusoids. Other vascular causes like portal vein thrombosis and nodular regenerative hyperplasia can also lead to sinusoidal dilatation and congestion in the liver. Obstruction of portal vein blood flow to the liver can lead to hepatocyte atrophy and an appearance of dilated sinusoids because of excess sinusoidal volume (6,7,10). Nodular regenerative hyperplasia can lead to sinusoidal dilatation by a combination of compression of hepatic microvasculature and areas of hepatocyte atrophy (11,12). Systemic inflammatory conditions like Crohn disease, rheumatoid arthritis, Still disease, and polymyalgia rheumatica (2,11) as well as granulomatous conditions like sarcoidosis without direct liver involvement (1,11). There are several reports in the literature that describe marked sinusoidal dilatation in liver biopsies in patients with Castleman disease (Figure 11.1) (2,13). Extrahepatic neoplasms without liver involvement: Sinusoidal dilatation has been most commonly associated with renal cell carcinoma (RCC) and Hodgkin lymphoma in the absence of liver involvement (11,14). RCC accompanied by liver dysfunction has been termed Stauffer syndrome (14,15). Sinusoidal dilatation can be seen in around 10% of patients with RCC in the absence of metastatic disease (14). Other tumors that have been associated with sinusoidal dilatation include carcinoma of the stomach, uterus, and colon (11). Drugs: Hormonal agents like oral contraceptives can cause sinusoidal dilatation, especially in zone 1 of the liver. Other: a. Mechanical artifact: Artifactual sinusoidal dilatation can result from mechanical reasons like rough handling or stretching of the biopsy (Figure 11.2). These changes are often more pronounced toward the edges. There is no hepatic plate atrophy or extravasation of RBC into the space of Disse.
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FIGURE 11. 1 Marked sinusoidal dilatation with plate atrophy in
Castleman disease.
b. Intraoperative biopsies: Sinusoidal dilatation can be observed in biopsies obtained during abdominal surgeries (2). The mechanism of sinusoidal dilatation and congestion (SDC) in these situations is unclear, but may be the result of alterations in portal blood flow during abdominal surgery that leads to transient SDC. c. Transplant biopsies: Sinusoidal dilatation is commonly seen in transplant biopsies in the absence of venous outflow obstruction. The reason is not clear, but it may be related to hemodynamic changes related to the vascular anastomosis. d. Cirrhosis and nonneoplastic liver adjacent to tumors: Localized venous outflow obstruction can result from regenerative nodules in cirrhosis or adjacent to mass lesions.
CONGESTION
F I G U R E 1 1 . 2 Artifactual sinusoidal dilatation not accompanied by hepatic plate atrophy.
5.
6.
7.
8.
9.
10.
Based on morphological features, it can be difficult to distinguish venous outflow obstruction from other causes of sinusoidal dilatation and congestion. The presence of prominent congestion and centrizonal fibrosis favor venous outflow obstruction but are not totally reliable for this distinction (2).
11.
References
13.
1. Poulsen H, Winkler K, Christoffersen P. The significance of centrilobular sinusoidal changes in liver biopsies. Scand J Gastroenterol Suppl. 1970;7:103–109. 2. Kakar S, Kamath PS, Burgart LJ. Sinusoidal dilatation and congestion in liver biopsy: is it always due to venous outflow impairment? Arch Pathol Lab Med. 2004;128:901–904. 3. Dilawari JB, Bambery P, Chawla Y, et al. Hepatic outflow obstruction (Budd-Chiari syndrome). Experience with 177 patients and a review of the literature. Medicine (Baltimore). 1994;73:21–36. 4. Tanaka M, Wanless IR. Pathology of the liver in Budd-Chiari syndrome: portal vein thrombosis and the histogenesis of veno-centric cirrhosis,
AND
12.
14.
15.
veno-portal cirrhosis, and large regenerative nodules. Hepatology. 1998; 27:488–496. Iwai M, Kitagawa Y, Nakajima T, et al. Clinical features, image analysis, and laparoscopic and histological liver findings in Budd-Chiari syndrome. Hepatogastroenterology. 1998;45:2359–2368. Wanless IR. Vascular disorders. In: MacSween RNM, Burt AD, Portman BC, Ishak KG, Scheuer PJ, Anthony PP, eds. Pathology of the Liver. 4th ed. New York, NY: Churchill Livingstone, Inc.; 2002:539–574. Kakar S, Batts KP, Poterucha JJ, Burgart LJ. Histologic changes mimicking biliary disease in liver biopsies with venous outflow impairment. Mod Pathol. 2004;17:874–878. Kandutsch S, Klinger M, Hacker S, Wrba F, Gruenberger B, Gruenberger T. Patterns of hepatotoxicity after chemotherapy for colorectal cancer liver metastases. Eur J Surg Oncol. 2008;34:1231–1236. Kumar S, DeLeve LD, Kamath PS, Tefferi A. Hepatic veno-occlusive disease (sinusoidal obstruction syndrome) after hematopoietic stem cell transplantation. Mayo Clin Proc. 2003;78:589–598. Shimamatsu K, Wanless IR. Role of ischemia in causing apoptosis, atrophy, and nodular hyperplasia in human liver. Hepatology. 1997;26: 343–350. Bruguera M, Aranguibel F, Ros E, Rodes J. Incidence and clinical significance of sinusoidal dilatation in liver biopsies. Gastroenterology. 1978;75:474–478. Reshamwala PA, Kleiner DE, Heller T. Nodular regenerative hyperplasia: not all nodules are created equal. Hepatology. 2006;44:7–14. Curciarello J, Castelletto R, Barbero R, et al. Hepatic sinusoidal dilatation associated to giant lymph node hyperplasia (Castleman’s): a new case in a patient with periorbital xanthelasmas and history of celiac disease. J Clin Gastroenterol. 1998;27:76–78. Aoyagi T, Mori I, Ueyama Y, Tamaoki N. Sinusoidal dilatation of the liver as a paraneoplastic manifestation of renal cell carcinoma. Hum Pathol. 1989;20:1193–1197. Delpre G, Ilie B, Papo J, Streifler C, Gefel A. Hypernephroma with nonmetastatic liver dysfunction (Stauffer’s syndrome) and hypercalcemia. Am J Gastroenterol. 1979;72:239–247.
Case 11.1
Budd-Chiari Syndrome Versus Biliary Disease SANJAY KAKAR
C L I N IC AL I N F OR M AT I ON
A 35-year-old woman presented with fatigue and abdominal pain. She has been on oral contraceptives for 5 years; there is no other history of medications. Physical exam revealed mild ascites, jaundice, mildly enlarged liver, and splenomegaly. Liver enzyme tests revealed elevation of alkaline phosphatase (5 times normal) and transaminases were slightly elevated (twice normal). Serological tests for hepatitis viruses and autoantibodies were negative. Ultrasound showed an enlarged liver, but the large bile ducts were normal and there was no evidence of bile duct obstruction.
lymphocytic infiltration of the bile duct is seen (lymphocytic cholangitis), but overt bile duct damage or duct loss was not seen (Figure 11.1.6).
DIAGNO SIS
Budd-Chiari syndrome (BCS) associated with portal changes mimicking chronic biliary disease.
R E A SON F OR R E F E R R AL
The biopsy shows features suggestive of bile duct obstruction, but there is no clinical or radiological evidence of biliary disease.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows zone 3 sinusoidal dilatation and congestion with hepatic plate atrophy (Figure 11.1.1) and hepatocellular necrosis (Figure 11.1.2). These changes are accompanied by extravasation of red blood cells into the space of Disse (Figure 11.1.3). Fibrosis is present in the pericentral region. In addition, most of the portal tracts show mild lymphocytic infiltrate and mild bile ductular reaction (Figure 11.1.4) with florid reaction in 1 portal tract (Figure 11.1.5). Focal
FIGURE 11. 1. 1 Sinusoidal dilatation and congestion predominantly
in zone 3 accompanied by hepatic plate atrophy.
F I G U R E 1 1 . 1 . 2 Hepatocellular necrosis around the central vein.
F I G U R E 1 1 . 1 . 3 The red blood cells have been pushed from the sinusoids into the potential space between the sinusoidal endothelium and hepatocytes (space of Disse).
177
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D I L ATAT I O N
FIGURE 11. 1. 4 Mild bile ductular reaction with intact bile duct.
AND
CONGESTION
F I G U R E 1 1 . 1 . 6 Mild portal lymphocytic inflammation with focal
bile duct involvement. TA BL E 1 1 . 1 . 1 Budd-chiari syndrome: etiology
FIGURE 11. 1. 5 Mild portal inflammation and prominent ductular
reaction in 1 portal tract.
D I SC U SSI ON
The pathologic features strongly raise the possibility of venous outflow obstruction. Based on the biopsy features, a CT scan was performed and demonstrated hepatic vein thrombosis, confirming the diagnosis of BCS. No abnormalities were seen in the biliary tree. Based on the history, the BCS is likely to be due to hypercoaguable state as a result of oral contraceptive use. Most cases of BCS present in a subacute fashion with painful hepatomegaly and ascites. In some instances, the diagnosis is made during the workup for chronic liver disease or cirrhosis. Rare cases can present with an acute fulminant picture; this presentation carries a very poor prognosis with 80% mortality (1,2). The important etiologies of BCS are listed in Table 11.1.1. The diagnosis of BCS is made by imaging techniques and biopsy. Ultrasound with Doppler flow studies is the
Thrombotic Causes
Mechanical Causes
(a) Hypercoaguable states Myeloproliferative disorders Pregnancy and oral contraceptives Antiphospholipid antibodies (SLE) Paroxysmal nocturnal hemoglobinuria Factor V Leiden
Membranous obstruction of inferior vena cava
(b) Factor deficiencies Protein C deficiency Protein S deficiency Antithrombin deficiency
Posttransplant kinking of hepatic venous outflow
Obstruction by tumor Extrinsic compression by tumor or mass
initial tool of choice; hepatic scintigraphy, CT, and MRI can also contribute to the diagnosis. Hepatic venography was considered the gold standard, but is now restricted to diagnostically challenging cases. The inflammation and ductular reaction in the portal tracts in this case raise the possibility of biliary disease. Since venous outflow obstruction can be associated with cholestasis and elevated alkaline phosphatase, the clinical profile can further reinforce the suspicion of a biliary etiology. The literature and textbooks have emphasized centrizonal changes in venous outflow obstruction, whereas portal changes are often overlooked. Portal tract changes that mimic biliary disease are frequently present in venous outflow obstruction. In a study of 34 patients with a confirmed diagnosis of venous outflow obstruction, pathologic changes in the portal tracts were present in more than half of the cases (3). The liver biopsies in these cases showed portal expansion with bile ductular reaction with mild lymphoplasmacytic infiltrate and portal or periportal fibrosis in nearly half of the cases. The ductular reaction is generally mild but can occasionally be florid. In few cases, there can be bile duct damage in the form of lymphocytic cholangitis. In some instances, periportal fibrosis can be seen without ductular reaction.
CASE
11.1
:
BUDD-CHIARI
SYNDROME
Although imaging studies can be done to confirm the absence of bile duct abnormalities depending on the clinical context, awareness of these morphologic changes can prevent overemphasizing the risk of biliary disease in this setting. The mechanism of bile ductular reaction in venous outflow obstruction is not known. It may be the result of low level of ischemic damage to the biliary tree as a result of increased venous pressure or compromised arterial flow due to abnormal shunts. Fibrosis in BCS typically starts as sinusoidal fibrosis around the central vein, but can progress to cirrhosis. Fibrosis is often present in cases with acute presentation, indicating that longstanding subclinical obstruction has been present (3). Based on the biopsy findings, other causes of venous outflow like right heart failure, tricuspid valve disease, and
VERSUS
BILIARY
DISEASE
179
constrictive pericarditis can be considered. However, there is no evidence of cardiac or pericardial disease based on clinical information. Similarly, there is no clinical basis to consider other causes of sinusoidal dilatation and congestion (Table 11.1.1).
References 1. Powell-Jackson PR, Ede RJ, Williams R. Budd-Chiari syndrome presenting as fulminant hepatic failure. Gut. 1986;27:1101–1105. 2. Sandle GI, Layton M, Record CO, Cowan WK. Fulminant hepatic failure due to Budd-Chiari syndrome. Lancet. 1980;1:1199. 3. Kakar S, Batts KP, Poterucha JJ, Burgart LJ. Histologic changes mimicking biliary disease in liver biopsies with venous outflow impairment. Mod Pathol. 2004;17:874–878.
Case 11.2
Sinusoidal Obstruction SANJAY KAKAR
C L I N I C A L I N F OR M AT I ON
A 27-year-old woman presented with acute onset of right upper quadrant pain and nausea. There is no significant medication history. There were 2 similar episodes in the past that had resolved spontaneously. On examination, there was jaundice and tender hepatomegaly. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were 350 IU/L; alkaline phosphatase was slightly elevated. Serum bilirubin was 10 mg/dL, with 70% being conjugated. Serological studies for hepatitis A, B, and C were negative. There were no autoantibodies and serum ceruloplasmin is normal. Gallbladder and large bile ducts were normal on ultrasound. R E A S ON F OR R E F E R R A L
The history and liver enzymes suggest acute hepatocellular injury, but there is minimal inflammation or hepatocellular injury on the biopsy.
F I G U R E 1 1 . 2 . 2 Mild dilatation and prominent congestion of sinu-
soids observed throughout the biopsy.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows normal portal tracts lacking significant inflammation and intact bile ducts. The hepatic parenchyma shows minimal hepatocellular damage, scattered prominent Kupffer cells and no significant inflammation (Figure 11.2.1). Sinusoidal dilatation is present throughout the biopsy but is not marked (Figure 11.2.2). Many of the dilated sinusoids are congested and are clogged with red blood cells (Figure 11.2.3). There is no fibrosis.
F I G U R E 1 1 . 2 . 3 Marked congestion is uniformly present in the
sinusoids.
DIAGNO SIS
Acute hepatic sickle cell crisis.
DISCUSSIO N FIGURE 11. 2. 1 Normal portal tracts and no significant inflamma-
tion or hepatocellular damage.
The clinical information indicates an acute process with hepatocellular injury evidenced by rise in transaminases. However, there is no significant inflammation and hepatocellular damage
180
CASE
11.2
:
SINUSOIDAL
is minimal. The sinusoidal dilatation and congestion raises the possibility of venous outflow obstruction. Based on the clinical information, there is no history of cardiac disease and the imaging studies were negative for Budd-Chiari syndrome. The clinical scenario does not support other etiologies of sinusoidal dilatation and congestion like systemic autoimmune disorders, granulomatous disorders, Castleman disease, and neoplasms. A closer examination of the congested hepatic sinusoids reveals that many are packed with sickle-shaped red blood cells (Figure 11.2.4). Further clinical information revealed that the patient had sickle cell anemia.
OBSTRUCTION
181
Hyperbilirubinemia in sickle cell anemia can result from hemolysis, biliary obstruction due to stones, and sickle cell hepatopathy (1–5). There is no evidence of active hemolysis or biliary obstruction in this patient. The clinical and pathologic features establish the diagnosis of acute hepatic sickle cell crisis. Sickle cell crisis selectively involves the liver in 10% of patients with sickle cell anemia, and less commonly with sickle cell trait (3). In most instances, it is a self-limited disease that results from ischemia due to vascular occlusion by sickled RBCs. The liver biopsy shows sinusoidal dilatation and congestion, sickled RBCs, focal necrosis, variable cholestasis, and prominent Kupffer cells (2,3). In rare instances, a severe variant of hepatic sickle cell crisis can result in widespread sickling and ischemic hepatocellular damage (3,4). The liver shows swollen hepatocytes, prominent necrosis, and marked cholestasis. This complication can be fatal, and the liver disease can be complicated by renal failure, hemorrhage, and encephalopathy. In severe cases, liver biopsy can be hazardous due to coagulopathy (4).
References
FIGURE 11. 2. 4 The sinusoids are packed with sickled red blood cells (sickle cell thrombi).
1. Mills LR, Mwakyusa D, Milner PF. Histopathologic features of liver biopsy specimens in sickle cell disease. Arch Pathol Lab Med. 1988;112:290–294. 2. Charlotte F, Bachir D, Nénert M, et al. Vascular lesions of the liver in sickle cell disease. A clinicopathological study in 26 living patients. Arch Pathol Lab Med. 1995;119:46–52. 3. Banerjee S, Owen C, Chopra S. Sickle cell hepatopathy. Hepatology. 2001;33:1021–1028. 4. Ahn H, Li CS, Wang W. Sickle cell hepatopathy: clinical presentation, treatment, and outcome in pediatric and adult patients. Pediatr Blood Cancer. 2005;45:184–190. 5. Bandyopadhyay R, Bandyopadhyay SK, Dutta A. Sickle cell hepatopathy. Indian J Pathol Microbiol. 2008;51:284–285.
Case 11.3
Veno-Occlusive Disease (Sinusoidal Obstruction Syndrome) SANJAY KAKAR
C L I N C A L I N F OR M AT I ON
A 42-year-old male with acute myeloid leukemia underwent stem cell transplantation. Two weeks later, he presented with weight gain, right upper quadrant pain, and jaundice. Physical examination revealed tender hepatomegaly and ascites. The liver enzymes showed elevated ALT and AST (both 500 IU/L) and alkaline phosphatase was twice normal. Doppler ultrasound revealed blood flow away from the liver in the portal vein. R E A S ON F OR R E F E R R A L
To establish the etiology of centrizonal necrosis in the setting of stem cell transplantation. PAT H OL OG I C F E AT U R E S
The liver biopsy showed marked dilatation and congestion of sinusoids around the central vein (Figure 11.3.1). The central veins show marked edema in the subendothelial region and perivenular necrosis (Figure 11.3.2). Similar changes are seen in the small hepatic vein (Figure 11.3.3). There is no significant inflammation and the portal tracts are normal. Trichrome stain showed mild sinusoidal fibrosis around the central vein.
F I G U R E 1 1 . 3 . 2 Subendothelial edema in the central vein with surrounding hepatocellular swelling and necrosis.
D I AG N OS I S
Sinusoidal obstruction syndrome (SOS) related to stem cell transplantation.
F I G U R E 1 1 . 3 . 3 Subendothelial edema in small hepatic venule with
perivenular necrosis.
DISCUSSIO N
FIGURE 11. 3. 1 Marked sinusoidal dilatation, congestion, and hepatic plate atrophy.
The striking sinusoidal changes and centrizonal injury implicate venous outflow obstruction. The clinical information and imaging studies do not support cardiac disease, Budd–Chiari syndrome, or other causes of sinusoidal dilatation and congestion. The history of stem cell transplantation and the biopsy findings confirm the diagnosis of veno-occlusive disease or SOS. SOS is thought to result from injury to the sinusoidal and venular endothelial cells (1–3). Recent studies have indicated
182
CASE
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:
VENO-OCCLUSIVE
that the primary event is sinusoidal injury and involvement of hepatic venules may not be always present. Hence, the term SOS has been proposed to replace veno-occlusive disease (1). The endothelial injury leads to edematous thickening of the subintimal zone of small hepatic veins, which in turn causes venous outflow obstruction with sinusoidal dilatation, congestion, and hepatocellular necrosis. Fibrin thrombi can be seen, but are uncommon. With time, venular and sinusoidal fibrosis can develop. In addition to stem cell or bone marrow transplant (1,4), SOS can also be observed due to endothelial injury as a result of chemotherapy (Table 11.3.1). A wide variety of drugs have been implicated. Oxaliplatin is used to reduce the size of liver metastasis from colorectal cancer before surgery and has been associated with SOS (5–7). Several drugs used for the treatment of leukemia/lymphoma and long-term use of immunosuppressive agent azathioprine have also been associated with SOS (4). Historically, veno-occlusive disease has been described as a result of toxicity of pyrrolizidine alkaloids in herbal medications as well as in herbal tea in southern Africa (8,9). Rare cases of veno-occlusive disease have been reported with liver transplantation and have a strong association with azathioprine use and acute rejection (10,11). The clinical diagnosis of SOS can be challenging. In the setting of stem cell transplantation, it typically occurs in the first 3 weeks. Clinical and laboratory features like weight gain due to salt and water retention by the kidneys, hyperbilirubuinemia, and reverse flow in portal vein on Doppler ultrasound raise the suspicion for SOS. Plasma levels of plasminogen activator inhibitor-1 are often elevated. Liver biopsy TA B LE 11. 3. 1 Etiologies of hepatic veno-occlusive disease (sinusoi-
dal obstruction syndrome) Chemotherapeutic Agents Colorectal cancer: oxaliplatin Leukemia/lymphoma: actinomycin D, mithramycin, dacarbazine, cytosine arabinoside, 6-thioguanine, anti-CD33 monoclonal antibody Immunosuppressive: azathioprine Radiation Therapy Abdominal radiation for Wilms tumor Transplant Related Stem cell transplantation Liver transplantation Toxins Pyrrolizidine alkaloids in African bush tea Herbal medications
DISEASE
183
can establish the diagnosis, but changes can be patchy in early disease leading to false-negative results (4). Overall, 50% to 80% of patients with SOS recover. The outcome of severe SOS is poor with high mortality (4). Other causes of hepatic dysfunction after stem cell transplant include acute graft versus host disease (GVHD), drug-induced hepatitis, infections, and relapse of leukemia with liver involvement. Typical features of GVHD like bile duct damage and apoptosis are not seen in SOS, whereas centrizonal hepatocellular damage is not characteristic of GVHD. Immunosuppressive agents like cyclosporine, a wide variety of antibiotics, and antifungal drugs can lead to drug-induced hepatitis. The presence of prominent inflammation, cholestasis, and noncentrizonal pattern of hepatocellular injury favors drug-induced hepatitis. The liver biopsy should always be evaluated for fungal organisms and involvement by leukemia/ lymphoma.
References 1. Shulman HM, Fisher LB, Schoch HG, Henne KW, McDonald GB. Venoocclusive disease of the liver after marrow transplantation: histological correlates of clinical signs and symptoms. Hepatology. 1994;19:1171– 1181. 2. DeLeve LD, Shulman HM, McDonald GB. Toxic injury to hepatic sinusoids: sinusoidal obstruction syndrome (veno-occlusive disease). Semin Liver Dis. 2002;22:27–42. 3. DeLeve LD. Hepatic microvasculature in liver injury. Semin Liver Dis. 2007;27(4):390–400. 4. Kumar S, DeLeve LD, Kamath PS, Tefferi A. Hepatic veno-occlusive disease (sinusoidal obstruction syndrome) after hematopoietic stem cell transplantation. Mayo Clin Proc. 2003;78:589–598. 5. Kandutsch S, Klinger M, Hacker S, Wrba F, Gruenberger B, Gruenberger T. Patterns of hepatotoxicity after chemotherapy for colorectal cancer liver metastases. Er J Surg Oncol. 2008;34:1231–1236. 6. Karoui M, Penna C, Amin-Hashem M, et al. Influence of preoperative chemotherapy on the risk of major hepatectomy for colorectal liver metastases. Ann Surg. 2006;243:1–7. 7. Nordlinger B, Benoist S. Benefits and risks of neoadjuvant therapy for liver metastases. J Clin Oncol. 2006;24:4954–4955. 8. Datta DV, Khuroo MS, Mattocks AR, Aikat BK, Chhuttani PN. Herbal medicines and veno-occlusive disease in India. Postgrad Med J. 1978;54:511–515. 9. Ridker PM. Hepatic veno-occlusive disease and herbal teas. J Pediatr. 1989;115:167. 10. Dhillon AP, Burroughs AK, Hudson M, Shah N, Rolles K, Scheuer PJ. Hepatic venular stenosis after orthotopic liver transplantation. Hepatology. 1994;19:106–111. 11. Sebagh M, Debette M, Samuel D, et al. “Silent” presentation of veno-occlusive disease after liver transplantation as part of the process of cellular rejection with endothelial predilection. Hepatology. 1999;30: 1144–1150.
Case 11.4
Amyloidosis SANJAY KAKAR
C L I N I C AL I N F OR M AT I ON
A 55-year-old woman with compensated biventricular heart failure had elevated liver enzymes (ALT 135, AST 125, ALP 425 U/L). These abnormalities were thought to be due to passive venous congestion. The ultrasound showed a nodular appearance raising concern for cirrhosis. Occasional larger nodules (2–3 cm) were also noted. A wedge liver biopsy was performed to assess the degree of liver damage and evaluate the liver nodules.
R E A S ON F OR R E F E R R A L
The liver showed a nodular appearance, but definite fibrosis or venous congestion was not seen. F I G U R E 1 1 . 4 . 2 The hepatocyte cell plates at the periphery of the
PAT H OL OG I C F E AT U R E S
nodules are compressed and atrophic.
The liver showed a nodular architecture (Figure 11.4.1) with compression of cell plates at the periphery of the nodules (Figure 11.4.2). Reticulin stain highlighted the nodular architecture. Trichrome stain showed lack of fibrous septa between the nodules (Figure 11.4.3). The portal tracts lacked significant inflammation, and bile ducts were intact. Globular eosinophilic deposits were seen in the sinusoids in some areas (Figure 11.4.4). The deposits showed homogenous light staining on trichrome (Figure 11.4.5). Congo red stain was positive in the deposits and showed apple-green birefringence under polarized light.
F I G U R E 1 1 . 4 . 3 Trichrome stain highlights the nodules and shows
lack of fibrous septa.
DIAGNO SIS
Amyloidosis with nodular regenerative hyperplasia.
DISCUSSIO N FIGURE 11. 4. 1 Nodular architecture of the liver without fibrous
septa.
Amyloidosis is a heterogeneous group of diseases characterized by deposition of glycoprotein fibrils in the extracellular matrix and blood vessel walls. The most common presenting
184
CASE
11.4
:
FIGURE 11. 4. 4 The sinusoids show globular eosinophilic deposits in
some areas of the biopsy.
AMYLOIDOSIS
185
has not been confirmed in a large Mayo Clinic series (33). Hepatic involvement portends a poor prognosis, as it is a reflection of advanced disease. Median survival is only 9 months and the 5-year survival 17%. Elevated bilirubin and congestive heart failure are adverse prognostic factors. Depending on the biochemical composition of the fibrils, amyloidosis can be divided into several subtypes. In primary or AL amyloidosis, the deposits are composed of monoclonal immunoglobulin light chain fragments. Some cases occur in association with systemic hematologic diseases like multiple myeloma and Waldenstrom macroglobulinemia. In secondary or AA amyloidosis, the deposits are composed of fragments of serum amyloid A, an acute phase reactant. The liver can be involved in dialysis-related amyloidosis, in which the deposits are composed of beta-2-microglobulin and is a consequence of decrease in renal excretory function. Liver involvement can be seen in up to 70% of cases and occurs in both AL (primary) and AA (secondary) amyloidosis. Amyloid deposition can occur in the sinusoids or blood vessel walls; both locations are affected in 20% of cases. The deposits are more often seen in blood vessels in AA amyloidosis (Figures 11.4.6 and 11.4.7), whereas the sinusoids are more commonly affected in AL amyloidosis (Figure 11.4.8). However, there is considerable overlap in these distribution patterns, and these are not reliable for definite distinction between AL and AA amyloidosis (35,36). The amyloid fibrils stain with Congo red and show apple-green birefringence under polarized light. The color varies from yellow-green to blue-green and can change with the rotation of the polarizer or analyzer. Different colors may be seen in different areas of the biopsy. Demonstration of birefringence is facilitated by using thick sections (10 microns), turning light to the maximum and pulling out color filters. Congophilia can be reduced after prolonged fixation. Examination of amyloid fibrils on Congo red-stained sections by a fluorescence microscope using fluorescein
FIGURE 11. 4. 5 Pale homogenous appearance of the sinusoidal
deposits on trichrome stain.
symptoms include weight loss, fatigue, abdominal pain, anorexia, early satiety, nausea, and dysgeusia. Hepatomegaly, ascites, edema, purpura, and splenomegaly can be present (32–34). In majority of the cases, extrahepatic manifestations such as nephrotic syndrome, heart failure, peripheral neuropathy, orthostatic hypotension, and/or carpal tunnel syndrome are also present. The most common biochemical abnormality is elevated alkaline phosphatase; mild elevation of liver transaminases occurs in one-third of cases (32–34). Due to the nonspecific symptoms and laboratory abnormalities, the diagnosis can easily be overlooked clinically. The presence of involuntary weight loss, hepatomegaly, and unexplained elevation of ALP, proteinuria, or hyposplenism should raise the clinical suspicion for hepatic amyloidosis. There has been concern about the risk of hepatic rupture following liver biopsy for amyloidosis, but
F I G U R E 1 1 . 4 . 6 Amyloid deposits in the blood vessels walls in the
portal tract.
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D I L ATAT I O N
FIGURE 11. 4. 7 Congo red stain highlights the amyloid deposits in
the vessel walls.
AND
CONGESTION
of nonimmunological origin. Electron microscopy is seldom required for diagnosis but can demonstrate central electronlucent core and nonbranching fibrils of indefinite length with a mean diameter of 10 nm. Deposition of monoclonal protein (M-protein) in tissue can occur in light-chain deposition disease, heavy-chain deposition disease, and light- and heavy-chain deposition disease (37,38). Deposition of amyloid-like noncongophilic occurs in the kidney in fibrillary and immunotactoid glumerulopathies. In rare instances, these are associated with extrarenal sites including liver (39,40). The fibrils in these conditions have larger diameter compared to amyloid fibrils, and electron microscopy is required for the distinction. In most cases, sinusoidal deposition of amyloid is obvious on the biopsy (Figure 11.4.8). In some instances, the deposits can be subtle, and the diagnosis requires a high index of suspicion. Nodular sinusoidal deposition of amyloid as in this case can be easily overlooked. The pale homogenous staining of amyloid on trichrome stain can be very helpful in raising the suspicion of amyloidosis. In this case, the amyloidosis was accompanied by nodular regenerative hyperplasia, a nonspecific response to vascular injury as a result of diverse etiologies (see Chapter 13). Further investigations revealed that the heart failure was a result of cardiac amyloidosis.
References
FIGURE 11. 4. 8 Congo red stain shows extensive sinusoidal amyloid
deposits with atrophy of hepatic plates.
isothiocyanate filter shows yellow fluorescence but is not specific for amyloid. Glycoprotein P component is present in all amyloid deposits, which can be demonstrated by immunohistochemistry. Immunohistochemistry for specific proteins like immunoglobulin light chains (AL amyloid) and SAA (AA amyloid) can also be done for further classification. Background staining can make interpretation difficult. Immunoglobulin deposits can occasionally be seen in amyloid
1. Gertz MA, Kyle RA. Hepatic amyloidosis (primary [AL], immunoglobulin light chain): the natural history in 80 patients. Am J Med. 1988;85:73–80. 2. Park MA, Mueller PS, Kyle RA, Larson DR, Plevak MF, Gertz MA. Primary (AL) hepatic amyloidosis: clinical features and natural history in 98 patients. Medicine (Baltimore). 2003;82:291–298. 3. Malnick S, Melzer E, Sokolowski N, Basevitz A. The involvement of the liver in systemic diseases. J Clin Gastroenterol. 2008;42:69–80. 4. Chopra S, Rubinow A, Koff RS, et al. Hepatic amyloidosis. A histopathologic analysis of primary (AL) and secondary (AA) forms. Am J Pathol. 1984;115:186–193. 5. Buck FS, Koss MN. Hepatic amyloidosis: morphologic differences between systemic AL and AA types. Hum Pathol. 1991;22:904–907. 6. Faa G, Van Eyken P, De Vos R, Fevery J, Van Damme B, De Groote J, Desmet VJ. Light chain deposition disease of the liver associated with AL-type amyloidosis and severe cholestasis. J Hepatol. 1991;12:75–82. 7. Buxbaum J, Gallo G. Nonamyloidotic monoclonal immunoglobulin deposition disease. Light-chain, heavy-chain, and light- and heavy-chain deposition diseases. Hematol Oncol Clin North Am. 1999;13:1235–1248. 8. Strøm EH, Hurwitz N, Mayr AC, Krause PH, Mihatsch MJ. Immunotactoid-like glomerulopathy with massive fibrillary deposits in liver and bone marrow in monoclonal gammopathy. Am J Nephrol. 1996; 16:523–528. 9. Hvala A, Ferluga D, Vizjak A, Koselj-Kajtna M. Fibrillary noncongophilic renal and extrarenal deposits: a report on 10 cases. Ultrastruct Pathol. 2003;27:341–347.
12 Peliosis Hepatis SANDRA FISCHER AND MAHA GUINDI
I N T ROD U C T I ON
TA BL E 1 2 . 1 Causes of peliosis hepatis
Peliosis hepatis is a condition with many underlying etiologies. It is defined as cystic blood-filled spaces in the liver and other organs (eg, spleen, lymph nodes). Peliosis hepatis has been recognized of clinical significance only since the middle of the 20th century. The term peliosis was originally applied to macroscopic lesions that look dusky or purple in color. Microscopic lesions may be confused with severe sinusoidal dilatation or with “evacuation of the liver cell plates,” a lesion seen after zonal hepatocellular dropout but without loss of the normal reticulin fibers (1) (Figure 12.1). The pathogenesis of peliosis hepatis is unknown. The lesion has been produced in experimental animals by administration of phalloidin presumably as a result of damage to the sinusoidal wall. Focal apoptosis of hepatocytes or sinusoidal endothelial cells and disruption of liver extracellular matrix seem to play a role in the pathogenesis (2). According to the mechanism of injury to the sinusoidal wall, the lesions can be classified as phlebectatic type, if associated with an intrinsic weakness of the wall, or parenchymal type, when secondary to hepatocyte necrosis (1). The blood-filled cystic spaces may have no endothelial lining initially, but subsequent re-endothelialization probably occurs. The lesions are randomly distributed without zonal preference. Anabolic steroids, diethylstilboestrol contraceptive steroids, tamoxifen, azathioprine, vitamin A, and thorotrast have been implicated as causative agents in humans (see Table 12.1). Microscopic lesions occur in patients receiving thiopurines for renal transplantation, liver transplantation, or various malignancies. A variety of chronic diseases including malnutrition,
Drugs
Androgens, arsenic compounds, azathioprine, busulfan, chemotherapeutic agents, contraceptive steroids, corticosteroids, danazol, diethylstilboestrol, estrone sulfate, fluoxymesterone, glucocorticoids, hydroxyprogesterone, hydroxyurea, medroxyprogesterone, mercaptopurine, methandrostenolone, methotrexate, methyltestosterone, synthetic estrogens, tamoxifen, testosterone, thioguanine, thorotrast, vinyl chloride, and vitamin A.
Chronic conditions
Malnutrition, tuberculosis, leprosy, vasculitis, bartonellosis, AIDS, and other immunosuppressed states.
Neoplasms
Hepatocellular adenoma/carcinoma, angiosarcoma, hairy cell leukemia, angioimmunoblastic lymphadenopathy, myeloproliferative disorders, Waldenström’s macroglobulinemia with light chain deposition, and Hodgkin disease.
leukemia, tuberculosis, leprosy, vasculitis, and AIDS have also been reported with macroscopic peliotic lesions. Peliotic lesions found in AIDS and other immunosuppressed patients are caused by rickettsial organisms (Bartonella species). The lesions are visible as red spots beneath the capsule of the liver, which may be greatly enlarged. Histologically, they appear as 1 to 4 mm cysts within the parenchyma, containing blood. These lesions have a myxoid stroma that has a bluish haze on routine haematoxylin and eosin staining and contain clumps of organisms that can be identified with Warthin-Starry staining. Patients often have peliosis of the spleen and lymph nodes and cutaneous angiomatous lesions. Increased alkaline phosphatase is usually present. The lesions do respond to antibiotics and should be distinguished from Kaposi sarcoma (1). Peliosis of the liver and spleen may be the result of sinusoidal wall injury induced by tumor cells. Peliosis hepatis also occurs within hepatocellular neoplasms such as adenoma and carcinoma, and angiosarcoma. Peliosis hepatis has rarely been associated with hairy cell leukemia, angioimmunoblastic lymphadenopathy, myeloproliferative disorders, and Waldenström’s macroglobulinemia. Peliosis hepatis and sinusoidal dilatation involving the perivenular and midzones have been reported in patients with Hodgkin disease. Although peliosis hepatis is usually of no clinical significance, macroscopic peliosis of liver or spleen may rupture spontaneously or after trauma.
References
FIGURE 12. 1 Peliosis hepatis. Low power view of blood-filled space
within liver parenchyma.
187
1. Wanless IR. Vascular disorders. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 5th ed. Philadelphia, PA: Churchill Livingstone/Elsevier; 2007:628–630. 2. Crawford JM, Liu C. Liver and biliary tract. In: Robbins, Cotran, eds. Pathologic Basis of Disease. 8th ed. Philadelphia, PA: Saunders/Elsevier; 2010:872.
Case 12.1
Alcoholic Lipopeliosis SANDRA FISCHER AND MAHA GUINDI
C L I N I C AL I N F OR M AT I ON
A 53-year-old man presented with decompensated end-stage liver disease due to alcoholic cirrhosis. The patient had been abstinent from alcohol for approximately 8 months prior to receiving a liver transplant. He was admitted 2 weeks prior to transplantation, with hepatorenal syndrome, encephalopathy, and refractory ascites. On the day preceding transplantation he developed hematemesis and hypotension and underwent upper endoscopy but no upper gastrointestinal source of bleeding was identified and no varices were seen. R E A S ON F OR R E F E R R A L
Decompensated cirrhosis likely due to alcoholic cirrhosis. PAT H OL OG I C F E AT U R E S
FIGURE 12.1.1 Alcoholic lipopeliosis. High power view of regenerative
The explanted liver showed severe cirrhosis, mild steatosis, but no active steatohepatitis. Many of the parenchymal nodules showed hepatocyte dropout of varying degrees, including dropout of the entire nodule, consistent with the ischemic complications of end-stage cirrhosis. There was a recanalized thrombus in the main portal vein, a common finding in end-stage cirrhosis and a feature that might lead to the necrosis of nodules. The sinusoids were dilated in areas and filled with large fat globules (Figure 12.1.1). The amount of lipopeliosis was small and focal, likely mirroring the small amount of steatosis.
nodule from explanted liver with alcohol-related cirrhosis showing fat globules released in distended sinusoids (elastic trichrome stain).
188
DIAGNO SIS
Alcoholic lipopeliosis arising in a setting of alcoholic cirrhosis.
Case 12.2
Lipopeliosis in Transplanted Donor Livers SANDRA FISCHER AND MAHA GUINDI
C L I N IC AL I N F OR M AT I ON
This is a deceased donor liver that had been retrieved at another hospital. Cold ischemic time was prolonged and the left lobe appeared ischemic. This was resected and the right lobe was engrafted. R E A SON F OR R E F E R R AL
Liver transplantation. PAT H OL OG I C F E AT U R E S
Histologic examination of the resected left lobe revealed zone 3 necrosis, which is in keeping with ischemic injury. There were perivenular (zone 3) large fat globules present within the sinusoids but not accompanied by an inflammatory reaction (Figure 12.2.1). A posttransplant liver biopsy of the right lobe showed typical lipopeliosis and cholestasis (Figure 12.2.2).
D I AG N OS I S
Lipopeliosis related to preservation injury.
D I S C U S S I ON
The term “lipopeliosis” had been introduced in 1992 to characterize an unusual liver lesion in which the sinusoids appear to become engorged by large fat globules (1). The mechanism
FIGURE 12. 2. 1 Early posttransplant cholestasis with lipopeliosis.
Low power view of biopsy showing steatosis and fat globules released in distended sinusoids.
F I G U R E 1 2 . 2 . 2 Alcoholic lipopeliosis. Macrophages around released fat (CD68 immunostain).
by which the lesion develops is that hepatocyte necrosis occurs in a steatotic graft after transplantation due to ischemia or preservation injury. The fat globules are then released from the injured hepatocytes and are sequestered in the sinusoids and/or the space of Disse (2). Lipopeliosis documented 1 week after transplantation can be cleared within 25 days, probably by macrophages. The clinical outcome can vary greatly and most probably depends on the extent of hepatocellular necrosis. Lipopeliosis seems to be fairly common; when it occurs it is not the primary cause of graft dysfunction (3). The “lipopeliosis” lesion has also been reported in native livers with alcoholic and nonalcoholic steatohepatitis and chronic hepatitis C with steatosis (4). In the nontransplant setting, a superimposed insult (eg., portal vein thrombosis, shock, hypovolemia associated with severe ascites and diuresis, or toxic/drug-related injury) may contribute to liver cell injury and necrosis, with the release of fat globules into the space of Disse. The lesion is easily detectable when florid but can be very subtle when mild, or when the biopsy is done later on in the course of the lesion, it may by then have started to resolve. A trichrome stain may help to make the extruded fat droplets stand out in contrast against the darker-staining surrounding hepatocytes (5). CD68 immunoperoxidase stain demonstrates the cytoplasm of macrophages surrounding the “empty spaces” that represent the extruded fat droplets indicating that the fat is no longer within the hepatocytic cytoplasm (Figure 12.2.2). Factor VIII–related antigen and type IV collagen immunoperoxidase stains help to delineate the contours of dilated sinusoids, or may show that fat droplets are present just outside the sinusoid, in the space of Disse and are compressing the sinusoids (Figure 12.2.3) (2).
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H E PAT I S
References 1. Ferrell L, Bass N, Roberts J, Ascher N. Lipopeliosis: fat induced sinusoidal dilatation in transplanted liver mimicking peliosis hepatis. J Clin Pathol. 1992;45:1109–1110. 2. Cha I, Bass N, Ferrell LD. Lipopeliosis. An immunohistochemical and clinicopathologic study of five cases. Am J Surg Pathol. 1994;18: 789–795. 3. Bioulac-Sage P, Balabaud C, Ferrell L. Lipopeliosis revisited: should we keep the term? Am J Surg Pathol. 2002;26:134–135. 4. Guindi M. The “lipopeliosis” lesion can occur in native livers too, not in transplanted ones only [abstract 1286]. Mod Pathol. 2007;20(suppl 2); 280A. 5. Adeyi O, Fischer SE, Guindi M. Liver allograft pathology: approach to interpretation of needle biopsies with clinicopathological correlation. J Clin Pathol. 2010;63:47–74.
FIGURE 12. 2. 3 Alcoholic lipopeliosis. Type IV collagen immunostain. Immunoreactivity highlighting the sinusoids (arrows). Released fat droplets (asterisks) outside sinusoids in space of Disse, compressing sinusoids.
13 Portal Hypertension Without Cirrhosis
Case 13.1
Hepatoportal Sclerosis SANDRA FISCHER AND MAHA GUINDI
C L I N IC AL I N F OR M AT I ON
A 27-year-old man was admitted with massive variceal bleed. Physical examination revealed palm erythema, clubbing and leukonychia, and splenomegaly only. His investigations showed low hemoglobin at 108, platelets 96 with a mean corpuscular volume (MCV) of 75, and a low ferritin; international normalized ratio (INR) was 1.32 and albumin normal. Viral markers and other etiological tests to reveal the cause of any underlying liver disease were negative. Computed tomography (CT) showed lobar redistribution in the liver, with patent paraumbilical vein, and major vessels grossly unremarkable. R E A SON F OR R E F E R R AL
The history and subsequent investigations suggest portal hypertension, but the biopsy does not show unequivocal features of cirrhosis.
F I G U R E 1 3 . 1 . 1 Hepatoportal sclerosis. Liver needle biopsy with no evidence of cirrhosis (Masson’s Trichrome stain).
PAT H OL OG I C F E AT U R E S
Sections from liver tissue showed mild architectural changes with only few fibrous septae. Features of cirrhosis were not appreciated (Figure 13.1.1). There was marked portal fibrosis and obliteration of intrahepatic terminal portal veins (Figure 13.1.2). Iron and periodic acid–Schiff diastase (PASd) stains were negative. Biliary-type lesions were not identified, and the bile ducts were preserved in numbers. Also, there was no significant necroinflammation to suggest hepatitis, and no steatosis (Figure 13.1.1).
D I AG N OS I S
Loss of portal veins with secondary arterialization of the liver, consistent with hepatoportal sclerosis.
D I S C U S S I ON
The pathologic features raise the possibility of noncirrhotic portal hypertension. Obliteration of small portal veins (obliterative portal venopathy) may develop secondary to local
inflammation, thrombosis, congestive portal venopathy, and toxic injury (eg, chronic exposure to arsenic). Hepatoportal sclerosis is essentially a diagnosis of exclusion, and other causes of portal vein loss should be excluded before a diagnosis of hepatoportal sclerosis is made. Highly regressed cirrhosis, extrahepatic portal vein thrombosis, hepatic vein thrombosis, intrabiliary parasites, and schistosomiasis represent important differential diagnoses (1). Other conditions associated with noncirrhotic portal hypertension include myeloproliferative syndromes, human immunodeficiency virus (HIV) infection, and the rare Adams-Oliver syndrome. In the 1960s, investigators in India introduced the term noncirrhotic portal hypertension to describe an entity that is characterized histologically by “obliterative portovenopathy” (2). Mikkelsen and coworkers introduced the term hepatoportal sclerosis in 1965 to describe similar histopathological findings in noncirrhotic liver (3). Other diagnostic names given to this condition include Banti disease, noncirrhotic portal fibrosis, noncirrhotic intrahepatic portal hypertension, benign intrahepatic portal hypertension, and idiopathic presinusoidal portal hypertension.
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HYPERTENSION
WITHOUT
CIRRHOSIS
identifiable alteration in hepatic features and the portal vein. In a patient with portal hypertension, it is crucial to confirm the presence or absence of cirrhosis, including the possibility of regressed (remodeled) cirrhosis. Size of the biopsy specimen size is very important, to accurately assess fibrosis. Regressed cirrhosis in particular can be easily missed when biopsy specimens are shorter than 2 cm. Regressed cirrhosis should be suspected when there is a reduction of both portal and hepatic veins, delicate remnants of fibrous septa, and an irregular arrangement of portal structures and hepatic veins, typically when hepatic veins are located in close approximation to portal tracts (1). If small portal veins are obliterated, hepatic veins are patent, and no architectural distortion is present, the disease likely involves only the portal veins or portal tracts.
References FIGURE 13.1.2 Hepatoportal sclerosis. Portal tract with fibrous expansion and obliteration of portal vein, hematoxylin and eosin (HE) stain.
The diagnosis of hepatoportal sclerosis requires consideration of clinical and imaging information in addition to biopsy findings. Idiopathic or noncirrhotic portal hypertension can be diagnosed on the basis of imaging studies that show no
1. Wanless IR. Vascular disorders in the liver. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. 2nd ed. Philadelphia, PA: Saunders/Elsevier;2009:1169–1229. 2. Dhiman RK, Chawla Y, Vasishta RK, et al. Non-cirrhotic portal fibrosis (idiopathic portal hypertension): experience with 151 patients and a review of the literature. Gastroenterol Hepatol. 2002;17(1):6–16. 3. Sarin SK, Kapoor D. Non-cirrhotic portal fibrosis: current concepts and management. J Gastroenterol Hepatol. 2002;17(5):526–534.
Case 13.2
Portal Vein Thrombosis SANDRA FISCHER AND MAHA GUINDI
C L I N I C A L I N F OR M AT I ON
This 55-year-old male, who had a diagnosis of Crohn disease 15 years ago, complicated by bowel perforation for which he underwent a terminal ileum resection, developed abdominal pain and loss of weight. Imaging studies showed that he had disease in the terminal ileum. He was started on antibiotics, steroids, and Imuran. A complete blood count (CBC) showed that his hemoglobin, white blood cell count, and platelets were low. A CT scan of the abdomen at that time showed that he had proximal superior mesenteric vein thrombosis, and he was started on Coumadin. At the same time, an upper gastrointestinal (GI) endoscopy showed that he had grade 2 to 3 esophageal varices, and he was started on Nadolol. A needle biopsy was performed to confirm/exclude cirrhosis. He later underwent liver transplantation. F I G U R E 1 3 . 2 . 2 Portal vein thrombosis. Portal tract containing ob-
R E A SON F OR R E F E R R AL
The history and clinical investigations suggest cirrhosis with portal hypertension, but a liver biopsy did not show underlying chronic liver disease. PAT H OL OG I C F E AT U R E S
A needle biopsy showed the majority of portal areas to have a small or absent portal vein (Figure 13.2.1). Slight ductular reaction was seen but no dilated forms to suggest congenital hepatic fibrosis. No evidence of cirrhosis was present. Furthermore, the explanted liver showed focal intimal thickening involving the left and right portal veins and
literated portal vein and several large arteries. The surrounding liver parenchyma has sinusoidal dilatation secondary to increased arterial supply (Masson’s Trichrome stain).
some smaller portal veins consistent with healed thrombus. The main portal vein was widely patent. CD34 immunostaining showed increased angiogenesis and some arterialization of the liver (Figure 13.2.2).
DIAGNO SIS
Portal vein thrombosis (PVT).
DISCUSSIO N
FIGURE 13. 2. 1 Portal vein thrombosis: large portal area with obliterated portal vein showing smooth muscle hypertrophy (Masson’s Trichrome stain).
Both local (hepatobiliary) and systemic (thrombophilic) risk factors are associated with thrombosis of the portal vein (1). In children, infectious causes of PVT, such as sepsis or omphalitis, are frequently present. Particularly in neonates, catheterization of the umbilical vein is an important risk factor for development of PVT. In the adult population, liver cirrhosis and hepatobiliary malignancies are the most common local precipitating factors that together account for a large proportion of cases of PVT. Based on clinical presentation and results of imaging, acute and chronic PVT can be identified. An acute obstruction of the main portal vein usually manifests itself as a sudden onset of abdominal pain, which may be very severe. On physical examination the majority of patients will exhibit splenomegaly, but ascites is usually absent. Doppler ultrasound, computerized tomography (CT), or magnetic resonance imaging (MRI) can all be applied to demonstrate either the absence
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of flow or the presence of a thrombus in the portal vein. The diagnosis of chronic PVT is often incidental or made later on when complications of chronic PVT occur. In response to PVT, portoportal and portosystemic collateral veins will develop to compensate for the decreased portal blood flow. The amount, size, and localization of collaterals differ strongly between patients. On imaging, the presence of a network of collateral vessels around the portal vein, a so-called portal cavernoma, is a typical feature of chronic PVT (1). Obliteration of small portal veins as seen in needle biopsies is a nonspecific finding. A peripheral liver biopsy is not indicated to establish a diagnosis of PVT as large vessels are not sampled with this procedure. Recanalization of large portal vein thrombi make these lesions difficult to recognize from
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a clinical and radiological point of view. Prior thrombosis is suspected when there is prominent intimal fibrosis of portal veins, especially those larger than 200 μm in diameter (2). Sometimes, a compensatory increase in the arterial supply to the liver following PVT can generate features that mimic nodular regenerative hyperplasia with parenchymal atrophy in zone 3 and periportal hyperplasia.
References 1. Hoekstra J, Janssen HL. Vascular liver disorders (II): portal vein thrombosis. Neth J Med. 2009;67(2):46–53. 2. Wanles IR. Vascular disorders in the liver. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. 2nd ed. Philadelphia, PA: Saunders/Elsevier; 2009:1169–1229.
Case 13.3
Budd-Chiari Syndrome SANDRA FISCHER AND MAHA GUINDI
C L I N IC AL I N F OR M AT I ON
A 47-year-old woman developed increased abdominal girth and ascites. Abdominal ultrasound showed irregular liver contour and hypertrophy of the caudate lobe. The large hepatic veins were not well visualized. Angiography revealed narrowing of the right and middle and left hepatic veins, and the right hepatic vein appeared obstructed. A diagnosis of Budd-Chiari syndrome (BCS) was made. The patient was referred to a hematologist, but no hypercoagulable state was found. Repeat ultrasound showed a hypervascular nodule in the right lobe approximately 1.8 cm in diameter. Its exact nature was not determined, but hepatocellular carcinoma was in the differential diagnosis. The patient subsequently developed liver failure and underwent cadaveric orthotopic liver transplantation. R E A SON F OR R E F E R R AL
Characterization of pattern of parenchymal injury and classification of right lobe nodule. PAT H OL OG I C F E AT U R E S
The features are of congestive liver disease in keeping with hepatic venous outflow obstruction evidenced by the fibrous intimal thickening and luminal obstruction by organized thrombus involving hepatic veins of all sizes (Figure 13.3.1). There is associated sinusoidal dilatation and congestion (Figure 13.3.2) with areas of hepatocyte necrosis and dropout. The pattern of parenchymal injury is variable. In areas where there is mainly hepatic vein obstruction without secondary
FIGURE 13. 3. 1 Hepatic vein thrombosis. Medium- and small-sized obliterated hepatic veins; perivenular congestive necrosis (elastic trichrome stain).
portal vein disease, there is a venocentric pattern of hepatocyte loss and/or septation (Figure 13.3.2). Hepatocyte necrosis near the obstructed hepatic veins results in a central-veinto-central-vein pattern of necrosis and, subsequently, fibrosis (Figure 13.3.2). In areas where there is secondary portal vein obstruction, venoportal septa are present. The right lobe nodule is a large parenchymal regenerative nodule (Figure 13.3.3). DISCUSSIO N
Acute obstruction of all 3 hepatic veins causes massive hepatomegaly with prominent engorgement of the liver parenchyma. With time, the affected lobes become smaller, whereas unaffected regions undergo compensatory hypertrophy, a phenomenon that most frequently affects the caudate lobe (1). Biopsies or explants show severe congestion and dilatation of sinusoids especially on zone 3. There may be hemorrhage within the liver cell plates, and recent thrombi within hepatic veins of any size and/or intimal fibrous thickening of hepatic veins larger than 100 μm in diameter. There is intimal thickening by fibrosis of the large- and medium-sized hepatic veins. Most veins undergo some recanalization with the formation of multiple luminal channels or delicate webs (1). Two patterns of parenchymal injury may be seen: venocentric and venoportal (1,2). Cases of pure hepatic vein obstruction typically lead to a characteristic venocentric pattern of septation also known as reverse nodularity. Hepatocyte necrosis occurs mainly near the obstructed hepatic veins, which results in a central-vein-to-central-vein pattern of necrosis and, subsequently, fibrosis. The portal tracts are seldom incorporated into the fibrous septa. When secondary portal vein thrombosis occurs, venoportal septa and, eventually, venoportal cirrhosis may develop (a pattern similar to that in posthepatitic cirrhosis) (1,2). Regions of liver with only mild parenchymal disease may develop a pattern of atrophy and compensatory hyperplasia that can be mistaken for nodular regenerative hyperplasia (1). Liver biopsies are helpful in confirming the diagnosis of hepatic venous outflow obstruction and exclude other entities that may be associated with very high transaminase elevations, but are immune-mediated, such as viral or autoimmune hepatitis. Questions regarding the severity of the disease including the presence of necrosis and fibrosis may be posed by the clinician at the time of biopsy. Regional variation in pathologic features may lead to spurious conclusions. Therefore, biopsy specimens taken for this purpose should be obtained from two sites to minimize sampling error (1). Further confirmation can be achieved by correlation with serum aminotransferase levels, liver function tests, and imaging studies of the large hepatic veins.
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FIGURE 13.3.2 (A) Hepatic vein (HV) with surrounding marked sinusoidal congestion in zone 3 (asterisk) (Masson’s Trichrome stain). (B) Chronic congestion with sinusoidal fibrosis and red blood cells present in the space of Disse (asterisk) (Masson’s Trichrome stain). (C) venocentric pattern of necrosis. Hepatocyte necrosis mainly near obstructed hepatic veins, causing a central-vein-to-central-vein pattern of necrosis and, subsequently, fibrosis. The portal tracts (PT) (arrow) are seen at the center of the periportal sleeve of residual hepatocytes (arrowheads) (Masson’s Trichrome stain). (D) Venoportal necrosis. Hepatocyte necrosis extending between portal tract (arrow pointing to bile duct in portal area) and hepatic vein, and, eventually, venoportal septation and venoportal cirrhosis when secondary portal vein thrombosis occurs (Masson’s Trichrome stain).
In severe cirrhosis, of any cause, there is often intimal thickening of medium-sized and large hepatic veins due to congestive venopathy, or thrombosis (3). As a result, accurate histologic differentiation of hepatic vein thrombosis from other types of cirrhosis often requires large enough tissue samples to allow for an evaluation of the large hepatic veins (1). Whether obstruction to blood flow is at the level of the small or large hepatic veins, histologic features are similar. Thus the differential diagnosis of BCS in biopsies includes congestive heart failure, constrictive pericarditis, and chronic veno-occlusive disease; and interpretation of the biopsy needs to be in the context of clinical history. In BCS, venous outflow obstruction may be high grade. Associated disturbed portal flow without extrahepatic portal vein thrombosis leads to decreased portal venous blood flow and increased arterial flow (4). A marked increase in hepatic
arterial perfusion was observed mainly in patients with longstanding BCS where it is preceded by severely impaired portal perfusion (4). Enlargement of the hepatic artery in this setting is regarded as a progressive and reactive compensatory adaptation. In order to maintain hepatic blood inflow in the face of a decrease in portal perfusion, arterial enlargement occurs analogous to the effect of “hepatic arterial buffer response” described by Lautt et al (5). Focal nodular hyperplasia (FNH)-like large regenerative nodules develop independent of cirrhosis in patients with chronic BCS where there is an enlarged hepatic artery (2,4). FNH-like nodules, that is nodular reactive hepatocytic hyperplastic lesions, occur in areas of arterial hyperemia which are highly perfused and shown to possess arborization in a nodular arrangement by arteriography (4). Thus, they appear similar in pathogenesis to the sporadic cases of FNH reported by
CASE
13.3:
BUDD-CHIARI
SYNDROME
197
FIGURE 13.3.3 (A) Large regenerative nodule with some focal nodular hyperplasia (FNH)-like features (Masson’s Trichrome stain). (B) Large
regenerative nodule. Artery associated with ductules (arrow head) and cholestatic hepatocytes (arrow) (Masson’s Trichrome stain). (C) Large regenerative nodule. Unpaired artery amidst benign hepatocytes (Masson’s Trichrome stain).
Wanless et al (6). These FNH-like lesions or large regenerative nodules are composed of benign hepatocytes arranged in double cell plates (2). The lesions, similar to sporadic FNH, do not contain portal veins. Cholestatic features may be present with rosettes, canalicular bile plugs, and collections of foamy macrophages. Cholestatic features tend to be more prominent in the larger nodules. Ductular reaction is seen in approximately 50% of nodules. The nodules appear to be supplied by an arterial tree with radial branches extending from the center of the nodule (2). These vessels are accompanied by variable amounts of fibrous stroma. The distinction of large adenoma-like or FNH-like regenerative nodules from true neoplastic lesions such as hepatic adenoma or well-differentiated hepatocellular carcinoma can be difficult. The difficulty stems from the fact that large adenoma-like or FNH-like regenerative nodules share a number of histologic features with well-differentiated hepatocellular neoplasms: lack of significant nuclear and architectural atypia and an arterial supply as shown by angiographic
and histological findings (7). In one report, large nodules were indistinguishable from adenomas (7). In another study, Wanless et al found large regenerative nodules differ from hepatic adenoma in that they have a single branching arterial supply that is often accompanied by a duct and/or ductular reaction. In routine forms of FNH, glutamine synthetase (GS) immunostaining marks hepatocytes in large anastomosing areas in a “map-like” pattern, often surrounding hepatic veins, whereas GS was not expressed in hepatocytes close to fibrotic bands containing arteries and ductules (8). In comparison, in hepatocellular adenomas or well-differentiated hepatocellular carcinoma, GS was shown to be positive but with a different perivenular or diffuse pattern rather than “map-like.” Thus GS represents a useful marker to distinguish true FNH from other hepatocellular nodules (8), but this same map-like pattern is not a reliable marker for FNH-like lesions, which can show variable staining patterns, as compared with true FNH. As noted above, distinction from well-differentiated hepatocellular carcinoma can also be difficult. Lack of any
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cytologic atypia and absence of reticulin deficiency is helpful, and absence of immunoreactivity with Glypican-3 immunostain can be helpful. Glypican-3 has high sensitivity for the diagnosis of hepatocellular carcinoma, but one should note that this stain is much less sensitive in extremely well-differentiated hepatocellular carcinomas (9). In one series, Glypican-3 expression was seen in only 50% of well-differentiated hepatocellular carcinomas. All hepatic adenomas and large regenerative nodules were negative, but in the same series 43% of high-grade dysplastic nodules were positive for Glypican-3 (9). Thus Glypican-3 is often not helpful in this setting. Clinical context and correlation with newer imaging techniques such as contrast ultrasound is also needed in these situations.
References 1. Wanless IR. Vascular disorders in the liver. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. 2nd ed. Philadelphia, PA: Saunders/Elsevier;2009:1169–1229. 2. Tanaka M, Wanless IR. Pathology of the liver in Budd-Chiari syndrome: portal vein thrombosis and the histogenesis of veno-centric cirrhosis,
3.
4.
5.
6. 7.
8.
9.
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veno-portal cirrhosis, and large regenerative nodules. Hepatology. 1998;27:488–496. Wanless IR, Wong F, Blendis LM, et al. Hepatic and portal vein thrombosis in cirrhosis: possible role in development of parenchymal extinction and portal hypertension. Hepatology. 1995;21:1238–1247. Cazals-Hatem D, Vilgrain V, Genin P, et al. Arterial and portal circulation and parenchymal changes in Budd-Chiari syndrome: a study in 17 explanted livers. Hepatology. 2003;37:510–519. Lautt WW, Legare DJ, d’Almeida MS. Adenosine as putative regulator of hepatic arterial flow (the buffer response). Am J Physiol. 1985;248: 331–338. Wanless IR, Mawdsley C, Adams R. On the pathogenesis of focal nodular hyperplasia of the liver. Hepatology. 1985;5:1194–1200. de Sousa JM, Portmann B, Williams R. Nodular regenerative hyperplasia of the liver and the Budd-Chiari syndrome. Case report, review of the literature and reappraisal of pathogenesis. J Hepatol. 1991;12:28–35. Bioulac-Sage P, Laumonier H, Rullier A, et al. Over-expression of glutamine synthetase in focal nodular hyperplasia: a novel easy diagnostic tool in surgical pathology. Liver Int. 2009;29(3):459–465. Shafizadeh N, Ferrell LD, Kakar S. Utility and limitations of glypican-3 expression for the diagnosis of hepatocellular carcinoma at both ends of the differentiation spectrum. Mod Pathol. 2008;21:1011–1018.
Case 13.4
Regressed Cirrhosis Case SANDRA FISCHER AND MAHA GUINDI
C L I N IC AL I N F OR M AT I ON
This 54-year-old male, born in Taiwan, immigrated to Canada 1 year ago, when he was found to have mildly elevated liver enzymes by his family physician: alanine transaminase (ALT) and aspartate transaminase (AST) in the 40 to 50 U/L range. Workup revealed positive hepatitis B (HBV) serology including positive HBV anticore antibodies (HBcAb) and HBV e-antigen (HBeAg). Abdominal ultrasound showed no mass lesions. There was hypertrophy of the left lobe of the liver and very mild nodularity of the liver contour raising the possibility of cirrhosis. An upper endoscopy showed grade esophageal varices. Platelet count was at the low end of normal. R E A SON F OR R E F E R R AL
Clinical history and investigations suggest cirrhosis with portal hypertension but a liver biopsy only showed a small amount of fibrosis and no obvious parenchymal nodules.
F I G U R E 1 3 . 4 . 2 Regressed cirrhosis. Obliterated terminal hepatic vein and perivenular sinusoidal dilatation (Masson’s Trichrome stain).
PAT H OL OG I C F E AT U R E S
The biopsy is of adequate size. The portal tracts appear remodeled with reduced collagen and many lack the portal vein (portal remnants) (Figure 13.4.1). Small hepatic veins are reduced in number and appear obliterated (Figure 13.4.2). There is loss of the normal alternation of portal tracts with hepatic veins. There is a small amount of visible fibrosis in the form of delicate fibrous spikes on portal areas and delicate septation
F I G U R E 1 3 . 4 . 3 Regressed cirrhosis. Expanded portal areas showing
long and delicate bridging fibrous septa (Masson’s Trichrome stain).
(Figure 13.4.3). Some septa appear incomplete or interrupted/ perforated (Figure 13.4.4). A few collagen fibrils are scattered in the parenchyma (Figure 13.4.5). There are a few occasions of ectopically placed hepatic veins (approximated to or abutting the adjacent portal tract (Figure 13.4.6).
FIGURE 13. 4. 1 Regressed cirrhosis. Arrow pointing to portal rem-
nant (portal tract lacking the portal vein); small bile duct apparent in portal remnant (arrowhead). Sinusoidal dilatation likely reflects shunting in cirrhosis (Masson’s Trichrome stain).
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DIAGNO SIS
Fibrosis with features of regressed cirrhosis.
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FIGURE 13.4.4 Regressed cirrhosis. Interrupted portal-to-portal sep-
F I G U R E 1 3 . 4 . 6 Regressed cirrhosis. Portal-to-central approxima-
tum, arrow pointing to gap in septum. Notice each of the 2 portal areas joined by this septum is a portal remnant (Masson’s Trichrome stain).
tions (adhesions) (Masson’s Trichrome stain). HV, hepatic vein; PT, portal tract.
FIGURE 13. 4. 5 Regressed cirrhosis. Collagen fibrils (arrows) interspersed in the parenchyma (Masson’s Trichrome stain).
amount was less than found in normal portal tracts, so that hepatocyte plates closely approximated the portal tract elements (1). Wanless et al suggest that livers with micronodular cirrhosis, macronodular cirrhosis, and incomplete septal cirrhosis (ISC) demonstrate a histologic continuum and that a continuum of regressive changes can be present within individual livers as well (1). Incomplete septal cirrhosis (ISC) is characterized histologically by delicate and incomplete fibrous septa (3,4). Livers with ISC demonstrated all of the features of the hepatic repair complex, including venoportal adhesions and aberrant veins that would not be expected in early-stage disease (1). These results supported the notion that ISC may arise from complete cirrhosis as regression of fibrosis occurs. It appears cirrhosis must become inactive with little or no ongoing parenchymal injury to allow for repair such that fibrous scars have the opportunity to become delicate and highly regressed. The differential diagnosis of regressed cirrhosis includes causes of noncirrhotic portal hypertension. Of special note are hepatoportal sclerosis, portal vein obstruction by any cause, for example portal vein thrombosis and nodular regenerative hyperplasia. Hepatoportal sclerosis (HPS) is discussed in detail in case 13.1. The Asian Pacific Association for the Study of the Liver (APASL) set up a Working Party on Portal Hypertension in 2002 with a mandate to develop a consensus on the various clinical aspects of portal hypertension, including consensus guidelines on the definition of HPS. The consensus was published in 2007 (5). The APASL consensus stipulated that HPS/noncirrhotic portal fibrosis (NCPF)/idiopathic portal hypertension (IPH) comprises a group of diseases that are characterized by an increase in portal pressure in the absence of cirrhosis of the liver and that the entity is of uncertain etiology. Subcapsular septation can be noted, whereas deeper parenchyma shows normal
D I SC U SSI ON
The features of regressed cirrhosis have been described by Wanless in several publications (1,2). Fibrosis gradually disappears leaving behind a remodeled parenchyma as a clue that overt cirrhosis was once present. The regression parameters (hepatic repair complex) are delicate perforated septa, isolated thick collagen fibers, delicate periportal fibrous spikes, portal tract remnants, hepatic vein remnants with prolapsed hepatocytes, hepatocytes within portal tracts or splitting septa, minute regenerative nodules, and aberrant parenchymal veins. Aberrant parenchymal veins were veins close to portal tracts within 5 hepatocyte diameters. Portal tract remnants had several appearances, including artery/duct pairs, unaccompanied arteries, or unaccompanied ducts, usually with absent portal vein. Portal tract collagen
CASE
13.4:
REGRESSED
architecture. The liver functions and structure primarily remain normal, and usually there are no signs of chronic liver disease (5). Histological features noted in autopsies include occasional portal to portal or portal to central bridging septa may be present (5,6). Thus HPS and regressed cirrhosis share minimal visible fibrosis, loss of small portal veins, and absence of overt parenchymal nodules surrounded by fibrosis. Dense portal tract fibrosis may also be the residuum of regressed cirrhosis (2). The distinction between HPS and regressed cirrhosis could be especially difficult in limited tissue such as a liver needle biopsy, especially if small in size. The presence of liver parenchymal architectural distortion (features listed above) in addition to the portal tract changes would favor regressed cirrhosis. Previous liver biopsies should be sought in a given patient in whom a current biopsy raises the possibility of regressed cirrhosis. Previous biopsy(ies), may show overt features of severe fibrosis or cirrhosis, thus providing a major clue to the diagnosis. This was indeed the case in the patient reported by Wanless et al, with chronic hepatitis B virus (1). The patient’s first biopsy showed cirrhosis with sinusoidal fibrosis and severe chronic hepatitis. A second biopsy 1 year later after lamivudine therapy showed no sinusoidal fibrosis, and apparent enlargement of cirrhotic nodules compared to the first biopsy. A third biopsy after another 2.5 years of therapy showed no overt nodularity or cirrhosis, only 1 incomplete fibrous septum, and a few small regions of atrophy. The APASL consensus defined HPS as being of uncertain etiology, thus the presence of known causes of chronic liver disease, for example positive viral serology for hepatitis B or hepatitis C, would make HPS an unlikely contender for portal hypertension (5). Since the APASL consensus regarded HPS as a “group of diseases,” it is possible that some cases of regressed cirrhosis were inadvertently included in reported cases of HPS, especially those reported prior to the description of regression in human cirrhosis. This notion is strengthened by some of the reported liver capsular appearances in HPS as showing “some
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nodularity resembling cirrhosis” (a feature of cirrhosis) upon gross examination of autopsy livers (5). Cirrhotic livers may show similar hypertrophic/atrophic variation within nodules and might be mistaken for nodular regenerative hyperplasia. In cirrhosis, especially after PVT, the centers of ischemic cirrhotic nodules become atrophic with some secondary hyperplasia usually at the periphery of these nodules. This pattern is similar to that in NRH, except that the underlying stroma is scarred in cirrhosis (7). It is not deemed suitable to use the term “nodular regenerative hyperplasia” in cirrhotic livers as that term has been applied to livers having little or no fibrous septation in the original description of NRH (8,9).
References 1. Wanless IR, Nakashima E, Sherman M. Regression of human cirrhosis. Morphologic features and the genesis of incomplete septal cirrhosis. Arch Pathol Lab Med. 2000;124:1599–1607. 2. Wanless IR. Cirrhosis. In: Odze RD, Goldblum JR, eds. Surgical Pathology of the GI tract, Liver, Biliary Tract, and Pancreas. 2nd ed. Philadelphia, PA: Saunders/Elsevier; 2009:1115–1145. 3. Popper H. What are the major types of hepatic cirrhosis? In: Ingelfinger F, Relman A, Finland M, eds. Controversy in Internal Medicine. Philadelphia, PA: Saunders; 1966:233–243. 4. Nevens F, Staessen D, Sciot R, et al. Clinical aspects of incomplete septal cirrhosis in comparison with macronodular cirrhosis. Gastroenterology. 1994;106:459–463. 5. Sarin SK, Kumar A, Chawla YK, et al. Noncirrhotic portal fibrosis/ idiopathic portal hypertension: APASL recommendations for diagnosis and treatment. Hepatol Int. 2007;1:398–413. 6. Schiano TD, Kotler DP, Ferran E, Fiel MI. Hepatoportal sclerosis as a cause of noncirrhotic portal hypertension in patients with HIV. Am J Gastroenterol. 2007;102:1–5. 7. Shimamatsu K, Wanless IR. Role of ischemia in causing apoptosis, atrophy, and nodular hyperplasia in human liver. Hepatology. 1997;26:343–350. 8. Wanless IR. Micronodular transformation (nodular regenerative hyperplasia) of the liver: a report of 64 cases among 2,500 autopsies and a new classification of benign hepatocellular nodules. Hepatology. 1990;11: 787–797. 9. Terminology of nodular hepatocellular lesions. International Working Party. Hepatology. 1995;22:983–993.
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14 Clinical and Morphological Spectrum of Liver Diseases in Pregnancy ANDREW KENNETH BURROUGHS AND AMAR PAUL DHILLON
I N T ROD U C T I ON
Liver disease in pregnancy can be considered in 2 categories. The first group consists of all of the acute and chronic diseases of the liver that can affect women of child-bearing age, including viral hepatitis, gallstone disease, and drug reactions. The frequency, clinical aspects, and histopathology of these conditions are no different generally from their expression in the population from which the pregnant patient is drawn (1). In regions such as Asia, Africa, and Central America where hepatitis E virus (HEV) is endemic, fulminant HEV hepatitis can occur with a high mortality. Herpes simplex virus is uncommon, but because these patients may present with severe fulminant hepatitis and effective antiviral treatment is available, a low threshold of suspicion for HSV infection must be maintained. The second group of diseases are particular to pregnancy. These comprise hyperemesis gravidarum, benign recurrent cholestasis (recurrent intrahepatic cholestasis of pregnancy, RCP), acute fatty liver of pregnancy (AFLP), and toxaemia/HELLP syndrome. The tendency of pregnancy to provoke itching and cholestasis can lead to the discovery of previously unsuspected chronic liver disease such as primary biliary cirrhosis, primary sclerosing cholangitis, or HCV infection. All pregnant women should be tested for HBV infection at the first antenatal visit, but this is a council of perfection, and HBV disease may be unsuspected until a later stage of the pregnancy when it can cause diagnostic confusion (1). The fact that pregnancy-independent diseases share morphological features with pregnancy-associated liver diseases means that before concluding a diagnosis of the latter, the possibility of hepatic drug reaction, viral, alcoholic, obesityrelated, biliary, and autoimmune diseases must be considered carefully clinically. Pregnancy-associated liver diseases usually occur in late pregnancy, and so the pregnancy itself will usually be obvious clinically. However, in some cases, for example, cases of severe RCP or toxaemia in patients with pre-existing kidney disease and hypertension, the disease may occur sooner, and pregnancy may not be immediately apparent. Therefore, the possibility of pregnancy should be considered specifically, confirmed, and the relevant information must be transmitted to the hepatopathologist, together with the liver biopsy. Close clinicopathological communication is always advisable, and this is especially so when considering pregnancy-associated liver disease. With AFLP especially the diagnosis critically rests on the demonstration of microvesicular steatosis and unless this is considered at an early stage with retention of appropriate material for frozen section staining for
fat (or pre-embedment osmium impregnation), the diagnosis is bound to remain speculative. The role of liver biopsy in the diagnosis and management of pregnancy-related liver disease is quite limited. In most instances, the diagnosis has to be made with clinical and noninvasive investigations only. As obstetric indications for early delivery of the fetus take precedence, biopsy may be contraindicated in view of the coagulopathy that can exist in the more severe pregnancy-related liver diseases, although transjugular biopsy is safe. When a liver biopsy is obtained in cases of suspected liver disease in pregnant patients, one of the most important considerations is the use of the biopsy to identify or exclude additional liver diseases coincidental to the pregnancy. H Y P ER EMESIS GR AV IDA RUM
This is severe and intractable vomiting requiring intravenous hydration. It occurs early in about 0.3% of pregnancies (1). Liver biopsy is rarely indicated unless it is necessary to exclude other conditions such as drug reaction and viral hepatitis, which are usually coincidental to the pregnancy itself. In cases of hyperemesis when liver biopsy is performed and when there are no other superimposed conditions, the histopathological appearance is within normal limits, or there may be minor, nonspecific changes. R ECUR R ENT INT R A H EPAT IC CH O LESTA S IS O F P R EGNA NCY
Recurrent cholestasis of pregnancy occurs in late pregnancy and is probably a result of various hormonal (including pregnancy-related elevation of oestrogen) and genetic factors. Approximately 0.1% of pregnancies can be affected (1). Up to 15% of RCP cases may be associated with the MDR3 (ABCB4) gene mutation, and in these cases, the cholestasis may be severe with an earlier (mid-trimester) onset than otherwise (2). The defect can be associated with gallbladder and intrahepatic cholesterol stones (3). Other bile acid transporter defects may be relevant in other cases (4). A family history of RCP or familial cholestatic disease is relevant, and further consideration of MDR3 mutations is necessary particularly in patients with cholesterol gallstones below 40 years of age (3). Liver biopsy in typical cases of RCP will show canalicular parenchymal cholestasis with a centrilobular predominance. Little inflammation is seen.
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AC U T E FAT T Y L I V E R OF P R E G N A N C Y
AFLP is a mitochondrial cytopathy (5). It affects about 1:14 000 pregnancies (1), but is more frequent in patients with mitochondrial fatty acid oxidation defects, for example, mothers who are heterozygous for long chain 3 hydroxyl co-enzyme A dehydrogenase deficiency (LCHAD), carrying a fetus homozygous for LCHAD, as the mother cannot metabolise the excess free fatty acids. It is more common in pregnancies with males and twins. Patients present with worsening nausea, vomiting, and abdominal pain followed by jaundice. There is hypoglycaemia and coagulopathy, and there can be gastrointestinal bleeding and hyponatremia. Signs of pre-eclampsia may be present in 50% of patients. Lactic acidosis and metabolic acidosis are related to defective mitochondrial energy supply and defects in oxidative phosphorylation. The compromised maternal mitochondrial metabolic reserve leads to accumulation of hepatocytic trigycerides (6). This is evident as a predominantly centrilobular hepatic microvesicular steatosis, which characterises AFLP, and this feature is considered diagnostic. Hepatocytic mitochondria may be enlarged and show crystalline inclusions. The steatosis tends to obscure concomitant liver cell loss, which can be seen as areas of collapse in the reticulin preparation and reactive Kupffer cells in the periodic acid–Schiff diastase stain. Centrilobular hepatocytes can also show regenerative mitotic activity. In severe cases, imaging studies will show reduction of the size of the liver. However, microvesicular steatosis has also been found in liver tissue from patients with pre-eclampsia (7). Therefore, it could be argued that the microvesicular steatosis in AFLP is not necessarily pathognomonic of the “AFLP syndrome.” It could be that AFLP and eclampsia are either related conditions or that they can co-exist together because they are not mutually exclusive. As usual, the histopathology must be interpreted within the relevant clinical context. TOX E MI A / H E L L P S Y N D ROM E
The relationship between toxaemia/HELLP syndrome and their pathophysiology is unsettled. Toxemia has been considered an unsatisfactory term because no causative toxin has
IN
PREGNANCY
been identified. Toxemia/pre-eclampsia signifies the presence of edema, proteinuria, and hypertension (T140/90) in a previously normotensive patient or worsening hypertension in patients with pre-existing hypertension usually in late pregnancy. This occurs in 5% to 10% of pregnancies. Eclampsia is when the condition is severe and there is cerebral involvement, with convulsions. There may be particularly pronounced hepatic involvement with hemolysis (H), elevated liver “function” tests (EL), and low platelet count (LP) constituting the “HELLP” syndrome (1). However, many patients with HELLP syndrome (which overall occurs in 0.2% to 0.6% of pregnancies) do not exhibit preceding hypertension and proteinuria. HELLP syndrome is considered to be a hepatic microangiopathy with hemolysis and endothelial damage, microthrombi with fibrin deposition and platelet consumption causing areas of hemorrhage and necrosis possibly with hematomas, capsular tearing, and bleeding into the peritoneum. Mild pre-eclampsia can show sinusoidal fibrin deposition with focal Disse space hemorrhage, and the histopathological diagnostic distinction from severe eclampsia/HELLP syndrome is basically a matter of the extent and degree of the vascular changes (2).
References 1. Hay JE. Liver disease in pregnancy. Hepatology. 2008;47:1067–1076. 2. Hepburn IS, Schade RR. Pregnancy-associated liver disorders. Dig Dis Sci. 2008;53:2334–2358. 3. Wasmuth HE, Glantz A, Keppeler H, et al. Intrahepatic cholestasis of pregnancy: the severe form is associated with common variants of the hepatobiliary phospholipid transporter ABCB4 gene. Gut. 2007; 56:265–270. 4. Hardikar W, Kansal S, Elferink RPJO, Angus P. Intrahepatic cholestasis of pregnancy: when should you look further? World J Gastroenterol. 2009;15:1126–1129. 5. Sherlock S, Dooley J. Diseases of the Liver and Biliary System. p477 10th ed. Blackwell Science; 1997. 6. Lee NM, Brady CW. Liver disease in pregnancy. World J Gastroenterol. 2009;15:897–906. 7. Burt AD. p899 Chapter 17: Liver pathology associated with diseases of other organ systems. Burt AD, Portmann B, Ferrell L, eds. MacSween’s Pathology of the Liver. 5th ed. Elsevier; 2007.
Case 14.1
Recurrent Cholestasis of Pregnancy ANDREW KENNETH BURROUGHS AND AMAR PAUL DHILLON
C L I N IC AL I N F OR M AT I ON
A 23-year-old woman presented with jaundice and itching 1 week after delivery at term of a normal male baby. She had a history of recurrent jaundice including a postpartum episode 2 years ago. Serum bilirubin was 6 times normal, alkaline phosphatase was 2 times normal, aspartate aminotransferase (AST) was 2 times normal, alanine aminotransferase (ALT) was 2 times normal, and platelets were 400 109/L. There was a “large gallstone” in the gallbladder but no obvious biliary dilatation on ultrasound imaging. R E A SON F OR R E F E R R AL
Recurrent cholestasis of pregnancy versus gallstone disease. PAT H OL OG I C F E AT U R E S
The liver biopsy at low magnification shows disarray of the liver cell plates (Figure 14.1.1). Marked parenchymal canalicular cholestasis is present, with “cholestatic rosettes” (Figures 14.1.2 and 14.1.3). Compared to the degree of histological cholestasis, there is little inflammation. Occasional eosinophils are present (Figure 14.1.2). There is little portal inflammatory or ductular reaction, no ductular bile plugging, and no portal tract edema or fibrosis (Figure 14.1.4). No copperassociated protein deposition was seen with the orcein stain.
F I G U R E 1 4 . 1 . 2 Central venule with pericentral canalicular cholesta-
sis and a little inflammation including an eosinophil (right border of picture) ( 400).
D I AG N OS I S
Parenchymal cholestasis consistent with recurrent cholestasis of pregnancy.
F I G U R E 1 4 . 1 . 3 Parenchymal canalicular cholestasis and a choles-
tatic “rosette” ( 400). DISCUSSIO N
F I G U R E 1 4 . 1 . 1 Disorganization of liver cell plates, with portal tract at the bottom of the picture, and central venule at the top ( 25).
The appearance is of histologically “pure” parenchymal cholestasis (Table 14.1.1). There are no “biliary” features such as portal tract expansion, edema, fibrosis, and copper-associated protein deposition, and there is little portal inflammation and ductular reaction which argue against biliary obstruction related to the gallstone that was found on ultrasound imaging. On the other hand, the presence of a gallstone at the early age (23 years) of this patient is consistent with a bile acid transporter defect.
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FIGURE 14. 1. 4 Portal tract with a little inflammation and little duc-
tular reaction ( 100). TA B LE 14. 1. 1 Causes of histologically “pure” parenchymal cholestasis Drug reaction Sepsis Lymphoma (as a noninfiltrative paraneoplastic phenomenon, for example, Hodgkin’s) Biliary transporter defect (including BRIC and recurrent cholestasis of pregnancy) Abbreviations: BRIC, benign recurrent intrahepatic cholestasis.
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The clinical differential diagnosis includes biliary (gallstone, primary sclerosing cholangitis, primary bilary cirrhosis) tract disease, viral hepatitis, and drug reaction (1). Malignancy such as Hodgkin’s lymphoma may manifest as a noninfiltrative paraneoplastic phenomenon. Each of these possibilities must still be considered specifically and excluded clinically. No ductular bile plugging (which might have indicated sepsis) was present. The finding of scattered eosinophils is unhelpful: their presence does not confirm drug reaction and their absence does not exclude drug reaction. Bile acid transporter genetic testing and documentation of relevant family history should be performed. In specialist centers, where these investigations are available, immunostaining for different biliary transporters can help to characterise cases where there is a deficiency. Recurrent cholestasis of pregnancy cannot be diagnosed definitively by liver biopsy alone, and further confirmatory clinical and laboratory investigations are necessary.
Reference 1. Hepburn IS, Schade RR . Pregnancy-associated liver disorders. Dig Dis Sci. 2008;53:2334–2358.
Case 14.2
Acute Fatty Liver of Pregnancy ANDREW KENNETH BURROUGHS AND AMAR PAUL DHILLON
C L I N IC AL I N F OR M AT I ON
A 31-year-old woman presented at 37 weeks of gestation with fetal distress. An emergency Caesarean section was performed at which time she was noted to be jaundiced. Blood tests (taken prior to the Caesarean section) shows that serum bilirubin was 2 times normal, alkaline phosphatase was 2 times normal, AST was 7 times normal, ALT was 10 times normal, platelets were 101 3 109/L, and blood glucose was 3.9 mmol/L. Liver ultrasound showed no abnormality. R E A SON F OR R E F E R R AL
Acute fatty liver of pregnancy versus drug reaction versus toxemia/HELLP syndrome. PAT H O L OG I C A L F E AT U R E S
At low magnification (Figure 14.2.1), the biopsy shows centrilobular hepatocytic cytoplasmic microvesicular change with normal portal tracts, and at higher magnification (Figures 14.2.2 and 14.2.3), the microvesicular change is confirmed with centrally placed hepatocytic nuclei and expanded, foamy cytoplasm with small droplets of fat. There is centrilobular liver cell loss, collapse, and mild inflammation including pigmented macrophages (Figure 14.2.4). Scanty normoblasts are present (Figure 14.2.5).
F I G U R E 1 4 . 2 . 2 Centrilobular microvesicular change with loss of centrilobular hepatocytes and a mild inflammatory infiltrate ( 100).
D I AG N OS I S
Acute fatty liver of pregnancy.
F I G U R E 1 4 . 2 . 3 Microvesicular steatosis: the hepatocyte nucleus is centrally placed and the cytoplasm is expanded, foamy, and contains small droplets ( 400).
DISCUSSIO N
FIGURE 14. 2. 1 Microvesicular change of centrilobular hepatocytes, with little inflammation ( 50).
The clinical context and blood tests suggest the possibility of a “hepatitic” process, and indeed to some extent this is explained by the centrilobular liver cell loss, which can be obscured by the occupation of these areas by hepatocytes swollen with microvesicular fat in acute fatty liver of pregnancy (AFLP). Bearing in mind the other causes of microvesicular steatosis (Table 14.2.1), specific clinical exclusion of drug reaction remains necessary. However, the lack of a sharp cutoff between the areas with liver cell loss and microvesicular change and the periportal/midlobular hepatocytes, and the lack of coagulative
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sized vacuoles, and centrally placed nuclei that may be indented by microvesicles. One should exclude a similar appearance due to liver cell ballooning as might be seen in alcoholic steatohepatitis or in association with cholestasis (a particular problem because the latter can also be a more prominent feature of AFLP than is evident in the present case). Staining for cytokeratin 8 can be helpful here: in microvesicular steatosis, the hepatocyte cytoskeleton is seen to be intact (Figure 14.2.6). Actually, this can also be appreciated in the haematoxylin and eosin preparation in well-fixed specimens (Figure 14.2.3). In ballooning degeneration, for example, in alcoholic steatohepatitis, apart from the clues rendered by the other features of alcoholic liver disease such as pericellular fibrosis and larger droplet fat, the ballooned hepatocytes of steatohepatitis show disruption of the cytoskeleton, which becomes clumped with other components of Mallory bodies (Figure 14.2.7). Ideally, of FIGURE 14. 2. 4 A periodic acid–Schiff diastase preparation highlights the centrilobular liver cell loss, collapse, and pigmented macrophages ( 200).
FIGURE 14. 2. 5 A few normoblasts are present in the centre of this
microscopic field ( 400).
F I G U R E 1 4 . 2 . 6 Cytokeratin 8 immunostaining demonstrates the
intact cytoskeleton of microvesicular steatotic hepatocytes ( 400).
TA B LE 14. 2. 1 Causes of microvesicular steatosis Acute fatty liver of pregnancy Drugs (valproate, acetaminophen, tetracycline, nucleoside analogues) Alcoholic foamy degeneration Urea cycle disorders Reye’s syndrome Total parenteral nutrition
necrosis are points in favour of AFLP, rather than, for example, acetaminophen toxicity. The occasional normoblasts seen in this case corresponds with the observation that circulating normoblasts are often found in AFLP (1). Without suitable material for the crucial histological demonstration of fat, close attention to morphological detail is required for the diagnosis of microvesicular steatosis. Microvesicular change is characterised by relatively uniformly sized hepatocytes, foamy cytoplasm with distinct uniformly
F I G U R E 1 4 . 2 . 7 Cytokeratin 8 immunostaining demonstrates the
disrupted cytoskeleton of ballooned hepatocytes in a case (not the present case) of alcoholic steatohepatitis ( 400).
CASE
14.2
:
ACUTE
FAT T Y
FIGURE 14. 2. 8 A case of microvesicular steatosis (not the present case) with a pre-embedment osmium stain (Marchi method) for fat ( 400).
course, if there is effective clinicopathological communication and if appropriate material can be organised, fat can be demonstrated directly and without equivocation (Figure 14.2.8).
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Even when fatty microvesicular change has been established, this supports AFLP, but this feature alone is neither specific nor conclusive of “AFLP syndrome”; (fatty) microvesicular change can be found as a feature within the setting of other conditions such as toxemia/HELLP syndrome and drug reaction; conversely, relatively minor degrees of necrosis, hemorrhage, and fibrin deposition can be seen in AFLP; more hemorrhage, fibrin, thrombi, and necrosis than in the present case would be expected in toxemia/HELLP syndrome; a greater degree of inflammation would raise other questions such as viral hepatitis. Concluding that AFLP syndrome is the predominant diagnosis requires a balanced evaluation of all of the clinical and pathological features as a whole, and is a matter of the degree of each of the changes in any individual case that supports or argues against each of the competing diagnoses, which after all may co-exist and may not in fact be mutually exclusive.
Reference 1. Burroughs AK, Seong NH, Dojcinov DM, Scheuer PJ, Sherlock SV. Idiopathic acute fatty liver of pregnancy in 12 patients. Q J Med. 1982;51:481–497.
Case 14.3
Toxemia/HELLP Syndrome ANDREW KENNETH BURROUGHS AND AMAR PAUL DHILLON
C L I N I C AL I N F OR M AT I ON
A 32-year-old woman presented at term feeling unwell and nauseous. There was no documented preeclampsia. Blood tests were: serum bilirubin was 2 times normal, ALP was normal, AST was 89 times normal, ALT was 86 times normal, platelets were 71 109/L, international normalized ratio was 2.4, and blood glucose was 2.7 mmol/L. There was evidence of renal failure (creatinine 2 times upper limit of normal range). Microangiopathic hemolytic features were not evident on blood film examination. Clinically, an acute hepatitic injury was diagnosed and an emergency Caesarean section was performed.
7 immunostaining reveals bile ducts and ductules within the necrotic regions (Figure 14.3.4). Diagnostic features are absent of most types of drug- and virus-related massive hepatic necrosis (MHN), venous outflow obstruction (VOO), and chronic liver disease. Viral inclusions (eg, herpes simplex virus [HSV]) are not present.
DIAGNO SIS
Toxemia/HELLP syndrome of pregnancy.
R E A S ON F OR R E F E R R A L
Severe acute hepatitis versus toxaemia/HELLP syndrome. PAT H O L OG I C AL F E AT U R E S
The biopsy shows extensive, irregular areas of coagulative and hemorrhagic necrosis, and minimal inflammation (Figure 14.3.1). There is so much necrosis that the relationship of the lobular structures has been obscured. A small amount of parenchyma remains, and in places this is seen to have a perivenular location (Figure 14.3.2). Portal tracts are difficult to identify (Figure 14.3.3). However, cytokeratin
F I G U R E 1 4 . 3 . 2 A rim of hepatocytes remains around a central
venule ( 100).
FIGURE 14. 3. 1 Extensive coagulative and hemorrhagic necrosis with some small islands of residual hepatocytes ( 25).
F I G U R E 1 4 . 3 . 3 An unrecognizable structure lies buried in a necrotic
region ( 100).
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TOXEMIA/HELLP
FIGUR E 14. 3. 4 Cytokeratin 7 immunostaining reveals that the struc-
ture is a portal tract including an abortive ductular reaction ( 100).
TA B LE 14. 3. 1 Causes of periportal hepatocellular damage Toxemia/HELLP syndrome of pregnancy Disseminated intravascular coagulation Toxins (phosphorus, ferrous sulphate, cocaine) Acute viral hepatitis (eg, HAV, HEV) Small for size liver grafts Abbreviations: HAV, hepatitis A virus; HEV, hepatitis E virus.
D I S C U S S I ON
The pathological features in this case support the interpretation of toxemia/HELLP syndrome rather than the alternative diagnoses. A key point in this case is the irregularity of the necrosis and hemorrhage (due to the superimposed vascular compromise of toxemia/HELLP syndrome) combined with a periportal propensity of the necrosis and preferential preservation of perivenular parenchyma. This combination favors toxemia/HELLP syndrome and effectively argues against some of the more important differential diagnostic possibilities such as necrosis due to drug toxicity and VOO that usually exhibit a more regular pattern of liver damage (see below). There may be little inflammation (as in this case) in severe hepatitis, but the rest of the histopathology in this case excludes the main clinical alternative diagnosis of MHN associated with fulminant hepatic failure due to drug reaction or viral infection (see below). Other causes of periportal hepatocellular damage have to be considered as well (Table 14.3.1). In the original histopathological assessment, there was difficulty in identifying the periportal predilection of the necrosis. Immunostaining for biliary cytokeratins can be helpful in orientation. Without specific attention to the combination of patchy hemorrhage and irregular areas of necrosis with a periportal predilection, or the recognition of residual
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centrilobular hepatocytes, there was difficulty in concluding any morphological diagnosis beyond “nonspecific hepatocellular necrosis.” In most cases of MHN caused by viral infection and drug reaction hepatitis, hepatic necrosis tends to be central/ midlobular. Consequently, even when most or all of the hepatocytes have been lost, with subtotal parenchymal reticulin collapse the portal tracts remain intact and are brought closer together (“approximated”) and are evenly spaced. They are made prominent with a florid ductular reaction and portal lymphoplasmacytic infiltrate. The necrosis of acetaminophen toxicity can be confused with toxemia, and exclusion of acetaminophen overdose should be addressed specifically by clinical enquiry and investigations. Microvesicular steatosis can be seen in both acetaminophen toxicity and toxemia. Attention to the morphology of acetaminophen-related centrilobular coagulative necrosis (in the early postacetaminophen time period) or the empty, collapsed macrophage-rich centrilobular regions (in subsequent postacetaminophen time periods) seen in acetaminophen-related injury is informative. In the present case, the retention of a rim of centrilobular hepatocytes (rather than the periportal rim of residual hepatocytes that would be expected in acetaminophen toxicity) is a strong pointer toward a diagnosis of toxemia/HELLP syndrome. In both toxemia/HELLP syndrome and VOO, liver hemorrhage can be seen in the space of Disse. In VOO, the hemorrhage is in a regular, repeated centrilobular location. The hemorrhage is accompanied by centrilobular hepatocytic atrophy and loss, centrilobular sinusoidal ectasia, and congestion, and there may be venous outflow stenosis and thrombosis. In toxemia/HELLP syndrome, the hemorrhage is irregular and unaccompanied by the other features characteristic of VOO. The patchy hemorrhage seen in the present case is also unusual in MHN caused by drug toxicity or viral infection, except HEV. Since HEV can cause severe liver disease in pregnant women with periportal injury as well, this possibility particularly should be excluded by the appropriate serological investigations (1). Appreciably more inflammation is usual in HEV, than was found in the present case. Another viral infection that is worthy of specific consideration and exclusion is HSV. Immunohistochemistry and serological investigation may be necessary (2). Even though in this case the biopsy appearance (detailed above) favors the morphological interpretation of toxemia/HELLP syndrome–related liver damage, it should be remembered that in cases of suspected toxemia/HELLP syndrome there is a large risk of biopsy sampling error because of the focal nature of the diagnostic features. Alternatively (as in this case), the tissue destruction can be so extreme that the relevant clues toward the correct diagnosis are obscured. Therefore, in either event, the absence of diagnostic features in a small biopsy sample cannot exclude, with confidence, a diagnosis of clinically suspected toxemia/HELLP syndrome. In cases with incomplete information and in atypical cases, biopsy is useful to confirm the clinical suspicion and to exclude additional and alternative diagnostic possibilities. For example, biopsy might form a useful part of the diagnostic
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jigsaw puzzle and may help to determine management in a patient presenting with fulminant hepatic failure, hypoglycemia, coagulopathy, and cerebral edema who could be suffering from acetaminophen toxicity (especially considering that toxicology several days after overdose when measurement of blood acetaminophen levels is unhelpful because serum levels have already fallen). Conversely, in a typical case of toxemia with a complete and consistent “noninvasive” dataset, liver biopsy is probably not necessary.
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References 1. Malcolm P, Dalton H, Hussaini HS, Mathew J. The histology of acute autochthonous hepatitis E virus infection. Histopathology. 2007;51:90–94. 2. Halliday J, Lokan J, Angus PW, Gow P. A case of fulminant hepatic failure in pregnancy. Hepatology. 2010;51:341–342.
15 Drug-Induced Liver Injury DAVID E. KLEINER
I N T ROD U C T I ON
Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF) in the United States, with acetaminophen alone responsible for 46% of adult ALF cases between 1998 and 2007 (1). Other drugs accounted for a further 11%. Over a 24-year period, DILI was the most common cause for the FDA to withdraw or attach black box warnings to drugs (2). The incidence of DILI is difficult to estimate because of the difficulties in accurately capturing likely cases in national registries, but a careful prospective study in the Dijon region of France performed over a period of 3 years reported an incidence of 14 cases per 100 000 people (3). This rate is more than 10 times higher than previous estimates based on physicians reporting to national and international registries. Increased awareness of the significance of DILI in drug development and clinical care has led to the establishment of prospective registries in Spain, Sweden, and the United States (4–6). The U.S. network, known as the Drug-Induced Liver Injury Network (DILIN, www.dilin.org), is an NIDDK-funded consortium of academic centers spread across the country that not only collects new cases of DILI but also serves as a source of expertise in the diagnosis of DILI (7). Data from these national networks have demonstrated that most new (nonacetaminophen) cases of DILI are due to anti-infectives (27–46%), followed by central nervous system agents (13–17%) and anti-inflammatory and pain medications (5–17%) (4–6). In the Swedish and U.S. cohorts, there were more women than men (about 1.5–1), whereas in the Spanish study, the numbers were about equal. The death rate varied from 5% to 9.2%, whereas the rate of chronicity (defined as the persistence of biochemical injury more than 6 months after stopping the agent) was 11% to 13%. DILI can have medical, legal, and regulatory consequences, and it is critical that the diagnosis be made accurately. L I V E R B I OP S Y A N D D I L I
There are a number of reasons why a liver biopsy may be performed in a suspected case of DILI (8). Determination of the injury pattern can be important in implicating or excluding particular agents. Table 15.1 lists the major nonneoplastic injury patterns observed in DILI. DILI can mimic essentially all non-DILI patterns of injury, but any individual agent will have a more restricted injury profile. The first task of the pathologist is to classify the pattern(s) of injury present in the biopsy. The pattern of injury can then be compared to reported DILI patterns for the suspected agents and can also be used to focus the non-DILI differential diagnosis by eliminating diseases that do not cause that particular injury. The pattern of injury can also
have implications for the mechanism of injury. For example, acute or chronic hepatitis patterns may suggest an autoimmune component, granulomas and eosinophils may suggest hypersensitivity, zonal necrosis may suggest a metabolic toxin, and microvesicular steatosis may suggest mitochondrial injury. Of equal importance to the classification of pattern is the determination of the degree of severity of the injury. Discrepancy between the degree of serum biochemical abnormalities and the severity of histological injury is common. Some types of injury, such as the distinction between necrosis and hepatitis or the evaluation of duct integrity, can only be made on biopsy, and these features may have prognostic implications. Alternatively, if the injury is mild, a needed medication may be continued. This has been the role of liver biopsy in the case of methotrexate injury, but the principle can be applied in other situations. Liver biopsy may be performed when there are unexplained serum biochemistries. In these cases, the pathologist should be particularly alert to the possibility of DILI, especially caused by herbal or over-the-counter agents. Patients may not provide a history of taking herbal medications unless specifically asked, thinking that because they are “natural,” they are safe. Nevertheless, herbal agents are increasingly recognized as a cause of liver injury and accounted for 9% of cases in the DILIN experience (6). Some patterns of injury are more likely to be caused by drugs or other agents, including cholestatic hepatitis, granulomatous hepatitis, eosinophilia, microvesicular steatosis, and zonal necrosis (9). Vascular injury patterns in Table 15.1 should also prompt a detailed medication or occupational exposure history. Finally, whenever unusual mixed patterns are present, such as cholestasis with steatohepatitis, DILI should be suspected.
EVA LUAT IO N O F SUSP ECT ED DILI
Unlike other liver diseases where the diagnosis is established by clinical tests, like hepatitis C infection, or by identification of a characteristic pattern of injury, like steatohepatitis, DILI remains a diagnosis of exclusion. There is no single test or combination of tests that establishes the diagnosis of DILI, leaving it an area where thoughtful investigation and expert opinion are the gold standards (10). Because it is difficult for even experienced physicians to become experts in DILI, scoring systems have been created to fill the expertise gap. The 2 scales applicable to liver disease are the Roussel Uclaf Causality Assessment Method (RUCAM) (11) and the Clinical Diagnostic Scale (CDS) (12). Both systems take into account various factors, including the type of biochemical injury, timing of drug intake relative to the onset of injury, the
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TA B LE 15. 1 Non-neoplastic injury patterns in DILI Typical Biochemical Presentation1
Relative Frequency Within DILI
Examples of Non-DILI Etiologies
Zonal necrosis
H
Uncommon
Hypoxic injury
Acute hepatitis
H
Common
Acute viral hepatitis, AIH2
Chronic hepatitis
H
Uncommon
Chronic viral hepatitis, AIH2
Granulomatous
C
Rare
Sarcoidosis, Infections
Mononucleosis-like
M to H
Rare
EBV hepatitis
Cholestatic hepatitis
C to H
Common
Acute viral hepatitis, AIH2
Acute (intrahepatic) cholestasis
C to M
Uncommon
Sepsis, obstruction
Chronic cholestasis (including duct paucity)
C to M
Uncommon
PBC
Chronic cholestasis (duct sclerosis)
C to M
Rare
PSC
Microvesicular steatosis
M
Rare
Alcoholic foamy degeneration
Macrovesicular steatosis
M
Uncommon
NAFLD2
Steatohepatitis
M
Rare
NASH2
Rare
Artifact, mass lesions, outflow obstruction
Rare
Outflow obstruction
Budd–Chiari
Rare
Outflow obstruction
Hepatoportal sclerosis
Rare
Injury Pattern Necroinflammatory Patterns
Cholestatic Patterns
Steatotic Patterns
Vascular Injury Patterns Sinusoidal dilation/peliosis SOS/VOD2
Nodular regenerative hyperplasia
M to H
C to M
Rare
Collagen-vascular diseases, lymphoproliferative diseases
1 Biochemical presentation defined by ratio (R) of alanine aminotransferase (ALT) to alkaline phosphatase, normalized to the upper limit of normal. (H) Hepatocellular, R 5; (M) Mixed, 2 5 R 5; (C) Cholestatic, R 2. 2 Abbreviations: AIH, autoimmune hepatitis; NAFLD, nonalcoholic fatty liver disease; NASH, nonalcoholic steatohepatitis; SOS/VOD, sinusoidal obstruction syndrome/ veno-occlusive disease.
time to resolve the injury, age of the patient, exclusion of other etiologies and drugs, prior reports of toxicity for the suspected agent and positive rechallenge with the agent. These “one size fits all” systems cannot include the nuances of particular drug injuries and they tend to work best in simple clinical situations where the suspects are limited and the presentation falls into one of the more common hepatocellular or cholestatic patterns. Neither system uses information from the liver biopsy as it is not a required part of the clinical evaluation. In the 1970s, Dr. Irey, chair of the Department of Environmental Pathology at the Armed Forces Institute of Pathology, proposed a method of evaluation based on 6 general principles, outlined in Table 15.2 (13). The first principle is Temporal Eligibility, which considers the timing of drug exposure with the injury. Clearly, the suspect drug must have been taken prior to onset of injury, but it is not always clear when the onset was. The patient may have had symptoms for days or weeks prior to presentation. The duration of exposure is also important to consider, and it is somewhat drug-specific. As a general rule, a drug must be taken for a few weeks to 6 months before toxicity can develop.
This is a typical time period for metabolic injury to develop from the accumulation of toxic metabolite or for an immunologic response. There are many exceptions though. A toxic dose of acetaminophen can be taken all at once in a suicide attempt, and significant toxicity can develop in a short time period if maximum doses are taken by susceptible individuals (14). Toxicity to amoxicillin-clavulanate typically develops 1 to 3 weeks after a 10-day course of therapy is complete. A few drugs, like nitrofurantoin, may be taken for more than a year before the patient becomes symptomatic. Exclusion of Competing Causes is a necessary part of any DILI evaluation. The investigators of the DILIN network recently published criteria for documenting cases of DILI (15). Although the guidelines are meant to apply to publications, they serve as an outline of evaluation in cases of suspected DILI. It is important to consider the patient’s primary disease as well as comorbidities such as heart failure, hypotension, sepsis, diabetes, obesity, and alcohol use. Laboratory tests to exclude viral hepatitis and autoimmune liver disease are important, as are imaging tests to exclude abnormalities or obstruction of duct system. It may not be practical to perform
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TA B LE 15. 2 Elements of causality analysis Temporal eligibility
Was the suspected agent started prior to the onset of liver injury? Was the agent given for an appropriate time or at a dose consistent with causing injury?
Exclusion of competing causes
Have other non-DILI etiologies been excluded by appropriate history, laboratory testing, and imaging studies?
Known potential for injury
Has the agent been previously reported to cause DILI? How common is DILI from the agent?
Precedent for pathologic pattern
What biochemical and histological presentations have been reported for DILI caused by the agent?
Dechallenge/ rechallenge
Did stopping the agent result in recovery? Was the rate of recovery compatible with DILI? If the patient was given the agent again (either planned or unplanned), did the injury recur?
Toxicology
Were blood levels of the agent measured and were they in the known toxic range?
Conclusion
Based on the evaluation of presentation, exposure, pattern of injury and follow-up, estimate the probability of DILI due to the suspect agent (17)
Definite
95% chance—all competing causes excluded, typical injury pattern for agent, positive rechallenge (if attempted), characteristic clincopathologic pattern
Likely
75–95% chance—most other possibilities excluded, but clinicopathologic signature of DILI either not well described for agent or not perfectly matched
Probable
50–75% chance—competing causes unlikely but cannot be fully excluded
Possible
25–50% chance—other etiologies possible and cannot be excluded
Not DILI
25% chance—other etiology identified, pattern does not match agent
Abbreviation: DILI, drug-induced liver injury. From Ref. 13.
the full evaluation in all cases and the liver biopsy can used to help guide the evaluation. For example, obstruction of the biliary tree is unlikely to cause an acute hepatitis, and canalicular cholestasis would be an unlikely result of chronic viral hepatitis. On the other hand, it would be difficult to conclude that DILI was present in an obese, diabetic patient whose biopsy showed only steatohepatitis, regardless of how liver enzymes rose and fell in association with a particular drug. In consulting on a case of DILI, the pathologist should be clear about which diseases could result in the pattern of injury and therefore need to be rigorously excluded in order to conclude that a drug had caused injury. The drug’s Known Potential for Injury is an important piece of circumstantial evidence that may implicate one drug over another. Literature reports of DILI are very important in establishing a drug’s potential to cause serious harm. If only 1 or 2 case reports have been published despite widespread use
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of a drug, then the likelihood is low that the drug is causing the patient’s liver injury. A patient taking both isoniazid and penicillin is much more likely to be harmed by the isoniazid, which has thousands of published examples of DILI, than the penicillin, for which only a couple of well-documented cases exist. There are many resources available to pathologists seeking information about DILI, including the online databases like Pubmed (www.ncbi.nlm.nih.gov/pubmed/) and other search engines, textbooks focused on DILI, and government agencies like the Food and Drug Administration (www.fda.gov). The literature search used to evaluate the drug’s potential for injury can be used to identify the biochemical and Pathologic Patterns associated with the suspect agent. The biochemical patterns are divided into hepatocellular, cholestatic, and mixed injury based on the ratio of ALT to alkaline phosphatase, after normalizing each laboratory value to its upper limit of normal (ULN) (16). The ratio, “R,” is defined at the point when the ALT or alkaline phosphatase rises to more than twice the ULN. When R is greater than 5, the injury is hepatocellular. Cholestatic injury is defined as an R value less than 2, whereas mixed injury has an R value between 2 and 5. The biochemical pattern is further refined by the presence of jaundice. Thus, if a drug typically causes hepatocellular jaundice, then this means that R is more than 5 and the bilirubin is elevated. Jaundice or elevated bilirubin levels are not required for an injury to be characterized as cholestatic. The biochemical pattern is poorly predictive of the histologic pattern, as can be seen in Table 15.1. A patient with hepatocellular jaundice might easily show zonal necrosis, acute hepatitis, or cholestatic hepatitis on biopsy. Cholestatic injury might turn out to be cholestatic hepatitis, granulomas, nodular regenerative hyperplasia, or even steatohepatitis on biopsy. The pathology pattern therefore provides much more information about the injury, which can also be compared to the literature reports of DILI by the suspected agent. Dechallenge is the act of observing what happens to the patient after the suspected drug is stopped. Most patients will show gradual recovery, with cholestatic injury typically taking longer to resolve than hepatocellular injury. About 10% of the time, the injury will take more than 6 months to resolve, despite therapy. In some patients with fulminant liver failure, it will not be possible to observe a full dechallenge because they undergo transplant or die. Similarly, a patient who develops drug-induced cirrhosis is unlikely to fully recover. In the absence of one of these special circumstances, failure of an injury to resolve is usually considered to be evidence against drug injury. Recurrence of an injury if a drug is restarted (rechallenge) is one of the strongest pieces of evidence for drug injury, but is unlikely to be used in practice except by accident or in situations where the drug is absolutely necessary. In immune-mediated injury, DILI may recur with as little as a single dose, whereas in injuries mediated by metabolic transformation, the drug may be needed to be given for weeks before recurrence of the injury. Toxicology is used rarely in DILI evaluation, and then only for specific agents like acetaminophen or for drugs with narrow therapeutic windows where blood-level monitoring is routinely performed. Most DILI is idiosyncratic, meaning that
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the dose is of little importance in deciding whether the patient will develop toxicity, and injury may occur while on therapeutic levels of medication. Toxicology may also serve to confirm that patients were taking specific medications when they are unable to provide history and other records are unavailable. After all of the evidence have been gathered, it may be possible to assign a likelihood of causality to the drug (Table 15.2). The terms presented here are those used by investigators in the DILIN network to assign levels of causality during expert review (17). Unfortunately, it may not be possible to complete the full analysis as outlined above during the time frame of liver biopsy evaluation. Depending on when the liver biopsy is performed during the course of the clinical workup, many of the tests excluding other causes of liver injury may not have been performed and DILI may only be suspected after reviewing the liver biopsy findings. In these situations, the pathologist’s diagnostic line should at least contain a description of the pattern of injury and its severity. The note should evaluate the findings in light of what is known at the time, including some evaluation of the potential of the suspect drugs to cause the observed histological changes. In the case examples that follow in this chapter, Irey’s method of evaluation will be used to show how the information in the history, on biopsy, and from the literature are combined to provide a full evaluation. AC K N OW L E D G M E N T
The author would like to acknowledge the DILIN network for the accrual and expert evaluation of 6 of the cases presented in this chapter (Cases 15.2, 15.3, 15.4, 15.5, 15.6, and 15.8).
References 1. Lee WM, Squires RH, Jr, Nyberg SL, Doo E, Hoofnagle JH. Acute liver failure: summary of a workshop. Hepatology. 2008;47:1401–1415.
LIVER
INJURY
2. Lasser KE, Allen PD, Woolhandler SJ, Himmelstein DU, Wolfe SM, Bor DH. Timing of new black box warnings and withdrawals for prescription medications. JAMA. 2002;287:2215–2220. 3. Sgro C, Clinard F, Ouazir K, et al. Incidence of drug-induced hepatic injuries: a French population-based study. Hepatology. 2002;36:451–455. 4. Andrade RJ, Lucena MI, Fernandez MC, et al. Drug-induced liver injury: an analysis of 461 incidences submitted to the Spanish registry over a 10-year period. Gastroenterology. 2005;129:512–521. 5. Bjornsson E, Olsson R. Outcome and prognostic markers in severe druginduced liver disease. Hepatology. 2005;42:481–489. 6. Chalasani N, Fontana RJ, Bonkovsky HL, et al. Causes, clinical features, and outcomes from a prospective study of drug-induced liver injury in the United States. Gastroenterology. 2008;135:1924–1934, e1–e4. 7. Hoofnagle JH. Drug-induced liver injury network (DILIN). Hepatology. 2004;40:773. 8. Kleiner DE. The pathology of drug-induced liver injury. Semin Liver Dis. 2009;29:364–72. 9. Goodman ZD. Drug hepatotoxicity. Clin Liver Dis. 2002;6:381–397. 10. Rochon J, Protiva P, Seeff LB, et al. Reliability of the Roussel Uclaf causality assessment method for assessing causality in drug-induced liver injury. Hepatology. 2008;48:1175–1183. 11. Danan G, Benichou C. Causality assessment of adverse reactions to drugs—I. A novel method based on the conclusions of international consensus meetings: application to drug-induced liver injuries. J Clin Epidemiol. 1993;46:1323–1330. 12. Maria VA, Victorino RM. Development and validation of a clinical scale for the diagnosis of drug-induced hepatitis. Hepatology. 1997;26:664–669. 13. Irey NS. Teaching monograph. Tissue reactions to drugs. Am J Pathol. 1976;82:613–647. 14. Watkins PB, Kaplowitz N, Slattery JT, et al. Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily: a randomized controlled trial. JAMA. 2006;296:87–93. 15. Agarwal VK, McHutchison JG, Hoofnagle JH; Drug-Induced Liver Injury Network. Important elements for the diagnosis of drug-induced liver injury. Clin Gastroenterol Hepatol. 2010;8:463–470. 16. Benichou C. Criteria of drug-induced liver disorders. Report of an international consensus meeting. J Hepatol. 1990;11:272–276. 17. Fontana RJ, Watkins PB, Bonkovsky HL, et al. Drug-Induced Liver Injury Network (DILIN) prospective study: rationale, design and conduct. Drug Saf. 2009;32:55–68.
Case 15.1
Acetaminophen-Induced Fulminant Liver Failure DAVID E. KLEINER
C L I N IC AL I N F OR M AT I ON
A 6-year-old boy presented to the emergency room after being found poorly responsive and lethargic by his mother. The child had developed a febrile illness about 1 week prior to admission and was receiving regular doses of a pediatric formulation of acetaminophen. When this medication ran out, the mother had started giving him a regular adult strength pill but was not sure how much he had received. He also had gastrointestinal symptoms with nausea and vomiting and had had little to eat or drink in the past 3 days. Laboratory tests sent from the emergency room showed an ALT of 8200 IU/L, an aspartate aminotransferase (AST) of 9600 IU/L, a total bilirubin of 9 mg/dL, and an acetaminophen level of 79 μg/mL about 15 hours from his last dose. N-acetylcysteamine was administered, but over the next day the child developed grade 3 encephalopathy and hypotension. An emergency liver transplantation was performed.
F I G U R E 1 5 . 1 . 1 Acetaminophen toxicity with zonal necrosis of perivenular hepatocytes with periportal sparing.
R E A SON F OR R E F E R R AL
Determine etiology of liver failure. PAT H OL OG I C F E AT U R E S
Sections of the explanted liver showed preserved hepatic architecture. Confluent coagulative necrosis was present in zone 3 and focally extended to zone 2 (Figure 15.1.1). Focally, the necrosis appeared to bridge between central veins. A small amount of hemorrhage was present around some of the veins. Examination of the interface between necrotic and viable liver showed occasional apoptotic hepatocytes in the viable areas (Figure 15.1.2). The viable hepatocytes were swollen and ballooned, and some were clearly steatotic. Mitotic figures were easily identified among the viable hepatocytes (Figure 15.1.3). There was no visible bile in hepatocytes or canaliculi. The portal areas showed occasional inflammatory cells, but the portal structures were intact and unremarkable (Figure 15.1.4). The degree of necrosis varied across the section from 30% to 50% of the parenchyma. D I AG N OS I S
Zone 3 necrosis with steatosis due to acetaminophen injury. D I S C U S S I ON
Most drugs that cause liver injury are idiosyncratic hepatotoxins. The liver injury is uncommon to very rare, unpredictable, not dependant on dose and not reproducible in animal
F I G U R E 1 5 . 1 . 2 Interface between necrotic and viable hepatocytes.
models. Acetaminophen is one of the rare drugs that is an intrinsic hepatotoxin, causing reproducible, dose-dependent toxicity. Hepatic injury occurs when the capacity to detoxify acetaminophen by the normal mechanisms of glucuronidation and sulfation is exceeded leading to oxidation by the cytochrome P450 (CYP) system to a toxic metabolite, N-acetylp-benzoquinone (NAPQI) (1). This can occur through drug overdose, either accidentally or with suicidal intention or at normal doses where the balance of detoxification has shifted. This latter situation applies when the hepatocyte glutathione levels have been depleted from malnutrition or chronic alcoholism. Alcohol (and other drugs) increases the level of CYP
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FIGURE 15. 1. 3 Steatosis and ballooning of viable hepatocytes with
mitotic activity.
LIVER
INJURY
and jaundice may develop. During the next couple of days the patient may feel somewhat better, but serious signs of liver injury appear 3 to 4 days after a toxic dose. The transaminase levels can be very high, over 10 000 IU/L, and jaundice may appear or worsen. Gastrointestinal symptoms may recur along with hepatic encephalopathy. The prognosis is poor if there is marked prolongation of the prothrombin time, renal failure, lactic acidosis, cerebral edema, or grade 3 or 4 encephalopathy. If the patient survives without a need for liver transplant, there is gradual resolution of the injury over the next several months (1). Although biopsies are seldom performed during the acute episode, the histologic changes are characteristic and may be seen on explants or at autopsy. There is zonal necrosis that is centered in zone 3 but may involve other zones in severe cases. The necrosis is confluent and coagulative, although apoptotic bodies can be seen among the viable hepatocytes. Inflammation is usually minimal, but scattered neutrophils and macrophages may be seen at the edge of the necrotic zone. The remaining viable hepatocytes usually show macrovesicular steatosis. Zone 3 necrosis is an uncommon pattern in DILI but can be seen with exposure to organics and toxins such as carbon tetrachloride and tannic acid. Halothane is also reported to cause zonal necrosis. The main non-DILI cause of zone 3 necrosis is hypoxic-ischemic injury; so in patients with heart failure, hypotension, or shock, it is important to correlate changes in enzymes with other clinical findings. Acetaminophen levels can be tested, and there is a useful nomogram that relates blood levels and time from last dose to toxicity. Acetaminophencysteine adducts can also be measured and have proven useful in the evaluation of unexplained ALF (5). If the patient presents soon after taking an overdose of acetaminophen, N-acetylcysteine can be given to prevent hepatotoxicity. If, as in this case, toxicity has already developed, the chances of reversing or limiting the injury are less. The causality analysis is presented in Table 15.1.1. In this case, even though it was not known how much acetaminophen had
FIGURE 15. 1. 4 Representative portal area showing minimal inflam-
matory infiltrate.
2E1, allowing oxidation to occur more readily. Although serious toxicity occurs when the dose of acetaminophen overwhelms the detoxification pathways, liver enzyme elevations can occur at normal doses in healthy adults (2). Acetaminophen is the single most common cause of acute liver failure (ALF) in the United States according to data gathered by the Acute Liver Failure Study Group. Between 1998 and 2003, the proportion of acetaminophen cases in their cohort rose from 28% to 51% (3). The proportion of ALF due to acetaminophen is lower in children, being 18% in children of 3 to 18 years of age and only 3% of infants under 3 years of age (4). After an overdose of acetaminophen, several stages of toxicity are recognized. Within the first day there were nonspecific gastrointestinal symptoms with nausea, vomiting, and abdominal pain as well as lethargy and malaise. The transaminases start to rise during this period,
TA BL E 1 5 . 1 . 1 Causality analysis—acetaminophen Temporal eligibility
Acetaminophen given over the last week, dose unknown
Exclusion of competing causes
Hypotension developed after onset of symptoms, no other drugs given, other etiologies of liver failure not tested
Known potential for injury
Acetaminophen is a known intrinsic hepatotoxin
Precedent for pathologic pattern
Zone 3 necrosis with steatosis is the classic injury pattern of acetaminophen
Dechallenge/ rechallenge
Dechallenge unable to be performed due to transplant. Rechallenge not performed.
Toxicology
Blood levels of acetaminophen were 79 μg/mL at 15 hours, well within the toxic range
Conclusion
Zone 3 necrosis with steatosis due (95% chance) to acetaminophen
CASE
15.1:
A C E TA M I N O P H E N - I N D U C E D
been given, toxicology could be performed. This piece of information, combined with the characteristic histologic pattern allows the diagnosis of acetaminophen toxicity with near certainty. Even though hypotension developed just prior to transplant, the biochemical injury preceded that complication. As a final cautionary note, this case illustrates the unfortunate, unintentional overdosing of a child with acetaminophen, a situation that can have serious consequences (6).
References 1. Larson AM. Acetaminophen hepatotoxicity. Clin Liver Dis. 2007;11: 525–548 vi.
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FAILURE
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2. Watkins PB, Kaplowitz N, Slattery JT, et al. Aminotransferase elevations in healthy adults receiving 4 grams of acetaminophen daily: a randomized controlled trial. Jama. 2006;296:87–93. 3. Larson AM, Polson J, Fontana RJ, et al. Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study. Hepatology. 2005;42:1364–1372. 4. Lee WM, Squires RH Jr, Nyberg SL, et al. Acute liver failure: Summary of a workshop. Hepatology. 2008;47:1401–1415. 5. James LP, Alonso EM, Hynan LS, et al. Detection of acetaminophen protein adducts in children with acute liver failure of indeterminate cause. Pediatrics. 2006;118:e676–e681. 6. Heubi JE, Barbacci MB, Zimmerman HJ. Therapeutic misadventures with acetaminophen: hepatotoxicity after multiple doses in children. J Pediatr. 1998;132:22–27.
Case 15.2
Statin-Associated Acute Hepatotoxicity DAVID E. KLEINER
C L I N I C AL I N F OR M AT I ON
An 82-year-old man with a history of diabetes and gastroesophageal reflux presented with a several week history of epigastric pain and nausea. He was jaundiced on physical examination. One month prior his liver tests had been essentially normal, but now testing showed ALT of 1737 IU/L, AST of 1919 IU/L, alkaline phosphatase of 260 IU/L, and total bilirubin of 5.3 mg/dL. Serologic results were negative for hepatitis A, B, and C, and the ANA was negative. ASMA was weakly positive. An abdominal CT showed no evidence of gallstones or biliary dilation. A medication history revealed that he had started simvastatin about 4 months prior to presentation. Other current medications included metformin (long term), bupropion (long term), and escitalopram (4 days). All medications were stopped. F I G U R E 1 5 . 2 . 2 Plasmacellular infiltrate in a portal area with inter-
R E A S ON F OR R E F E R R A L
face hepatitis and duct injury.
To confirm suspected drug-induced liver injury. PAT H OL OG I C F E AT U R E S
Examination of the liver biopsy showed a diffuse hepatocellular injury characterized by numerous foci of lobular inflammation, scattered apoptotic hepatocytes, Kupffer cell hyperplasia, and lobular disarray (Figure 15.2.1). With the portal areas, the infiltrate varied from mild and periportal to dense and was associated with interface hepatitis and bile duct injury (Figure 15.2.2). Plasma cells were present in increased
F I G U R E 1 5 . 2 . 3 Steatosis and ballooning injury with lobular
inflammation.
FIGURE 15. 2. 1 Marked lobular inflammation and lobular disarray in
statin-induced liver injury.
numbers in both the portal areas and the parenchymal infiltrate. Small fat droplets were present in most hepatocytes. Occasional foamy cells with microvesicular steatosis were also present as well as rare ballooned hepatocytes (Figure 15.2.3). There was canalicular and hepatocellular cholestasis, which was pale and difficult to see on routine stains (Figure 15.2.4), but clearly visible on the copper stain (Figure 15.2.5). The Masson Trichrome stain demonstrated portal fibrotic expansion (Figure 15.2.6).
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S TAT I N - A S S O C I AT E D
ACUTE
H E PAT O T OX I C I T Y
221
DIAGNO SIS
Acute cholestatic hepatitis due to simvastatin. Probable underlying fatty liver disease.
DISCUSSIO N
FIGURE 15. 2. 4 Dilated canaliculi with pale-staining bile.
FIGURE 15. 2. 5 Pale green bile is visible within canaliculi and hepatocytes on rhodanine stain.
FIGURE 15. 2. 6 Portal fibrotic expansion on Masson Trichrome stain.
The statins are a class of lipid-lowering drugs that act by inhibiting hydroxymethylglutaryl coenzyme A reductase, a key enzyme in the cholesterol biosynthetic pathway. Their general effectiveness, safety profile, and expanding list of indications have made statins among the most commonly prescribed medications worldwide. Clinical trials of statins have reported a low (0.5–2%) incidence of ALT elevations greater than 3 times the ULN (1,2). Although these biochemical abnormalities have caused some concern, they are generally asymptomatic and without serious consequences (3). Studies have shown that statins can be safely used in the presence of underlying liver diseases such as nonalcoholic fatty liver disease (4). Of more concern are the relatively rare reports of serious hepatotoxicity. Drug-Induced Liver Injury Network investigators have recently reviewed literature evidence of serious statin hepatotoxicity (5). Statins have been reported to cause 2 major patterns of serious liver injury. The more common form is an acute cholestatic hepatitis, as demonstrated by this case. All statins currently in use have been reported to cause this injury. Patients have usually been taking the statin for several months prior to developing hepatotoxicity, but a few patients have been reported with injury only after 3 or 4 years of therapy. The biochemical pattern of injury is often hepatocellular with transaminase elevations 5 to 20 times the upper limit of normal and most cases are jaundiced as well. Biopsies show variable degrees of inflammation and intrahepatic cholestasis. The prognosis is generally favorable, with only a few patients dying or requiring liver transplant. Statins have also been implicated in causing an autoimmune-like hepatitis. It is thought that some of these cases may represent a triggering effect, since the hepatitis did not resolve when the drug was withdrawn. Patients have positive serology, mainly elevated titers of ANA, but other autoantibodies have also been reported including anti–smooth muscle and antihistone antibodies (6). Biopsies show necroinflammatory changes compatible with autoimmune hepatitis. Cholestasis on biopsy has not been reported in these cases, although the bilirubin can be elevated. The analysis of this case is shown in Table 15.2.1. The patient had been taking simvastatin for 4 months prior to developing liver injury, within the window of reported cases of statin hepatotoxicity. Since the pattern of injury on biopsy was acute cholestatic hepatitis, the differential diagnosis includes acute viral and autoimmune hepatitis, which were excluded by serological testing. It would be important in this case to repeat tests for hepatitis C after several months, because acute hepatitis C may not detectable in clinical tests during the episode of jaundice. Although duct obstruction is unlikely given
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TA B LE 15. 2. 1 Causality analysis—simvastatin Temporal eligibility
4 months of therapy is at the median for statin injury
Exclusion of competing causes
Viral and autoimmune hepatitis, obstruction excluded, other drugs less likely
Known potential for injury
Rare, but well documented reports of hepatocellular jaundice due to statins
Precedent for pathologic pattern
Biopsies of statin-induced injury have shown cholestatic hepatitis in multiple reports
Dechallenge/ rechallenge
Biochemical evidence of injury resolved over the next 6 weeks after stopping medication
Toxicology
Not performed
Conclusion
DILI very likely (75–95%) due to simvastatin
LIVER
INJURY
Based on this reasoned approach, it is very likely that simvastatin caused this patient’s liver injury. It is difficult to be absolutely certain because of the relative rarity of statininduced hepatotoxicity. It is important to note that not all of the pathology observed in this case may be attributed to the drug. The steatosis present in the background may have been due to underlying fatty liver disease since it has not been previously noted to be a part of the statin injury pattern. In other respects, this case matches the literature reports of statin injury, both clinically and on biopsy.
References
Abbreviaton: DILI, drug-induced liver injury.
the pattern of enzyme elevations and the pathology, gallstones were excluded by imaging studies. The patient was taking 3 other drugs which need to be considered. Metformin, bupropion, and escitalopram are very rare causes of cholestatic hepatitis, but the latency period in reported cases is about 1 to 3 months after starting the drugs (7–9). This makes the other drugs unlikely candidates for the patient’s injury. As discussed above, statins have been demonstrated to cause an acute cholestatic hepatitis, which matches the presentation of the current case. Finally, the patient’s symptoms and serum biochemistries resolved with discontinuation of the drug. No rechallenge was attempted and no toxicology was performed.
1. de Denus S, Spinler SA, Miller K, Peterson AM. Statins and liver toxicity: a meta-analysis. Pharmacotherapy. 2004;24:584–591. 2. Silva MA, Swanson AC, Gandhi PJ, Tataronis GR. Statin-related adverse events: a meta-analysis. Clin Ther. 2006;28:26–35. 3. Chalasani N, Aljadhey H, Kesterson J, et al. Patients with elevated liver enzymes are not at higher risk for statin hepatotoxicity. Gastroenterology. 2004;126:1287–1292. 4. Chalasani N. Statins and hepatotoxicity: focus on patients with fatty liver. Hepatology. 2005;41:690–695. 5. Russo MW, Scobey M, Bonkovsky HL. Drug-induced liver injury associated with statins. Semin Liver Dis. 2009;29:412–422. 6. Ahmad S. Lovastatin-induced lupus erythematosus. Arch Intern Med. 1991;151:1667–1668. 7. Alvaro D, Onetti-Muda A, Moscatelli R, Atili AF. Acute cholestatic hepatitis induced by bupropion prescribed as pharmacological support to stop smoking. A case report. Dig Liver Dis. 2001;33:703–706. 8. Del Val Antonana A, Ortiz Polo I, Rosello Sastre E, Moreno-Osset E. Hepatotoxicity related to escitalopram. Med Clin (Barc). 2008;131:798. 9. Desilets DJ, Shorr AF, Moran KA, Holtzmuller KC. Cholestatic jaundice associated with the use of metformin. Am J Gastroenterol. 2001;96: 2257–2258.
Case 15.3
Drug-Induced Autoimmune Hepatitis DAVID E. KLEINER
C L I N IC AL I N F OR M AT I ON
A 21-year-old man presented with nausea, vomiting, and jaundice. He had been placed on minocycline for acne, 100 mg/day about 11 weeks prior to presentation, but had stopped the medication 1 week earlier due to fatigue and unintended weight loss. His past medical history was only significant for mild asthma, treated with albuterol and fluticasone-salmeterol (both inhaled medications). Laboratory evaluation showed an ALT of 1343 IU/L, AST of 867 IU/L, alkaline phosphatase of 783 IU/L, and a total bilirubin of 5.7 mg/dL. Viral serologies for hepatitis A, B, and C, EBV and CMV were negative, but ANA was positive at 1:1280. ASMA and AMA were negative. Quantitative IgG was elevated at 1870 mg/dL. He was started on corticosteroids and responded rapidly, with normalization of serum biochemistries within 3 weeks. FIGURE 15.3.2
R E A SON F OR R E F E R R AL
Foci of lobular inflammation and apoptotic
hepatocytes.
Evaluate etiology of hepatitis. PAT H OL OG I C F E AT U R E S
On low power examination, the inflammation was mainly concentrated in the portal areas with scattered foci of lobular inflammation in the parenchyma (Figure 15.3.1). The hepatocytes were enlarged, with reactive nuclear changes, and acidophil bodies were easily identified (Figure 15.3.2). Hepatocyte rosetting was seen, but there was no parenchymal cholestasis or lobular disarray. The inflammatory infiltrate in
F I G U R E 1 5 . 3 . 3 Portal inflammation with increased numbers
of eosinophils.
FIGURE 15. 3. 1 Chronic hepatitis pattern with minocycline showing moderate portal inflammation and scattered foci of lobular inflammation.
the portal areas was a mix of lymphocytes, plasma cells, and histiocytes, with prominent eosinophils (Figure 15.3.3). Most of the edges of portal areas were involved by interface hepatitis (Figure 15.3.4). Bile duct injury was present in several portal areas (Figure 15.3.5). A Masson Trichrome stain showed mild portal fibrotic expansion but no bridging fibrosis. The overall histologic pattern was most similar to chronic hepatitis, because of the portal-dominant inflammation and lack of cholestatic features or lobular disarray.
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FIGURE 15. 3. 4 Near-circumferential interface hepatitis around a typical portal area.
FIGURE 15. 3. 5 Injured duct within a portal area showing marked
inflammation.
D I AG N OS I S
LIVER
that mimics idiopathic AIH. The drug injury can mimic all aspects of idiopathic disease, including clinical presentation, positive serologies for autoantibodies, elevated immunoglobulin levels, and histologic manifestations. The diagnostic criteria for AIH have been published, and there has been a recent proposal to simplify these criteria (3,4). Both systems assign points for various disease features with certain scores qualifying as probable or definite AIH. The simplified criteria consider autoantibodies, immunoglobulin levels, and absence of viral hepatitis in the score, but a diagnosis of definite AIH requires a liver biopsy. Given that one must exclude idiopathic AIH in order to make a diagnosis of DIAIH, it is reasonable to ask how one can ever make a diagnosis of DIAIH with certainty. First, certain drugs have characteristically been associated with AIHlike presentations (Table 15.3.1). These drugs, particularly nitrofurantoin and minocycline, have all been associated with drug injury that matches AIH. Some herbal agents, particularly germander, have also been associated with DIAIH (5). Although most studies of DIAIH are single case reports or small series, the Mayo Clinic has recently published their experience with cases of DIAIH and compared them with cases of AIH accrued during the same time period (6). They identified 24 cases of DIAIH and 237 cases of AIH over a 10-year period. Most of the DIAIH cases were due to either minocycline or nitrofurantoin. The patients with DIAIH did not differ from those with AIH in terms of gender, age, autoantibody positivity, immunoglobulin level, necroinflammatory activity, or fibrosis. None of their cases of DIAIH had cirrhosis on biopsy, although cirrhosis has been reported for nitrofurantoin (7,8). The one major difference was that the patients with DIAIH were more likely to be managed with steroids alone, and in all cases where immunosuppression was withdrawn, the hepatitis did not recur. The causality analysis for this case is presented in Table 15.3.2. The histologic considerations in the differential diagnosis are mainly other causes of chronic hepatitis such as the hepatitis viruses and AIH. Given his young age and the presence of duct injury, the overlap disease of primary sclerosing cholangitis (PSC) and AIH should be considered, TA BL E 1 5 . 3 . 1 Currently approved drugs associated with autoimmune
Minocycline-induced autoimmune hepatitis.
hepatitis Clometacine
D I SC U SSI ON
Immune-mediated drug injury may be divided into 2 basic forms, immunoallergic DILI (IA-DILI) and drug-induced autoimmune hepatitis (DIAIH) (1,2). Patients with IA-DILI have evidence of a hypersensitivity reaction with fever, skin rash, and peripheral eosinophilia. Biopsies may show a wide range of histologies, from pure cholestasis to acute hepatitis. Autoantibodies may be present but are not required, and the clinical presentation is usually distinct from that of idiopathic AIH. In contrast, DIAIH is the term applied to drug injury
INJURY
Diclofenac Fenofibrate Methyldopa Minocycline Nitrofurantoin Papaverine Propylthiouracil Statins
CASE
15.3:
DRUG-INDUCED
TA B LE 15. 3. 2 Causality analysis—minocycline Temporal eligibility
Minocycline may develop after weeks to years of therapy
Exclusion of competing causes
Viral hepatitis excluded, other medications were inhalants, which almost never cause liver injury
Known potential for injury
Minocycline is well documented to cause an AIH-like injury
Precedent for pathologic pattern
Both acute and chronic hepatitis patterns have been reported
Dechallenge/ rechallenge
The patient was treated with steroids and rapidly improved, a trial of steroid withdrawal was planned
Toxicology
Not done
Conclusion
DILI definitely (95% certainty) due to Minocycline
Abbreviations: AIH, autoimmune hepatitis; DILI, drug-induced liver injury.
but there were no features of chronic cholestasis in the biopsy. The patient was treated with steroids resulting in rapid symptomatic and biochemical resolution, which would also argue against an overlap syndrome. The hepatitis viruses were excluded by serological evaluation. EBV, which can sometimes cause a chronic hepatitis-like injury, was also excluded. In other respects, the clinical presentation had all of the features
AU T O I M M U N E
H E PAT I T I S
225
of AIH. Although the biopsy did not show a prominent plasmacellular infiltrate, the other changes were compatible with AIH. Because minocycline is well known to cause DIAIH and because there were no other apparent considerations for the etiology of the liver disease, this injury was considered to be due to minocycline.
References 1. Liu ZX, Kaplowitz N. Immune-mediated drug-induced liver disease. Clin Liver Dis. 2002;6:755–774. 2. Uetrecht J. Immunoallergic drug-induced liver injury in humans. Semin Liver Dis. 2009;29:383–392. 3. Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31:929–938. 4. Hennes EM, Zeniya M, Czaja AJ, et al. Simplified criteria for the diagnosis of autoimmune hepatitis. Hepatology. 2008;48:169–176. 5. Ben Yahia M, Mavier P, Metreau JM, et al. Chronic active hepatitis and cirrhosis induced by wild germander. 3 cases. Gastroenterol Clin Biol. 1993;17:959–962. 6. Bjornsson E, Talwalkar J, Treeprasertsuk S, et al. Drug-induced autoimmune hepatitis: clinical characteristics and prognosis. Hepatology. 2010;51:2040–2048. 7. Iwarson S, Lindberg J, Lundin P. Nitrofurantoin-induced chronic liver disease. Clinical course and outcome of five cases. Scand J Gastroenterol. 1979;14:497–502. 8. Sharp JR, Ishak KG, Zimmerman HJ. Chronic active hepatitis and severe hepatic necrosis associated with nitrofurantoin. Ann Intern Med. 1980;92:14–19.
Case 15.4
Drug-Induced Cholestatic Hepatitis DAVID E. KLEINER
C L I N I C AL I N F OR M AT I ON
A 59-year-old African-American woman presented with fatigue, pruritus, dark urine, and jaundice. She had a history of hyperthyroidism and had been placed on methimazole, 20 mg/day, about 6 weeks earlier. She did not have fever or rash. Her past medical history was significant for sarcoidosis, asthma, and hypertension. Her laboratory data at presentation included an AST of 98 IU/L, ALT of 159 IU/L, alkaline phosphatase of 397 IU/L, and a total bilirubin of 5.6 mg/dL. The methimazole was discontinued. Serological studies for hepatitis viruses as well as ASMA and AMA were negative, but ANA was positive at 1:160. She was admitted to the hospital 2 days later where imaging studies showed a thickened gallbladder wall without evidence of cholelithiasis or intrahepatic duct dilation. She was discharged and followed in an outpatient clinic. Her bilirubin peaked at 18.4 mg/dL 2 weeks later. Resolution of jaundice was very gradual.
F I G U R E 1 5 . 4 . 2 Portal area with lymphohistiocytic inflammation
and duct injury. Several eosinophils are present. R E A S ON F OR R E F E R R A L
Exclusion of sarcoidosis or autoimmune hepatitis (AIH) as causes for the persistent jaundice. PAT H OL OG I C F E AT U R E S
On biopsy, there was a mild to moderate portal infiltrate with mild, focal interface hepatitis (Figure 15.4.1). The portal infiltrate was composed mainly of lymphocytes and histiocytes, but eosinophils were also present in most portal areas (Figure 15.4.2). The bile ducts were injured and showed
F I G U R E 1 5 . 4 . 3 Canalicular and hepatocellular cholestasis.
FIGURE 15. 4. 1 Mild portal inflammation with scattered spots of
lobular inflammation and mild steatosis in methimazole-induced cholestatic hepatitis.
reactive epithelial changes, but there was no evidence of duct paucity. The parenchyma revealed prominent canalicular and hepatocellular cholestasis (Figure 15.4.3). There was no evidence of chronic cholestasis, and the copper stain was negative. There were numerous foci of lobular inflammation, mostly in the form of microgranulomas, as well as rare acidophil bodies (Figures 15.4.4 and 15.4.5). Well-formed epithelioid granulomas were not present. Mild macrovesicular steatosis was present, but not in any zonal distribution. The trichrome stain showed mild concentric portal fibrotic expansion. The iron stain showed moderate hepatocellular iron in zone 1 distribution (Figure 15.4.6).
226
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C H O L E S TAT I C
H E PAT I T I S
227
DIAGNO SIS
Cholestatic hepatitis, with mild hepatitis and marked cholestasis, likely due to methimazole. Moderate hepatocellular hemosiderosis and mild steatosis.
DISCUSSIO N
FIGURE 15. 4. 4 Acidophil body with hypertrophic Kupffer cells in
the sinuses.
FIGUR E 15. 4. 5 Spotty lobular inflammation with microgranulomas
and steatosis ( 400).
FIGUR E 15. 4. 6 Accumulation of iron in hepatocytes and portal
macrophages.
The biopsy was performed because of a clinical picture complicated by a history of sarcoidosis, the positive ANA, and imaging studies that showed some abnormalities of the gallbladder but no duct dilation or stones. The biopsy presents a variety of findings, including inflammation, cholestasis, steatosis, and iron overload. The steatosis was mild and azonal in distribution. There was evidence of steatohepatitis. The iron accumulation is concerning in that there is no obvious etiology in the history but the degree of hemosiderosis is not severe enough to warrant immediate investigation. Setting aside the steatosis and iron accumulation, what remains is cholestasis and hepatitis that are not easily explained by AIH, sarcoidosis, or intermittent biliary obstruction. Cholestatic hepatitis is a mixed injury pattern that combines the hepatocellular and canalicular bile accumulation of obstructive jaundice with the portal and lobular inflammation and hepatocyte injury of hepatitis. In his classic text on druginduced liver injury (DILI) (1), Dr. Hyman Zimmerman noted the use of several terms for this pattern, including “cholangiolitic cholestasis,” “hepatocanalicular jaundice,” and “hypersensitivity cholestasis,” but cholestatic hepatitis is simpler and preferred over other terms. The cholestatic component may consist of bile accumulation in hepatocytes, bile plugs in canaliculi or both, and is most prominent in zone 3. Ductal and cholangiolar cholestasis are not typically seen in cholestatic hepatitis. The hepatitic component may resemble acute hepatitis, with a predominance of lobular inflammation, lobular disarray, and confluent necrosis, or it may resemble chronic hepatitis, in which the portal inflammation stands out over the lobular inflammation, as it did in this case. As the inflammation becomes very mild, there is overlap with the pattern of pure intrahepatic or acute cholestasis. When the inflammation is severe, there is overlap with the pattern of acute hepatitis, particularly when the cholestatic changes are mild. It is important to exclude chronic cholestatic injury, particularly ductal sclerosis or paucity, because these changes lead to a different histologic differential diagnosis. It is important to recognize cholestatic hepatitis, particularly when the inflammation is distributed in a chronic hepatitis pattern, because there are very few non-DILI etiologies to consider. Large duct obstruction may lead to cholestasis with inflammation, but the inflammation is usually mild and there may be other evidence to point to obstruction, such as portal edema, ductal cholestasis, or acute cholangitis. Sepsis and postsurgical jaundice may both show zone 3 cholestasis on biopsy, but the cholestasis is usually bland and these
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etiologies are easily excluded. Chronic viral hepatitis, AIH, and the chronic cholestatic diseases of primary biliary cirrhosis and primary sclerosing cholangitis rarely have hepatocellular or canalicular cholestasis as a feature of early-stage disease. In contrast, cholestatic hepatitis is a commonly reported pattern of DILI. Some drug classes have been particularly associated with this pattern of injury, including the antibacterials, antifungals, statins, antithyroid agents (except propylthiouracil), and the major tranquilizers. The analysis of this case is summarized in Table 15.4.1. As noted above, there was clinical concern for competing causes of liver injury, notably sarcoidosis and AIH. The biopsy was effective in excluding these diseases. Sarcoidosis is unlikely to cause significant intrahepatic cholestasis without
TA B LE 15. 4. 1 Causality analysis—methimazole Temporal eligibility
Patient had 6 weeks of therapy, most cases of methimazole injury have presented after 2 to 12 weeks of therapy
Exclusion of competing causes
The pathology was not characteristic of sarcoidosis or AIH. Viral hepatitis excluded by serology. Imaging showed normal ducts
Known potential for injury
Methimazole has been implicated in multiple cases of DILI
Precedent for pathologic pattern
The pathology observed most often in methimazole DILI is cholestasis or cholestatic hepatitis
Dechallenge/ rechallenge
Gradual resolution of jaundice after cessation of therapy, no rechallenge attempted
Toxicology
Not done
Conclusion
DILI very likely (75–95%) due to methimazole
Abbreviations: AIH, autoimmune hepatitis; DILI, drug-induced liver injury.
LIVER
INJURY
extensive bile duct destruction by granulomas. The inflammatory infiltrate, degree of injury, and presence of cholestasis all make AIH unlikely. Extrahepatic obstruction should always be considered in a case of cholestatic hepatitis, but the imaging showed no duct dilation and the slow recovery from the jaundice would make stone-related obstruction unlike in retrospect. The biopsy did not show specific features of large duct obstruction (portal edema, ductal cholestasis). The degree and character of the inflammation as well as the presence of duct injury would argue against this possibility. Methimazole, however, is well reported to cause cholestasis and cholestatic jaundice. Some cases are associated with features of hypersensitivity, including fever and rash. Agranulocytosis (neutropenia) has also been reported (2,3). Most cases develop between 2 and 12 weeks after initiation of drug therapy. Cholestatic changes are the most commonly reported pathology present in 15 out of 23 cases summarized by Woeber (4). Some patients can develop severe hepatitis, and deaths have been reported (5). Recovery from jaundice can be very slow, taking 3 to 5 months in some cases (3). Based on the characteristic injury pattern and the exclusion of competing etiology of liver injury, the evidence points to methimazole hepatotoxicity.
References 1. Zimmerman HJ. Hepatotoxicity: the adverse effects of drugs and other chemicals on the liver. 2nd ed. Philadelphia, PA: Lippincott, Williams & Wilkins; 1999. 2. Specht NW, Boehme EJ. Death due to agranulocytosis induced by methimazole therapy. J Am Med Assoc. 1952;149:1010–1011. 3. Vitug AC, Goldman JM. Hepatotoxicity from antithyroid drugs. Horm Res. 1985;21:229–234. 4. Woeber KA. Methimazole-induced hepatotoxicity. Endocr Pract. 2002;8:222–224. 5. Baker B, Shapiro B, Fig LM, Woodbury D, Sisson JC, Beierwaltes WH. Unusual complications of antithyroid drug therapy: four case reports and review of literature. Thyroidology. 1989;1:17–26.
Case 15.5
Drug-Induced Ductopenia DAVID E. KLEINER
C L I N IC AL I N F OR M AT I ON
A 10-year-old girl developed a punctate rash over her chest, trunk, and neck 7 weeks after taking a 5-day course of azithromycin. During the next week, she developed cough, fever, and sore throat and went to a local emergency room. She was given a dose of cephtriaxone and another prescription for azithromycin. She took two doses of the azithromycin, but the rash continued to worsen and she was admitted to a hospital the following day. Work-up at this time revealed negative culture for Streptococcus as well as abnormal liver–associated enzymes: ALT of 411 IU/L, AST of 376 IU/L, alkaline phosphatase of 460 IU/L, and a total bilirubin of 3.4 mg/dL. The rash involved her oral and conjuctival mucosa, and a skin biopsy confirmed Stevens-Johnson syndrome. An abdominal ultrasound exam was normal. Viral and autoantibody serologies were negative. Her liver chemistry abnormalities persisted despite resolution of the rash, and 2 weeks after presentation, a liver biopsy was performed. Her bilirubin and alkaline phosphatase gradually returned to normal over the next 5 months, but her transaminases remained elevated more than a year after the initial event.
were enlarged, with pale staining, and slightly pigmented cytoplasm (Figure 15.5.2). There were enlarged vacuolated macrophages in the sinusoids. Occasional apoptotic hepatocytes were present. Although bile stasis was difficult to appreciate on the routine stains, the copper stain showed distinctive zones of hepatocytes with green-tinged cytoplasm (Figure 15.5.3). Some portal areas showed mild inflammation, but plasma cells and eosinophils were not evident (Figure 15.5.4). Close examination of the portal areas revealed that most lacked an identifiable duct and a formal count found only one duct in 18 portal tracts (Figure 15.5.5).
R E A SON F OR R E F E R R AL
Evaluation of possible etiologies for the persistently abnormal liver chemistries. PAT H OL OG I C F E AT U R E S
Liver biopsy at low magnification showed minimal necroinflammatory infiltrate (Figure 15.5.1). In zone 3, the hepatocytes
F I G U R E 1 5 . 5 . 2 Zone 3 injury with pale, swollen hepatocytes and sinusoidal macrophages.
FIGURE 15. 5. 1 Small portal area without inflammation and en-
F I G U R E 1 5 . 5 . 3 Green pigmentation of hepatocytes is apparent on
larged pale hepatocytes in zone 3.
the copper stain.
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FIGURE 15.5.4 Small portal area with mild lymphocytic inflammation.
LIVER
INJURY
infection of the biliary tree. Hodgkin’s lymphoma and histiocytosis X have also been associated with ductopenia, as have a variety of congenital and developmental diseases. If all known etiologies (including drugs and toxins) have been excluded, the term idiopathic adulthood ductopenia is applied. The list of drugs and other agents associated with VBDS is long and growing (Table 15.5.1). The initial presentation may be similar to cholestatic hepatitis. Many patients present with an acute onset of jaundice and elevated levels of alkaline phosphatase and gamma glutamyltransferase. The transaminases may be modestly elevated or normal. Unlike cholestatic hepatitis, the abnormalities in bilirubin or cholestatic enzymes persist for months and may worsen, leading to liver failure from biliary cirrhosis and the need for transplantation (Figure 15.5.6). The pathophysiology that leads to VBDS is poorly understood, although immune mechanisms are almost certainly involved in some cases. If biopsies are performed early TA BL E 1 5 . 5 . 1 Drugs associated with duct paucity
FIGURE 15. 5. 5 Small portal area without a visible duct.
Aceprometazine Ajmaline Amineptine Amitriptyline Amoxicillinclavulanate Ampicillin Arsenicals Azathioprine Azithromycin Barbiturates Candesartan Carbamazepine Carbutamide Chlorothiazide Chlorpromazine Cimetidine Clindamycin
Cromolyn Cyamemazine Cyclohexyl propionate Cyproheptadine Diazepam Erythromycin Estradiol Flucloxacillin Glibenclamide Glycyrrhizin Gold Haloperidol Ibuprofen Imipramine Itraconazole Methyltestosterone Moxifloxacin
Norandrostenolone Phenylbutazone Phenytoin Prochlorperazine Sulpiride Tenoxicam Terbinafine Tetracycline Thiabendazole Tiopronin Tolbutamide Trifluoperazine Trimethoprimsulfamethoxazole Troleandomycin Xenalamine
D I AG N OS I S
Cholestatic injury with marked bile duct paucity, probably related to azithromycin.
D I SC U SSI ON
This case is an example of ductopenia that was probably related to drug injury. Ductopenia is the hallmark of vanishing bile duct syndrome (VBDS), which is the term used for the collection of diseases that can give rise to ductopenia (1,2). The most common causes for VBDS are the chronic cholestatic diseases of primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), where VBDS may develop with progression to cirrhosis. VBDS may also be associated with hepatic sarcoidosis, graft-versus-host disease and liver transplant rejection. A form of VBDS may be seen in HIV-infected patients where it is thought to be secondary to opportunistic
F I G U R E 1 5 . 5 . 6 Ductopenic portal area from an explant following
prolonged jaundice due to moxifloxacin.
CASE
15.5:
DRUG-INDUCED
in the course of the disease, there is often a pattern of cholestatic hepatitis with nonsuppurative duct injury. However, given the rarity of VBDS with respect to drug-induced cholestatic hepatitis, most patients with cholestatic hepatitis do not progress to ductopenia. Some cases have an immunoallergic phenotype, with fever, rash, and eosinophilia, and StevensJohnson syndrome is a complication of many drugs associated with ductopenia. In several reports, both Stevens-Johnson syndrome and ductopenia occur together (3). Drug-induced ductopenia should be suspected in any case of drug-induced cholestasis in which either the jaundice or the enzyme abnormalities persist beyond 6 months. Imaging is helpful to exclude a large duct problem, but a liver biopsy is the only way to assess for ductopenia, since the damage is almost always confined to the smallest branches of the duct tree. A diagnosis of ductopenia can be made when at least half of the portal areas lack a duct (1). Bile ducts may be differentiated from ductular reaction by location and size: the main duct is usually located near the artery and has approximately the same outer diameter. A cytokeratin 7 or 19 immunostain can also be helpful, particularly when inflammation may be obscuring duct remnants. A copper stain can be helpful in picking up early chronic cholestasis, but it may be negative, as it was in this case. The prognosis may depend on the extent of small duct injury, but there does not seem to be good correlation between the degree of ductopenia on biopsy and outcome. It should be noted that there is a separate type of chronic cholestatic injury that may be drug-induced and associated with ductopenia. Biliary sclerosis with fibro-obliterative PSClike lesions has been observed after hepatic artery floxuridine infusions (4) or after treatment with scolicides (5). The chemotherapeutic injury is thought to be related to microvascular injury of the peribiliary capillaries, whereas scolicides may directly injure the bile duct epithelium. The analysis of this case is summarized in Table 15.5.2. With respect to the case at hand, azithromycin causes cholestatic hepatitis that presents 1 to 3 weeks after a 5-day course of treatment (6–8). It had not been reported to cause ductopenic injury at the time the case was first seen and evaluated. However, there is now a case report of azithromycin-induced ductopenia in a 62-year-old man (9). In a 10-year-old child, the main differential diagnostic considerations would be exclusion of extrahepatic obstruction or a PSC autoimmune hepatitis syndrome. Both of these are adequately excluded by a combination of clinical testing and histologic evaluation. Consistent with the finding of duct paucity on biopsy, the patient had a very prolonged recovery, lasting more than a year after the initial injury.
DUCTOPENIA
231
TA BL E 1 5 . 5 . 2 Causality analysis—azithromycin Temporal eligibility
Latency of 2 months after taking azithromycin is longer than most reported cases, but within the 1- to 3-month window for immunoallergic reactions
Exclusion of competing causes
Viral and autoantibody studies were negative. Imaging did not identify an obstructive cause; other causes of ductopenia would be unusual at this age
Known potential for injury
Rare cause of cholestatic hepatitis
Precedent for pathologic pattern
One recent case report of ductopenic injury
Dechallenge/rechallenge
With short-course antibiotic therapy, the course is usually over by the time the symptoms begin. The patient was “rechallenged” with 2 doses of azithromycin after which her symptoms worsened
Toxicology
Not done
Conclusion
Ductopenia probably (50–75%) due to azithromycin. Case is less certain because of the long latency and the fact that ductopenia had not been reported at the time the patient presented.
References 1. Desmet VJ. Vanishing bile duct syndrome in drug-induced liver disease. J Hepatol. 1997;26(suppl 1):31–35. 2. Reau NS, Jensen DM. Vanishing bile duct syndrome. Clin Liver Dis. 2008;12:203–217. 3. Srivastava M, Perez-Atayde A, Jonas MM. Drug-associated acuteonset vanishing bile duct and Stevens-Johnson syndromes in a child. Gastroenterology. 1998;115:743–746. 4. Ludwig J, Kim CH, Wiesner RH, Krom RA. Floxuridine-induced sclerosing cholangitis: an ischemic cholangiopathy? Hepatology. 1989;9: 215–218. 5. Castellano G, Moreno-Sanchez D, Gutierrez J, Moreno-Gonzalez E, Colina F, Solis-Herruzo JA. Caustic sclerosing cholangitis. Report of four cases and a cumulative review of the literature. Hepatogastroenterology. 1994;41:458–470. 6. Chandrupatla S, Demetris AJ, Rabinovitz M. Azithromycin-induced intrahepatic cholestasis. Dig Dis Sci. 2002;47:2186–2188. 7. Longo G, Valenti C, Gandini G, Ferrara L, Bertesi M, Emilia G. Azithromycin-induced intrahepatic cholestasis. Am J Med. 1997;102:217–218. 8. Suriawinata A, Min AD. A 33-year-old woman with jaundice after azithromycin use. Semin Liver Dis. 2002;22:207–210. 9. Danica J, Irena H, Davor R, et al. Vanishing bile duct syndrome associated with azithromycin in a 62-year-old man. Basic Clin Pharmacol Toxicol. 2010;106:62–65.
Case 15.6
Methotrexate-Induced Chronic Liver Disease DAVID E. KLEINER
C L I N I C AL I N F OR M AT I ON
A 64-year-old woman was referred for evaluation of liver disease related to methotrexate therapy. She had psoriatic arthritis for 20 years, and 11 years prior to the current evaluation had been placed on methotrexate (20 mg/week). Her current total cumulative dose was about 2900 g of methotrexate. Her past medical history was also significant for obesity and hypothyroidism. She was not diabetic and did not drink alcohol. Serological tests for hepatitis viruses were negative as was anti-SMA. ANA was positive at 1:40. Three liver biopsies had already been performed and these were reported to show steatosis with minimal inflammation and possibly progressive periportal fibrosis. Her liver enzyme tests were mainly normal throughout her therapy, although recently she had mildly elevated tests, with ALT 52 IU/L, AST 51 IU/L, and alkaline phosphatase of 153 IU/L. F I G U R E 1 5 . 6 . 2 Lymphoplasmacytic infiltrate with mild interface
hepatitis.
R E A S ON F OR R E F E R R A L
Staging of liver disease and exclusion of obesity-related fatty liver disease. PAT H OL OG I C F E AT U R E S
The hepatic architecture was disrupted by wide bands of portal-based fibrosis that crossed the width of the biopsy (Figure 15.6.1). There was a mild to moderate portal inflammatory infiltrate associated with mild interface hepatitis (Figure 15.6.2). Increased numbers of plasma cells were seen in the portal infiltrate. The parenchyma
FIGURE 15.6.3 Mild macrovesicular steatosis and nuclear variability.
FIGURE 15. 6. 1 Moderate portal inflammation and mild steatosis.
showed mild macrovesicular steatosis in no particular zonal distribution (Figure 15.6.3). Mild nuclear variation was apparent. Ballooning injury was seen within the parenchyma (Figure 15.6.4) as well as near some portal tracts (Figure 15.6.5). No well-formed Mallory-Denk bodies were seen. Fibrosis was difficult to stage due to the narrow gauge of the core, but Masson stains did show probable bridging fibrosis based on the width of the fibrotic tracts (Figure 15.6.6). No zone 3 perisinusoidal fibrosis was present, although there were preserved central veins (Figure 15.6.7). 232
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FIGURE 15. 6. 4 Ballooning injury with small foci of lobular
CHRONIC
LIVER
DISEASE
233
F I G U R E 1 5 . 6 . 7 No perisinusoidal fibrosis is present.
inflammation.
DIAGNO SIS
Chronic hepatic injury likely due to methotrexate, with mild inflammation, mild steatosis, and probable bridging fibrosis, Roenigk Stage IIIB.
DISCUSSIO N
FIGUR E 15. 6. 5 Periportal ballooning injury and mild portal
inflammation.
FIGURE 15. 6. 6 Wide fibrotic band with trapping of hepatocytes.
Methotrexate was introduced in the mid-1950s as a therapy for childhood leukemias but was soon noted to ameliorate the symptoms of arthritis in rheumatoid arthritis and psoriasis. Methotrexate inhibits intracellular metabolism and purine biosynthesis by inhibiting or interfering with dihydrofolate reductase and thymidylate synthase. Hepatotoxicity of high-dose methotrexate was recognized very soon after its introduction (1). Methotrexate has been associated with a variety of pathologic changes, but the most serious toxicity is fibrosis that leads to cirrhosis. Although many of the classical studies on the pathology of methotrexate were done without pretreatment biopsies and in an era prior to the discovery of hepatitis C and the appreciation of the prevalence of NAFLD and NASH, there is a consensus that long-term therapy with methotrexate increases the risk for cirrhosis. Several risk factors have been identified, including alcohol use, obesity, and diabetes (2). Interestingly, all of these risk factors can induce liver disease that is in the differential of the pattern of injury caused by methotrexate. Weekly, rather than daily, dosing of methotrexate also reduces the risk of serious liver injury. The histologic changes observed by light microscopy are not specific for methotrexate injury and include steatosis, inflammation, nuclear enlargement and variation (anisonucleosis), and fibrosis (3–5). The steatosis is typically macrovesicular and may be mild to marked. Ballooning hepatocellular injury may be seen. The inflammation is generally mild, lymphohistiocytic, and portal, with scattered foci of lobular
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inflammation as seen in other chronic liver diseases. There is often significant nuclear variability, with nuclear enlargement, multinucleation, and vacuolation. Methotrexate injury may show a stellate portal fibrosis early in the disease course that later progresses to portal-portal and portal-central bridging fibrosis and cirrhosis. The incidence of cirrhosis varies widely (8–46% in psoriasis), but most studies do not adequately control for underlying liver disease. Patients with psoriasis seem to be at somewhat greater risk for serious liver injury than those with rheumatoid arthritis. The liver biopsy has played an important role in monitoring liver disease in patients on long-term methotrexate therapy. Although recent guidelines have reduced the frequency of biopsy as well as tempering the need for pretreatment baseline biopsy, the liver biopsy remains the best method for gauging the severity of the liver disease (6). Newer, noninvasive techniques, such as ultrasound fibrosis measurement or serum fibrosis markers, are being explored but have not yet supplanted the liver biopsy. The mainstay of grading the hepatic injury in methotrexate therapy is the Roenigk scale, summarised in Table 15.6.1. Unlike more modern systems of grading and staging liver disease, the Roenigk classification does not explicitly separate fibrosis from other features. It is clear though that grades I and II deal with prefibrotic changes, whereas grades IIIA to IV only consider fibrosis in the stratification. Clinical decisions are based on the degree of fibrosis. Current guidelines recommend more frequent monitoring at grade IIIA and consideration for stopping therapy at grades IIIB and IV (6,7). Since fibrosis is the most important feature, it would not be unreasonable to substitute a more familiar fibrosis staging system for the Roenigk classification. The case under consideration here presents some difficulty in deciding the role of obesity-related NAFLD in this patient’s hepatic pathology, summarized in Table 15.6.2. Studies have reported NASH-like pathology in patients treated with methotrexate, usually in those with obesity or diabetes (8). The prior biopsies in this case were not available for review but were reported to show steatosis and inflammation with little or no fibrosis. A specific pattern of steatohepatitis was not noted. When the current biopsy was studied prior to reviewing the history, the overall pattern was thought to be more like a chronic hepatitis, because of the significant portal TA B LE 15. 6. 1 Roenigk classification of liver injury from methotrexate
Grade
Fibrosis
Changes of Steatosis, Portal Inflammation and Anisonucleosis
Grade I
None
Up to mild degrees of injury
Grade II
None
Moderate to marked changes
Grade IIIA
Mild (periportal, short septae)
Any degree
Grade IIIB
Moderate/severe (bridging fibrosis)
Any degree
Grade IV
Cirrhosis
Any degree
Adapted from Ref. 9.
LIVER
INJURY
TA BL E 1 5 . 6 . 2 Causality analysis—methotrexate Temporal eligibility
11 years of therapy with methotrexate, with a total dose of 2900 mg
Exclusion of competing causes
Viral studies were negative, ANA titer was low, no history of diabetes or alcohol; obesity-related NAFLD still possible, but the pathology did not show specific features of NASH
Known potential for injury
Methotrexate has been documented in numerous series to cause chronic liver disease
Precedent for pathologic pattern
The pattern of injury in this case is typical for what has been reported in methotrexate injury
Dechallenge/ rechallenge
Liver enzyme abnormalities resolved after stopping the drug. Rechallenge was not performed
Toxicology
Not done
Conclusion
Chronic liver disease with probable bridging fibrosis likely (75–95%) due to methotrexate
inflammation, interface hepatitis, and portal-based fibrosis, than steatohepatitis or fatty liver disease. Indeed, although there was ballooning injury, it was as much periportal as parenchymal and there was no perisinusoidal fibrosis. Still, portal inflammation may increase with increasing stage of fibrosis in NASH, and the characteristic zonal distribution of lesions may be lost. Nevertheless, because there were no specific features pointing toward steatohepatitis as the underlying disease, it was judged that the injury in this case was most likely due to methotrexate.
References 1. Colsky J, Greenspan EM, Warren TN. Hepatic fibrosis in children with acute leukemia after therapy with folic acid antagonists. AMA Arch Pathol. 1955;59:198–206. 2. Nyfors A, Poulse H. Liver biopsies from psoriatics related to methotrexate therapy. 1. Findings in 123 consecutive non-methotrexate treated patients. Acta Pathol Microbiol Scand [A]. 1976;84:253–261. 3. Aponte J, Petrelli M. Histopathologic findings in the liver of rheumatoid arthritis patients treated with long-term bolus methotrexate. Arthritis Rheum. 1988;31:1457–1464. 4. Kremer JM, Lee RG, Tolman KG. Liver histology in rheumatoid arthritis patients receiving long-term methotrexate therapy. A prospective study with baseline and sequential biopsy samples. Arthritis Rheum. 1989;32:121–127. 5. West SG. Methotrexate hepatotoxicity. Rheum Dis Clin North Am. 1997;23:883–915. 6. Reuben A. Methotrexate contraversies. In: Kaplowitz N, DeLeve LD, eds. Drug-Induced Liver Disease. New York, NY: Informa Healthcare; 2007:683–706. 7. Visser K, Katchamart W, Loza E, et al. Multinational evidence-based recommendations for the use of methotrexate in rheumatic disorders with a focus on rheumatoid arthritis: integrating systematic literature research and expert opinion of a broad international panel of rheumatologists in the 3E Initiative. Ann Rheum Dis. 2009;68:1086–1093. 8. Langman G, Hall PM, Todd G. Role of non-alcoholic steatohepatitis in methotrexate-induced liver injury. J Gastroenterol Hepatol. 2001;16:1395–1401. 9. Roenigk HH, Jr., Auerbach R, Maibach HI, et al. Methotrexate in psoriasis: revised guidelines. J Am Acad Dermatol. 1988;19:145–156.
Case 15.7
Liver Injury Due to Total Parenteral Nutrition DAVID E. KLEINER
C L I N C I A L I N F OR M AT I ON
A baby boy was born prematurely at 27 weeks and weighed 850 g at birth. The infant was admitted to a neonatal intensive care unit, where meconium ileus was diagnosed. A portion of the small intestine was removed and the infant was placed on total parenteral nutrition (TPN) for nutritional support until he could tolerate enteral feeding. Two weeks after starting TPN, he became jaundiced and was noted to have elevated alkaline phosphatase and gamma glutamyltransferase. The transaminases were initially normal. TPN feedings continued but he succumbed 6 weeks later to sepsis. At autopsy, the biliary tree was not dilated and there were no stones in the gallbladder or bile duct. R E A SON F OR R E F E R R AL
Etiology of jaundice: obstruction, sepsis, or TPN.
F I G U R E 1 5 . 7 . 2 There was no bile duct injury, cholangitis, or portal
edema. PAT H OL OG I C F E AT U R E S
Sections of liver taken at autopsy showed generally preserved hepatic architecture. There was fibrotic expansion of portal areas with early bridging fibrosis (Figure 15.7.1). There was mild lymphocytic inflammation and clusters of pigmented macrophages in the portal areas. There was no duct injury, duct paucity, portal edema, or bile stasis in the interlobular bile ducts (Figure 15.7.2). There was extensive rosette formation, and many rosettes contained a plug of inspissated bile (Figure 15.7.3). Many of the hepatocyte plates were 2 cells thick, consistent with regeneration. There was little or no lobular inflammation.
F I G U R E 1 5 . 7 . 3 Canalicular bile stasis, hepatocyte rosettes, and
widened liver cell plates.
DIAGNO SIS
Cholestatic hepatitis with mild inflammation, prominent cholestasis, and early bridging fibrosis due to TPN.
DISCUSSIO N
FIGURE 15. 7. 1 Portal expansion with inflammation and fibrosis.
TPN is an effective and generally safe technique to provide partial or complete nutritional support for patients with either acute or chronic intestinal failure (1,2). Because TPN is not 235
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a drug, per se, but a nutritional supplement, liver injury from TPN is not always considered together with drug-induced liver injury. The incidence of biochemical abnormalities is high, even during short courses of TPN. Between 42% and 93% of adults may have elevated transaminases with lower numbers showing abnormalities of bilirubin or alkaline phosphatase (3). There are 2 basic patterns of injury seen with TPN, steatosis, and cholestasis/cholestatic hepatitis. Steatosis is the most common complication, particularly in adults. The steatosis is macrovesicular and distributed in zone 1, allowing distinction from the zone 3 distribution of steatosis in NAFLD. The steatosis may appear after only a few weeks of TPN, accompanied by mild portal and lobular inflammation. There may be mild (1-3 ULN) elevations of transaminases (4). The bilirubin may rise slightly, but the development of jaundice suggests progression to cholestatic liver injury. In neonates treated for 1 to 2 weeks or adults on longterm TPN, cholestatic liver disease may develop. In neonates, TPN is generally started soon after birth and the liver disease progression has been carefully studied (5,6). Infants who die within a week of starting TPN generally show steatosis in a zone 1 distribution without cholestasis. After a couple of weeks of TPN, canalicular cholestasis appears, with bile plugs most prominent in zone 3. Infants treated for 1 to 3 months develop ductular reaction and periportal fibrosis, which can progress to bridging fibrosis and cirrhosis. Inflammation is usually mild or absent. Neutrophils can be seen around reactive ductules. Liver failure can occur with prolonged treatment. The etiology of TPN-induced liver injury is not entirely clear and probably multifactorial (1). Because the nutritional content reaches the liver via the hepatic artery rather than the portal vein, the flow of nutrients through the hepatic acinus is altered. This causes adaptive changes within the hepatic acinus. The lack of enteral nutrition causes changes in gastrointestinal hormone release, including loss of physiologic cholecystokinin release and decreased enterohepatic circulation (7,8). Reduced cholecystokinin levels also decrease gallbladder emptying and increase the risk for stones and sludge. Enterocyte atrophy from lack of stimulation may allow increased bacterial translocation across the gut (9). Bacterial overgrowth within the lumen of the unused gut increases the conversion of deoxycholate to lithocholate, one of the more toxic bile salts. Over the years, toxicity of various components of TPN has been recognized and formulations have been altered to make the mixture less injurious. The patient’s underlying disease may also increase the susceptibility to TPN-induced injury. Known risk factors include prolonged TPN therapy, prematurity, low birth weight, malnutrition (low serum albumin), sepsis, jejunostomy, and gastrointestinal surgery. Combining TPN with enteral feeding can reduce the potential for injury by countering some of the consequences of intestinal atrophy. The causality analysis is presented in Table 15.7.1. In this case, the infant received a total of 8 weeks of TPN prior to death from sepsis. The jaundice developed at 2 weeks, consistent with the pattern of TPN-induced cholestasis. At
LIVER
INJURY
TA BL E 1 5 . 7 . 1 Causality analysis—TPN Temporal eligibility
TPN was given for 8 weeks, well documented as sufficient time to develop cholestatic liver injury
Exclusion of competing causes
Obstruction excluded at autopsy, sepsis may have contributed to some of the cholestasis, but cannot be the primary cause based on the time course
Known potential for injury
TPN is well known to cause cholestatic injury in premature infants
Precedent for pathologic pattern
Cholestasis and cholestatic hepatitis with fibrosis progression are the typical pathology observed in neonates with TPN injury
Dechallenge/ rechallenge
Not applicable—infant received TPN until death
Toxicology
Not done
Conclusion
Cholestatic hepatitis due (95% chance) to TPN
Abbreviation: TPN, total parenteral nutrition.
autopsy, the liver showed a pattern of cholestatic hepatitis, with only mild portal inflammation but prominent cholestasis. Portal and early septal fibrosis was present, also consistent with the known progression of the cholestatic liver disease from TPN. Macroscopic and microscopic features of extrahepatic obstruction were not seen, so obstructive jaundice is easily dismissed from consideration. Sepsis may have contributed to bile stasis, but cholangiolar cholestasis was not seen and the jaundice developed weeks before the sepsis. This premature infant was clearly at risk to develop TPNinduced cholestasis, and after excluding the other possibilities, it is possible to state with confidence that the changes observed were due to TPN.
References 1. Guglielmi FW, Regano N, Mazzuoli S, et al. Cholestasis induced by total parenteral nutrition. Clin Liver Dis. 2008;12:97–110, viii. 2. Kwan V, Georg J. Liver disease due to parenteral and enteral nutrition. Clin Liver Dis. 2004;8:893–913. 3. Baker AL, Rosenber IH. Hepatic complications of total parenteral nutrition. Am J Med. 1987;82:489–497. 4. Bengoa JM, Hanauer SB, Sitrin MD, Baker AL, Rosenber IH. Pattern and prognosis of liver function test abnormalities during parenteral nutrition in inflammatory bowel disease. Hepatology. 1985;5:79–84. 5. Cohen C, Olse MM. Pediatric total parenteral nutrition. Liver histopathology. Arch Pathol Lab Med. 1981;105:152–156. 6. Mullick FG, Moran CA, Isha KG. Total parenteral nutrition: a histopathologic analysis of the liver changes in 20 children. Mod Pathol. 1994;7:190–194. 7. Hofman AF. Defective biliary secretion during total parenteral nutrition: probable mechanisms and possible solutions. J Pediatr Gastroenterol Nutr. 1995;20:376–390. 8. Forchielli ML, Walke WA. Nutritional factors contributing to the development of cholestasis during total parenteral nutrition. Adv Pediatr. 2003;50:245–267. 9. Alverdy J, Chi HS, Sheldo GF. The effect of parenteral nutrition on gastrointestinal immunity. The importance of enteral stimulation. Ann Surg. 1985;202:681–684.
Case 15.8
Amiodarone-Induced Phospholipidosis DAVID E. KLEINER
C L I N IC AL I N F OR M AT I ON
A 62-year-old man was admitted to the hospital for evaluation of jaundice. He had an extensive history of cardiac disease including ischemic cardiomyopathy, atrial fibrillation, coronary artery bypass grafts, and pacemaker placement. He had received amiodarone for 9 years. Three years prior to this admission, he had an episode of hypoxic hepatitis documented by biopsy. His current laboratory evaluation showed an ALT of 781 IU/L, AST 734 IU/L, alkaline phosphatase 119 IU/L, and total bilirubin 3 mg/dL. Serologies for hepatitis viruses were negative, but ANA was positive at 1:640. After admission, the transaminase levels gradually fell, but the bilirubin rose and a biopsy was performed. The patient died while still in the hospital from multiorgan failure.
macrovesicular steatosis, the hepatocytes showed microvesiculation (Figure 15.8.2). Pale pink Mallory-Denk bodies could also be seen in many hepatocytes, a finding accentuated by immunostaining for ubiquitin (Figure 15.8.3). Within the fibrous bands were many small collections of foamy macrophages containing coarsely granular, pale, pigmented material (Figure 15.8.4). The pigmented material stained purple on a diastase-digestion PAS stain (Figure 15.8.5).
R E A SON F OR R E F E R R AL
Determine etiology of cirrhosis. PAT H OL OG I C F E AT U R E S
The hepatic architecture was diffusely distorted by bands of bridging fibrosis that surrounded small regenerative nodules and isolated small groups of hepatocytes (Figure 15.8.1). Extensive sinusoidal fibrosis was present. The inflammatory infiltrate was generally mild and was mainly composed of lymphocytes. There was focal disruption of the limiting plate at many points by fibrosis and inflammation, associated with prominent ductular reaction. Although there was little
FIGURE 15. 8. 1 Micronodular cirrhosis with minimal steatosis and mild inflammation.
F I G U R E 1 5 . 8 . 2 Hepatocytes with microvesicular steatosis and pale eosinophilic Mallory-Denk bodies (arrow).
F I G U R E 1 5 . 8 . 3 Numerous Mallory-Denk bodies stained with
antiubiquitin.
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FIGURE 15. 8. 4 Foamy macrophages containing pale blue-gray
material.
FIGURE 15. 8. 5 PAS-positive, diastase-resistant, coarsely granular
material in the foamy macrophages.
LIVER
INJURY
presented with hepatosplenomegaly. When drug therapy is stopped, the drug gradually disappears from the cells and the phospholipidosis resolves. Besides amiodarone and Coralgil, a large number of drugs have been reported to cause phospholipidosis, including perhexiline maleate, chlorpheniramine, thioridazine, the aminoglycoside antibiotics, the selective serotonin reuptake inhibitors (SSRIs), tamoxifen, and others. Phospholipidosis is a dose-dependent process in which the drug gradually accumulates within lysosomes over time. There are several theories as to how the lamellar bodies form (2). Many of these amphiphilic drugs have been shown to interfere with lysosomal phospholipase either by direct inhibition or by binding to phospholipids and blocking digestion. These changes would result in the accumulation of phospholipids within the lysosome. The drugs may interfere with normal trafficking of membrane phospholipids between the plasma membrane and the Golgi so that increased amounts of phospholipids are sequestered in lysosomes. It is unclear if phospholipidosis, by itself, is toxic to cells. Hepatocyte culture studies with amiodarone showed that lamellar bodies developed prior to evidence of cell toxicity and at lower drug concentrations than were necessary to cause toxicity (3). Phospholipidosis has also been observed in patients in the absence of hepatoxicity (4). It is therefore possible that phospholipidosis may represent an adaptive response in which cells are able to sequester potentially harmful agents within lysosomes, thus tempering their toxicity. Histologically, the diagnostic feature is the lamellar body, which is a whorled, laminated collection of phospholipid membranes within a lysosome. Lamellar bodies are also seen in some genetic lipid storage diseases, such as Niemann-Pick disease (Figure 15.8.6). Lamellar bodies can be found in the liver within hepatocytes or macrophages as well as in other organs, such as lymph nodes and lung (5). The light microscopic appearance is not specific, but the presence of foamy cells with coarsely granular PAS-positive material is characteristic of phospholipidosis in amiodarone-induced liver injury. In addition to lamellar bodies, Mallory-Denk bodies are a typical finding. They are often more numerous than is typically seen in NASH or alcoholic liver disease and are more likely to
D I AG N OS I S
Cirrhosis with mild inflammatory activity, numerous Mallory-Denk bodies, and phospholipidosis due to amiodarone.
D I SC U SSI ON
This case highlights an unusual histological change observed in amiodarone injury—phospholipidosis. Drug-induced phospholipidosis is essentially a lipid-storage disease in which phospholipid membranes accumulate within lysosomes as inclusion bodies (1,2). Cationic amphiphilic drugs, such as amiodarone, are sequestered within these stacks of membranes. Phospholipidosis was first described in patients treated with diethylaminoethoxyhexestrol (trade name Coralgil) who
F I G U R E 1 5 . 8 . 6 Transmission electron micrograph of lamellar bodies in a case of Niemann-Pick disease.
CASE
15.8:
AMIODARONE-INDUCED
be found in zone 1. Amiodarone has been shown to increase cytokeratin 8 (CK8) monomers within treated cells and also activate the enzyme involved in cross-linking CK8 to form larger complexes which are the building materials for MalloryDenk bodies (6). Other histologic features include macro- and microvesicular steatosis, periportal and perisinusoidal fibrosis, lymphocytic inflammation, and cholestasis (7,8). Cirrhosis is uncommon, but well reported. An acute form of amiodaronerelated toxicity also exists, occurring within a day of intravenous loading (9). Patients develop a severe acute hepatocellular injury that usually resolves after stopping the infusion, but fulminant hepatic failure has occurred. It is possible that the drug vehicle, Polysorbate 80, is the true culprit. Although the case described here had a very complicated clinical presentation, with multiple co-morbidities, the biopsy showed characteristic changes of amiodarone toxicity. The causality analysis is presented in Table 15.8.1. The main
TA B LE 15. 8. 1 Causality analysis—amiodarone Temporal eligibility
Nine years of therapy with amiodarone
Exclusion of competing causes
Although not detailed, the other drugs he was taking were not reported to cause the pathologic pattern of cirrhosis with Mallory-Denk bodies; hepatitis virus screen was negative; ANA positive, but autoimmune hepatitis not consistent with pathology
Known potential for injury
Amiodarone is well described to cause DILI
Precedent for pathologic pattern
Cirrhosis with Mallory-Denk bodies and phospholipidosis is characteristic of amiodarone injury
Dechallenge/ rechallenge
Patient died soon after biopsy
Toxicology
Not done
Conclusion
Cirrhosis with Mallory-Denk bodies and phospholipidosis due (95% chance) to amiodarone
PHOSPHOLIPIDOSIS
239
diagnostic considerations from the pathology point of view would be other causes of cirrhosis, including viral and autoimmune hepatitis, as well as steatohepatitis. Viral hepatitis and alcohol were excluded by serologic tests and history, respectively. The pathology is helpful in excluding autoimmune hepatitis and steatohepatitis because both of these etiologies would be unlikely to result in cirrhosis with so many MalloryDenk bodies. A combined clinical-pathologic approach permits the confident elimination of all etiologies of liver injury except for amiodarone.
References 1. Anderson N, Borlak J. Drug-induced phospholipidosis. FEBS Lett. 2006;580:5533–5540. 2. Reasor MJ, Hastings KL, Ulrich RG. Drug-induced phospholipidosis: issues and future directions. Expert Opin Drug Saf. 2006;5:567–583. 3. Sun EL, Petrella DK, McCloud CM, Cramer CT, Reasor MJ, Ulrich RG. Amiodarone-induced cytoplasmic lamellar body formation in cultured primary rat and human hepatocytes: relationship to cell function and cytotoxicity. In Vitro Toxicol. 1997;10:459–470. 4. Guigui B, Perrot S, Berry JP, et al. Amiodarone-induced hepatic phospholipidosis: a morphological alteration independent of pseudoalcoholic liver disease. Hepatology. 1988;8:1063–1068. 5. Dake MD, Madison JM, Montgomery CK, et al. Electron microscopic demonstration of lysosomal inclusion bodies in lung, liver, lymph nodes, and blood leukocytes of patients with amiodarone pulmonary toxicity. Am J Med. 1985;78:506–512. 6. Robin MA, Descatoire V, Pessayre D, Berso A. Steatohepatitis-inducing drugs trigger cytokeratin cross-links in hepatocytes. Possible contribution to Mallory-Denk body formation. Toxicol In Vitro. 2008;22: 1511–1519. 7. Lewis JH, Mullick F, Ishak KG, et al. Histopathologic analysis of suspected amiodarone hepatotoxicity. Hum Pathol. 1990;21:59–67. 8. Lewis JH, Ranard RC, Caruso A, et al. Amiodarone hepatotoxicity: prevalence and clinicopathologic correlations among 104 patients. Hepatology. 1989;9:679–685. 9. Rizzioli E, Incasa E, Gamberini S, et al. Acute toxic hepatitis after amiodarone intravenous loading. Am J Emerg Med. 2007;25: 1082 e1–1082 e4.
Case 15.9
Drug-Induced Microvesicular Steatosis DAVID E. KLEINER
C L I N I C AL I N F OR M AT I ON
A 42-year-old man with chronic hepatitis B was presented to an emergency room with lethargy, weakness, myalgias, anorexia, and nausea. He had been enrolled in a clinical trial of an investigational new drug, fialuridine, for chronic hepatitis B, but had stopped taking the drug 3 weeks earlier due to symptoms of neurotoxicity after receiving a total of 11 weeks of therapy. Laboratory evaluation showed an ALT of 100 IU/L, total bilirubin 5.8 mg/dL, prothrombin time 15.4 s, albumin 2.8 g/dL, ammonia 77 umol/L, and lactate of 18.8 mmol/L. A diagnosis of hepatic failure was made, and he underwent transplantation about 1 week after initial presentation.
diffuse microvesicular steatosis (Figure 15.9.2). The microvesiculation was so fine in some cells that the cytoplasm had a granular appearance (Figure 15.9.3). Megamitochondria were seen in some hepatocytes, but no Mallory-Denk bodies were noted (Figure 15.9.4). There were no areas of confluent or zonal necrosis and only rare apoptotic hepatocytes. A marked ductular reaction extended from the portal areas deep into the parenchyma. Canalicular and hepatocellular cholestasis was present, best seen on the iron stain (Figure 15.9.5). Immunostains for hepatitis B surface and core stains were positive, but in fewer cells than in the pretreatment biopsy.
R E A S ON F OR R E F E R R A L
Progression of chronic hepatitis B versus drug-induced liver injury as the cause for the hepatic failure.
PAT H OL OG I C F E AT U R E S
A pretreatment biopsy was available for comparison with the explanted liver. The pretreatment biopsy showed mild portal inflammation with focal interface hepatitis (Figure 15.9.1). There were scattered foci of lobular inflammation. No steatosis was seen. Mild portal fibrotic expansion was present on the Masson Trichrome stain. Immunostains for hepatitis B surface and core antigens were positive. The explant revealed mild portal inflammation and interface hepatitis similar in degree to the pretreatment biopsy. The hepatocytes, however, showed
F I G U R E 1 5 . 9 . 2 Explant showing diffuse microvesicular steatosis and
persistent chronic hepatitis.
FIGURE 15. 9. 1 Pretreatment biopsy showing chronic hepatitis with
mild activity and no steatosis.
F I G U R E 1 5 . 9 . 3 Microvesicular steatosis.
240
CASE
15.9:
DRUG-INDUCED
MICROVESICULAR
S T E AT O S I S
241
TA BL E 1 5 . 9 . 1 Drugs and toxins associated with microvesicular
steatosis
FIGURE 15. 9. 4 Megamitochondria in a background of microvesicu-
lar steatosis.
FIGURE 15. 9. 5 Iron stain showing canalicular cholestasis.
D I AG N OS I S
Marked microvesicular steatosis and intrahepatic cholestasis due to fialuridine. Chronic hepatitis B with mild activity and portal fibrotic expansion.
D I S C U S S I ON
Microvesicular steatosis is a rare pattern of liver disease that is usually due to drug or toxic injury (Table 15.9.1). The associations outside of drugs and toxins are unusual and have rather specific clinical associations. These non–drug-induced liver injury (DILI) etiologies include fatty liver of pregnancy, alcoholic foamy degeneration (arguably a toxic injury), multiple hornet stings, and a variety of genetically transmitted metabolic diseases mainly related to lipid metabolism,
Acetylsalicylic acid (aspirin) Amineptine Amiodarone Calcium hopantenate Camphor Chlortetracycline Demeclocycline Desferoxamine Didanosine Fialuridine Hypoglycin (Jamaican vomiting sickness) Ibuprofen Indinivir Indomethacin Jin bu huan (herbal) Ketoprofen Margosa oil (herbal) Methyl salicylate Oxytetracycline Pennyroyal oil (herbal) Pentanoic acid (herbal) Piroxicam Pirprofen Riluzole Rolitetracycline Stavudine Syo-saiko-to (herbal) Tetracycline Tolmetin Valproic acid Vitamin A Warfarin
mitochondria, and the urea cycle. Essentially, all of these can be excluded by history, leaving only drug or toxic injury as a possibility. All these agents appear to cause mitochondrial injury (1,2) by inhibition of beta-oxidation (e.g., aspirin, amineptine, tetracycline, and valproate) or oxidative phosphorylation (e.g., amiodarone), or mitochondrial DNA replication (didanosine, stavudine, and fialuridine). Thus, identification of microvesicular steatosis as the pattern of injury in a new agent, as is the situation in this case example, can help narrow the possible mechanisms of injury (3). Microvesicular steatosis is frequently associated with lactic acidosis and hypoglycemia due to impaired mitochondrial function. If mitochondria are affected outside the liver, there may be evidence of other organ dysfunction, such as myopathy or pancreatitis. Patients may present with hepatomegaly and nonspecific symptoms of fatigue, nausea, vomiting, and weakness or they may present in fulminant failure, with hyperammonemia, jaundice, and hepatic encephalopathy. The transaminases may not be particularly elevated. On liver biopsy, microvesicular steatosis is recognized as a foamy change in the hepatocyte cytoplasm. The nucleus is not displaced as in macrovesicular steatosis but may be indented by the microvacuoles. The vacuoles may be smaller than the resolving power of a light microscope, in which case the hepatocyte cytoplasm may look finely granular. A fat stain such as
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oil red O or Sudan Black can be very helpful, and electron microscopy will also demonstrate fine vacuolation. The histologic differential diagnosis includes small droplet macrovesicular steatosis, in which there may be multiple small vacuoles instead of a single large one. The distinction is mainly based on size and quantity. If the cell contains uncountable numbers of small vacuoles, it is probably microvesicular steatosis. It is not unusual to see some macrovesicular steatosis in a case of microvesicular steatosis as is true for this case (Figure 15.9.2). Some diseases that are predominantly macrovesicular, such as NASH, will show some microvesicular steatosis, but unless the latter is diffuse, the case should not be diagnosed as microvesicular steatosis. Other histologic features of microvesicular steatosis include megamitochondria, which are seen as eosinophilic, PAS-negative, cytoplasmic inclusions about 1 to 3 microns in size and Mallory-Denk bodies. Hepatocellular and canalicular cholestasis can be seen, as in this case, but the overall pattern remains that of microvesicular steatosis. There is usually little inflammation, unless there is an underlying liver disease like viral hepatitis. Confluent necrosis is not a feature of microvesicular steatosis, although occasional acidophil bodies can be found. This case presented a challenge clinically (Table 15.9.2), because fialuridine was still an experiment agent and there TA B LE 15. 9. 2 Causality analysis—fialuridine Temporal eligibility
11 weeks of therapy with drug prior to the development of toxicity, but with a lag time of 3 weeks between stopping drug and DILI onset
Exclusion of competing causes
Not taking other drugs, exacerbation of hepatitis B excluded on pathologic exam
Known potential for injury
No prior reports of hepatotoxicity, but related drugs didanosine and zidovudine had both been implicated in syndromes of lactic acidosis and hepatic failure
Precedent for pathologic pattern
Didanosine had been reported to cause microvesicular steatosis
Dechallenge/rechallenge
Patient underwent liver transplantation, limiting observation of dechallenge; no rechallenge performed
Toxicology
Not done
Conclusion
Microvesicular steatosis due (95% chance) to fialuridine
Abbreviation: DILI, drug-induced liver injury.
LIVER
INJURY
had been no reports of hepatotoxicity in preclinical human or animal studies or in the phase I toxicity and pharmacokinetic studies (4,5). It was, unfortunately, the index case in a series of patients who developed hepatic failure from fialuridine. In the clinical trial that enrolled this patient, out of 15 patients enrolled, 5 died from liver failure and 2 survived with transplantation. Although drug toxicity was suspected clinically based on the development of lactic acidosis and hepatic failure, there were some doubts because the patient had stopped taking the drug and the serum half-life was thought to be short. Other nucleoside analogues, notably zidovudine and didanosine, have both been reported to cause lactic acidosis and liver failure (6–8). The finding of microvesicular steatosis on liver biopsy clinched the diagnosis of DILI. Didanosine has been implicated in causing microvesicular steatosis, providing a related precedent (9). In subsequent studies, it was shown that fialuridine was incorporated into mitochondrial DNA at a high level in addition to causing termination of DNA replication (10).
References 1. Fromenty B, Pessayre D. Inhibition of mitochondrial beta-oxidation as a mechanism of hepatotoxicity. Pharmacol Ther. 1995;67:101–154. 2. Pessayre D, Mansouri A, Haouzi D, et al. Hepatotoxicity due to mitochondrial dysfunction. Cell Biol Toxicol. 1999;15:367–373. 3. Tang W. Drug metabolite profiling and elucidation of drug-induced hepatotoxicity. Expert Opin Drug Metab Toxicol. 2007;3:407–420. 4. Kleiner DE, Gaffey MJ, Sallie R, et al. Histopathologic changes associated with fialuridine hepatotoxicity. Mod Pathol. 1997;10:192–199. 5. McKenzie R, Fried MW, Sallie R, et al. Hepatic failure and lactic acidosis due to fialuridine (FIAU), an investigational nucleoside analogue for chronic hepatitis B. N Engl J Med. 1995;333:1099–1105. 6. Chattha G, Arieff AI, Cummings C, et al. Lactic acidosis complicating the acquired immunodeficiency syndrome. Ann Intern Med. 1993;118:37–39. 7. Bissuel F, Bruneel F, Habersetzer F, et al. Fulminant hepatitis with severe lactate acidosis in HIV-infected patients on didanosine therapy. J Intern Med. 1994;235:367–371. 8. Olano JP, Borucki MJ, Wen JW, et al. Massive hepatic steatosis and lactic acidosis in a patient with AIDS who was receiving zidovudine. Clin Infect Dis. 1995;21:973–976. 9. Lai KK, Gang DL, Zawacki JK, et al. Fulminant hepatic failure associated with 2’,3’-dideoxyinosine (ddI). Ann Intern Med. 1991;115:283–284. 10. Lewis W, Griniuviene B, Tankersley KO, et al. Depletion of mitochondrial DNA, destruction of mitochondria, and accumulation of lipid droplets result from fialuridine treatment in woodchucks (Marmota monax). Lab Invest. 1997;76:77–87.
16 Cytoplasmic Globules ELAINE S. CHAN AND MATTHEW M.YEH
I N T ROD U C T I ON
A number of globules or inclusion bodies can be found within the cytoplasm of hepatocytes. These include alpha-1-antitrypsin globules, alpha-1-antichymotrypsin globules, Mallory-Denk bodies, megamitochondria, and pale bodies/fibrinogen storage inclusions, among others. Although cytoplasmic globules may be found in normal liver, when present, especially abundant, they are often associated with various pathologic states. Alpha-1-antitrypsin (AAT) is a serine protease inhibitor, encoded by SERPINA1, and is produced primarily in the hepatocytes. AAT deficiency is an autosomal recessive inherited metabolic disorder. The normal gene product is PiM; the most common deficiency alleles are PiS and PiZ, and PiZZ (where Pi stands for protease inhibitor and ZZ represents the banding pattern by isoelectric focusing) phenotype accounts for most cases of severe AAT deficiency (1). AAT deficiency is a codominant condition that predisposes to pulmonary emphysema and liver disease. As a serine protease inhibitor, AAT normally inhibits neutrophil elastase, thereby preventing the enzyme from disrupting elastin within the pulmonary alveolar connective tissue. In AAT-deficient patients, emphysema or chronic obstructive pulmonary disease is often noted. In addition, certain mutant genotypes are predisposed to hepatic disorders. For example, in individuals with the genotype PiZZ, there is pathologic polymerization of mutant AAT within the endoplasmic reticulum that cannot be transported to the Golgi apparatus, resulting in the intrahepatocytic accumulation of the mutant AAT proteins, which can be detected as cytoplasmic globules within the hepatocytes. This can in turn lead to the development of hepatic diseases, including cirrhosis and hepatocellular carcinoma (2,3). A1AT deficiency represents the most common genetic cause of neonatal liver disease. The disease usually manifests as persistent jaundice at 4 to 8 weeks of age. Morphologic changes include canalicular cholestasis, giant cell transformation of hepatocytes, and hepatocyte ballooning degeneration (see Chapter 10). Interlobular bile ducts may be reduced in number. Other histologic changes may also include ductular reaction and fibrosis, but the typical globules are usually not seen in the first few months after birth (4). In fetuses with PiZZ phenotype, granular deposits of A1AT can be detected by immunohistochemistry in liver by the second trimester (5). Similar to AAT, alpha-1-antichymotrypsin (ACT) is also a serine protease inhibitor. This plasma protein is encoded by SERPINA3 and is synthesized in the liver. Although its physiological function is not entirely clear, it can inhibit neutrophil cathepsin G and mast cell chymase, both of which are able to convert angiotensin-1 to the active angiotensin-2 (6). Defects in the SERPINA3 gene have been associated with chronic
obstructive pulmonary disease (7), as well as hepatic disorders. The most common type of ACT deficiency is caused by mutation in exon III leading to Pro to Ala substitution (8). Although the pathogenesis of ACT deficiency is not entirely clear, it has been thought that ACT deficiency leads to pulmonary and liver disease in a similar fashion as AAT deficiency, namely, through decreased suppression of biological activity of protease in the lung and through accumulation of abnormally folded protease inhibitor molecules in the hepatocytes, respectively. Aside from cytoplasmic globules caused by mutant AAT or ACT, a number of other cytoplasmic inclusions or globules can be observed in hepatocytes. These may mimic the mutant AAT or ACT globules and cause diagnostic pitfalls, such as Mallory-Denk bodies, intracellular hyaline bodies, megamitochondria, pale bodies in fibrinogen storage disease, and pseudoground glass hepatocytes and so on. The primary constituents of Mallory-Denk bodies are ubiquitinated keratins 8 and 18, small amounts of chaperones (heat shock proteins 25/60/70) and the polyubiquitin-binding protein p62 (9). Correspondingly, Mallory-Denk bodies can be labeled with antibodies to CK8, CK18, p62, and ubiquitin by immunohistochemistry. Mallory-Denk bodies are often seen in the ballooned hepatocytes in alcoholic hepatitis or nonalcoholic steatohepatitis (10–15) and even in the carcinoma cells of hepatocellular carcinoma. Although immunohistochemical staining represents a more sensitive method for Mallory-Denk body detection than conventional histologic staining (16), the use of immunohistochemistry is not as yet a routine practice in the clinical setting. Megamitochondria are observed in hepatocytes in both physiological and pathological conditions. It is not unusual to identify a few megamitochondria along with normal-sized mitochondria within a given cell. They are also detected more frequently in the livers of older normal subjects in comparison to younger individuals and are regarded as physiological changes related to aging (17). Megamitochondria formation has been described in numerous human pathological conditions, but they are most commonly seen in alcoholic liver injury. In fact, the presence of megamitochondria has been used as a diagnostic feature of alcoholic liver injury. The incidence of megamitochondria among chronic alcoholics vary from 25% to 93%, whereas the incidence of megamitochondria in nonalcoholics range from 0% to 37% (18–20). Bruguera et al (21) found that the presence of megamitochondria was correlated with the amount of alcohol consumed and to the shortness of abstinence prior to biopsy. They observed that megamitochondria may disappear within 1 month of abstinence, and therefore, the presence of megamitochondria should alert pathologists to the diagnosis
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of alcoholism. Besides, in alcoholic liver injury, megamitochondria have also been described in nonalcoholic steatohepatitis (22). Pale bodies are formed by intraceullar storage of secretory proteins, such as fibrinogen, albumin, C3, and C4 (23,24,25). These secretory proteins accumulate in large dilated cisternae of the rough endoplasmic reticulum, thought to be due to a defective intracellular transport or an excretion disturbance. Pale bodies have been identified in 5% to 6% (23,26) of resected hepatocellular carcinoma, especially of the fibrolamellar variant (27). They have also been observed in fibrinogen storage disease (28), which can be associated with hypofibrinoginemia and mutant variant of the fibrinogen molecule (29), but they can also be found transiently in the livers of patients who have acute infection without hypofibrinogenemia (30).
References 1. Fairbanks KD, Tavill AS. Liver disease in alpha-1-antitrypsin deficiency: a review. Am J Gastroenterol. 2008;103(8):2136–2141. 2. Lomas DA, Evans DL, Finch JT, Carrell RW. The mechanism of Z alpha-1-antitrypsin accumulation in the liver. Nature. 1992;357(6379): 605–607. 3. Sivasothy P, Dafforn TR, Gettins PG, Lomas DA. Pathogenic alpha-1antitrypsin polymers are formed by reactive loop-beta-sheet A linkage. J Biol Chem. 2000;275(43):33663–33668. 4. Mowat AP. Hepatitis and cholestasis in infancy: intrahepatic disorders. In: Mowat AP, ed. Liver disorders in children. London, UK: Butterworths & Co; 1982:50. 5. Malone M, Mieli-Vergani G, Mowat AP, Portmann B. The fetal liver in PiZZ alpha-1-antitrypsin deficiency: a report of five cases. Pediatr Pathol. 1989;9(6):623–631. 6. Rubin H, Wang ZM, Nickbarg EB, et al. Cloning, expression, purification, and biological activity of recombinant native and variant human alpha 1-antichymotrypsins. J Biol Chem. 1990;265(2):1199–1207. 7. Poller W, Faber JP, Weidinger S, et al. A leucine-to-proline substitution causes a defective alpha-1-antichymotrypsin allele associated with familial obstructive lung disease. Genomics. 1993;17(3):740–743. 8. Elzouki AN, Verbaan H, Lindgren S, Widell A, Carlson J, Eriksson S. Serine protease inhibitors in patients with chronic viral hepatitis. J Hepatol. 1997;27(1):42–48. 9. Strnad P, Zatloukal K, Stumptner C, Kulaksiz H, Denk H. Mallory-Denkbodies: lessons from keratin-containing hepatic inclusion bodies. Biochim Biophys Acta. 2008;1782(12):764–774. 10. Brunt EM. Nonalcoholic steatohepatitis. Semin Liver Dis. 2004;24(1): 3–20. 11. Zatloukal K, French SW, Stumptner C, et al. From Mallory to MalloryDenk bodies: what, how and why? Exp Cell Res. 2007;313(10): 2033–2049.
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12. Burt AD, Mutton A, Day CP. Diagnosis and interpretation of steatosis and steatohepatitis. Semin Diagn Pathol. 1998;15(4):246–258. 13. Pinto HC, Baptista A, Camilo ME, Valente A, Saragoça A, de Moura MC. Nonalcoholic steatohepatitis. Clinicopathological comparison with alcoholic hepatitis in ambulatory and hospitalized patients. Dig Dis Sci. 1996;41(1):172–179. 14. Yeh MM, Brunt EM. Pathology of fatty liver: differential diagnosis of nonalcoholic fatty liver disease. Diagnostic Pathology. 2008;14:586–597. 15. Li MK, Crawford JM. The pathology of cholestasis. Semin Liver Dis. 2004;24(1):21–42. 16. Ray MB. Distribution patterns of cytokeratin antigen determinants in alcoholic and nonalcoholic liver diseases. Hum Pathol. 1987;18(1):61–66. 17. Wilson PD, Franks LM. The effect of age on mitochondrial ultrastructure. Gerontologia. 1975;21(2):81–94. 18. Yokoo H, Singh SK, Hawasli AH. Giant mitochondria in alcoholic liver disease. Arch Pathol Lab Med. 1978;102(4):213–214. 19. Junge J, Horn T, Christoffersen P. Megamitochondria as a diagnostic marker for alcohol induced centrilobular and periportal fibrsis in the liver. Virchows Arch A Pathol Anat Histopathol. 1987;410(6):553–558. 20. Stewart RV, Dincsoy HP. The significance of giant mitochondria in liver biopsies as observed by light microscopy. Am J Clin Pathol. 1982;78(3):293–298. 21. Bruguera M, Bertran A, Bombi JA, Rodes J. Giant mitochondria in hepatocytes: a diagnostic hint for alcoholic liver disease. Gastroenterology. 1977;73(6):1383–1387. 22. Yeh MM, Brunt EM. Pathology of nonalcoholic fatty liver disease. Am J Clin Pathol. 2007;128(5):837–847. Review. 23. Moon WS, Yu HC, Chung MJ, Kang MJ, Lee DG. Pale bodies in hepatocellular carcinoma. J Korean Med Sci. 2000;15(5):516–520. 24. Callea F, de Vos R, Togni R, Tardanico R, Vanstapel MJ, Desmet VJ. Fibrinogen inclusions in liver cells: a new type of ground-glass hepatocyte. Immune light and electron microscopic characterization. Histopathology. 1986;10(1):65–73. 25. Ng IO, Ng M, Lai EC, Wu PC. Endoplasmic storage disease of liver: characterization of intracytoplasmic hyaline inclusions. Histopathology. 1989;15(5):473–481. 26. Nakashima O, Sugihara S, Eguchi A, Taguchi J, Watanabe J, Kojiro M. Pathomorphologic study of pale bodies in hepatocellular carcinoma. Acta Pathol Jpn. 1992;42(6):414–418. 27. Craig JR, Peters RL, Edmondson HA, Omata M. Fibrolamellar carcinoma of the liver: a tumor of adolescents and young adults with distinctive clinico-pathologic features. Cancer. 1980;46(2):372–379. 28. Callea F, Brisigotti M, Fabbretti G, Bonino F, Desmet VJ. Hepatic endoplasmic reticulum storage diseases. Liver. 1992;12(6):357–362. 29. Brennan SO, Wyatt J, Medicina D, Callea F, George PM. Fibrinogen brescia: hepatic endoplasmic reticulum storage and hypofibrinogenemia because of a gamma284 Gly-->Arg mutation. Am J Pathol. 2000;157(1):189–196. 30. Marucci G, Morandi L, Macchia S, et al. Fibrinogen storage disease without hypofibrinogenaemia associated with acute infection. Histopathology. 2003;42(1):22–25.
Case 16.1
Alpha-1-Antitrypsin Deficiency ELAINE S. CHAN AND MATTHEW M.YEH
C L I N IC AL I N F OR M AT I ON
A 52-year-old woman with no known history presents with elevated serum aminotransferase and liver cirrhosis of unknown etiology. She has no history of cigarette, alcohol, or illicit drug use. Family history is noncontributory. Serological markers are negative for viral or autoimmune hepatitis. There is no laboratory evidence of hemochromatosis, Wilson disease, or autoimmune diseases. A presumptive diagnosis of cirrhosis attributed to nonalcoholic steatohepatitis was made, and the patient was referred for a liver transplant consultation. A liver biopsy was performed. R E A S ON F OR R E F F E R AL
The liver biopsy shows cirrhosis with many intrahepatocytic globules that are periodic acid–Schiff (PAS) positive and diastase resistant. The referring pathologist’s specific question is whether the finding represents alpha-1-antitrypsin (AAT) deficiency. PAT H OL OG I C F E AT U R E S
Abnormal accumulation of mutant alpha-1antitrypsin as periodic acid-Schiff–positive, diastase-resistant globules in a patient with mutations in the SERPINA1 gene (PAS stain with diastase).
FIGURE 16.1.2
A liver biopsy shows distortion of the hepatic architecture and the formation of regenerative nodules consistent with cirrhosis. Intracytoplasmic globules can be seen on H&E–stained sections (Figure 16.1.1). The globules are round to oval, eosinophilic, and homogeneous with a waxy appearance. These cytoplasmic globules are strongly PAS positive and diastase resistant (Figure 16.1.2). Immunohistochemical stain for alpha1-antitrypsin is strongly positive (Figure 16.1.3).
F I G U R E 1 6 . 1 . 3 Alpha-1-antitrypsin (AAT) immunohistochemi-
cal stain highlighting the mutant AAT globules within the hepatocytes. Note the peripheral accentuation of the globules secondary to incomplete penetration of the immunohistochemical stain.
LA BO R ATO RY R ESULT S FIGURE 16. 1. 1 Eosinophilic cytoplasmic globules detected in the
hepatocytes of a patient with alpha-1-antitrypsin deficiency. The globules tend to have a periseptal and periportal distribution.
Serum electrophoresis reveals hypoalbuminemia with decrease in alpha-1-globulin fraction. Serum alpha-1-antitrypsin is lower than the normal reference range. Protease inhibitor phenotyping indicates Z homozygosity (PiZZ).
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D I AG N OS I S
Alpha-1-antitrypsin deficiency–associated cirrhosis.
D I SC U SSI ON
The patient has cirrhosis of unknown cause and was given a presumptive diagnosis of nonalcoholic steatohepatitis clinically. Microscopic examination reveals cirrhosis accompanied by the presence of intrahepatocytic globules. The cytoplasmic globules are accentuated by PAS stain with diastase. To elucidate the identity of the intracytoplasmic globules, immunohistochemical stain with alpha-1-antitrypsin is performed. The cytoplasmic globules show strong reactivity with AAT. Hence, the morphologic and immunohistochemical features are consistent with AAT deficiency–related cirrhosis. However, since the diagnosis of AAT deficiency is based on laboratory findings, additional laboratory testing is performed and the patient is found to have low plasma AAT and the homozygous PiZZ phenotype by isoelectric focusing, thus confirming the diagnosis of AAT deficiency. AAT deficiency was not initially suspected in the patient because it is a relatively uncommon cause of liver cirrhosis, especially in the absence of emphysema and a history of childhood liver disease. This case drives home the point the use of PASd stain in populations where this disease is prevalent and that the possibility of AAT deficiency should be considered when other more common causes of liver cirrhosis are excluded. AAT deficiency is persistently under-recognized, with AAT-deficient patients visiting an average of 3 different physicians and experiencing a mean delay of 7.2 years between initial symptoms and definitive diagnosis (1). Also, adult-onset cirrhosis secondary to AAT deficiency can occur without
GLOBULES
antecedent childhood liver disease. In cases of cirrhosis with other known etiology, the diagnosis of AAT deficiency should still be entertained, as it is not uncommon to have co-existing, previously undetected AAT deficiency in patients with other known liver disease (2). Therefore, if AAT-like globules are found in end-stage liver cirrhosis, they should be examined carefully, with the aid of special and immunohistochemical stains. Of note, AAT immunohistochemical stain typically stains small globules in their entirety and larger ones at the periphery (3). When a diagnosis of AAT deficiency is suspected based on positive PASd and immunohistochemical stains, the patient’s plasma AAT concentration should be tested. AAT is an acute phase reactant and may be elevated in conditions such as infection, hormonal stimulation, and cirrhosis. Plasma AAT can also be decreased in liver necrosis. Therefore, it is necessary to perform phenotyping by isoelectric focusing, currently considered to be the gold standard for the diagnosis of AAT deficiency as AAT-positive globules are not specific to AAT deficiency and can be found in acute and chronic hepatitis, cirrhosis, hepatocellular carcinoma, as well as other liver diseases (4,5). Typically, liver biopsy is not essential in the workup of AAT deficiency; however, histologic examination can be useful in assessing the extent of liver injury and fibrosis, and excluding other concomitant liver diseases. As mentioned at the beginning of the chapter, AAT globules should be distinguished from other cytoplasmic globules or inclusion bodies (Table 16.1.1) such as Mallory-Denk bodies, intracellular hyaline bodies, megamitochondria, pale bodies in fibrinogen storage disease, and pseudoground glass hepatocytes. Mallory-Denk bodies are present in alcoholic hepatitis and nonalcoholic steatohepatitis, chronic biliary diseases, Wilson disease, and amiodarone hepatotoxicity. Also,
TA B LE 16. 1. 1 Characteristics of different intracytoplasmic globules/inclusions Intracytoplasmic Globules
H&E
PASd
Alpha-1-antitrypsin deficiency
Round to oval, eosinophilic, and homogeneous globules
Positive
Alpha-1-antitrypsin
Alpha-1-antichymotrypsin deficiency
Granular
Positive
Alpha-1-antichymotrypsin
Mallory-Denk bodies
Eosinophilic, dense, branching, “twisted rope”
Negative
Blue with red center after chromotrope aniline blue labeling
CK8, CK18, p62, ubiquitin
Intracellular hyaline bodies
Globular, homogeneous, dense, eosinophilic cytoplasmic inclusions, often accompanied by a surrounding, clear halo
Negative
Congo red
p62
Megamitochondria
Round, oblong, or needle shaped, homogenous, regularly contoured
Negative
Pale bodies/fibrinogen storage bodies
Homogenous, palely eosinophilic, with a distinct border, and ground glass–like
Negative
Other Stains
Immunohistochemistry
Fibrinogen, occasionally weakly positive for albumin
CASE
16.1
:
ALPHA-1-ANTITRYPSIN
FIGURE 16. 1. 4 Mallory-Denk bodies with the characteristic twisted-rope appearance in alcoholic hepatitis or nonalcoholic steatohepatitis.
as Mallory-Denk bodies represent the result of chronic and accumulative injury to the liver (6), they can be found in advanced fibrosis, cirrhosis (7–10), or hepatocellular carcinoma (11–13). They are characterized as ropy, branched, and eosinophilic inclusions within the cytoplasm, typically in swollen or ballooned hepatocytes (Figure 16.1.4). In noncirrhotic liver, they are relatively easy to distinguish from AAT globules, as they are typically present with relevant histologic findings, such as steatosis and ballooned hepatocytes and in the appropriate clinical setting, such as metabolic syndrome or alcohol use. They are more challenging to distinguish when the liver is cirrhotic, as most of the above-mentioned features are no longer present. Intracellular hyaline bodies are globular, homogeneous, dense, and eosinophilic cytoplasmic inclusions that may mimic AAT globules, albeit they are typically accompanied by a surrounding clear halo and are most often identified in hepatocellular carcinoma and idiopathic copper toxicosis (14); therefore, the clinical scenario may differ from A1AT deficiency. Morphologically, hepatic megamitochondria are round, oblong, cigar or needle-shaped (15,16), homogenous, regularly contoured, and eosinophilic intracytoplasmic inclusions (Figure 16.1.5). Under light microscopy, the diameter of megamitochondria is roughly one-third that of the hepatocytic nucleus (17), but it may vary. Although morphologically resembling AAT globules, they are PAS-negative. Pale bodies (Figure 16.1.6) are homogenous, palely eosinophilic, with a distinct border, and ground glass–like, resembling the ground glass change characteristic of hepatitis B surface antigen (HbsAg)-containing hepatocytes. Similar to ground glass hepatocytes, pale bodies often occupy the entire cytoplasm, displacing the nuclei to the periphery and leaving a small rim of clear cytoplasm. Unlike AAT globules, they are negative for PAS stain, but are positive for fibrinogen, and are
DEFICIENCY
247
F I G U R E 1 6 . 1 . 5 Megamitochondria showing as round to oblong eosinophilic inclusions.
F I G U R E 1 6 . 1 . 6 Cytoplasmic, homogenous pale bodies seen in fibrolamellar hepatocellular carcinoma.
occasionally weakly positive for albumin. Ultrastructurally, pale bodies appear as amorphous, granular, or fibrillar material within dilated cisternae of the rough endoplasmic reticulum, which are moderately electron dense (18–20). Ground glass hepatocytes in chronic hepatitis B may mimic AAT globules, but typically they do not have the round and globular appearance of AAT globules and are PASnegative. Similarly, the recently described glycogen pseudoground glass change in hepatocytes may resemble AAT globules and is morphologically similar to the ground glass change seen in chronic hepatitis B infection, with distinct, circumscribed, gray-glassy inclusions surrounded by a rim of cytoplasm; however, the background livers showed only mild or no inflammation and mild or no fibrosis. Different from AAT globules and ground glass hepatocytes, the pseudoground glass change is PAS-positive and diastase-sensitive (21,22).
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AAT globules also need to be distinguished from the pale, round, or kidney-shaped inclusions in Lafora disease, which are weakly positive for PAS with diastase. They also stain with colloidal iron and silver stains.
References 1. Stoller JK, Fromer L, Brantly M, Stocks J, Strange C. Primary care diagnosis of alpha-1-antitrypsin deficiency: issues and opportunities. Cleve Clin J Med. 2007;74(12):869–874. 2. Iezzoni JC, Gaffey MJ, Stacy EK, Normansell DE. Hepatocytic globules in end-stage hepatic disease: relationship to alpha-1-antitrypsin phenotype. Am J Clin Pathol. 1997;107(6):692–627. 3. Ishak KG. Inherited metabolic diseases of the liver. Clin Liver Dis. 2002;6(2):455–479, viii. 4. Qizilbash A, Young-Pong O. Alpha-1-antitrypsin liver disease differential diagnosis of PAS-positive, diastase-resistant globules in liver cells. Am J Clin Pathol. 1983;79(6):697–702. 5. Hall P, Herrmann R, Brennan J, Mackinnon M. Detection of alpha1-antitrypsin in hepatocytes in acute and chronic hepatitis. Pathology. 1987;19(4):415–418. 6. Zatloukal K, French SW, Stumptner C, et al. From Mallory to MalloryDenk bodies: what, how and why? Exp Cell Res. 2007;313(10): 2033–2049. 7. Matteoni CA, Younossi ZM, Gramlich T, Boparai N, Liu YC, McCullough AJ. Nonalcoholic fatty liver disease: a spectrum of clinical and pathological severity. Gastroenterology. 1999;116(6):1413–1419. 8. Mendler MH, Kanel G, Govindarajan S. Proposal for a histological scoring and grading system for non-alcoholic fatty liver disease. Liver Int. 2005:294–304. 25(2):294–304. Erratum in: Liver Int. 2005;25(3): 682–683. 9. Cortez-Pinto H, Baptista A, Camilo ME, De Moura MC. Nonalcoholic steatohepatitis—a long-term follow-up study: comparison with alcoholic hepatitis in ambulatory and hospitalized patients. Dig Dis Sci. 2003;48(10):1909–1913.
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10. Gramlich T, Kleiner DE, McCullough AJ, Matteoni CA, Boparai N, Younossi ZM. Pathologic features associated with fibrosis in nonalcoholic fatty liver disease. Hum Pathol. 2004;35(2):196–199. 11. Jensen K, Gluud C. The Mallory body: morphological, clinical and experimental studies (Part 1 of a literature survey). Hepatology. 1994; 20(4 pt 1):1061–1077. 12. Lewis JH, Mullick F, Ishak KG, Ranard RC, Ragsdale B, Perse RM, Rusnock EJ, Wolke A, Benjamin SB, Seeff LB, et al. Histopathologic analysis of suspected amiodarone hepatotoxicity. Hum Pathol. 1990; 21(1):59–67. 13. Richer M, Robert S. Fatal hepatotoxicity following oral administration of amiodarone. Ann Pharmacother. 1995;29(6):582–586. 14. Denk H, Stumptner C, Fuchsbichler A, et al. Are the Mallory bodies and intracellular hyaline bodies in neoplastic and non-neoplastic hepatocytes related? J Pathol. 2006;208(5):653–661. 15. French SW, Nash J, Shitabata P, et al. Pathology of alcoholic liver disease. VA Cooperative Study Group 119. Semin Liver Dis. 1993;13(2):154–169. 16. Junge J, Horn T, Christoffersen P. Megamitochondria as a diagnostic marker for alcohol induced centrilobular and periportal fibrosis in the liver. Virchows Arch A Pathol Anat Histopathol. 1987;410(6):553–558. 17. Bruguera M, Bertran A, Bombi JA, Rodes J. Giant mitochondria in hepatocytes: a diagnostic hint for alcoholic liver disease. Gastroenterology. 1977;73(6):1383–1387. 18. Moon WS, Yu HC, Chung MJ, Kang MJ, Lee DG. Pale bodies in hepatocellular carcinoma. J Korean Med Sci. 2000;15(5):516–520. 19. Callea F, de Vos R, Togni R, et al. Fibrinogen inclusions in liver cells: a new type of ground-glass hepatocyte. Immune light and electron microscopic characterization. Histopathology. 1986;10(1):65–73. 20. Ng IO, Ng M, Lai EC, Wu PC. Endoplasmic storage disease of liver: characterization of intracytoplasmic hyaline inclusions. Histopathology. 1989;15(5):473–481. 21. Wisell J, Boitnott J, Haas M, et al. Glycogen pseudoground glass change in hepatocytes. Am J Surg Pathol. 2006;30(9):1085–1090. 22. Thomas RM, Schiano TD, Kueppers F, Black M. Alpha-1antichymotrypsin globules within hepatocytes in patients with chronic hepatitis C and cirrhosis. Hum Pathol. 2000;31(5):575–577.
Case 16.2
Alpha-1-Antichymotrypsin Deficiency ELAINE S. CHAN AND MATTHEW M.YEH
C L I N IC AL I N F OR M AT I ON
A 61-year-old man presents with malaise and weakness. Jaundice and mild hepatomegaly are noted. alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels are slightly elevated. Alkaline phosphatase, serum ferritin, serum copper, and serum ceruloplasmin are within normal reference ranges. Serological studies for hepatitis A, B, and C and autoimmune hepatitis are all negative. A liver biopsy was performed. R E A SON F OR R E F E R R AL
The liver biopsy shows PAS-positive, diastase-resistant globules. Immunohistochemical stain for alpha-1-antitrypsin (AAT) is negative. The referring pathologist is curious about the nature of these globules. PAT H OL OG I C F E AT U R E S
The liver biopsy shows patchy inflammatory mononuclear infiltrate with mild interface hepatitis. Intracytoplasmic globules are scattered within the hepatocytic cytoplasm, especially in the hepatocytes near the portal tracts. The globules are weakly periodic acid–Schiff (PAS) positive, diastase resistant. Immunohistochemistry shows no reactivity with AAT or fibringoen antibodies. There is, however, strong positivity with alpha-1-antichymotrypsin (ACT) antibodies in the intrahepatocytic globules.
D I AG N OS I S
Intrahepatocytic alpha-1-antichymotrypsin globules.
D I S C U S S I ON
The presence of PAS-positive, diastase-resistant, granules led initially to a differential diagnosis of AAT deficiency– associated chronic hepatitis. However, immunohistochemistry demonstrates a lack of AAT immunoreactivity in the cytoplasmic globules. Plasma level of AAT is within normal limits as well. Immunohistochemical staining with antibodies to ACT antigen is positive in these globules, with accentuation at the periphery (Figure 16.2.1). Multiple case reports in the literature have demonstrated that ACT deficiency is associated with chronic liver disease. However, since the prevalence of ACT deficiency in the population is very low, ACT deficiency is usually not in the differential diagnosis when chronic liver disease is
F I G U R E 1 6 . 2 . 1 Immunohistochemical staining for alpha-1-antichymotrypsin (ACT) demonstrates the presence of ACT globules within the cytoplasm of the hepatocytes. (Courtesy of Dr. Linda Ferrell, University of California, San Francisco.)
encountered and therefore rarely investigated in the clinical setting. Cytoplasmic globules have been demonstrated in hepatocytes of patients with cirrhosis associated with ACT deficiency. A case series shows that patients with hepatitis C virus (HCV) infection and low levels of serum ACT are more prone to developing cirrhosis to those with HCV only (1). In addition, there appears to be no established correlation between plasma levels of ACT and the abundance of globules in hepatocytes (2). It has been suggested that simultaneous heterozygous AAT and ACT mutations increase the risk of liver disease (2). Ultrastructurally, the inclusions have been described as fluffy material in the dilated cistern of the endoplasmic reticulum (3). This case and other published case reports (4) of hepatic diseases in patients with ACT deficiency illustrate the importance of including ACT deficiency in the differential diagnosis when intrahepatocytic globules/ inclusion bodies are encountered, especially when immunohistochemical stain for AAT is negative and the plasma level of AAT is normal. SUMMA RY
When intracytoplasmic globules/inclusion bodies are observed within the hepatocytes, it is crucial in distinguishing between physiologic and pathologic conditions, in arriving at a correct diagnosis, and in determining the severity of the hepatic involvement. Although immunohistochemistry with AAT and ACT is useful, it is by no means absolutely specific. Thus,
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immunohistochemical results should always be interpreted with caution. Also, it should be noted that AAT globules are not specific in individuals with AAT deficiency. They are not uncommonly found in liver cirrhosis due to various etiologies and in severely ill and older patients who have high concentration of AAT in the blood (5).
References 1. Thomas RM, Schiano TD, Kueppers F, Blac M. Alpha-1-antichymotrypsin globules within hepatocytes in patients with chronic hepatitis C and cirrhosis. Hum Pathol. 2000;31(5):575–577.
GLOBULES
2. Yoon D, Kueppers F, Genta RM, Klintmalm GB, Khaoustov VI, Yoff B. Role of alpha-1-antichymotrypsin deficiency in promoting cirrhosis in two siblings with heterozygous alpha-1-antitrypsin deficiency phenotype SZ. Gut. 2002;50(5):730–732. 3. Lindmark B, Millward-Sadler H, Callea F, Eriksso S. Hepatocyte incusions of alpha 1-antichymotrypsin in a patient with partial deficiency of alpha 1-antichymotrypsin and chronic liver disease. Histopathology. 1990;16(3):221–225. 4. Ortega L, Balboa F, González L. alpha(1)-Antichymotrypsin deficiency associated with liver cirrhosis. Pediatr Int. 2010;52(1):147–149. 5. Carlson J, Eriksson S, Hägerstran I. Intra- and extracellular alpha-1antitrypsin in liver disease with special reference to Pi phenotype. J Clin Pathol. 1981;34(9):1020–1025.
17 Glycogenic Abnormalities on Liver Biopsy MICHAEL TORBENSON
In most surgical pathology liver specimens, glycogen is inapparent on hematoxylin and eosin (HE) stains. However, the liver contains abundant glycogen that can be visualized with periodic acid–Schiff (PAS) stains in both healthy and diseased livers. As part of normal energy metabolism, the liver takes up excess glucose from the blood stream and converts it to glycogen by the process of glycogenesis. Glycogen is a polymeric chain of glucose molecules that serves as a storage form for glucose. Glycogen can be rapidly converted back to glucose if needed to meet the body’s energy demands. In some cases, glycogen accumulation in the liver reaches pathological levels and can cause disease. This occurs primarily in 2 conditions: (1) mutations that occur in various enzymes within glycogen metabolism pathways, leading to abnormal accumulation of glycogen; (2) glycogenic hepatopathy, a distinctive clinicopathological entity where the normal balance between glycogenesis and glycogenolysis is disrupted and excess glycogen accumulates within hepatocytes. Glycogenic hepatopathy is not associated with known mutations. Instead, glycogenic hepatopathy is caused in most cases by high and poorly controlled levels of serum glucose. G LY C O G E N S TOR AG E D I S E A S E S
There are many glycogen storage diseases that present as abnormal accumulations of glucose within the hepatocytes (1,2). These include primarily types Ia/b, IIIa/b, VI, IX, and XI. The hepatocytes in glycogen storage diseases are markedly swollen and filled with glycogen (Figure 17.1).
FIGURE 17. 1 Glycogen storage disease type IIIa. The hepatocytes are swollen and pale. There is no inflammation or fatty change in this case. Scattered glycogenated nuclei are seen.
A precise diagnosis of the subtype of glycogen storage disease cannot be reliably made on the basis of histology alone. Instead, the biopsy is useful to demonstrate the abnormal accumulation of glycogen. Additional biochemical assays are then needed to precisely classify the type of glycogen storage disease. Clinical features may also be helpful in some cases, but the degree of clinical overlap and the frequent presence of significant clinical ambiguities limit this approach and precise biochemical assays are typically needed. UR EA CY CLE DEFECT S
In addition to individuals with glycogen storage disease, marked glycogen accumulation is often seen in individuals with inherited defects in urea cycle enzymes. In one study, marked liver glycogen accumulation was reported in 8/11 children with urea cycle defects, including those with ornithine transcarbamylase deficiency, argininosuccinate lyase deficiency, and carbamoyl phosphate synthetase deficiency (3). The histological findings can be essentially identical to that of both glycogen storage disease as well as that of glycogenic hepatopathy (Figure 17.2), but the clinical settings are distinctively different. Classically, individuals with urea cycle defects present in infancy or childhood. However, increasing numbers of individuals with milder forms of disease are being reported in adults. The histological findings in adults have not been well described but presumably may resemble that of glycogenic hepatopathy.
Argininesuccinatelyase deficiency. The hepatocytes are swollen and pale, similar to that seen in glycogen storage diseases. FIGURE 17.2
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ON
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G LY C O G E N I C H E PATOPAT H Y
Glycogenic hepatopathy closely resembles glycogen storage diseases on routine light microscopy (Figure 17.3). There may be subtle histological differences in some cases. For example, there tends to be more diffuse hepatocyte swelling and greater cytoplasmic clumping of glycogen in glycogen storage diseases, but these subtle findings are not sufficiently sensitive or specific to be of routine use and it is really the clinical parameters that differentiate these 2 entities. For example, glycogenic hepatopathy typically occurs in the setting of poorly controlled diabetes and is responsive to diabetic control. The presence of significant fibrosis, which can develop in some forms of glycogen storage disorders, would also argue against glycogenic hepatopathy (Figure 17.4). C L I N I C AL F I N D I N G S
The classic clinical setting for the development of glycogenic hepatopathy is the presence of elevated blood sugars and elevated insulin levels, usually in the setting of type I diabetes mellitus and poor glycemic control. Glycogenic hepatopathy has been referred to by other descriptive names over the years, all of which emphasize the key finding of excess glycogen accumulation (Table 17.1). Glycogenic hepatopathy was first documented in 1930 in a study that described the Mauriac syndrome (4). The Mauriac
F I G U R E 1 7 . 4 Cirrhosis associated with glycogen storage disease (same case as in Figure 17.1). The presence of advanced fibrosis or cirrhosis would be unusual for glycogenic hepatopathy and instead suggests a glycogen storage disease.
TA BL E 1 7 . 1 Other descriptive names for glycogenic hepatopathy Diabetes mellitus–associated glycogen storage Hepatomegaly (14) Hepatic glycogenosis (15) Liver glycogenosis (16) Liver glycogen storage (17,18)
FIGURE 17. 3 Glycogenic hepatopathy. Note that the histological changes are essentially identical to that of glycogen storage disease (Figure 17.1) in that the main finding is of swollen hepatocytes with clear cytoplasm. In glycogen hepatopathy, there can be a range of glycogen accumulation, from mild to marked, as shown in this image, where the findings will be essentially identical to that of inherited glycogen storage disease.
syndrome results from poorly controlled type I diabetes and includes features of growth retardation, delayed puberty, cushingoid features, and hypercholesterolemia. These clinical findings are accompanied by hepatomegaly, abnormal liver enzymes, and marked accumulation of glycogen within hepatocytes on liver biopsy. The Mauriac syndrome was first described soon after the introduction of insulin into clinical care, highlighting the strong association between this disease and insulin treatment of diabetics. The Mauriac syndrome is rarely seen today because of improved diagnosis and care of type I diabetes. However, less severe clinical manifestations of type I diabetes are still seen, including glycogenic hepatopathy (5). In fact, most current reports of glycogenic hepatopathy are in type I diabetic patients, typically in the setting of rapid reversal of ketosis or in periods of poor diabetic control. At clinical presentation, a wide variety of clinical signs and symptoms have been observed in patients with glycogenic hepatopathy (Table 17.2). Of note, elevated transaminase levels and hepatomegaly are almost universal findings. In some cases, the patient’s hepatic enzymes can be dramatically elevated and can exceed 10 times the upper limit of normal (6). Also of importance, the enzymes’ levels may fluctuate considerably over time (7). However, in all cases, the liver’s synthetic function is well preserved. For this reason,
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ABNORMALITIES
TA B LE 17. 2 Summary of clinical symptoms and signs. A single
representative reference is provided Findings at Presentation Clinical Symptoms Abdominal distension (9) Anorexia (9) Nausea (15)
ON
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glycogen within the cytoplasm of hepatocytes. PAS staining will disappear after digestion with diastase. However, it should be remembered that even normal livers will have PAS positivity and the typical HE appearance is required to make the diagnosis of glycogenic hepatopathy. Electron microscopy is not needed to make the diagnosis but has been performed in previous studies, confirming the presence of glycogen accumulation at the ultrastructural level (15,5,6).
Right upper quadrant pain (6)
MECH A NISMS
Shortness of breath (6) Clinical Signs Ascites (6) Hepatomegaly (7,19) Poor growth (9) Vomiting (15) Laboratory Test Abnormalities Ketoacidosis (6) Elevated serum glucose (20) Increased liver enzymes (ALT/AST) (11) Liver enzyme flares (ALT/AST) (7) Increase serum lipids (13) Abbreviations: ALT, alanine aminotransferase; AST, aspartate transaminase.
glycogenic hepatopathy is not associated with low albumin levels or clotting abnormalities from decreased synthesis of clotting factors. Although rare, ascites is a dramatic presentation of glycogenic hepatopathy (6,8,15). The presence of ascites can be clinically misinterpreted as evidence for advanced liver disease. However, the ascites is not due to advanced fibrosis nor to low albumin levels but appears to result from compression of the sinusoids by the glycogen-laden hepatocytes, which restricts blood flow within the liver. The ascites of glycogenic hepatopathy typically resolves with adequate control of blood sugar (6,8,15). Also of note, both fatty liver disease as well as glycogenic hepatopathy can appear echogenic on ultrasound evaluation (9,15–17). Because of this, individuals with glycogenic hepatopathy may have an erroneous diagnosis of fatty liver disease at the time of liver biopsy. C LI N I C AL C OU R S E
The hepatomegaly and abnormal liver enzymes associated with glycogenic hepatopathy will improve with better glycemic control (15,16,9,10,11). In addition, histological resolution has also been documented in follow-up liver biopsies (6,12). H I S TOL OG I C F I N D I N G S
The distinctive histologic findings along with a history of diabetes are usually sufficient to make a diagnosis of glycogenic hepatopathy. A PAS stain can be used to highlight the
Glycogenic hepatopathy occurs in the setting of excess blood glucose that is also accompanied by high insulin levels. Glucose in the blood will passively diffuse into hepatocytes in a process that is driven largely by the glucose concentration gradient. Thus, high glucose levels lead to elevated levels of glucose diffusion into the hepatocytes. Once the glucose is in the hepatocyte cytoplasm, it is rapidly converted to glycogen and the glycogen is trapped within the cytoplasm. Over time, this leads to hepatocyte swelling. High levels of insulin can drive this process by increasing the conversion rate to glycogen. Interestingly, Manderson et al found that the hepatic levels of glycogen phosphorylase (PGYL), an enzyme that plays a key role in glycogenolysis, appeared lower than normal in 2 cases of glycogenic hepatopathy (13), but the precise role for genetic susceptibility remains undefined.
References 1. McAdams AJ, Hug G, Bove KE. Glycogen storage disease, types I to X: criteria for morphologic diagnosis. Hum Pathol. 1974;5:463–487. 2. Jevon GP, Finegold MJ. Reliability of histological criteria in glycogen storage disease of the liver. Pediatr Pathol. 1994;14:709–721. 3. Miles L, Heubi JE, Bove KE. Hepatocyte glycogen accumulation in patients undergoing dietary management of urea cycle defects mimics storage disease. J Pediatr Gastroenterol Nutr. 2005;40:471–476. 4. Mauriac P. Gros ventre, hepatomegalie, troubles de las croissance chez les enfants diabetiques traits depuis plusieurs annes par l’insuline. Gax Hebd Med Bordeaux. 1930;26:402–410. 5. Lorenz G, Barenwald G. Histologic and electron-microscopic liver changes in diabetic children. Acta Hepatogastroenterol (Stuttg). 1979;26:435–438. 6. Torbenson M, Chen YY, Brunt E, et al. Glycogenic hepatopathy: an underrecognized hepatic complication of diabetes mellitus. Am J Surg Pathol. 2006;30:508–513. 7. van den Brand M, Elving LD, Drenth JP, van Krieken JH. Glycogenic hepatopathy: a rare cause of elevated serum transaminases in diabetes mellitus. Neth J Med. 2009;67:394–396. 8. Bronstein HD, Kantrowitz PA, Schaffner F. Marked enlargement of the liver and transient ascites associated with the treatment of diabetic acidosis. N Engl J Med. 1959;261:1314–1318. 9. Munns CF, McCrossin RB, Thomsett MJ, Batch J. Hepatic glycogenosis: reversible hepatomegaly in type 1 diabetes. J Paediatr Child Health. 2000;36:449–452. 10. Tomihira M, Kawasaki E, Nakajima H, et al. Intermittent and recurrent hepatomegaly due to glycogen storage in a patient with type 1 diabetes: genetic analysis of the liver glycogen phosphorylase gene (PYGL). Diabetes Res Clin Pract. 2004;65:175–182. 11. Olsson R, Wesslau C, William-Olsson T, Zettergren L. Elevated aminotransferases and alkaline phosphatases in unstable diabetes mellitus without ketoacidosis or hypoglycemia. J Clin Gastroenterol. 1989;11: 541–545.
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12. Fridell JA, Saxena R, Chalasani NP, et al. Complete reversal of glycogen hepatopathy with pancreas transplantation: two cases. Transplantation. 2007;83:84–86. 13. Manderson WG, McKiddie MT, Manners DJ, Stark JR. Liver glycogen accumulation in unstable diabetes. Diabetes. 1968;17:13–16. 14. Nakamuta M, Ohashi M, Goto K, Tanabe Y, Hiroshige K, Nawata H. Diabetes mellitus-associated glycogen storage hepatomegaly: report of a case and review of the Japanese literature. Fukuoka Igaku Zasshi. 1993;84:354–358. 15. Chatila R, West AB. Hepatomegaly and abnormal liver tests due to glycogenosis in adults with diabetes. Medicine (Baltimore). 1996;75: 327–333.
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16. Carcione L, Lombardo F, Messina MF, Rosano M, De Luca F. Liver glycogenosis as early manifestation in type 1 diabetes mellitus. Diabetes Nutr Metab. 2003;16:182–184. 17. Torres M, Lopez D. Liver glycogen storage associated with uncontrolled type 1 diabetes mellitus. J Hepatol. 2001;35:538. 18. Evans RW, Littler TR, Pemberton HS. Glycogen storage in the liver in diabetes mellitus. J Clin Pathol. 1955;8:110–113. 19. Sweetser S, Kraichely RE. The bright liver of glycogenic hepatopathy. Hepatology. 2010;51:711–712. 20. Bassett JT, Veerappan GR, Lee DH. Glycogenic hepatopathy: a rare cause of increased aminotransferase levels in a diabetic patient. Clin Gastroenterol Hepatol. 2008;6:A26.
Case 17.1
Glycogenic Hepatopathy MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
A 16-year-old boy with a long history of type I diabetes presented with abdominal pain. He had been active on the swimming team and had been supplementing his diet because of the vigorous exercise. His blood glucose levels showed increased fluctuation during this time. Blood testing showed an ALT level of 450 and an AST level of 721 IU/mL. Ultrasound showed a strongly echogenic liver consistent with fatty liver disease. A biopsy was performed to investigate the marked AST and ALT elevations. R E A SON F OR R E F E R R AL
No fatty change was seen. There were scattered cytoplasmic eosinophilic globules with equivocal PAS-d staining. The case was referred with the question of whether this was alpha-1antitrypsin deficiency (AAT). PAT H O L OG I C A L F E AT U R E S
The liver biopsy specimens show a diffuse hepatocyte cytoplasmic clearing (Figure 17.1.1). No fatty change is seen. Rare apoptotic bodies are present, but there is no significant inflammation. Glycogenated nuclei are also easily found. No fibrosis is seen on trichrome stain. Scattered cytoplasmic eosinophilic globules are present (Figure 17.1.2), but there is no zonal distribution, and they appear smaller than typical alpha-1antitrypsin globules. A repeat PAS-d stain is negative. An iron stain is negative.
F I G U R E 1 7 . 1 . 2 Megamitochondria. The hepatocytes have numerous small red structures that are round to globoid in shape (arrows). These megamitochondria will be periodic acid-Schiff diastase negative and lack the zone 1 preference of alpha-1-antitrypsin. If you like, you can also stain the megamitochondria with a phosphotungstic acid-haematoxylin stain (see Figures 17.1.3 and 17.1.4).
DIAGNO SIS
Glycogenic Hepatopathy.
DISCUSSIO N
The biopsy findings are typical of glycogenic hepatopathy. Likewise, the clinical history is a perfect fit for this diagnosis. The pink globules that are seen represent mega-mitochondria. These large abnormal mitochondrial structures are not unique to glycogenic hepatopathy and are also commonly found in fatty liver disease as well as other chronic liver diseases. Sometimes they can resemble the globules of AAT. However, the globules typical of AAT tend to be larger and have a strong zone 1 distribution, especially in noncirrhotic livers. The globules of AAT are also strongly PAS-d positive in a properly stained section (Figure 17.1.3). If you are still uncertain, then a phosphotungstic acid-haematoxylin (PTAH) stain will nicely highlight the mega-mitochondria (Figure 17.1.4). Other Histologic Findings in Type I Diabetes FIGURE 17. 1. 1 Glycogenic hepatopathy. This is a more striking case of
glycogenic hepatopathy than shown in Figure 17.3. The hepatocytes are swollen with cleared cytoplasm.
Fatty liver
Although glycogenic hepatopathy is the most frequent histological finding in type I diabetic patients who have
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FIGURE 17. 1. 3 Periodic acid-Schiff diastase. Alpha-1-antitrypsin
globules. In this typical case of alpha-1-antitrypsin deficiency, numerous intracellular globules of alpha-1-antitrypsin protein are seen. In alpha-1-antitrypsin deficiency, the globules tend to have a zone 1 distribution, whereas megamitochondria are typically azonal.
hepatomegaly, fatty liver disease is also common in this setting. For example, in one study of 99 children with diabetes and hepatomegaly, glycogen accumulation was the most common finding associated with hepatomegaly. Moderate glycogen accumulation was seen in 22% of cases and marked glycogen accumulation in 19% of cases (1). However, fatty liver was also seen in nearly half of the total number of cases. Although the fatty change was usually mild, it did appear to explain the hepatomegaly in 8% of the children (1). Hepatosclerosis
Recently, an additional pattern of liver injury, termed “hepatosclerosis,” has been described in a series of liver biopsies from 12 diabetic patients (2). The liver biopsy specimens showed dense sinusoidal fibrosis, even though the livers were noncirrhotic. These findings were not accompanied by fatty liver or by glycogenic hepatopathy. Interestingly, the patients
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F I G U R E 1 7 . 1 . 4 Phosphotungstic acid–hematoxylin. megamito-
chondria. This stain highlights the usual mitochondria as numerous tiny blue dots in the hepatocyte cytoplasm. The megamitochondria can be seen as much larger structures with a thin clear halo around them. In the case shown, the megamitochondria are almost as big as some of the nuclei.
often had extensive histories of microangiopathic complications from their diabetes mellitus that involved multiple organ systems, suggesting that hepatosclerosis is a result of microangiopathic disease of the liver. Follow-up
The patients liver enzymes normalized with improved glycemic control. The abdominal pain also subsided.
References 1. Lorenz G, Barenwald G. Histologic and electron-microscopic liver changes in diabetic children. Acta Hepatogastroenterol (Stuttg). 1979;26:435–438. 2. Harrison SA, Brunt EM, Goodman ZD, et al. Diabetic Hepatosclerosis: perisinusoidal fibrosis without steatohepatitis amongst diabetics. Hepatology. 2003;38:666A.
Case 17.2
Glycogen in the Liver: Abnormal Versus Normal MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
A 61-year-old woman presented with headaches and spontaneous bleeding from oral mucosal membranes. Further workup showed mildly but persistently abnormal ALT levels (1.5–2.0 times the upper limit of normal). Her AST and alkaline phosphatase levels were within normal limits to slightly elevated. Her bilirubin was slightly elevated. She is non-obese, and viral studies and autoimmune studies were negative. She had a long history of Crohn disease but had good disease control for several decades. She had mild type II diabetes, currently managed by dietary considerations. A liver biopsy was performed. R E A SON F OR R E F E R R AL
The question raised on referral was whether the PAS positivity on the liver biopsy indicated glycogenic hepatopathy. F I G U R E 1 7 . 2 . 2 PAS. The same case as in Figure 17.1. The PAS stain is strongly and diffusely positive, but this finding alone is insufficient for the diagnosis of glycogenic hepatopathy.
PAT H OL OG I C F E AT U R E S
The liver biopsy showed no significant inflammation, fatty change, or fibrosis (Figure 17.2.1). The lobules showed mild hepatocyte disarray and rare apoptotic bodies. A reticulin stain suggested equivocal nodular regenerative hyperplasia type changes. An iron stain showed mild predominately Kupffer cell iron accumulation. A PAS stain was strongly positive (Figure 17.2.2).
DIAGNO SIS
Normal glycogen content.
DISCUSSIO N
Although the biopsy specimen shows subtle abnormalities, the findings do not strongly suggest a specific etiology. Strong hepatocyte PAS positivity is seen; however, the HE findings are not that of glycogenic hepatopathy. In glycogenic hepatopathy, the hepatocytes are diffusely enlarged and appear pale, often with accentuation of the cell membranes on routine HE stains. Overall, the PAS stain findings are within normal limits. PAS stains are often no longer part of the routine evaluation of liver biopsies (including within my practice). Because of this, many pathologists do not have an extended experience with evaluating PAS stains in various situations. Instead, PAS stains are often performed only when there is a history of diabetes and no other clear histological explanation for elevated liver enzymes. In such cases, strong but normal PAS staining can sometimes be misleading. This case illustrates the importance of having HE findings consistent with the diagnosis of glycogenic hepatopathy and not relying on a strong PAS stain for diagnosis. FIGURE 17. 2. 1 The liver showed mild lobular disarray with rare
apoptotic bodies and rare mitotic figures. The specimen does not show the typical hepatocyte clearing of glycogenic hepatopathy.
Follow-up
Subsequent studies found the patient had a hyperviscosity syndrome, which provides an explanation for the mild liver changes.
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Case 17.3
Glycogenic Hepatopathy, Cause Uncertain MICHAEL TORBENSON
C L I N I C AL I N F OR M AT I ON
A 39-year-old malnourished man with a history of substantial, daily alcohol use and mental illness had normal ALT, and AST 1.5–2.5 times the upper limit of normal. He was a poor historian but claimed he had been sober for several months. He presented with chronic intermittent abdominal pain. He was not taking any medications. Alkaline phosphatase levels were normal. Clinically, fatty liver disease was suspected based on clinical history and ultrasound findings. A biopsy was performed to evaluate further the abdominal pain and to stage the liver fibrosis. R E A S ON F OR R E F E R R A L
The biopsy showed cytoplasmic clearing that suggested glycogenic hepatopathy, but there was no clinical history of type I diabetes, so the case was referred with the question as to whether this was still consistent with glycogenic hepatopathy. PAT H OL OG I C F E AT U R E S
On biopsy, hepatocytes are moderately enlarged and appear pale with accentuation of the cell membranes (Figure 17.3.1). The overall hepatic architecture is preserved, and there is no significant fibrosis. Glycogenated nuclei are occasionally seen. There is minimal patchy nonspecific portal chronic inflammation with no significant lobular inflammation. There is also mild (approximately 5%) macrovesicular steatosis. Minimal zone 3 pericellular fibrosis is present on trichrome stain.
DIAGNO SIS
Glycogenic hepatopathy.
DISCUSSIO N
The histological findings are entirely consistent with the diagnosis of glycogenic hepatopathy and do no not strongly suggest another etiology. What is unusual, however, is the lack of a clinical history to suggest diabetes. This case brings up the wider differential for cases of histologically typical glycogenic hepatopathy. Medication effect: Although this patient does not have any history of medication usage, glycogenic hepatopathy can be associated with medications. For example, short-term–high-dose steroid therapy can lead to glycogenic hepatopathy (1). In fact, the clinical presentation after high-dose steroid therapy (hepatomegaly and elevated transaminases elevations), as well as the histological findings, can be identical to that of glycogenic hepatopathy in the setting of diabetes mellitus. Alpha-glucosidase inhibitors are currently under study to treat individuals with type II diabetes mellitus (2). Alphaglucosidase inhibitors such as emiglitate and miglitol can induce hepatic glycogen accumulation in animal models when given at high dosages (3). However, it remains to be seen whether glycogenic hepatopathy will be a clinical side effect in patients treated with alpha-glucosidase inhibitors. It seems likely that the list of medications that can cause glycogenic hepatopathy will increase as this histological pattern of injury becomes increasingly recognized. Malnutrition: It is counterintuitive that malnutrition can lead to glycogenic hepatopathy. It has not been well described in the limited literature on the liver pathology of malnutrition and is probably not a typical finding. Nevertheless, glycogenic hepatopathy was observed in a 22-year-old patient with anorexia nervosa who presented with abnormal liver enzymes (4). The liver biopsy showed changes typical of glycogenic hepatopathy, and the patient’s liver enzyme abnormalities improved after nutritional therapy (4). In the case under consideration, malnourishment could potentially explain the glycogenic hepatopathy, but the precise etiology remains unresolved. Further evaluation to rule out subclinical diabetes or insulin resistance would also be important in this case.
FIGURE 17. 3. 1 The biopsy shows a milder case of glycogenic hepat-
opathy. The hepatocytes show moderate accumulations of glycogen.
Follow-up
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H E PAT O PAT H Y,
References 1. Iancu TC, Shiloh H, Dembo L. Hepatomegaly following short-term high-dose steroid therapy. J Pediatr Gastroenterol Nutr. 1986;5:41–46. 2. van de Laar FA, Lucassen PL, Akkermans RP, van de Lisdonk EH, Rutten GE, van Weel C. Alpha-glucosidase inhibitors for patients with type 2 diabetes: results from a Cochrane systematic review and metaanalysis. Diabetes Care. 2005;28:154–163.
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3. Lembcke B, Lamberts R, Wohler J, Creutzfeldt W. Lysosomal storage of glycogen as a sequel of alpha-glucosidase inhibition by the absorbed deoxynojirimycin derivative emiglitate (BAYo1248). A drug-induced pattern of hepatic glycogen storage mimicking Pompe’s disease (glycogenosis type II). Res Exp Med (Berl). 1991;191:389–404. 4. Komuta M, Harada M, Ueno T, et al. Unusual accumulation of glycogen in liver parenchymal cells in a patient with anorexia nervosa. Intern Med. 1998;37:678–682.
Case 17.4
Glycogenic Hepatopathy, Type II Diabetes MICHAEL TORBENSON
C L I N I C AL I N F OR M AT I ON
A 53-year-old obese male underwent bariatric surgery. He has type II diabetes mellitus and mild hypertension under good control. During the surgery, the liver was biopsied to stage and grade the fatty liver disease. R E A S ON F OR R E F E R R A L
a distinctive nodularity (Figure 17.4.1). The zone 3 hepatocytes do not appear to be atrophic as would be typical of nodular regenerative hyperplasia. This HE impression is confirmed by a reticulin stain. Only mild focal portal fibrosis is seen on trichrome, and advanced fibrosis is clearly not the cause of the nodularity. A PAS stain shows that the cleared hepatocytes and the vague nodularity are due to glycogen accumulation.
The biopsy shows a mild but distinctive nodularity in addition to the mild fatty change. The case was referred with the question of whether this nodularity represented nodular regenerative hyperplasia.
DIAGNO SIS
PAT H OL OG I C F E AT U R E S
Glycogenic hepatopathy, associated with diabetes type II.
The wedge biopsy shows mild (approximately 5%) macrovesicular steatosis. In addition, the zone 3 hepatocytes have a mild but distinctive cytoplasmic clearing, giving the biopsy DISCUSSIO N
Although glycogenic hepatopathy is most commonly seen in type I diabetic patients, it has also been reported in a type II diabetic patient after large doses of glucose were given to counteract an overdose of long-acting insulin (1). In addition, adults who are insulin dependent because of poorly controlled type II diabetes mellitus can develop glycogenic hepatopathy that closely resembles the changes seen in children with type I diabetes (2). Also of note, adults with type II diabetes can have milder forms of liver glycogenosis that only become evident when biopsies are performed to evaluate the liver for other disease processes, such as chronic hepatitis C or fatty liver disease (2). The clinical and pathological correlates of glycogenosis in this setting have not been well characterized to date, but this case appears to fit into this category. FIGURE 17. 4. 1 In this wedge biopsy from an individual undergoing
bariatric surgery, the liver shows only mild fatty change. A trichrome stain showed no significant fibrosis, and a reticulin stain showed no evidence of nodular regenerative hyperplasia. However, there is a distinct nodularity to the liver. In this case, the nodularity is a result of glycogen accumulation with a distinct zone 3 distribution. This glycogen accumulation has led the zone 3 hepatocytes having a more clear appearance to their cytoplasm on the H&E. A PAS stain confirmed the increased glycogen in the clear areas.
References
260
1. Tsujimoto T, Takano M, Nishiofuku M, et al. Rapid onset of glycogen storage hepatomegaly in a type-2 diabetic patient after a massive dose of long-acting insulin and large doses of glucose. Intern Med. 2006;45: 469–473. 2. Chatila R, West AB. Hepatomegaly and abnormal liver tests due to glycogenosis in adults with diabetes. Medicine (Baltimore). 1996;75: 327–333.
Case 17.5
Glycogen Pseudo–Ground-Glass MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON DIAGNO SIS
A 21-year-old man with stage IV Hodgkin’s lymphoma presented with fluctuating liver enzymes over a 7-month period, with AST and ALT levels ranging from 1 to 2 times the upper limit of normal. He had just finished chemotherapy. All viral studies were negative.
Glycogen pseudo–ground-glass inclusions.
DISCUSSIO N R E A SON F OR R E F E R R AL
The hepatocytes look like they contain hepatitis B groundglass cytoplasmic changes, but all viral serological and DNA testing has been negative. Thus, the etiology of the findings was unclear, and the case was sent for consultation.
PAT H OL OG I C F E AT U R E S
The biopsy shows a panlobular distribution of hepatocytes with distinctive, well-circumscribed, gray inclusions surrounded by a rim of normal cytoplasm (Figure 17.5.1). These changes are not accompanied by significant inflammation, fatty change, or fibrosis. No lymphoma is seen. Immunostains for hepatitis B surface antigen are negative.
FIGURE 17. 5. 1 Pseudo–ground-glass change is also associated with the abnormal accumulation of glycogen, but in this disease pattern the glycogen accumulation leads to discrete inclusion-like deposits. These deposits can closely mimic the ground-glass inclusions of chronic hepatitis B infection.
Glycogen pseudo–ground-glass change is a recently described entity that is seen in immunosuppressed individuals on numerous medications (1,2) and is associated with the accumulation of abnormal forms of glycogen (1). There does not appear to be a single drug or class of drugs that can consistently cause this change, but instead it appears that different drugs can lead to the same effect. The common denominator is immunosuppression combined with numerous medications. The differential includes ground glass changes that can be seen in later stages of chronic hepatitis B infection (Figure 17.5.2). Immunostains for hepatitis B surface antigen are helpful in ruling out hepatitis B infection, especially if serological testing has not been performed or is not available (Figure 17.5.3). The differential also includes drug effects such as cyanamide, Lafora bodies, fibrinogen, and uremia (Table 17.5.1). As is evident in Table 17.5.1, ground-glass type changes and their mimics tend to be associated with smooth endoplasmic reticulum proliferation, abnormal glycogen accumulation, or,
F I G U R E 1 7 . 5 . 2 Ground-glass inclusions of chronic hepatitis B are
shown. They can look identical to the inclusions of pseudo–ground glass.
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TA BL E 1 7 . 5 . 1 Causes of pseudo–ground-glass type inclusions
in hepatocytes Staining Properties
Cyanamide
PAS diastase sensitivea
glycogen granules and dilated smooth endoplasmic reticulum
Fibrinogen
PAS Fibrinogen C3, C4 positive/
granular/fibrillar material within rough endoplasmic reticulum
Glycogen
PAS diastase sensitive
glycogen, occasional organellesb
Type IV glycogen storage disease
PAS partially diastasesensitivec colloidal iron negative
nonmembrane-bound fibrillar and granular material
Lafora
PAS diastase resistant colloidal iron positive
Fibril-like structures and electron-dense clumps
Uremia
PAS
smooth endoplasmic reticulum
FIGURE 17. 5. 3 Immunostain for hepatitis B surface antigen. In
some cases, clinical history and laboratory testing information is limited. HE findings alone are not sufficiently reliable in separating pseudo–ground glass from hepatitis-B-related changes. Immunostains for hepatitis B can be useful in separating hepatitis B ground-glass change from pseudo–ground glass change.
Electron Microscopy Findings
Type of Inclusion
Abbreviations: C3, C4, cytokeratin 3 and 4; PAS, periodic acid–Schiff diastase.
less commonly, protein accumulation. PAS diastase sensitivity can be of some help in this differential but should be used cautiously as the degree of digestion sensitivity or resistance can vary considerably between laboratories. In most cases, the distinctive clinical situations will clarify nature of the material.
References 1. Wisell J, Boitnott J, Haas M, et al. Glycogen pseudoground glass change in hepatocytes. Am J Surg Pathol. 2006;30:1085–1090. 2. Bejarano PA, Garcia MT, Rodriguez MM, Ruiz P, Tzakis AG. Liver glycogen bodies: ground-glass hepatocytes in transplanted patients. Virchows Arch. 2006;449:539–545. 3. Bruguera M, Lamar C, Bernet M, Rodés J. Hepatic disease associated with ground-glass inclusions in hepatocytes after cyanamide therapy. Arch Pathol Lab Med. 1986;110:906–910.
a Cyanamide pseudo–ground glass has been described as both diastase sensitive(3,4) and diastase resistant.(5) Most cases in the literature appear to be diastase sensitive. b Additional details of the organelles was obscured by poor preservation. c Pseudo–ground glass in type IV glycogen storage disease is variably diastase sensitive(6,7)
4. Hashimoto K, Hoshii Y, Takahashi M, et al. Use of a monoclonal antibody against Lafora bodies for the immunocytochemical study of groundglass inclusions in hepatocytes due to cyanamide. Histopathology. 2001; 39:60–65. 5. Zimmerman HF, Ishak KG. Hepatic injury due to drugs and toxins. In: MacSween RNM, Anthony PP, Scheuer PJ, Burt AD, Portmann BC, eds. Pathology of the liver. London, UK: Churchill Livingstone; 1995:563–634. 6. Sahoo S, Blumberg AK, Sengupta E, et al. Type IV glycogen storage disease. Arch Pathol Lab Med. 2002;126:630–631. 7. Vazquez JJ. Ground-glass hepatocytes: light and electron microscopy. Characterization of the different types. Histol Histopathol. 1990;5: 379–386.
Case 17.6
Smooth Endoplasmic Reticulum Proliferation MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
A 58-year-old man with chronic hepatitis C and human immunodeficiency virus (HIV) was biopsied for staging and grading of liver disease. He has no history of diabetes.
basophilic and slightly granular change to their cytoplasm (Figure 17.6.1). Distinctive inclusions with a rim of cytoplasm are not seen. There is marked lipofuscin but only mild patchy portal chronic inflammation and no significant lobular inflammatory activity.
R E A SON F OR R E F E R R AL
This case was referred for consultation as to whether the findings were those of glycogenic hepatopathy. DIAGNO SIS PAT H OL OG I C F E AT U R E S
Smooth endoplasmic reticulum proliferation.
The biopsy specimen shows a diffuse change affecting the hepatocyte cytoplasm. The cells appear swollen with a
DISCUSSIO N
The biopsy specimen shows a striking example of smooth endoplasmic reticulum proliferation. The change can mimic glycogenic hepatopathy at first, but further examination shows a lack of the distinctive cytoplasmic rarification of glycogenic hepatopathy. Instead, the cytoplasm has a diffuse gray stippled appearance that represents proliferation of the endoplasmic reticulum. In my practice, I see this most commonly in individuals with HIV/hepatitis C virus (HCV) coinfection, and it appears most likely to represent a drug effect. Others have also reported similar drug effects with phenytoin and barbiturates (1). The smooth endoplasmic reticulum proliferation in milder cases often does not involve the entire cell cytoplasm and often does not involve all hepatocytes. FIGURE 17. 6. 1 Diffuse smooth endoplasmic reticulin proliferation
in an individual with hepatitis C and human immunodeficiency virus coinfection. These changes can resemble glycogenic hepatopathy to some degree, but the smooth endoplasmic reticulin proliferation gives the hepatocyte cytoplasm a more basophilic and stippled appearance.
References
263
1. Chatila R, West AB. Hepatomegaly and abnormal liver tests due to glycogenosis in adults with diabetes. Medicine (Baltimore). 1996;75: 327–333.
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18 Macrophage Infiltrate RYAN M. GILL, SANJAY KAKAR, AND LINDA D. FERRELL
I N T ROD U C T I ON
Macrophages represent an important component of the acute inflammatory response and within days often represent the predominant cell type at sites of injury. Macrophages are activated by cytokines (eg, interferon-gamma [IFN- ]) and other nonimmune stimuli; the activated macrophage is larger, produces more cytokines, and has enhanced phagocytic capacity. In the setting of chronic inflammation, macrophages may accumulate and mediate significant tissue destruction and contribute to subsequent fibrosis. Macrophage activation can also occur in the setting of ischemia reperfusion, for example, following liver transplantation, and may contribute to injury through release of reactive oxygen species and cytokines, such as tumor necrosis factor alpha (1,2). Focal accumulation of activated macrophages, often with an epithelioid appearance, defines granulomatous inflammation (see Chapter 5); others may fuse to form multinucleate giant cells, or they may proliferate in a diffuse fashion, which is the focus of this chapter. In the liver, the macrophage is termed the Kupffer cell and is attached to the luminal surface of sinusoidal endothelial cells. Kupffer cells account for 80% of the mononuclear phagocytic system (3). Although still important in immune modulation, the Kupffer cell is less efficient at antigen presentation than other macrophages (4) and more readily utilizes its phagocytic and digestive abilities to efficiently ingest and remove particulate and soluble material, as well as micro-organisms/ endotoxin and degenerated cells from portal blood (5). Kupffer cells are more numerous in periportal sinusoids (6) and are derived at least in part from circulating monocytes (7); they proliferate in response to hepatic injury (8,9) and demonstrate functional heterogeneity (6,10), with report that periportal Kupffer cells are more phagocytically active (11). Kupffer cells can also migrate to areas of liver injury (12) and rapidly remove apoptotic hepatocytes. Once apoptotic hepatocytes have been phagocytosed, the macrophage (or clump of macrophages) may persist for weeks to months as evidence of previous injury (Figure 18.1). Kupffer cell–derived cytokine networks can even modulate hepatocyte function (13). Kupffer cells are recognized histologically as plump cells with abundant cytoplasm; they are easiest to appreciate when present in aggregates. The presence of phagocytosed periodic acid-Schiff (PAS)–positive, diastase (D)-resistant granular ceroid material allows them to be easily identified with a PASd stain (Figure 18.2). Kupffer cells can also be labeled using immunohistochemical lysosomal markers (CD68 and lysozyme) or the more specific macrophage marker, CD163. Historically, the term histiocyte has been used to denote macrophages in tissue sections. In the liver, a macrophage pattern of injury (in which abundant large macrophages are seen diffusely filling
F I G U R E 1 8 . 1 Persistent macrophages (arrows) after hepatocyte
injury.
F I G U R E 1 8 . 2 PASd-resistant ceroid material in macrophages.
sinusoids) likely represents an inherited enzyme defect (ie, a storage disorder resulting in accumulation of metabolic products), an infectious etiology, or an immunologic etiology. Distinction between these categories can often be made at high power through characterization of the phagocytosed material (Table 18.1). Drugs like amiodarone can lead to accumulation of phospholipids in the hepatocytes and occasionally in Kupffer cells (phospholipidosis) that can mimic storage diseases. In addition, rare neoplastic macrophage tumors or neoplastic mimics of a macrophage infiltrate may be encountered in the liver.
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TA B LE 18. 1 Classification of macrophage infiltrates by cytoplasmic
contents Metabolic Products Disorders of glycoprotein metabolism Disorders of amino acid metabolism Disorders of lipoprotein and lipid metabolism Disorders of iron metabolism Ceroid/lipofuscin-containing macrophages Phospholipidosis related to drugs like amiodarone Organisms Disseminated histoplasmosis Visceral leishmaniasis Disseminated cryptococcus Hematopoietic Cells Hemophagocytic lymphohistiocytosis Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease)
I N F I LT R AT E
seizures, and cherry-red macular spots to a more severe infantile form with gargoyle-like facies, peripheral neuropathy, impaired coordination, corneal opacities, impaired hearing, and hepatosplenomegaly. Types II and III are autosomal recessive diseases linked to 4q21–23 (14) with defective N-acetylglucosamine 1-phosphotransferase resulting in defective lysosomal enzyme targeting. Type II presents with early growth retardation, gingival hyperplasia, hepatomegaly, skeletal dysplasia, and psychomotor retardation (15). Type III presents in adulthood with less severe but similar features. Definitive diagnosis may require fibroblast culture and measurement of enzyme activity. Kupffer cells are enlarged and contain vacuolated cytoplasm. Hepatocytes, endothelial cells, stellate cells, and biliary epithelial cells demonstrate vacuoles at the ultrastructural level (16). Disorders of Amino Acid Metabolism
TA B LE 18. 2 Storage disorders with primarily Kupffer cell
involvement (by light microscopy) Disorders of Glycoprotein Metabolism Mucolipidosis I, II, & III Disorders of Amino Acid Metabolism Cystinosis Disorders of Lipoprotein and Lipid Metabolism Familial HDL deficiency Wolman disease Sulphatide lipidosis (metachromatic leukodystrophy) Ceramidase deficiency (Farber disease) Glycosyl ceramide lipidosis (Gaucher disease) Sphingomyelin-cholesterol lipidosis (Niemann-Pick disease) Disorders of Iron Metabolism Hemochromatosis, type IV (ferroportin disease) Unclassified Hermansky-Pudlak syndrome
M AC RO PH AG E I N F I LT R AT E — STOR AG E D I SORDER S
Cystinosis is an autosomal recessive disease with mutation in CTNS leading to accumulation of L-cystine crystals in lysosomes. In severe forms, crystal accumulation leads to renal tubular dysfunction and renal failure in childhood. Crystal deposition in the cornea and conjunctiva may lead to photophobia and allows for diagnosis through slit lamp evaluation. Crystals are also classically identified in neutrophils. Although most patients do not present with liver dysfunction, hepatomegaly is not uncommon. Liver biopsy may show perivenular hypertrophied Kupffer cells with intracytoplasmic cystine crystals (Figure 18.3), which demonstrate silver birefringence under polarized light. An association with portal hypertension has been noted (17,18) and a possible fibrogenic role for cystine-laden Kupffer cells has been proposed (19). Disorders of Lipoprotein and Lipid Metabolism
Disorders of lipoprotein and lipid metabolism account for the largest group of storage disorders with predominant macrophage involvement. Familial high-density lipoprotein deficiency (Tangier disease) is an autosomal recessive disease
Inherited storage disorders encountered by pathologists predominantly involve enzyme defects. Further distinction can be made between storage disorders involving hepatocytes as well as Kupffer cells (and occasionally other liver cell types) and those primarily presenting with macrophage involvement (Table 18.2). The latter typically involve defects in lysosomal enzymes important for breakdown of specific metabolic products. Disorders of Glycoprotein Metabolism
Mucolipidoses are rare lysosomal storage diseases with multiple combinatorial defects in the metabolism of mucopolysaccharide, lipid, and glycoprotein. Type I (termed sialidosis) is caused by mutation of NEU1 leading to a deficiency of lysosomal sialidase (neuraminidase). Clinical presentation ranges from late onset of visual defects, myoclonus, ataxia, hyperreflexia,
F I G U R E 1 8 . 3 Hypertrophied Kupffer cells with intracytoplasmic crystals in a case of cystinosis.
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involving mutation of ABCA1 on chromosome 9q31 (20). This leads to cholesterol accumulation in macrophages. Clinical presentation includes orange and enlarged tonsils, lymphadenopathy, hepatosplenomegaly, and peripheral neuropathy. Some patients have been reported to have hyperbilirubinemia (21,22). Liver biopsy shows abundant foamy Kupffer cells with birefringent cholesterol crystals (needle shaped and PAS negative) (23,24). In Wolman disease there is reduced lysosomal acid lipase (25), which results in abundant lipid and cholesterol crystals in macrophages (but also to some extent in hepatocytes) and a clinical presentation of diarrhea, emesis, and failure to thrive, with death typically by one year of life. Foamy macrophages are encountered in liver, spleen, adrenal glands, and intestines (as well as in bone marrow). Stains for lipid (eg, oil red O) on frozen sections may be helpful in identifying this entity. Ultrastructural analysis can also identify the predominant triglyceride droplets and cholesterol crystals. In sulphatide lipidosis (metachromatic leukodystrophy) the defect is in arylsulphatase A-mediated degradation of 3-O-sulphogalactosylceramide, which leads to demyelination and resultant neurologic symptoms. Presentation is variable but in its most severe form may manifest as progressive mental retardation, quadriplegia, and ataxia as well as hyperpyrexia. Liver biopsy may show periportal macrophages with metachromatic granules (26), which can be highlighted with a trichrome stain. Ceramidase deficiency (Farber disease) results in inability to degrade ceramide into sphingosine and fatty acid. Classic features of severe disease include early joint disease, subcutaneous wrist nodules, and a hoarse cry. Type IV ceramidase deficiency has been associated with neonatal hepatosplenomegaly and early death. Liver biopsy has reportedly demonstrated a diffuse expansion of Kupffer cells (27), which may be vacuolated. Glycosyl ceramide lipidosis, more commonly referred to as Gaucher disease, is the most common lysosomal storage disorder and is caused by a deficiency in acid-beta-glucosidase, which, along with Niemann-Pick disease (sphingomyelincholesterol lipidosis involving deficient acid sphingomyelinase), is described in the case studies.
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MACRO P H AGE INFILT R AT E—INFECT IO U S
Several infectious organisms are associated with a diffuse sinusoidal proliferation of macrophages (Table 18.1). Histoplasmosis is most often caused by Histoplasma capsulatum, especially in the Ohio River Valley. As an opportunistic infection, it is usually disseminated in the immune compromised. Hepatic involvement may result in hepatomegaly and small (3–4 μm) yeast can be identified in Kupffer cells. Although small granulomas may form, the disease may also present with diffuse macrophage infiltrate in the sinusoids. Distinction from leishmaniasis is possible since, of the 2, only H. capsulatum will stain with fungal stains, and H. capsulatum also does not have the kinetoplast identified in Leishmania sp. Disseminated Cryptococcus infection caused by Cryptococcus neoformans can be indistinguishable from histoplasmosis in the liver (when the organism is small and engulfed by Kupffer cells) and occurs in the same clinical settings. This is rarely a diagnostic dilemma since Cryptococcus more typically demonstrates variability in size, from 5 to 20 μm. Identification of a mucoid capsule is also characteristic, but if there is any doubt, culture allows for definitive classification. Visceral leishmaniasis (aka kala azar) is caused by several related protozoa (Leishmania sp.), which directly infect Kupffer cells and which can be diagnosed through morphologic identification of amastigotes (Figure 18.4). Visceral leishmaniasis is endemic in the Middle East, Asia, South America, Africa, and parts of Europe. Clinical presentation is with hepatosplenomegaly, fever, lymphadenopathy, and pancytopenia with hypergammaglobulinemia (30). The liver may be massively enlarged and will show Kupffer cell hyperplasia and hypertrophy with characteristic intracellular amastigotes (2–3 μm, ovoid clear organisms with a basophilic nucleus and paranuclear rod-shaped kinetoplast, often best seen on touch preparations). Note that in some cases, organisms may not be as readily identified. Steatosis may be encountered and fibrin ring granulomas have been described (31). In chronic adult cases fibrosis may develop. Before treatment with amphotericin B, visceral leishmaniasis
Disorders of Iron Metabolism
Type IV hemochromatosis, with its mutations in SLC40A1 (also known as the ferroportin-1 gene), which encodes an iron export protein abundant in Kupffer cells may first manifest as iron overload in Kupffer cells before appearing in hepatocytes (see Chapter 20). Unclassified
Hermansky-Pudlak syndrome is an autosomal recessive disorder without a well-defined etiology (28,29), which is characterized by oculocutaneous albinism and a defect in platelet aggregation. PASd-positive ceroid pigment deposition occurs in macrophages and may be appreciated on liver biopsy as tan granular material in hypertrophied Kupffer cells.
F I G U R E 1 8 . 4 Visceral leishmaniasis demonstrating a Kupffer cell
filled with amastigotes.
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I N F I LT R AT E
was usually fatal; with modern therapy (which in addition to liposomal amphotericin B includes sodium stibo-gluconate, and miltefosine), the prognosis is much improved in the immune competent. MAC RO PH AG E I N F I LT R AT E — I M M U N OL OGIC
“Immunologic disorders” include a spectrum of abnormalities leading to hemophagocytic lymphohistiocytosis (HLH), a clinicopathologic syndrome with proliferation of benignappearing histiocytes that may show phagocytosis of erythrocytes (hemophagocytosis). Bone marrow samples are more likely to demonstrate this finding than liver biopsy; hepatic involvement is characterized by Kupffer cell proliferation with variable hemophagocytosis (32,33) as well as a portal-based lymphohistiocytic infiltrate with a predominance of T cells. It is typical for Kupffer cells to stain less intensely with PAS in the setting of hemophagocytosis (34), and they frequently demonstrate siderosis (34), possibly secondary to preceding blood transfusions. In addition to morphologic demonstration of hemophagocytosis, HLH commonly presents with fever, splenomegaly, cytopenias (in at least 2 cell lines), hypertriglyceridemia, hypofibrinogenemia, and an elevated ferritin (>500 μg/L), as well as with sCD25 greater than 2400 U/mL and decreased NK-cell activity; 5 of these 8 criteria must be met to diagnose the syndrome (35). Although cytopenias may correlate with disease severity, they have not been found to correlate with hepatic involvement (34). In the setting of a child with acute liver failure and high ferritin, distinction from perinatal hemochromatosis can be critical, as the latter may be successfully treated with liver transplant (36,37). HLH may be inherited (inheritance is autosomal recessive with several described mutations), as in the fatal familial hemophagocytic lymphohistiocytosis (Farquhar disease) syndrome, which presents in the first year of life and involves a defect in granule-mediated cytotoxicity (eg, perforin) or natural killer (NK) cell function leading to uncontrolled macrophage activation. Inherited HLH may also manifest as part of an immune deficiency syndrome (eg, Chediak-Higashi syndrome, Girscelli syndrome, or X-linked lymphoproliferative syndrome). Also, severe combined immune deficiency (SCID) patients may develop “fatal infectious mononucleosis,” a terminal event involving massive hemophagocytosis, which may also involve the liver (Figures 18.5 and 18.6). HLH may be acquired in association with infection (usually Epstein-Barr virus [EBV]), toxins, malignancies (particularly in NK or T cell lymphomas, in which EBV is often still implicated), or rheumatic diseases with macrophage activation syndrome (38). Treatment involves immunosuppressive agents and cytotoxic drugs, but the prognosis is poor. Stem cell transplant is an option for patients with a genetic etiology. Among the reactive histiocytic proliferations, another consideration is sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease), first described by Drs. Rosai and Dorfman (39), which is of unknown etiology but may represent a reactive macrophage proliferation rather than a true neoplastic process. It is most common in
F I G U R E 1 8 . 5 Liver with hemophagocytosis in a patient with “fatal infectious mononucleosis.” (Courtesy of Dr. Elaine S. Jaffe.)
the pediatric population and most patients present with massive painless cervical lymph nodes; other lymph nodes can be involved and a significant subset will have extranodal involvement, including the liver in approximately 3% to 17% of cases (40). Leukocytosis and polyclonal hypergammaglobulinemia are associated with this diagnosis. Spontaneous remission is expected, but this may be protracted over months to years, and liver involvement is associated with a less optimal prognosis (40). When mass effect complicates the patient’s course, surgery may be indicated. Histologically, macrophages have abundant cytoplasm and an intermediate to large round nucleus with vesicular chromatin and 1 to several nucleoli. The slightly eosinophilic cytoplasm often contains phagocytosed lymphocytes or emperipolesis by a variety of cells (eg, neutrophils, red blood cells, or plasma cells). The proliferating histiocytes express CD68, CD163, and S-100 but are negative for CD1a and dendritic markers such as CD21. MACRO P H AGE INFILT R AT E— NEO P LA ST IC A ND MIMICS
Histiocytic sarcoma is a rare malignancy derived from macrophages, which has been described in the liver (41,42). Histologically, malignant histiocytes demonstrate a range of cytologic atypia, including possible multinucleate cells and stain with macrophage markers. Hemophagocytosis may also be present. In addition to CD68 and CD163, CD45, HLA-DR, CD43, and
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FIGURE 18. 6 CD163 immunostain highlights macrophages with
hemophagocytosis in this case of “fatal infectious mononucleosis.” (Courtesy of Dr. Elaine S. Jaffe.)
CD4 immunostains are usually positive and can be helpful in differentiating histiocytic sarcoma from other hematolymphoid neoplasms. S100 and langerin are negative or only weak and focally positive and histiocytic sarcoma does not express specific melanoma markers (allowing distinction from melanoma following staining with HMB-45, Melan-A, or tyrosinase). Clonal immunoglobulin or T-cell receptor gene rearrangements have rarely been reported. Histiocytic sarcoma is an aggressive malignancy, and patients may not respond well to treatment. Malignant tumors with a sinusoidal pattern of spread (such as hepatosplenic T-cell lymphoma or metastatic melanoma) can mimic macrophage infiltration. Morphologic observation of cytologic features should be helpful in ruling out metastatic tumor, but immunohistochemical stains can readily resolve indeterminate cases. Note that melanoma may express CD68 (and activated or neoplastic macrophages may label with S100, as described above) but should lack expression of the more specific histiocytic marker, CD163.
References 1. Bilzer M, Gerbes AL. Preservation injury of the liver: mechanisms and novel therapeutic strategies. J Hepatol. 2000;32:508–515. 2. Le Moine O, Louis H, Demols A, et al. Cold liver ischemia-reperfusion injury critically depends on liver T cells and is improved by donor pretreatment with interleukin 10 in mice. Hepatology. 2000;31:1266–1274.
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3. Saba TM. Physiology and physiopathology of the reticuloendothelial system. Arch Intern Med. 1970;126:1031–1052. 4. Rogoff TM, Lipsky PE. Role of the Kupffer cells in local and systemic immune responses. Gastroenterology. 1981;80:854–860. 5. Rifai A, Mannik M. Clearance of circulating IgA immune complexes is mediated by a specific receptor on Kupffer cells in mice. J Exp Med. 1984;160:125–137. 6. Wake K, Decker K, Kirn A, et al. Cell biology and kinetics of Kupffer cells in the liver. Int Rev Cytol. 1989;118:173–229. 7. Gale RP, Sparkes RS, Golde DW. Bone marrow origin of hepatic macrophages (Kupffer cells) in humans. Science. 1978;201:937–938. 8. Bouwens L, Baekeland M, Wisse E. Cytokinetic analysis of the expanding Kupffer-cell population in rat liver. Cell Tissue Kinet. 1986;19:217–226. 9. Johnson SJ, Hines JE, Burt AD. Macrophage and perisinusoidal cell kinetics in acute liver injury. J Pathol. 1992;166:351–358. 10. te Koppele JM, Thurman RG. Phagocytosis by Kupffer cells predominates in pericentral regions of the liver lobule. Am J Physiol. 1990;259: G814–G821. 11. Romert P, Quistorff B, Bhenke O. Histological evaluation of the zonation of colloidal gold uptake by the rat liver. Tissue Cell. 1993;25:19–32. 12. MacPhee PJ, Schmidt EE, Groom AC. Evidence for Kupffer cell migration along liver sinusoids, from high-resolution in vivo microscopy. Am J Physiol. 1992;263:G17-G23. 13. Maher JJ, Friedman SL. Parenchymal and nonparenchymal cell interactions in the liver. Semin Liver Dis. 1993;13:13–20. 14. Watanabe S, Phillips MJ. Ca2+ causes active contraction of bile canaliculi: direct evidence from microinjection studies. Proc Natl Acad Sci U S A. 1984;81:6164–6168. 15. Gumucio DL, Gumucio JJ, Wilson JA, et al. Albumin influences sulfobromophthalein transport by hepatocytes of each acinar zone. Am J Physiol. 1984;246:G86-G95. 16. Rappaport AM, Borowy ZJ, Lougheed WM, Lotto WN. Subdivision of hexagonal liver lobules into a structural and functional unit: role in hepatic physiology and pathology. Anat Rec. 1954;119:11–33. 17. DiDomenico P, Berry G, Bass D, Fridge J, Sarwal M. Noncirrhotic portal hypertension in association with juvenile nephropathic cystinosis: case presentation and review of the literature. J Inherit Metab Dis. 2004;27:693–699. 18. Rossi S, Herrine SK, Navarro VJ. Cystinosis as a cause of noncirrhotic portal hypertension. Dig Dis Sci. 2005;50:1372–1375. 19. Klenn PJ, Rubin R. Hepatic fibrosis associated with hereditary cystinosis: a novel form of noncirrhotic portal hypertension. Mod Pathol. 1994;7:879–882. 20. Rust S, Walter M, Funke H, et al. Assignment of Tangier disease to chromosome 9q31 by a graphical linkage exclusion strategy. Nat Genet. 1998;20:96–98. 21. Brook JG, Lees RS, Yules JH, Cusack B. Tangier disease (alphalipoprotein deficiency). JAMA. 1977;238:332–334. 22. Ferrans VJ, Fredrickson DS. The pathology of Tangier disease. A light and electron microscopic study. Am J Pathol. 1975;78:101–158. 23. Bale PM, Clifton-Bligh P, Benjamin BN, Whyte HM. Pathology of Tangier disease. J Clin Pathol. 1971;24:609–616. 24. Dechelotte P, Kantelip B, de Laguillaumie BV, Labbe A, Meyer M. Tangier disease. A histological and ultrastructural study. Pathol Res Pract. 1985;180:424–430. 25. Pagani F, Pariyarath R, Garcia R, et al. New lysosomal acid lipase gene mutants explain the phenotype of Wolman disease and cholesteryl ester storage disease. J Lipid Res. 1998;39:1382–1388. 26. Wolfe HJ, Pietra GG. The visceral lesions of metachromatic leukodystrophy. Am J Pathol. 1964;44:921–930. 27. Antonarakis SE, Valle D, Moser HW, Moser A, Qualman SJ, Zinkham WH. Phenotypic variability in siblings with Farber disease. J Pediatr. 1984;104:406–409. 28. Oh J, Ho L, Ala-Mello S, et al. Mutation analysis of patients with Hermansky-Pudlak syndrome: a frameshift hot spot in the HPS gene and apparent locus heterogeneity. Am J Hum Genet. 1998;62:593–598.
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29. Schallreuter KU, Frenk E, Wolfe LS, Witkop CJ, Wood JM. HermanskyPudlak syndrome in a Swiss population. Dermatology. 1993;187:248–256. 30. Badaro R, Jones TC, Carvalho EM, Sampaio D, Reed SG, Barral A, Teixeira R, et al. New perspectives on a subclinical form of visceral leishmaniasis. J Infect Dis. 1986;154:1003–1011. 31. Moreno A, Marazuela M, Yebra M, et al. Hepatic fibrin-ring granulomas in visceral leishmaniasis. Gastroenterology. 1988;95:1123–1126. 32. Hsu TS, Komp DM. Clinical features of familial histiocytosis. Am J Pediatr Hematol Oncol. 1981;3:61–65. 33. Favara BE. Histopathology of the liver in histiocytosis syndromes. Pediatr Pathol Lab Med. 1996;16:413–433. 34. Tsui WM, Wong KF, Tse CC. Liver changes in reactive haemophagocytic syndrome. Liver. 1992;12:363–367. 35. Janka GE, Schneider EM. Modern management of children with haemophagocytic lymphohistiocytosis. Br J Haematol. 2004;124:4–14. 36. Parizhskaya M, Reyes J, Jaffe R. Hemophagocytic syndrome presenting as acute hepatic failure in 2 infants: clinical overlap with neonatal hemochromatosis. Pediatr Dev Pathol. 1999;2:360–366.
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37. Natsheh SE, Roberts EA, Ngan B, Chait P, Ng VL. Liver failure with marked hyperferritinemia: “ironing out” the diagnosis. Can J Gastroenterol. 2001;15:537–540. 38. Sawhney S, Woo P, Murray KJ. Macrophage activation syndrome: a potentially fatal complication of rheumatic disorders. Arch Dis Child. 2001;85:421–426. 39. Rosai J, Dorfman RF. Sinus histiocytosis with massive lymphadenopathy. A newly recognized benign clinicopathological entity. Arch Pathol. 1969;87:63–70. 40. Foucar E, Rosai J, Dorfman R. Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease): review of the entity. Semin Diagn Pathol. 1990;7:19–73. 41. Akishima Y, Akasaka Y, Yih-Chang G, et al. Histiocytic sarcoma with fatal duodenal ulcers. Pathol Res Pract. 2004;200:473–478. 42. Hornick JL, Jaffe ES, Fletcher CD. Extranodal histiocytic sarcoma: clinicopathologic analysis of 14 cases of a rare epithelioid malignancy. Am J Surg Pathol. 2004;28:1133–1144.
Case 18.1
Gaucher Disease RYAN M. GILL, SANJAY KAKAR, AND LINDA D. FERRELL
C L I N IC AL I N F OR M AT I ON
DISCUSSIO N
A 17-year-old male presented to his primary care physician with a history of prolonged epistaxis. Physical examination documented moderate to severe hepatosplenomegaly, and laboratory values were significant for mild thrombocytopenia (50 10ˆ12/L). The patient was of Ashkenazi Jewish descent. A bone marrow biopsy showed mild megakaryocytic hyperplasia and was followed by a liver biopsy. R E A SON F OR R E F E R R AL
Macrophage infiltrate, suspicious for a storage disorder. PAT H OL OG I C F E AT U R E S
Liver biopsy demonstrated perivenular hypertrophy and hyperplasia of Kupffer cells, including some very large forms with lightly eosinophilic “crinkled” cytoplasm and central or eccentric nuclei (Figure 18.1.1). A PAS stain highlighted macrophage “striations” (Figure 18.1.2), typical of Gaucher cells. Hepatic plates were focally disrupted, but the architecture was otherwise intact and there was no fibrosis.
D I AG N OS I S
Perivenular Gaucher cells, no evidence of fibrosis.
FIGURE 18. 1. 1 Kupffer cells with a crinkled fibrillated appearance
in Gaucher disease.
Gaucher disease is an autosomal recessive disease in which patients are deficient in acid beta-glucosidase (glucocerebrosidase), which results in accumulation of glucocerebroside in macrophages (1,2). The most common form is type I, which is prevalent in the Ashkenazi Jewish population and which has variable presentation at any age. Patients with type I Gaucher disease typically have hepatosplenomegaly and skeletal disease (metaphyseal aseptic necrosis, bone pain, spontaneous fractures, degenerative hip disease, and possibly an “Erlenmeyer flask” deformity) but lack neurodegeneration. Type II disease presents in infancy with predominant neurodegeneration and moderate hepatosplenomegaly as well as possible ichthyosis (3). Type II disease does not have an ethnic predilection, and death usually occurs before 3 years of age. Type III disease is similar to type I disease, except that it is usually detected before age 50 and has associated terminal neurodegeneration. This form is more common in patients of Swedish ancestry. Hepatosplenomegaly can lead to platelet sequestration and mild thrombocytopenia (4). Diagnosis may be confirmed through assay of acid beta-glucosidase enzyme in white blood cells or fibroblasts. Recombinant enzyme replacement therapy is available, which results in rapid reversal of hepatomegaly (5–8) but does not mitigate neurologic disease. Morphologic findings in the liver include focal or perivenular macrophage hyperplasia and hypertrophy with characteristic striated, crinkled, or fibrillary cytoplasm, which can be highlighted with a PAS or trichrome stain. Hepatocyte atrophy, fibrosis, and portal hypertension may occur, and rare
FIGURE 18.1.2 Gaucher cells in a liver biopsy from a patient with Gaucher disease demonstrating characteristic PAS-positive striations.
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cases of cirrhosis have been described (9,10). Ultrastructural analysis demonstrates Kupffer cell cytoplasm packed with tubules. Macrophages resembling Gaucher cells have been described in several hematological disorders like chronic myelogenous leukemia, myelodysplastic syndrome, acute lymphoblastic leukemia, and plasma cell neoplasms. These have been referred to as pseudo-Gaucher cells and are morphologically and immunohistochemically indistinguishable from Gaucher cells. These cells usually occur in the bone marrow and rarely in the liver. On electron microscopy, pseudo-Gaucher cells have heterogenous inclusions and dense fibrillary bodies compared with the tubular inclusions of Gaucher cells (11,12).
References 1. Brady RO, Kanfer JN, Bradley RM, Shapiro D. Demonstration of a deficiency of glucocerebroside-cleaving enzyme in Gaucher’s disease. J Clin Invest. 1966;45:1112–1115. 2. Cox TM, Schofield JP. Gaucher’s disease: clinical features and natural history. Baillieres Clin Haematol. 1997;10:657–689. 3. Sidransky E, Ginns EI. Clinical heterogeneity among patients with Gaucher’s disease. JAMA. 1993;269:1154–1157.
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4. Zimran A, Kay A, Gelbart T, Garver P, Thurston D, Saven A, Beutler E. Gaucher disease. Clinical, laboratory, radiologic, and genetic features of 53 patients. Medicine (Baltimore). 1992;71:337–353. 5. Barton NW, Brady RO, Dambrosia JM, et al. Replacement therapy for inherited enzyme deficiency-Macrophage-targeted glucocerebrosidase for Gaucher’s disease. N Engl J Med. 1991;324:1464–1470. 6. Grabowski GA, Barton NW, Pastores G, et al. Enzyme therapy in type 1 Gaucher disease: comparative efficacy of mannose-terminated glucocerebrosidase from natural and recombinant sources. Ann Intern Med. 1995;122:33–39. 7. Germain DP. Gaucher’s disease: a paradigm for interventional genetics. Clin Genet. 2004;65:77–86. 8. Grabowski GA, Leslie N, Wenstrup R. Enzyme therapy for Gaucher disease: the first 5 years. Blood Rev. 1998;12:115–133. 9. Lachmann RH, Wight DG, Lomas DJ, Fisher NC, Schofield JP, Elias E, Cox TM. Massive hepatic fibrosis in Gaucher’s disease: clinicopathological and radiological features. QJM. 2000;93:237–244. 10. Cajaiba MM, Reyes-Múgica M. Gaucher or pseudo-Gaucher? The challenge of several diseases colliding in a pediatric patient. Hum Pathol. 2009;40:594–598. 11. Zidar BL, Hartsock RJ, Lee RE, et al. Pseudo-Gaucher cells in the bone marrow of a patient with Hodgkin’s disease. Am J Clin Pathol. 1987;87:533–536. 12. James SP, Stromeyer FW, Chang C, Barranger JA. Liver abnormalities in patients with Gaucher’s disease. Gastroenterology. 1981;80:126–133.
Case 18.2
Niemann-Pick Disease RYAN M. GILL, SANJAY KAKAR, AND LINDA D. FERRELL
C L I N IC AL I N F OR M AT I ON
A 25-year-old woman was noted to have hepatosplenomegaly and elevated total bilirubin (8 mg/dL). Abdominal computed tomography (CT) scan suggested the possibility of cirrhosis and a liver biopsy was performed. R E A SON F OR R E F E R R AL
Cryptogenic cirrhosis. PAT H OL OG I C F E AT U R E S
Liver biopsy shows focal or diffuse aggregates of hypertrophic vacuolated foamy periportal and sinusoidal macrophages (Figure 18.2.1). In some areas, the hepatocytes also show vacuolization and are pale, making distinction from macrophages difficult. On PAS stain the foamy cells are pale staining and lack striations (Figure 18.2.2). A Gomori trichrome stain demonstrates cirrhosis (Figure 18.2.3). Ultrastructural analysis demonstrated macrophages with densely packed laminated cytoplasmic inclusions (Figure 18.2.4).
F I G U R E 1 8 . 2 . 2 Niemann-Pick disease with PAS-negative foamy
macrophages.
D I AG N OS I S
Niemann-Pick disease with cirrhosis. D I S C U S S I ON
Niemann-Pick disease is a group of autosomal recessive sphingomyelin-cholesterol lipidoses that are separated into
F I G U R E 1 8 . 2 . 3 Niemann-Pick disease with cirrhosis on Gomori
trichrome stain.
FIGURE 18.2.1 Niemann-Pick disease with sinusoidal and periportal foamy macrophages.
types A, B, C, and most recently D (1). Types A and B are caused by mutation in SMPD1, which leads to sphingomyelin accumulation in histiocytes. Type A presents shortly after birth with hepatosplenomegaly, lymphadenopathy, and possibly hydrops fetalis (2–4). Macular cherry- red spots may be identified on physical examination. This is followed by neurologic impairment during infancy and leads to seizure and death by 5 years of age. Type B may be diagnosed in infancy, childhood, or adulthood. Although type B is characterized by hepatosplenomegaly (and patients may develop cirrhosis), pulmonary function typically
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I N F I LT R AT E
On biopsy, the presence of foamy vacuolated macrophages in the liver, bone marrow, or other sites is often an early clue to the diagnosis, which may be assisted by functional and molecular studies. Ultrastructurally, laminated cytoplasmic inclusions ranging from 1 to 5 micrometers in diameter (7) are characteristic. Progressive liver fibrosis may develop in Niemann-Pick disease, and can progress to cirrhosis in both children and adults (8,9). Therapeutic options are limited at present.
References
FIGURE 18. 2. 4 Transmission electron micrograph of Kupffer cell
with characteristic laminated inclusions in Niemann-Pick disease.
deteriorates more prominently than hepatic function and can be terminal. Splenic rupture is also a significant cause of death in type B patients. Types C and D (“Nova Scotia type”) are distinct from A and B in that they are caused by a defect that leads to accumulation of cholesterol and lipid in lysosomes and involve different candidate genes. They may present at any age, and patients develop neurologic complications at a slower rate; there is also often a history of neonatal cholestasis, and liver failure can develop in a minority of patients (5). There are also rare reports of associated hepatocellular carcinoma (6).
1. James SP, Stromeyer FW, Chang C, Barranger JA. Liver abnormalities in patients with Gaucher’s disease. Gastroenterology. 1981;80:126–133. 2. Greer WL, Riddell DC, Gillan TL, et al. The Nova Scotia (type D) form of Niemann-Pick disease is caused by a G3097-->T transversion in NPC1. Am J Hum Genet. 1998;63:52–54. 3. Crocker AC, Farber S. Niemann-Pick disease: a review of eighteen patients. Medicine (Baltimore). 1958;37:1–95. 4. Meizner I, Levy A, Carmi R, Robinsin C. Niemann-Pick disease associated with nonimmune hydrops fetalis. Am J Obstet Gynecol. 1990;163:128–129. 5. Kelly DA, Portmann B, Mowat AP, Sherlock S, Lake BD. Niemann-Pick disease type C: diagnosis and outcome in children, with particular reference to liver disease. J Pediatr. 1993;123:242–247. 6. Gartner JC Jr, Bergman I, Malatack JJ, et al. Progression of neurovisceral storage disease with supranuclear ophthalmoplegia following orthotopic liver transplantation. Pediatrics. 1986;77:104–106. 7. Lynn R, Terry RD. Lipid histochemistry and electron microscopy in adult Niemann-Pick disease. Am J Med. 1964;37:987–994. 8. Takahashi T, Akiyama K, Tomihara M, et al. Heterogeneity of liver disorder in type B Niemann-Pick disease. Hum Pathol. 1997;28:385–388. 9. Tassoni JP Jr, Fawaz KA, Johnston DE. Cirrhosis and portal hypertension in a patient with adult Niemann-Pick disease. Gastroenterology. 1991;100:567–569.274
19 Approach to Liver Biopsy With Minimal or Nonspecific Histologic Findings DHANPAT JAIN AND SANJAY KAKAR
It is often frustrating in clinical practice to get a liver biopsy with minimal or nonspecific changes in the setting of liver enzyme abnormalities. Most commonly it occurs in the setting of a milder form of an already known disease, and this seldom causes clinical problems. An example of this is a liver biopsy from a patient with chronic hepatitis C infection showing no fibrosis (stage 0) and minimal inflammatory activity (grade 0–1). However, there are certain disorders that typically present with subtle or nonspecific histopathologic changes that can be easily overlooked. A list of such disorders seen commonly in practice and their corresponding clinical patterns are listed in Table 19.1. These are briefly discussed here; details can be found in the respective chapters. Despite an extensive search in some cases, the etiology of the liver enzyme abnormalities still remains unexplained. Sampling error, exposure to an unidentified toxin/drug, and hepatic manifestations of an unidentified or subclinical systemic disorder are likely causes in such situations. It cannot be overemphasized that the spectrum of drug-induced liver disease is wide, and it is not unfair to say that for every liver disorder there is a drug toxicity that can mimic it. Hence, for any liver injury of unclear etiology, drug-induced liver injury should always be carefully evaluated and excluded. H E PAT I T I C D I SE ASE S Resolving Hepatitis
If the biopsy is performed late in the course of acute hepatitis, the clinical and biochemical picture can resemble acute hepatitis with mild elevations of transaminases, but the biopsy shows mild changes. These include no or mild portal/ acinar inflammation with or without mild hepatocellular TA B LE 19. 1 Differential diagnosis in liver biopsy
with mild or nonspecific changes Hepatitic Pattern Resolving hepatitis Nonspecific reactive hepatitis Viral hepatitis (false-negative serology) Connective tissue diseases Celiac disease Biliary Diseases Primary biliary cirrhosis Primary sclerosing cholangitis Mast cell disorders Vanishing bile duct syndrome
Metabolic Disorders Glycogenic hepatopathy Hypervitaminosis A Wilson disease Alpha-1-antitrypsin deficiency Portal Hypertension Idiopathic portal hypertension Venous outflow obstruction Nodular regenerative hyperplasia Other Amyloidosis
damage. The most striking finding is the presence of macrophages in the sinusoids. Cytoplasmic pigment (lipofuscin) is often present and can be highlighted with (periodic acidSchiff diastase) PASd stain. This picture reflects the resolving phase of acute hepatitis. Adverse drug reaction is generally the most common cause. Viral Hepatitis
In most cases of hepatitis B and C, the diagnosis is established by serology, and the biopsy is performed for grading and staging. In some instances, especially with hepatitis C, serological tests can give false-negative results. Polymerase chain reaction (PCR) for hepatitis C should always be considered before the biopsy findings are regarded as nonspecific. Nonspecific Reactive Hepatitis
This represents changes in the liver in response to systemic inflammatory processes, febrile illnesses, or inflammation somewhere in the splanchnic bed. Mild elevation of alanine transaminase (ALT) and aspartate transaminase (AST) can be present. On biopsy, the changes tend to be mild and focal. Mild lymphocytic infiltrate may be seen in the portal tracts; plasma cells and eosinophils may rarely be present. Lymphoid aggregates may be present in older patients. Interface hepatitis is minimal, if present. Few foci of lymphocytic inflammation and focal necrosis can be seen in the hepatic parenchyma. Small macrophage collections can occur in the sinusoids. Nonspecific reactive hepatitis needs to be distinguished both from resolving hepatitis and hepatitis C as described above. Collagen Vascular Diseases
Liver involvement can also occur in systemic lupus erythematosus (SLE), rheumatoid arthritis, mixed connective tissue disease, and Sjogren syndrome. The presence of autoantibodies and derangement of liver enzymes raises the possibility of autoimmune hepatitis (AIH). However, the inflammation and hepatocellular damage in these diseases is mild. Apart from mild nonspecific inflammation, other histological changes that can be seen are steatosis, sinusoidal dilatation, and nodular regenerative hyperplasia. Celiac Disease
The most frequent manifestation of liver involvement by celiac disease is mild elevations of transaminases. This can be observed in 40% to 50% of untreated patients. Histologically, 275
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these patients show nonspecific reactive hepatitis and revert to normal within 6 to 12 months of gluten-free diet. Other histological manifestations include acute hepatitis, chronic hepatitis, nodular regenerative hyperplasia, and, rarely, cirrhosis. In addition, coexisting celiac disease is seen in 3% to 6% of AIH, primary biliary cirrhosis (PBC), and PSC. The relationship of celiac disease and autoimmune liver disease is not clear. Autoimmune liver dysfunction often does not respond to gluten-free diet. Serological tests for celiac disease should be done in all cases of unexplained liver dysfunction. B I L I A RY D I SE ASE S Primary Biliary Cirrhosis
The majority of the patients (50%–60%) are asymptomatic at diagnosis and the biopsy is often performed due to incidental hepatomegaly, elevated alkaline phosphatase, or antimitochondrial antibodies (AMA). The distribution of bile duct injury is heterogeneous early in the course of the disease, and hence typical findings may not be seen on biopsy. The morphological findings include nonspecific portal inflammation, minimal bile duct injury, or even no pathological changes. The majority of asymptomatic patients with normal alkaline phosphatase and AMA titer 1:40 or higher, become symptomatic during follow-up, even if the biopsy does not show diagnostic changes. Hence in the setting of AMA positivity, the possibility of PBC should always be raised even if the biopsy findings are normal or nonspecific. Primary Sclerosing Cholangitis
Like PBC, histological changes can be patchy in early disease and may not be represented in the biopsy. If histological changes are nonspecific, PSC cannot be excluded on histologic grounds. Visualization of the biliary tree by cholangiography is the gold standard for diagnosis of PSC. Mast Cell Disease
Liver involvement manifests as portal infiltrates, often with mild bile duct damage and can mimic biliary disease. High index of suspicion is necessary to obtain immunohistochemical stains like tryptase, CD25, and/or CD117 to conclusively identify mast cells.
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and drugs are common underlying causes; however, the etiology may not be obvious in some cases. The clinical course is unpredictable with spontaneous resolution in some cases and progression to end-stage liver disease requiring transplantation in others. META BO LIC DISEA SES
The histologic findings in several metabolic disorders can be subtle and overlooked on hematoxylin and eosin (HE) sections. Glycogenic hepatopathy is characterized by diffusely swollen hepatocytes due to excess accumulation of glycogen. This commonly occurs in poorly controlled type 1 diabetes. There is no significant inflammation, steatosis, or hepatocellular damage. Hepatic stellate cells (Ito cells) are modified fibroblasts that store lipids and vitamin A in the normal liver. They are located in the space of Disse between the sinusoidal endothelium and the hepatocytes but are generally not easily visible. In certain conditions, especially hypervitaminosis A, excessive lipid gets stored in the stellate cells (stellate cell lipidosis). These lipid-laden cells can easily be mistaken for hepatocytes with steatosis. Their characteristic morphology and location along the sinusoids between the hepatic plates distinguishes them from steatotic hepatocytes. Wilson disease should always be considered in young patients (50 years) who present with unexplained liver dysfunction. Histological findings can include acute hepatitis, chronic hepatitis, steatosis, and cirrhosis. Nonspecific changes like mild inflammation and mild steatosis can be the only histological changes. The diagnosis can be established by serum ceruloplasmin levels and/or copper estimation from the paraffin block. Alpha-1-antitrypsin (AAT) deficiency is characterized by cytoplasmic globules that are typically seen in periportal or periseptal hepatocytes. In homozygous disease, the globules are large and numerous. However, in heterozygous disease, the globules can be small and inconspicuous. Hence PASd stain should be done in all cases with unexplained liver dysfunction. Immunohistochemistry may reveal globules in some cases that were not detected on PASd stain. The presence of globules is not specific for AAT deficiency and can occur with acute inflammation and alcoholic liver disease. Serum levels of AAT are not reliable for ruling out either homozygous or heterozygous disease; the diagnosis is confirmed by typing using isoelectric focusing or molecular techniques like single-strand conformational polymorphism (SSCP) and DNA sequencing.
Vanishing Bile Duct Syndrome and Idiopathic Adult Ductopenia
P O RTA L H Y P ERT ENSIO N
Loss of bile ducts can be patchy and may not involve all portal areas equally. Bile duct damage, ductular reaction, inflammation, or hepatocellular damage may not be seen, and the loss of bile ducts can be overlooked. Cytokeratin (CK) 7 and cytokeratin 19 stains may be helpful to highlight the missing ducts. CK7 stain, in addition, may show strong staining of the periportal hepatocytes. Biliary disorders like PBC or PSC
Some diseases can lead to portal hypertension without significant histologic changes in the liver, especially on needle biopsies. These include idiopathic portal hypertension (also called noncirrhotic portal fibrosis and hepatoportal sclerosis), nodular regenerative hyperplasia, and portal vein thrombosis. Venous outflow obstruction manifests as sinusoidal dilatation and congestion that can be overlooked on the biopsy.
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Amyloid deposits in the liver can be seen in vessel walls in the portal tracts or in the sinusoids. Some cases show nodular deposits in the sinusoids. Amyloidosis can be missed if the deposits are sparse and not accompanied by liver parenchymal changes like atrophy. The pale blue homogenous appearance of amyloid deposits on the trichrome stain can serve as a useful trigger to obtain specific stains like Congo red.
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Diabetes-associated hepatosclerosis is related to microangiopathy in long-standing diabetes. The hepatic arterioles in the portal tracts show mild thickening and hyalinization similar to diabetic hyaline arteriosclerosis in kidneys and other organs. In addition, they may also show variable amount of perisinusoidal, perivenular, or portal fibrosis. The bile ducts appear histologically normal, although alkaline phosphatase can be elevated.
Case 19.1
Mild Hepatic Steatosis Versus Ito Cell Lipidosis KATHARINE VAN PATTEN, SANJAY KAKAR, AND DHANPAT JAIN
C L I N I C AL I N F OR M AT I ON
A 62-year-old asymptomatic woman was found to have mildly elevated liver transaminases (AST 49 U/L, ALT 60 U/L). Viral hepatitis and autoimmune serologic studies were negative. The physical examination was unremarkable and the patient had no contributory past medical history. R E A S ON F OR R E F E R R A L
Unclear reasons for elevated transaminases in light of negative viral and autoimmune serologies and near normal appearance of the liver biopsy. PAT H OL OG I C F E AT U R E S
The liver biopsy appeared normal on low magnification without any inflammatory changes or fibrosis (Figure 19.1.1). On closer examination, the only significant finding noted was the presence of multivacuolated cells with peripheral crescentshaped nuclei within the hepatic lobules (Figure 19.1.2). The vacuoles appeared to indent the nuclei in many of the cells producing a scalloped nuclear outline (Figure 19.1.2). These cells lay outside the hepatic cords as highlighted by the reticulin stain (Figure 19.1.3). Electron microscopy (EM) showed that the cells are located in the perisinusoidal space of Disse. The ultrastructure of the lipid vacuoles, nuclear scalloping, and the location of the cells were consistent with hepatic
F I G U R E 1 9 . 1 . 2 Higher magnification showing typical morphology
of lipidotic Ito cells with multiple lipid vacuoles in the cells with scalloped nuclei located adjacent to the hepatic cords.
F I G U R E 1 9 . 1 . 3 Reticulin stain shows empty spaces corresponding
to the lipidotic Ito cells.
Ito (stellate) cells (Figures 19.1.3 and 19.1.4). On further inquiry, the patient admitted to having used excessive multivitamin pills daily. The serum vitamin A levels were not available.
FIGURE 19. 1. 1 (A) Low magnification of the liver biopsy showing
near normal histology. (B) Higher magnification showing few vacuolated cells that simulate steatotic hepatocytes.
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Ito (stellate) cell lipidosis.
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Electronmicrograph showing multivacuolated Ito cells in the space of Disse.
FIGURE 19. 1. 4
D I S C U S S I ON
Hepatic Ito cells are also known as stellate cells, perisinusoidal cells, or fat storing cells. They are located in the space of Disse between the hepatocytes and the sinusoidal endothelium. Under normal conditions, the cells store the majority of the body’s vitamin A in small lipid droplets in their cytoplasm (1). Ito cells in their quiescent state are difficult to recognize on HE-stained sections of liver. In chronic liver disease, the Ito cells can lose their fat droplets and transform into an activated myofibroblastic state (2). These cells play an important role in fibrogenesis, in part by producing extracellular matrix. Ito cells express a variety of markers including alpha–smooth muscle actin when activated as myofibroblasts but not in the quiescent or lipidotic state (1). In the setting of excess vitamin A ingestion, the Ito cells’ lipid droplets increase dramatically in size, and the cells become easily visible in histologic sections as fat-laden cells, and the condition is termed “Ito cell lipidosis” (ICL) (1). Most commonly, Ito cells in this setting are mistaken for steatotic hepatocytes. They are relatively easy to identify in nonsteatotic liver, and it becomes increasingly difficult to recognize them in a steatotic liver. The Ito cells typically are smaller than hepatocytes, have wispy cytoplasmic strands separating the lipid vacuoles, and the lipid vacuoles indent a peripherally placed nucleus (Figure 19.1.2). The Ito cells may be differentiated from hepatocytes by their location outside the hepatic cords as highlighted by reticulin stain (Figure 19.1.3), smaller size, and most importantly their scalloped nuclear outline similar to a lipoblast. The perisinusoidal location in the space of Disse and morphologic details of Ito cells are best appreciated on EM (Figure 19.1.4). However, EM is not necessary to make a
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diagnosis of ICL in routine practice. One of the biggest limitations in this area of diagnostic pathology is the lack of a reliable immunohistochemical marker for these lipidotic cells applicable in paraffin sections. The presence of vitamin A in these cells by fluorescence can be demonstrated on frozen tissue or biochemical quantitation on wet liver tissue but is seldom possible in clinical practice. Ito cell lipidosis may also result from conditions other than excess vitamin A intake (Table 19.1.1). ICL has been reported in patients with cholestasis, chronic pancreatitis, diabetes, human immunodeficiency virus (HIV) infection, PBC, early alcoholic disease, and certain drugs (3–6). Fish oil and vitamin E consumption are also believed to enhance the risk for vitamin A toxicity. It is controversial whether topical retinoids can also cause ICL (7,8). In a study by Levin et al of 14 cases of ICL, 5 patients (35.7%) had a history of oral vitamin A intake, while 2 patients (14.2%) were using only topical retinoids (1). Rare congenital disorders of vitamin A metabolism can result in vitamin A toxicity, even with normal vitamin A intake (9). It has also been suggested that decreased synthesis of retinol-binding protein by the liver or defective transport of vitamin A from Ito cells to the hepatocytes may also result in ICL (5,10). In general, patients with ICL do not show features of systemic vitamin A toxicity, which requires a much higher level of vitamin A excess. It is important to recognize that the serum vitamin A levels may be normal in ICL and cannot be used to exclude this diagnosis. In the study by Levine et al, 2 of the 7 tested patients showed normal serum vitamin A levels (1). The most common liver enzyme abnormality in these patients is elevation of alkaline phosphatase, although in some cases the liver enzymes are within normal limits. Regardless of the cause, the distribution of these cells has been shown to be focal, zonal, or sometimes diffuse (1). Significant ICL has been reported to occur in about 1.1% of all nontransplant liver biopsies; however, we believe this to be an underestimate. In our experience, finding a few scattered lipidotic Ito cells in liver biopsies with other disorders is not uncommon. The clinical significance of this finding has not been systematically studied. Lipidotic Ito cells are most likely
TA BL E 1 9 . 1 . 1 Sources of excess vitamin A and other etiologies
of Ito cell lipidosis Sources of excess vitamin A
Vitamin supplements Fish oil Fresh liver Topical retinoids (controversial)
Other diseases associated with Ito cell lipidosis
Cholestasis Chronic pancreatitis Diabetes AIDS Alcoholic liver disease Primary biliary cirrhosis Drugs (methotrexate, steroids, valproic acid)
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would be appropriate if clinical and laboratory abnormalities persist despite stopping vitamin A. In conclusion, underrecognition of ICL is common in routine practice and is largely due to a lack of familiarity with the entity.
References
FIGURE 19. 1. 5 A case of chronic hepatitis C with Ito cell lipidosis
where these cells can be easily confused with steatotic hepatocytes.
to be overlooked when a concomitant more obvious disorder is present in the liver biopsy (Figure 19.1.5). Vitamin A toxicity has been reported to result in progressive liver injury leading to cirrhosis, and withdrawal in most cases results in either stable disease or regression of the fibrosis. The consequences of a milder form of the disease remain unclear at present. Clinically, consideration for reducing or stopping the vitamin A intake and follow-up with serial liver transaminase levels should be undertaken. The role of follow-up biopsies is yet undefined in this setting; however, it
1. Levine PH, Delgado Y, Theise ND, West AB. Stellate-cell lipidosis in liver biopsy specimens. Recognition and significance. Am J Clin Pathol. 2003;19(2):254–258. 2. Friedman SL, Wei S, Blaner WS. Retinol release by activated rat hepatic lipocytes: regulation by Kupffer cell-conditioned medium and PDGF. Am J Physiol. 1993;264(5 pt 1):G947–G952. 3. Bronfenmajer S, Schaffner F, Popper H. Fat-storing cells (lipocytes) in human liver. Arch Pathol. 1966;82(5):447–453. 4. Latry P, Bioulac-Sage P, Echinard E, et al. Perisinusoidal fibrosis and basement membrane-like material in the livers of diabetic patients. Hum Pathol. 1987;18(8):775–780. 5. Dupon M, Kosaifi T, Le Bail B, Lacut Y, Balabaud C, Bioulac-Sage P. Lipid-laden perisinusoidal cells in patients with acquired immunodeficiency syndrome. Liver. 1991;11(4):211–219. 6. Hautekeete ML, Geerts A, Seynaeve C, Lazou JM, Kloppel G, Wisse E. Contributions of light and transmission electron microscopy to the study of the human fat-storing cell. Eur J Morphol. 1993; 31(1–2):72–76. 7. Fallon MB, Boyer JL. Hepatic toxicity of vitamin A and synthetic retinoids. J Gastroenterol Hepatol. 1990;5(3):334–342. 8. Vahlquist A. Long-term safety of retinoid therapy. J Am Acad Dermatol. 1992;27(6 pt 2):S29–S33. 9. Carpenter TO, Pettifor JM, Russell RM, et al. Severe hypervitaminosis A in siblings: evidence of variable tolerance to retinol intake. J Pediatr. 1987;111:507–512. 10. Nyberg A, Berne B, Nordlinder H, et al. Impaired release of vitamin A from liver in primary biliary cirrhosis. Hepatology. 1988;8(1): 136–141.
20 Interpreting Iron in Liver Specimens MICHAEL TORBENSON
Significant progress has been made over the past several decades in understanding the causes and significance of iron accumulation in the liver. There has also been an increased effort to standardize terminology used when discussing iron-related disease. We shall use the following commonly used definitions: the term “hemochromatosis” indicates hepatic iron accumulation in the setting of a genetic mutation; the term “siderosis” indicates hepatic iron accumulation without genetic mutations; the term “genetic nonhemochromatotic iron overload disorder” will be used to refer to a range of rare genetic disorders that lead to iron accumulation that is primarily deposited in Kupffer cells and macrophages. M A J O R PROT E I N S A N D C E L L S I N VOLV E D I N I RON M E TAB OL I S M
There are many proteins and cells involved in iron metabolism that are relevant to iron overload in liver pathology. The major ones are listed below as a quick reference.
OV ERV IEW O F NO R MA L IRO N META BO LIS M
The healthy adult body contains a total of approximately 3 to 5 grams of iron (as a point of reference, a U.S. nickel weighs 5 grams). About 20 mg of iron is needed each day for normal physiological functions, largely heme synthesis, but the majority of this daily need is met through recycling of damaged and obsolescent red blood cells. Because of the efficiency of this red blood cell recycling, only 1 to 2 mg per day is needed in a healthy diet. Iron is important in several metabolic processes outside of heme synthesis, including oxidative phosphorylation and DNA synthesis. Despite this importance, iron can be toxic at high levels. Thus, iron levels are tightly regulated within the body. The human body has no physiological way to excrete iron. Instead, regulatory mechanisms are focused on iron absorption from the intestine. Separate, but tightly integrated, controls also regulate blood iron levels. Iron Absorption
Proteins DMT: Ferritin:
Ferroportin:
Hemojuvelin:
Hemosiderin: Transferrin:
Dimetal transporter-1. Transports iron from gut lumen to enterocyte cytoplasm Protein located in the cell cytoplasm that has an enormous capacity to bind iron; major physiological storage form of iron Transports iron out of cells into the blood stream (principally enterocytes and macrophages, hepatocytes) The precise role of this membrane-bound protein is not clear. However, it appears to interact with important signaling pathways (bone morphogenic protein [BMP], SMAD) that have hepcidin as a downstream target. Without hemojuvelin, these signaling pathways are not able to activate hepcidin in a normal fashion. Abnormal deposits of iron Transports iron in blood
Iron is absorbed primarily in the duodenum and proximal jejunum. Heme-iron (about 10% of a typical diet) is taken up by the enterocytes after disassociation from globin, whereas nonheme iron (about 90% of a typical diet) is first reduced from a ferric to a ferrous state and then transported by a protein called dimetal transporter-1 (DMT-1) across the cell membrane into the enterocytes (Figure 20.1). There are several additional iron transport mechanisms for getting luminal iron into the enterocyte cytoplasm, but they appear to be less important. Once iron is within the enterocytes, it has two main possible fates. If the body is iron replete, then the iron remains within the cytoplasm of the enterocytes and is stored as ferritin. When the enterocyte eventually dies and is sloughed, the iron within the cell’s cytoplasm is lost within the fecal stream. This is a key control mechanism to prevent iron overload. In contrast, if the body needs iron, then the iron is transported out of the enterocytes by ferroportin with some help by accessory proteins, including ceruloplasmin and hephaestin, and enters the blood stream where it is bound by transferrin and circulates within the blood.
Cells Enterocytes: Hepatocytes:
Macrophages:
Absorption and short-term storage of iron Major producer of ferritin, hepcidin Major organ for storage of iron in the form of ferritin, hemosiderin Main recycler of old/damaged red blood cells Major cell type for storage of iron in the form of ferritin, hemosiderin
Getting Iron From the Blood to Cells Throughout the Body
All cells have mechanisms to determine whether they have sufficient iron stores within their cytoplasm to meet their needs. If cells need more iron, they increase their expression of transferrin receptors. Currently, there are 2 known receptors: transferrin receptor 1 and transferrin receptor 2. Transferrin receptor 1 is on all nucleated cells, whereas receptor 2 is primarily found in the liver. These receptors are located in the cell 281
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B A
C FIGURE 20. 1 (A) Overview of iron absorption; (B) When the body needs iron in its tissues, iron is shunted out of the enterocytes and
exported into the blood; (C) When the body does not need iron, then the enterocytes will store the iron in their cytoplasm. Eventually, the enterocyte dies and is lost into the intestinal lumen, at which time the iron will be lost with it. Abbreviations: Dcytb, duodenal cytochrome B; DMT, dimetal transporter; HCP, haem carrier protein.
membrane and can bind to and take in transferrin-bound iron from the blood. In healthy individuals, the blood contains much more transferrin protein than iron and the transferrin levels are approximately 30% saturated with iron. As blood iron levels increase, the excess transferrin proteins serve as a sort of buffer and will bind more iron to prevent excess free iron in the blood. Thus, increased serum transferrin levels can serve as a sensitive early indicator of excess iron absorption. All nucleated cells have transferrin receptors that can uptake transferrin-bound iron to meet the cells’ needs. Hepatocytes, with their abundant transferrin receptors, take up any excess iron, which then can be stored in the form of ferritin and, in times of great excess, as hemosiderin.
Iron Storage
If there is excess iron in the body, it can be incorporated into ferritin molecules for storage, largely in hepatocytes and macrophages. Ferritin is produced principally by the liver and is found in the liver cytoplasm, where it can hold up to 4500 atoms of iron per ferritin protein complex. Ferritin is typically not observed on Perls’ Prussian Blue stain, but occasionally it can be seen as a diffuse blush of blue in hepatocyte cytoplasm. The iron in ferritin can be rapidly accessed for physiological needs. If ferritin levels are excessive over a sufficiently long period of time, hemosiderin deposits can then develop. Hemosiderin is typically granular and golden brown on HE staining and is composed of iron and various proteins, principally degraded ferritin. The vast majority of the metal
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in hemosiderin is iron but small amounts of copper and calcium can also be detected. Despite an identical HE appearance of hemosiderin in both genetic and nongenetic causes of iron overload, there are differences in both the metallic as well as the organic components at the molecular level (1). In contrast to ferritin, the iron in hemosiderin is not as readily available for biological needs. In sum, there are two important reservoirs of iron that can both be tapped to keep iron levels in the blood at physiologically correct levels: (1) iron stored within enterocytes and (2) iron stored as ferritin, principally in hepatocytes and macrophages. Both reservoirs have separate but interconnected control mechanisms that serve to regulate iron flow into the blood. If they both are unable to meet the demands for iron, then iron deficiency develops; if they have dysregulated (mutated) control mechanisms, then hemochromatosis can develop.
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A
H E PC I D I N : C E NT R A L R E G U L ATOR OF I RO N TRAFFICKING Hepcidin
Hepcidin is the central regulator of iron stores in the body. Hepcidin is a secreted protein whose major source is hepatocytes. Peripheral adipose tissue can also be an important source, particularly with obesity. Hepcidin functions as a hormone and lowers blood iron levels. Hepcidin tracks iron levels similar to how insulin tracks blood sugar levels; in other words, if iron levels are high, hepcidin levels will be high, but if iron levels are low, hepcidin levels will be low (Figure 20.2). Control of Iron Release from Stores in the Enterocytes, Liver, and Macrophages
When blood levels are low, iron is released from enterocytes into the blood. In addition, iron is released from hepatocytes and macrophages where it has been stored as ferritin. However, when blood iron levels are adequate, then iron is blocked from being released from these two compartments. Hepcidin is the main regulator of this process: it blocks iron release from hepatocytes, macrophages, and enterocytes. Hepcidin accomplishes this by causing degradation of ferroportin, the protein that regulates transport of iron from enterocytes, macrophages, and hepatocytes into the blood. When hepcidin levels are low, there is increased iron absorption from the gut and increased release of iron into the blood from the iron stored in macrophages and hepatocytes. Hepcidin is an acute phase reactant and levels can be elevated in a variety of inflammatory and infectious conditions. In addition to inflammation, hepcidin levels are also increased by excess body iron stores. Many other factors are known to influence hepcidin levels (Figure 20.2). Recent findings have shown the central role of hepcidin in hemochromatosis. In fact, many of the mutations that
B F I G U R E 2 0 . 2 (A) Hepcidin blocks iron absorption from the intestine. Hepcidin also blocks iron that is stored in hepatocytes and macrophages from being released; (B) The regulation of hepcidin is complicated, but there are many known factors that can increase or decrease hepcidin levels.
lead to hemochromatosis, whether in hemochromatosis type 1 (HFE), juvenile hemochromatosis (HAMP), hemojuvelin (HJV), hemochromatosis type 3 (TfR2), all lead to decreased hepcidin production or impaired hepcidin function (2). A deficiency of hepcidin function first manifests as increased serum transferrin saturation levels. Later, increased serum ferritin levels are found and eventually increased serum iron levels are seen. This chronic excess of blood iron levels eventually leads to the accumulation of hemosiderin deposits in the liver and other organs.
References 1. Ward RJ, O’Connell MJ, Dickson DP, et al. Biochemical studies of the iron cores and polypeptide shells of haemosiderin isolated from patients with primary or secondary haemochromatosis. Biochim Biophys Acta. 1989;993:131–133. 2. Pietrangelo A. Hemochromatosis: an endocrine liver disease. Hepatology. 2007;46:1291–1301.
Case 20.1
Genetic Hemochromatosis MICHAEL TORBENSON
C L I N I C AL I N F OR M AT I ON
A 56-year-old woman underwent liver transplantation for alcohol-related cirrhosis and a 4 cm hepatocellular carcinoma. On histological examination, the liver showed marked iron accumulation including iron in the bile ducts. R E A S ON F OR R E F E R R A L
The liver contained large amounts of iron and was referred with the question of whether these histological findings were diagnostic of genetic hemochromatosis. PAT H O L OG I C AL F E AT U R E S
On Perls’ iron stain, the liver shows marked iron deposition with iron deposited fairly uniformly throughout the nodules. Heavy iron deposits are present in both the hepatocytes and the Kupffer cells (Figure 20.1.1). Overall, the iron is heaviest at the periphery of the nodules and tapers somewhat toward the center (Figure 20.1.2). Iron is also seen in septal-sized bile ducts (Figure 20.1.3). Follow-up genetic studies on this patient confirmed C282Y homozygosity.
F I G U R E 2 0 . 1 . 2 Perls’ iron stain; a zone 1 pattern of iron deposition was still evident in some of the cirrhotic nodules.
D I AG N OS I S
Cirrhosis in the setting of alcoholic liver disease and genetic hemochromatosis.
F I G U R E 2 0 . 1 . 3 Perls’ iron stain; iron was also present within the
biliary epithelium of septal-sized bile ducts. DISCUSSIO N
FIGURE 20. 1. 1 Perls’ iron stain; the liver showed marked iron accumulation with iron present in both hepatocytes and Kupffer cells.
The histological findings are certainly consistent with genetic hemochromatosis. However, histological findings are not diagnostic for genetic mutations per se. In genetic hemochromatosis, iron classically accumulates initially within zone 1 hepatocytes, and a clear gradient can often be seen in the amount of iron between zone 1 and zone 3 hepatocytes, even with advanced iron accumulation. In addition, the iron distribution often has a distinctive clustering around the bile canaliculi (Figure 20.1.4). With time, injury and death of hepatocytes will
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FIGURE 20. 1. 4 Perls’ iron stain; iron can be found in some cases deposited in hepatocytes immediately around the canaliculi.
FIGURE 20. 1. 5 Perls’ iron stain; iron can be found in small proliferation bile ductules in many cases that do not have genetic hemochromatosis.
lead to a redistribution of some iron into Kupffer cells and portal macrophages. However, a zone 1 distribution of iron can be seen in other non-hemochromatosis conditions, particularly once a liver is cirrhotic, and a diagnosis of hemochromatosis should not be based on recognizing a zonal pattern alone. The zone 1 predominant pattern of iron deposition is most likely a pattern seen whenever there is dysregulation of hepcidin, either through mutations or through reduced hepcidin production due to cirrhosis or other causes. Iron can also be seen in biliary epithelium on iron stain. Of note, iron is commonly seen in reactive bile ductules in areas of subacute parenchymal collapse in cirrhotic livers (Figure 20.1.5). This finding appears to have no association with hemochromatosis. Iron can also be deposited in the epithelium of the bile duct proper, as was seen in this case. In general, this pattern of iron deposition tracks better with the
H E M O C H R O M AT O S I S
285
F I G U R E 2 0 . 1 . 6 Perls’ iron stain; in some cases, iron can also be
found in endothelial cells.
overall severity of deposition within the liver and less so with HFE mutations per se. However, there is very little data that examines this specific question. With iron overload due to transfusion dependent anemias and similar causes, iron is classically first deposited in Kupffer cells, and with time there is involvement of the hepatocytes. Iron can also be seen in some cases either exclusively in portal endothelial cells (Figure 20.1.6) or in a combination of endothelial, hepatocyte, and Kupffer cell iron accumulation. At this time, there has not been any specific linkage of endothelial iron accumulation to a disease process or genetic mutation. In 1 study, endothelial iron positivity was linked to decreased interferon response in individuals with chronic hepatitis C infection (1). However, this finding has not been replicated and currently the etiology and significance of endothelial iron accumulation remains unclear. In regard to this particular consulting case, there is no reliable way to precisely parse out the roles of genetic versus environmental factors in the iron accumulation: they both contributed and their relative contributions cannot be discerned by histology. However, we discuss genetic cause of iron overload in more detail below. MUTAT IO NS IN IRO N- R ELAT ED GENES
There are a number of mutations that lead to hemochromatosis. The number will probably continue to grow with time. Despite this, these conditions share a core set of common findings as listed below: 1. As noted previously, a common mechanism is that all mutations, at least in part, involve abnormally low levels or dysfunction of hepcidin. 2. Most mutations are inherited—new sporadic mutations appear to be very rare. 3. Most mutations are recessively inherited.
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4. The clinical consequences include iron deposition in the liver, heart, joints, and endocrine organs. There is an established increased risk for hepatocellular carcinoma and possibly increased risks for cholangiocarcinoma as well as other nonhepatic malignancies. 5. Blood findings progress in severity from elevated transferrin saturation levels, to elevated ferritin levels, to elevated iron levels. 6. Histologically, iron is deposited primarily in hepatocytes. Classic findings on iron stains for hemochromatosis include a zone 1 distribution of iron deposits, a pericanalicular pattern of iron deposits within the hepatocyte cytoplasm, and iron deposits in bile duct epithelial cells. However, these features are not specific for hemochromatosis. 7. Clinical management revolves around phlebotomy, which can be life saving as it can prevent the clinical sequelae listed above (No. 4). Individuals have intact erythropoiesis, and so they tolerate phlebotomy well.
HFE Mutations
HFE mutations were first linked to hereditary hemochromatosis in 1996. Since that time, over 37 mutations in this gene have been reported (16), but by far the most numerically and clinically important are C282Y and H63D mutations. C282Y mutations are strongly linked to northern European genetic ancestry (16) (Table 20.1.1), whereas H63D mutations have a wider ethnic distribution (3). Overall, the C282Y mutation accounts for 80% to 90% of hereditary hemochromatosis cases, whereas H63D accounts for approximately 60% of non-C282Y hereditary hemochromatosis cases (2,4). Other mutations, such as S65C, have also been linked to iron accumulation, but these mutations are significantly less common and data on their clinicopathological significance is limited. Gene penetrance is variable for all HFE mutations and to accommodate this, 4 clinical stages of the disease have been defined: genetic predisposition without abnormality, asymptomatic iron overload, iron overload with early symptoms, and iron overload with organ damage most commonly seen in the liver, heart, joints, pancreas, and other endocrine organs (5).
TABLE 20.1.1 HFE mutations in northern European populations
Genetic Status
Population Frequency
C282Y heterozygote
9.2
C282Y homozygote
0.4
H63D heterozygote
21.6
H63D homozygote
2.0
C282Y/H63D compound heterozygote
1.8
Wild/Wild From Ref. 16.
65.1
IRON
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SPECIMENS
Individuals with C282Y mutations are at greater risk for iron accumulation than those with H63D mutations. Not surprisingly, C282Y homozygotes are at higher risk for iron accumulation than are C282Y heterozygotes. However, there is great phenotypic variation, even in individuals with C282Y homozygosity, underscoring the importance of other factors such as polymorphisms or mutations in other genes, environmental influences, and demographics such as age and gender. For example, in a major population-based study from Australia, 203 individuals who were homozygous for C282Y mutations were followed for 12 years. Twenty eight percent of the men, but only 1% of women, developed ironoverload–related diseases (6). This same research group also examined C282Y/H63D compound heterozygotes and found that only 1/82 men and none of the 95 women developed iron-overload–related disease over a 12-year study interval (7). This and other data argue for a strong protective effect for female gender. However, this does not appear to be solely due to physiological blood loss, and other gender-associated polymorphisms appear likely (reviewed in Wood et al) (8). The mechanism by which HFE mutations lead to iron accumulation are incompletely understood. At this time there are 2 major theories. The first suggests that the HFE protein is critical in determining the enterocytes’ internal “set point” for determining its cellular iron state. With HFE mutations, the enterocyte set point incorrectly indicates the cell is iron deficient, leading to increased enterocyte absorption of iron. The second theory focuses on the observation that, for incompletely understood reasons, individuals with HFE mutations have abnormally low plasma hepcidin levels. These low levels of hepcidin then lead to gradual excess iron absorption and deposition in the hepatocytes and other organ tissues. Both theories have supporting data from both animal models and human observations, suggesting both will be at least partially correct in the end. Causes of Death in HFE -Related Hemochromatosis
Clinical follow-up studies have consistently identified cirrhosis and liver decompensation as well as hepatocellular carcinoma as leading causes of death in individuals who are untreated or incompletely treated for HFE hemochromatosis (Table 20.1.2). However, there is also an increased risk for morbidity from heart failure and complications of diabetes. An increased risk for nonliver cancer has also been identified in some but not all studies. Treatment by phlebotomy can substantially lower the risk of death. A single unit of blood can safely remove 200 to 450 mg of iron, and over a period of time, usually a year or 2, phlebotomy can restore safe levels of iron within the blood. Liver Transplantation for HFE Iron Overload
Overall, hereditary hemochromatosis is an uncommon indication for an orthotopic liver transplantation (OLT). An early study of liver transplant outcomes that examined 5180 liver transplantations reported that only 56 (1%) of the
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20.1:
GENETIC
transplantations were for hemochromatosis (9). This and other early studies reported an overall decreased posttransplant survival rate for patients with hereditary hemochromatosis compared with those transplanted for other causes of chronic liver disease, with major causes of mortality including TA B LE 20. 1. 2 Morbidity in individuals with clinical HFE
hemochromatosis
287
H E M O C H R O M AT O S I S
infection, cardiac failure, and cancer development (9–11). However, a more recent study has shown great improvement over the last decade in the survival of individuals transplanted for hemochromatosis (12). This increased survival likely reflects better patient selection and pre- and posttransplant management. Despite this, cardiovascular disease continues to be an important cause of morbidity and mortality (12). When examining an explanted liver with iron overload, any foci (even subcentimeter foci) with decreased iron deposition should be targeted for sectioning to evaluate for carcinoma. These “iron-free foci” are often associated with dysplastic nodules or with frank carcinoma. They can rarely be seen on needle biopsies also, and, when present, should be indicated in the report evaluated for malignancy.
Data
Milman et al (13)
Niederau et al (14)
Fargion et al (15)
Number of deaths
147
69
44
Length of follow-up
8.5 years, median
14 years, mean
4 years, median
Ethnicity
Danish
German
Italian
Cirrhosis, no cancer
32
20
23
Hepatocellular carcinoma
23
28
45
Non-liver cancer
11
12
14
Cardiovascular disease
11
20
7
Cerebrovascular disease
5
Not stated
Not stated
Hemojuvelin mutations are the most common cause of juvenile hemochromatosis. Nevertheless, this remains a relatively rare disease. There can be marked hepatocellular iron overload, and the disease typically runs a severe clinical course.
Respiratory disease
5
Not stated
Not stated
Hepcidin (Usually Children/Early Onset)
Sepsis
3
Not stated
Not stated
OT H ER MUTAT IO NS C AUSING GENET I C H EMO CH RO MATO SIS
Causes of death (%)
Other mutations in key iron-related genes can also lead to genetic hemochromatosis. These mutations are summarized in Table 20.1.3 as well as briefly described below. Hemojuvelin Mutations (Usually Children/Early Onset)
This rare form of genetic iron overload has marked hepatocellular iron overload and typically runs a severe clinical course.
TA B LE 20. 1. 3 Overview of genetic iron diseases involving the liver Gene
Also Known as (Some Names Used in the Literature)
Chromosome
Transmission
Onset
Iron Location
HFE
Hemochromatosis type 1
6p21.3
Recessive
Late
Hepatocytes Kupffer cells
HJV (hemojuvelin)
Juvenile hemochromatosis type 2A
1p21
Recessive
Early
Hepatocytes Kupffer cells
HAMP (hepcidin)
Juvenile hemochromatosis type 2B
19q13.1
Recessive
Early
Hepatocytes Kupffer cells
TfR2
Hemochromatosis type 3
7q22
Recessive
Late
Hepatocytes Kupffer cells
SCL11A2 (DMT-1)
None yet
12q13
Recessive
Early
Hepatocytes Kupffer cells
SLC40A1 (ferroportin)
Ferroportin disease type B
2q32
Dominant
Late
Hepatocytes Kupffer cells
Diseases With Iron Deposited Primarily in Mesenchymal Cells SLC40A1 (ferroportin)
Ferroportin disease type A (hemochromatosis type 4)
2q32
Dominant
Late
Kupffer cells hepatocytes
Tf (transferrin)
Hypotransferrinemia
3q21
Recessive
Early
Kupffer cells hepatocytes
CP (ceruloplasmin)
Hypoceruloplasminemia
3q23-35
Recessive
Late
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Hypogonadism and cardiac disease are also prominent clinical manifestations. Transferrin Receptor Gene 2 (Usually Adults/Late Onset)
This rare form of genetic iron overload has marked hepatocellular iron overload and has a variable clinical course. DMT-1 Mutations (Usually Older Children)
This very rare disease has very few reported cases (about 4 to date), so data is quite limited. Children present with severe microcytic anemia. Iron accumulation is primarily in hepatocytes but, in very young children, biopsies can be negative for iron. N O N H E MOC H ROM ATOT I C I RON OV E R L OA D D I S E A S E (I E , P R E D OM I N AT E LY M E S E N C Y M A L I RON AC C U M U L AT I ON )
Ferroportin disease is a classic example of hereditary iron overload where the iron accumulation can be predominately in Kupffer cells. In contrast to the causes of hemochromatosis discussed above, all of which have elevated transferrin saturation levels early in the disease course, transferrin saturation levels in ferroportin disease do not become elevated until much later in the disease course. Ferroportin disease also stands out for its dominant inheritance pattern. Of note, there is substantial phenotypic variability and the disease is divided into 2 subtypes with different disease manifestations. Several other rare forms of genetic nonhemochromatotic iron overload disorder are also listed in Table 20.1.3. Clinically, ferroportin disease is characterized by increased serum ferritin but low or normal transferrin saturation
FIGURE 20. 1. 7 Perls’ iron stain; although the specificity of this find-
ing is uncertain, clumpy foci of iron deposits have been reported in ferroportin disease.
IRON
IN
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SPECIMENS
(type A). The inheritance pattern is autosomal dominant, and, histologically, the iron is deposited in Kupffer cells more than hepatocytes (type A), though for ferroportin disease type B the data is somewhat more mixed, and hepatocytes can have similar or more iron than Kupffer cells. Histologically, iron deposits can also be found in larger clumped foci (Figure 20.1.7). Clinically, both types are milder than HFE-mutation–associated hemochromatosis. Type A ferroportin disease tends to be milder than type B. Also of note, ferroportin disease does not respond well to phlebotomy due to an impaired erythropoiesis response.
References 1. Kaji K, Nakanuma Y, Harada K, Sakai A, Kaneko S, Kobayashi K. Hemosiderin deposition in portal endothelial cells is a histologic marker predicting poor response to interferon-alpha therapy in chronic hepatitis C. Pathol Int. 1997;47:347–352. 2. Mura C, Raguenes O, Ferec C. HFE mutations analysis in 711 hemochromatosis probands: evidence for S65C implication in mild form of hemochromatosis. Blood. 1999;93:2502–2505. 3. Settin A, El-Bendary M, Abo-Al-Kassem R, El Baz R. Molecular analysis of A1AT (S and Z) and HFE (C282Y and H63D) gene mutations in Egyptian cases with HCV liver cirrhosis. J Gastrointestin Liver Dis. 2006;15:131–135. 4. Limdi JK, Crampton JR. Hereditary haemochromatosis. Qjm. 2004;97:315–324. 5. Pietrangelo A. Hereditary hemochromatosis—a new look at an old disease. N Engl J Med. 2004;350:2383–2397. 6. Allen KJ, Gurrin LC, Constantine CC, et al. Iron-overload-related disease in HFE hereditary hemochromatosis. N Engl J Med. 2008;358: 221–230. 7. Gurrin LC, Bertalli NA, Dalton GW, et al. HFE C282Y/H63D compound heterozygotes are at low risk of hemochromatosis-related morbidity. Hepatology. 2009;50:94–101. 8. Wood MJ, Powell LW, Ramm GA. Environmental and genetic modifiers of the progression to fibrosis and cirrhosis in hemochromatosis. Blood. 2008;111:4456–4462. 9. Kilpe VE, Krakauer H, Wren RE. An analysis of liver transplant experience from 37 transplant centers as reported to Medicare. Transplantation. 1993;56:554–561. 10. Farrell FJ, Nguyen M, Woodley S, et al. Outcome of liver transplantation in patients with hemochromatosis. Hepatology. 1994;20:404–410. 11. Brandhagen DJ, Alvarez W, Therneau TM, et al. Iron overload in cirrhosis-HFE genotypes and outcome after liver transplantation. Hepatology. 2000;31:456–460. 12. Yu L, Ioannou GN. Survival of liver transplant recipients with hemochromatosis in the United States. Gastroenterology. 2007;133: 489–495. 13. Milman N, Pedersen P, á Steig T, Byg KE, Graudal N, Fenger K. Clinically overt hereditary hemochromatosis in Denmark 1948–1985: epidemiology, factors of significance for long-term survival, and causes of death in 179 patients. Ann Hematol. 2001;80:737–744. 14. Niederau C, Fischer R, Purschel A, Stremmel W, Häussinger D, Strohmeyer G. Long-term survival in patients with hereditary hemochromatosis. Gastroenterology. 1996;110:1107–1119. 15. Fargion S, Mandelli C, Piperno A, et al. Survival and prognostic factors in 212 Italian patients with genetic hemochromatosis. Hepatology. 1992;15:655–659. 16. Hanson EH, Imperatore G, Burke W. HFE gene and hereditary hemochromatosis: a HuGE review. Human Genome Epidemiology. Am J Epidemiol. 2001;154:193–206.
Case 20.2
Grading Iron MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
A 46-year-old man was biopsied to stage and grade chronic hepatitis C. An iron stain shows moderate iron accumulation.
and density of blue staining correlates, albeit imperfectly, with tissue iron concentrations. The stain is not as sensitive for very low levels of iron but is easier and more reproducible than other methods such as the Tirmann-Schmeltzers method, which can identify both ferric and ferrous forms of iron.
R E A SON F OR R E F E R R AL
Ferritin: Normally no ferritin will be seen. However, in cases of elevated serum ferritin levels, ferritin may be seen as a light diffuse blue blush of the hepatocyte or Kupffer cell cytoplasm (Figure 20.2.2). Hemosiderin: Hemosiderin can be seen as brown granular deposits on HE stains and as a bright blue granular staining on iron stain. Residual brown granular material is often seen on iron stain and represents lipofuscin in most cases.
The case was referred for recommendations for the best grading system for iron overload. PAT H OL OG I C F E AT U R E S
The biopsy shows moderate zone 1 hepatocellular iron accumulation (Figure 20.2.1).
D I AG N OS I S
Moderate hepatocellular iron accumulation in the setting of chronic hepatitis C .
D I S C U S S I ON
The major histochemical stain used to detect iron in the liver is Perls’ Prussian Blue (note that the most correct spelling is Perls or Perls’ Prussian Blue, not Perl’s Prussian Blue). This stain is named after Max Perls, a German pathologist who first suggested the stain. The basic chemistry of Perls’ Prussian Blue is that iron in the ferric state will react with hydrochloric acid to form ferric ferrocyanide, an insoluble blue compound (Prussian Blue) that can be seen histologically. The distribution
FIGURE 20. 2. 1 Perls’ iron stain; moderate iron accumulation is seen
within periportal hepatocytes.
When evaluating a surgical pathology liver specimen, it is prudent patient care to provide information on the amount of iron accumulation in the hepatocellular and Kupffer cell compartments that is sufficiently detailed to be clinically actionable when appropriate. A description is sufficient for this purpose, and there is no data to support an additional need to provide a formal number based on a specific scoring system. However, if the pathologists or clinicians prefer to provide a formal numerical assessment, that is fine. Sufficient scoring system detail should then be provided to allow a reader of the report to determine what the numbers mean. For example, a statement of the sort “iron grade 2” is in itself fairly useless and is strongly discouraged as neither the magnitude of the scale nor the location of the iron is apparent from this statement. As discussed above, there is no reliable way to determine whether the iron seen in a typical hepatitis C biopsy, such as
F I G U R E 2 0 . 2 . 2 Perls’ iron stain; a light blue blush on iron stain can be seen in some cases and represents ferritin.
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the case under consideration, is because of genetic versus nongenetic causes. In these situations, my practice is to report the iron as described above. When iron levels reach the moderate to marked levels in noncirrhotic specimens, then I indicate in a note that the iron accumulation is more than is seen in typical cases of chronic hepatitis C and that further genetic testing may be of interest as clinically indicated. Iron-Grading Systems
There are many iron-grading systems that have been proposed over the years. They vary considerably in their approach: some are based on zonation of iron distribution, some on the lowest magnification that discernable granules can be seen, some on the percentage of hepatocytes positive for iron. There is a nice summary of these iron-grading systems by Dr. Randall G Lee in Diagnostic Liver Pathology, also available online (http://tpis1.upmc.com:81/tpis/dlp/DLPHome.html; click on Chapter 9 and find Table 9-3). This book chapter is somewhat dated and does not cover several newer systems but is still very useful. The system by Deugnia and Turlin (1) has the advantage of having been validated, but it is too complex to be readily adopted for routine diagnostic use. Is any system clearly the best? Probably not, but I personally use a schema (Table 20.2.1) based on the percentage of hepatocytes positive for iron, similar to that described by LeSage et al (2). For routine diagnostic purposes, I include the descriptor (eg, “mild,” etc) in the pathology report but do not routinely provide the corresponding numerical grade. I believe that this simple-to-use classification system provides sufficient clinical information for patient care. But there are many reasonable alternatives to consider if you prefer a different approach. A modified Scheuer’s system (shown in Table 20.2.2) is also a very useful and popular system. If employed, separate numbers should be given for hepatocellular and the reticuloendothelial iron.
IRON
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TABLE 20.2.1 My iron scoring system (similar to that of LeSage)
Grade
Description
Hepatocytes (%)
Lobular Kupffer Cells (%)
None
None
0
None
1
Minimal
5
5
2
Mild
5–30
5–30
3
Moderate
31–60
31–60
4
Marked
60
60
Note: For studies, I also record the zonal pattern of iron and whether the distribution is homogeneous. For some studies, I also record endothelial iron and portal macrophage iron. From Ref. 2.
TA BL E 2 0 . 2 . 2 Modified Scheuer’s system Grade
Description
0
Iron granules absent or iron granules barely seen at 400
1
Iron granules resolved at 250
2
Iron granules resolved at 100
3
Iron granules resolved at 25
4
Iron deposits resolved at 10 or iron deposits visible without magnification
From Ref. 3.
References 1. Deugnier Y, Turlin B. Pathology of hepatic iron overload. World J Gastroenterol. 2007;13:4755–4760. 2. LeSage GD, Baldus WP, Fairbanks VF, et al. Hemochromatosis: genetic or alcohol-induced? Gastroenterology. 1983;84:1471–1477. 3. Turlin B, Deugnier Y. Evaluation and interpretation of iron in the liver. Semin Diagn Pathol. 1998;15:237–245.
Case 20.3
Hepatic Iron Index MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
A 43-year-old man with cryptogenic cirrhosis undergoes liver transplantation. R E A SON F OR R E F E R R AL
The liver shows marked iron accumulation. It was unclear to the referring pathologist what role the hepatic iron index currently plays in evaluating biopsies, as compared with genetic testing. PAT H OL OG I C F E AT U R E S
The liver shows established cirrhosis with moderate to marked iron accumulation (Figure 20.3.1). There is no other strong histological clue to the underlying liver disease.
Quantitative Measurement of Hepatic Iron Concentrations
The normal adult liver has between 10 to 36 μmol iron/g dry weight of liver. Hepatic iron concentrations measured in fresh liver tissue or in paraffin-embedded tissue are equivalent. Thus, paraffin-embedded tissues are preferred over fresh tissues in most cases because they allow direct visualization of the tissue and assure the tissue is representative. This prevents submission of tissue that is largely composed of collapsed/ fibrotic stroma or a nodule that is either unusually high or low in stainable iron compared with the rest of the tissue. Excess iron accumulation has been classified as mild (up to 150 μmol iron/g dry weight of liver), moderate (151–300), and marked (>301) (1). Iron levels greater than 400 μmol are the most strongly associated with cirrhosis but lower levels of iron also contribute to fibrosis progression in the setting of other liver diseases.
D I AG N OS I S
Hepatic Iron Index
Cirrhosis with marked iron overload.
D I S C U S S I ON
Given the routine availability of HFE genetic testing, the hepatic iron index has little role for diagnosing hemochromatosis in most cases. However, clinical requests for iron quantitation are not uncommon and can still be useful in patient care in some situations.
Historically, the hepatic iron index was calculated as an aid to interpreting quantitative tissue iron levels. The hepatic iron index adjusts the total iron concentration for age, based on the observation that hepatic iron concentrations tend to increase steadily with age in individuals with genetic hemochromatosis, but not in individuals with secondary iron overload. In a noncirrhotic liver, a hepatic iron index greater than 1.9 was considered suggestive of genetic hemochromatosis. Given the advances in understanding the causes of hemochromatosis and the readily available genetic testing for HFE mutations in many parts of the world, the diagnostic role of the hepatic iron index has somewhat diminished in importance, but direct measurement of hepatic iron concentration remains useful in guiding therapy, and we still get many requests for blocks to be submitted for quantitative iron analysis. The formula for the hepatic iron index is as follows: μg iron per gram dry weight of liver/55.846 Patient’s Age The value of 55.846 represents the atomic weight of iron. Noninvasive Measurements of Hepatic Iron
FIGURE 20. 3. 1 Perls’ iron stain; established cirrhosis with moderate
to marked iron accumulation is seen.
Magnetic resonance imaging (MRI)-based imaging studies have advanced in recent years to the point that they can reasonably assess iron accumulation and can also distinguish hepatic from reticuloendothelial iron deposits. There have been multiple validation studies, and MRI has established for itself an important role in measuring iron in the liver. Recent expert opinion review articles on hemochromatosis
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have highlighted the changing role of the biopsy in managing patients with HFE hemochromatosis (2,3). Biopsies continue to be important in determining the fibrosis stage and to search for any associated lesions (eg, evaluation of mass lesion). Some experts (3) foresee a further diminution of the role of liver biopsies with the advent of noninvasive markers of liver fibrosis.
IRON
IN
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SPECIMENS
References 1. Deugnier Y, Turlin B. Pathology of hepatic iron overload. World J Gastroenterol. 2007;13:4755–4760. 2. Pietrangelo A. Hemochromatosis: an endocrine liver disease. Hepatology. 2007;46:1291–1301. 3. Deugnier Y, Brissot P, Loreal O. Iron and the liver: update 2008. J Hepatol. 2008;(48)(suppl 1):S113–S123.
Case 20.4
Marked Hepatic Iron but No Genetic Mutation MICHAEL TORBENSON
C L I N IC AL I N F OR M AT I ON
DISCUSSIO N
A 63-year-old woman with cryptogenic cirrhosis underwent liver transplantation. Genetic testing for HFE mutations were negative. Although fatty liver has not been documented by biopsy, she is obese with type II diabetes, hypertension, and hyperlipidemia.
Iron can accumulate in cirrhotic livers of individuals who do not have clinical findings of genetic hemochromatosis. In a classic study by Ludwig et al, iron stains were positive in 32% of 447 liver explants with varying underlying liver diseases. For those diseases with at least 5 cases in this study, the proportions of cases with any degree of positivity by iron stain were as follows: hereditary hemochromatosis (100%), cryptogenic cirrhosis (65%), alcohol cirrhosis (63%), chronic hepatitis B cirrhosis (65%), AAT cirrhosis (56%), chronic hepatitis C cirrhosis (42%), primary biliary cirrhosis (PBC) (10%), and primary sclerosing cholangitis (PSC) (7%). In this same study, the number of cases with a hepatic iron index of greater than 1.9 were as follows: hereditary hemochromatosis (HH) (100%), alpha-1-antitrypsin (AAT) (28%), cryptogenic cirrhosis (19%), alcohol cirrhosis (14%), chronic hepatitis B cirrhosis (18%), chronic hepatitis C cirrhosis (7%), PBC (1%), and cirrhosis from PSC (1%). This and other data sets document that other diseases can have iron deposition within the liver and that in AAT deficiency and in cryptogenic cirrhotic livers, 20% or more of cases can have hepatic iron indexes greater than 1.9. Another important observation from these data is that biliary cirrhosis is only rarely associated with iron overload. An important study by Kowdley et al (1) found that patients with significant hepatic iron accumulation had decreased survival following transplantation regardless of whether they had an HFE mutation. The reason(s) for this are unclear, but at least in a subset of these individuals, there can be significant extrahepatic stores of iron at the time of transplantation, often clinically unrecognized (2). In cases such as these, the stress of surgery or other posttransplant factors may place this group of patients at increased risk for heart failure.
R E A SON F OR R E F E R R AL
Based on the clinical findings, she most likely has fatty liver disease–associated cirrhosis. But there is also marked iron accumulation. PAT H OL OG I C F E AT U R E S
The liver shows established cirrhosis with moderated to marked and somewhat patchy iron accumulation (Figure 20.4.1). No specific findings to suggest an alternative cause for her cirrhosis is seen and a diagnosis of cryptogenic cirrhosis, most likely fatty liver disease, based on clinical history is rendered (see Case 4.5 for further discussion on fatty liver and iron stores). Subsequent HFE mutational studies were positive for H63D heterozygosity.
D I AG N OS I S
Cryptogenic cirrhosis, most likely due to nonalcoholic fatty liver disease. Moderate iron accumulation with H63D heterozygosity.
References 1. Kowdley KV, Brandhagen DJ, Gish RG, et al. Survival after liver transplantation in patients with hepatic iron overload: the national hemochromatosis transplant registry. Gastroenterology. 2005;129:494–503. 2. Fenton H, Torbenson M, Vivekanandan P, Yeh MM, Hart J, Ferrell L. Marked iron in liver explants in the absence of major hereditary hemochromatosis gene defects: a risk factor for cardiac failure. Transplantation. 2009;87:1256–1260.
FIGURE 20. 4. 1 Perls’ iron stain. Sections of the liver showed established cirrhosis with moderate patchy hepatocellular and Kupffer cell iron accumulation.
293
Case 20.5
Iron in the Setting of Chronic Hepatitis C MICHAEL TORBENSON
C L I N I C AL I N F OR M AT I ON
A 46-year-old man was biopsied to stage and grade chronic hepatitis C. An iron stain shows mild iron accumulation. R E A S ON F OR R E F E R R A L
The referring pathologist raised the question as to the significance of the iron in this liver biopsy. PAT H OL OG I C F E AT U R E S
The biopsy showed moderate portal chronic inflammation and mild lobular activity with mild portal fibrosis on trichrome stain. Overall the histological findings were that of typical chronic hepatitis C infection. An iron stain showed mild hepatocellular iron accumulation in zone 1 hepatocytes (Figure 20.5.1).
D I AG N OS I S
Chronic hepatitis C with mild hemosiderosis.
D I SC U SSI ON
Iron deposits including both hepatocellular as well as reticuloendothelial are seen in liver biopsies of individuals with chronic hepatitis C virus (HCV), with a reported range of 5% to 48% (1–6). Overall, the median is approximately 30% for
FIGURE 20. 5. 1 Perls’ iron stain. The liver shows mild hepatocellular
iron accumulation.
these studies, and the variation presumably reflects differences in gender, viral genotypes, and the proportion of cirrhotics in the cohort. Livers with genotype 3 infection tend to have more hepatocellular iron than other genotypes (4). In the majority of cases, the iron deposits are mild, occasionally moderate, and only very rarely severe. A large body of literature has been published on the question of the significance of HFE mutations in chronic HCV. Unfortunately, despite all of the work, the literature is substantially mixed on the question of whether HFE mutations increase the risk for fibrosis progression. This current state of confusion likely reflects the many different study populations, study designs, as well as variable penetration of genetic hemochromatosis. Many studies also do not adequately control for potentially confounding variables such as gender, viral genotypes, duration of HCV infection, and so on. Nevertheless, one reasonable way to synthesize the data on HFE mutations and HCV is as follows: (1) individuals with chronic HCV do not have an increased risk for HFE mutations (1,7–9); (2) once an individual has chronic HCV infection, HFE mutations may increase the rate of fibrosis progression (10) and the presence of HFE mutations is associated with higher fibrosis stages in many (1,7–12) but not all studies (2,3). The strength of the association between HFE mutations and fibrosis has been measured by both relative risks, where a relative risk of 4.6 has been reported (9) and the odds ratio, where an odds ratio for C282Y heterozygosity has been reported ranging from 2.5 to 30 (1,7,10). Overall, C282Y alleles appear to have a stronger risk for fibrosis than H63D alleles (10). With a sufficiently long duration of chronic HCV infection, the risk of cirrhosis is high regardless of HFE mutational status, and the effect of HFE mutations may be harder to discern (10). Interestingly, for unclear reasons, HFE mutations have also been linked to increased inflammation on liver biopsy in some studies (8,9). Despite the observations linking HFE mutations to increased fibrosis and less consistently to increased inflammation, HFE mutation status has typically not been associated with increased iron deposits by histochemical analysis (3,8,9). In contrast, H63D, but not C282Y mutations, were associated with increased hepatic iron concentrations in 1 study (10). Most of the data discussed above is from studies that looked at HFE mutations. The question then naturally arises of the meaning of mild to moderate iron deposits in individuals with chronic HCV who lack HFE mutations. Unfortunately, the data are no more clear on this point and the same “take home message” as above appears to apply: most likely there is either no role or a very limited role in terms of fibrosis progression for minimal or very mild iron on a liver biopsy; for moderate iron there is likely a modest role. For marked iron accumulation, a role in fibrosis progression seems very likely even if it has not yet been specifically demonstrated.
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IRON
IN
THE
SETTING
Of note, there is only limited longitudinal data or paired biopsy studies on the role of iron in fibrosis progression, and it is hoped that future studies will permit a more accurate and nuanced understanding of the role of iron in fibrosis progression. One of the few paired biopsy studies that specifically analyzed the role for iron found no role for fibrosis progression in 214 individuals, but the time interval between biopsies was only 2.5 years, which limits the findings applicability (13).
6.
7.
8.
References 1. Gehrke SG, Stremmel W, Mathes I, Riedel HD, Bents K, Kallinowski B. Hemochromatosis and transferrin receptor gene polymorphisms in chronic hepatitis C: impact on iron status, liver injury and HCV genotype. J Mol Med. 2003;81:780–787. 2. Thorburn D, Curry G, Spooner R, et al. The role of iron and haemochromatosis gene mutations in the progression of liver disease in chronic hepatitis C. Gut. 2002;50:248–252. 3. Negro F, Samii K, Rubbia-Brandt L, et al. Hemochromatosis gene mutations in chronic hepatitis C patients with and without liver siderosis. J Med Virol. 2000;60:21–27. 4. Sebastiani G, Vario A, Ferrari A, et al. Hepatic iron, liver steatosis and viral genotypes in patients with chronic hepatitis C. J Viral Hepat. 2006;13:199–205. 5. Pirisi M, Scott CA, Avellini C, et al. Iron deposition and progression of disease in chronic hepatitis C. Role of interface hepatitis, portal
9.
10.
11.
12.
13.
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CHRONIC
H E PAT I T I S
C
295
inflammation, and HFE missense mutations. Am J Clin Pathol. 2000;113: 546–554. Valenti L, Pulixi EA, Arosio P, et al. Relative contribution of iron genes, dysmetabolism and hepatitis C virus (HCV) in the pathogenesis of altered iron regulation in HCV chronic hepatitis. Haematologica. 2007;92:1037–1042. Erhardt A, Maschner-Olberg A, Mellenthin C, et al. HFE mutations and chronic hepatitis C: H63D and C282Y heterozygosity are independent risk factors for liver fibrosis and cirrhosis. J Hepatol. 2003; 38:335–342. Martinelli AL, Franco RF, Villanova MG, et al. Are haemochromatosis mutations related to the severity of liver disease in hepatitis C virus infection? Acta Haematol. 2000;102:152–156. Geier A, Reugels M, Weiskirchen R, et al. Common heterozygous hemochromatosis gene mutations are risk factors for inflammation and fibrosis in chronic hepatitis C. Liver Int. 2004;24:285–294. Tung BY, Emond MJ, Bronner MP, Raaka SD, Cotler SJ, Kowdley KV. Hepatitis C, iron status, and disease severity: relationship with HFE mutations. Gastroenterology. 2003;124:318–326. Smith BC, Gorve J, Guzail MA, et al. Heterozygosity for hereditary hemochromatosis is associated with more fibrosis in chronic hepatitis C. Hepatology. 1998;27:1695–1699. Bonkovsky HL, Troy N, McNeal K, et al. Iron and HFE or TfR1 mutations as comorbid factors for development and progression of chronic hepatitis C. J Hepatol. 2002;37:848–854. Ryder SD, Irving WL, Jones DA, et al. Progression of hepatic fibrosis in patients with hepatitis C: a prospective repeat liver biopsy study. Gut. 2004;53:451–455.
Case 20.6
Neonatal Hemochromatosis LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
A female infant, born at term to a 30-year-old healthy mother, developed hypoglycemia on the first day of life. The baby became lethargic and bradycardic by day 3, requiring ventilatory assistance. The patient was also anemic, requiring transfusion, and received fresh frozen plasma for what was thought to be disseminated intravascular coagulopathy. The patient was also treated with ampicillin and gentamicin for possible sepsis. Abdominal ultrasound revealed ascites and reduced portal vein blood flow to the liver. Laboratory tests included markedly elevated total bilirubin at 22 mg/dL, with mild transaminase elevations. TORCH titer (toxoplasma, other infections, rubella, cytomegalovirus, herpes virus) determinations for infectious processes were unremarkable, screening tests for galactosemia and tyrosinemia were negative, and serum AAT level was normal. No maternal risks for growth or congenital abnormalities were found, and the infant had not received fructose. The patient died at 5 weeks of age, and an autopsy was performed.
acini (Figure 20.6.2). Abundant iron was diffusely present in hepatocytes (Figure 20.6.3), 4 on a scale of 0 to 4 and diffuse throughout the liver, with much less iron present in stromal or other mesenchymal cells (1). No significant inflammatory changes were present. Some multinucleate hepatocytes were present but were not a prominent finding. Bile ducts were present in portal zones. There was no fatty change or extramedullary hematopoiesis. Prominent macrophage infiltrates typical of storage or metabolic disorders were not present. Other organs demonstrated pigment in parenchymal
R E A S ON F OR R E F E R R A L
The liver showed extensive parenchymal destruction and intraparenchymal fibrosis but without nodularity, suggesting a possible inherited or metabolic disorder. PAT H OL OG I C F E AT U R E S
The liver was firm and shrunken and microscopically demonstrated a diffuse fibrosis in the parenchyma, with both sinusoidal and pericellular patterns and rare small nodule formation (Figure 20.6.1). Bile plugs were noted in cholangiolar-like structures as well as within hepatocyte rosettes/
FIGURE 20. 6. 1 Trichrome stain; liver parenchyma is severely
distorted by extensive fibrosis with limited nodule formation.
F I G U R E 2 0 . 6 . 2 Hepatocytes, mostly in small clusters, are surrounded
by extensive fibrous tissue. Cholestasis, few pigmented macrophages, and ductular reaction are present.
F I G U R E 2 0 . 6 . 3 Iron stain; iron is moderately prominent in hepatocytes but is also present in stromal cells. Small ductular structures with bile are present.
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FIGURE 20. 6. 4 Iron stain; iron is present in cardiac muscle.
cells, including the myocardium (Figure 20.6.4), exocrine and endocrine pancreas, thyroid follicular cells, bronchial glands, and gastric antral mucosal epithelial cells. The placenta was not siderotic, and the spleen showed minimal (1) iron in scattered macrophages.
D I AG N OS I S
Neonatal hemochromatosis.
H E M O C H R O M AT O S I S
297
failure, similar to what is seen in end-stage cirrhosis. (8,9). In the case of secondary iron overload with cirrhosis, the lack of hepcidin production by the severely damaged liver may result in the hepatocyte iron overload and also may shift iron from the reticuloendothelial system (macrophages) to organs and thus cause the extrahepatic iron overload (9). The differential diagnosis typically includes other inherited disorders, as the pattern of fibrosis can be similar in metabolic disorders. Since almost all inheritable metabolic disorders do not present at this early age with liver failure due to extensive fibrosis, the list is quite short. For example, in tyrosinemia, which can occasionally present early in life, the presentation is typically not earlier than 3 to 4 months of age. Galactosemia and fructosemia do not cause this kind of fibrosis until the patient has been exposed to these sugars. Zellweger syndrome (due to absence of peroxisomes) can also present in the perinatal period but typically does not show the massive liver parenchymal damage as seen here so early in the course, and instead tends to show a more neonatal hepatitis– like pattern of injury with possible ductopenia. The neonatal hepatitis–like pattern of injury has more giant cells and lacks the extensive and well-established fibrosis of neonatal hemochromatosis (see Chapter 10). Thus, overall, this change is somewhat unique for this age group in that the patient is born with advanced fibrosis and liver failure and may represent a secondary iron overload rather than primary iron-related injury.
References D I S C U S S I ON
Neonatal, or perinatal, hemochromatosis (NH) (1,2) is one of the most common causes of cirrhosis and death in the perinatal period. This entity typically presents in the first few days of life as severe liver disease manifested by ascites, hypoglycemia, hyperbilirubinemia, and/or other symptoms of liver failure. Anemia and bleeding problems are also typically present. If NH is suspected clinically, some have suggested that MRI might be helpful to demonstrate the iron in the liver and other organs (other than the spleen), such as pancreas (3,4). Early treatment with antioxidant-chelation is not very successful, so transplantation is often the treatment of choice (5,6). No inheritable defect has been demonstrated, but siblings can be affected, which suggests an inheritable or maternal link. Other inheritable or congenital associations have also been noted including Down syndrome. However, the disease in siblings may also suggest that liver injury is not due to iron but other causes like intrauterine ischemia or various forms of intrauterine hepatitis, including an alloimmune form of hepatitis (7). The iron overload may be secondary to the liver
1. Whitington PF. Fetal and infantile hemochromatosis. Hepatology. 2006;43(4):654–660. 2. Witzleben CL, Uri A. Perinatal hemochromatosis: entity or end result? Hum Pathol. 1989;20:335–340. 3. Udell IW, Barshes NR, Voloyiannis T, et al. Neonatal hemochromatosis: radiographical and histological signs. Liver Transpl. 2005;11(8): 998–1000. 4. Williams H, McKiernan P, Kelly D, Baumann U. Magnetic resonance imaging in neonatal hemochromatosis; Are we there yet? Liver Transpl. 2006;12:1725. 5. Heffron T, Pillen T, Welch D, et al. Medical and surgical treatment of neonatal hemochromatosis: single center experience. Pediatr Transplant. 2008;11(4):347–348. 6. Grabhorn E, Richter A, Burdelski M, Rogiers X, Ganschow R. Neonatal hemochromatosis: long-term experience with favorable outcome. Pediatrics. 2006;118(5):2060–2065. 7. Whitington PF. Neonatal hemochromatosis: a congenital alloimmune hepatitis. Semin Liver Dis. 2007;27(3):243–250. 8. Deugnier Y, Brissot P, Loreal O. Iron and the liver: Update 2008. J Hepatol. 2008;48:S113-S123. 9. Fenton H, Torbenson M, Vivekanandan P, Yeh MM, Hart J, Ferrell L. Marked iron accumulation in liver explants in the absence of major gene defects of hereditary hemochromatosis: a risk factor for cardiac failure. Transplantation. 2007;87:1256–1260.
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21 Wilson Disease LINDA D. FERRELL
Wilson disease (WD) is an autosomal recessive disorder that results from the accumulation of copper in various tissues due to the lack of synthesis of a membrane-associated copper transport protein. Regulation of copper balance involves the liver, with excess copper excreted in the bile and eventually in the stool. Modern diets typically contain about 1 mg/day of copper, which is about 25% more than needed; thus, about 0.25 mg/day needs to be excreted. Wilson disease patients have a defect in this excretion (1). The gene responsible for WD has been identified on chromosome 13 and designated as ATP7B. Numerous mutations in this gene have been identified, and no one mutation accounts for more than 30% of the total group of mutations; so most patients are compound heterozygotes (2). Thus, it has not proven practical to develop a DNA test for diagnosis to date. It is possible that the large number of mutations may account for some of the variability in clinical and pathological presentation. C L I N I C AL P R E S E N TAT I ON S
The patients generally present as teens or young adults and almost never before the age of 5 years. The disease may present with either hepatic disease (more frequently seen in children, young adults) or neurological symptoms (older patients). The hepatic disease may present in a variety of forms, including acute and chronic patterns (Table 21.1). Presentation with liver disease after 50 years of age is very rare (3). The fulminant pattern may be the first clinical presentation of the disease and mimics fulminant viral hepatitis. The associated severe hemolysis points toward WD. Fulminant WD can be associated with normal ceruloplasmin as the serum levels become elevated during the hepatitic flare as a “nonspecific acute phase reactant” response. Kayser-Fleischer (KF) rings tend to be found in the later stages, more typically in patients with neurological syndromes (2). In asymptomatic WD, the earliest changes include fatty change, glycogenated nuclei, and rare hepatocyte spotty necrosis (4). The acute hepatitic and fulminant forms have the
microscopic pattern of acute hepatitis of variable severity (5), with the fulminant form typically showing severe hepatocyte damage and dropout, with confluent, bridging, and/or panacinar necrosis. A variable degree of inflammatory infiltrate is typically present. This form may be the first clinical presentation of the disease, but in many cases periportal fibrosis or even a background of cirrhosis may be evident indicating previously undetected disease. Copper may be difficult to identify on sections in this form, and, if present, may be seen in macrophages rather than hepatocytes. The chronic hepatitic form usually has the features of active chronic hepatitis with interface hepatitis and variable degree of lobular inflammation and necrosis; bridging necrosis may be present (4,6). Chronic hepatitic changes may be associated with bridging fibrosis or cirrhosis and the amount of inflammatory infiltrate may vary from none to marked. Cirrhosis, when present, tends to be a macronodular, but micronodular form may also be seen, especially in the young patients with superimposed fulminant failure (7). Electron microscopy in WD shows characteristic mitochondrial changes, including variation in size and vacuolar defect in the cristae that is thought to be fairly pathognomonic for WD (5). Several recommended methods for screening for WD are available, as noted by Brewer et al.
TA B LE 21. 1 Various presentations in Wilson disease Hepatic
Acute hepatitis, chronic hepatitis, cirrhosis, liver failure
Neurological
Tremor, Parkinsonism, dysarthria, dystonia, other movement disorders
Behavioral
Loss of ability to focus on tasks, emotionality, depression, bizarre behaviors, insomnia, other behavioral disturbances
Adapted from Brewer et al (1).
299
1. Serum ceruloplasmin. This test is easy to do, and low serum ceruloplasmin will point to diagnosis in 75% of cases. However, ceruloplasmin levels can be normal in WD, particularly in the hepatitic variants, and many heterozygotes have values in low range. 2. Twenty-four–hour urine copper. This value will be less than 100 μg in symptomatic WD. A lower value in symptomatic, untreated patients typically excludes the diagnosis. However, the urine copper can be elevated in the absence of WD, if the liver disease is long-standing and has an obstructive component. 3. Quantitative copper assay on liver biopsy. This is the gold standard for diagnosis. The value is more than 200 μg/g dry weight of liver (normal 20–50 μg/g) in most cases. Patients with obstructive liver disease can have copper levels similar to those seen in WD. Heterozygotes may also show high hepatic copper but is typically not over 125 μg/g. The liver biopsy may show high copper content even when staining for copper is negative. It is thought that the copper stains only identify certain types of bound copper. 4. Slit-lamp examination for KF rings. This test is close to 100% diagnostic for patients with neurological or psychiatric symptoms but not nearly as helpful for hepatic presentations. Patients with obstructive liver disease may also develop KF rings.
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The diagnosis depends on the finding of low serum ceruloplasmin (although 5%–10% of patients may have normal ceruloplasmin, especially those with a fulminant course with hepatic necrosis as noted above), increased 24-hour urine copper, and increased hepatic copper content (greater than 200– 250 μg/g dry weight). The early diagnosis of WD is important as therapy will prevent the complications of copper overload. D I FFE R E N T I A L D I AG N OSI S
The histopathology of the various forms of WD may be indistinguishable from other causes of hepatitis or cirrhosis by light microscopy, including viral, autoimmune, and drug etiologies, but features such as fatty change, glycogenated hepatocytic nuclei, Mallory-Denk bodies in periportal hepatocytes, and moderate to marked copper deposits may help to make the diagnosis of WD. Unfortunately, triad of changes (fat, glycogenated nuclei, and Mallory-Denk bodies) are also features of steatohepatitis, and with the increase of obesity in children and young adults, there is potential to miss the diagnosis of WD. AS S E S S M E N T O F C OP P E R D E P OS I T S B Y L I GH T M I C ROSC OP Y
Copper staining may be helpful but tends to be patchy. It is typically seen in the hepatocytes but can also be present in portal macrophages and Kupffer cells. In cirrhotic livers, many nodules may have no copper, whereas it may be abundant in others. In chronic obstructive liver disease, the copper is seen in periportal hepatocytes; this pattern can usually be distinguished from that of WD. Commonly used stains for identifying copper deposits include orcein, rhodanine, rubeanic acid, and crystal violet. The intensity of copper staining by histochemical stains may not correlate with the dry weight copper results. This may be related to the patchy distribution or inability of histochemical stains to highlight all the bound or unbound hepatic copper. A N T I C O P P E R D RU G T R E AT M E N T
Several agents have been used for the treatment of WD (8). Zinc is the most recently FDA-approved drug for treatment of WD. Zinc acts by induction of intestinal cell metallothionein, which has a high affinity for copper. Once induced, it binds copper from food and endogenous secretions such as in saliva, gastric, and intestinal juices and holds it within the intestinal cell, which sloughs into the lumen of the bowel at a 6-day
DISEASE
turnover rate, taking the copper with it for excretion in the stool. Zinc thus produces a mucosal block of copper absorption. Because of the substantial secretion of copper in saliva and gastric juices, this mechanism produces a negative copper balance and produces a sustained loss of copper. A recent longterm study of zinc monotherapy demonstrated better response in patients with neurologic disease and a less satisfactory response in patients with liver disease, perhaps due to the liver dysfunction in the latter group of patients (9). Other agents are available as well (10). Penicillamine was the first orally effective drug developed as a chelator for copper, but it is more toxic than zinc therapy, and is now mostly limited to use in patients with acute, relatively severe disease when one is trying to avoid liver transplantation. Toxicity includes hypersensitivity reactions, suppression of bone marrow, proteinuria, development of autoimmune disorders such as lupus or Goodpasture syndrome, reduced immune response resulting in infections, skin disorders such as elsastosis perforans serpiginosa, and collagen disorders such as facial wrinkling. Trientine is also a chelator, and is thought to be safer than penicillamine. Tetrathiomolybdate is an anticopper agent that prevents absorption of dietary and endogenously secreted copper.
References 1. Brewer GJ, Fink JK, Hedera P. Diagnosis and treatment of Wilson’s disease. Sem Neurol. 1999;19:261–270. 2. Ferenci P. Wilson’s Disease. Clin Gastroenterol Hepatol. 2005;3(8): 726–733. 3. Ala A, Borjigin J, Rochwarger A, Schilsky M. Wilson disease in septuagenarian siblings: raising the bar for diagnosis. Hepatology. 2005;41: 668–670. 4. Stromeyer FW, Ishak KG. Histology of the liver in Wilson’s disease: a study of 34 cases. Am J Clin Pathol. 1980;73:12–24. 5. Portmann B, Thompson R, Roberts E, Paterson A. Genetic and metabolic liver disease. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 5th ed. Edinburgh, UK: Elsevier; 2007:249–254. 6. Scott J. Wilson’s disease presenting as chronic active hepatitis. Gastroenterol. 1978;74:645–651. 7. Davies SE, Williams R, Portmann B. Hepatic morphology and histochemistry of Wilson’s disease presenting as fulminant hepatic failure: a study of 11 cases. Histopath. 1989;15:385–394. 8. Aaseth J, Flaten TP, Anderson O. Hereditary iron and copper deposition: diagnostics, pathogenesis, and therapeutics. Scand J Gastroenterol. 2007;42:673–681. 9. Linn FH, Houwen RH, van Hattum J, van der Kleij S, van Erpecum KJ. Long-term exclusive zinc monotherapy in symptomatic Wilson disease: experience in 17 patients. Hepatology. 2009;50:1442–1452. 10. Brewer GJ, Askari F, Dick RB, et al. Treatment of Wilson’s disease with tetrathiomolybdate: V. Control of free copper by tetrathiomolybdate and a comparison with trientine. Transl Res. 2009;154:70–77.
Case 21.1
Fulminant Form of Wilson Disease LINDA D. FERRELL
C L I N IC AL I N F OR M AT I ON
A 19-year-old woman was referred for fulminant liver failure of unknown etiology. The patient had been well until about 2 weeks prior to her hospital admission when she first experienced vomiting, fatigue, and dark-colored urine. Over a period of several days she became more lethargic and experienced 2 seizures with loss of consciousness. Viral serologies were negative, and there was no history of toxic exposure or acetaminophen use. There were no KF rings or neurologic involvement. Studies for quantitative copper on the liver were then submitted as well, which revealed a value of 711 μg/g (normal 10–15 μg/g). The serum copper values received after her demise were 394 mg/dL (normal 75–150 mg/dL) and serum ceruloplasmin 11 mg/dL (normal 18–45 mg/dL). The patient soon developed sepsis followed by cardiac arrest and death within 24 hours of admission. R E A SON F OR R E F E R R AL
F I G U R E 2 1 . 1 . 2 Trichrome stain of liver at lower magnification shows pale zones of necrosis consistent with necrosis surrounding regenerative nodules. The darker blue areas are residual portal zones and central veins.
To determine the etiology of liver failure of unknown etiology. PAT H OL OG I C F E AT U R E S
The liver at autopsy was smaller than normal and had a grossly nodular appearance (Figure 21.1.1) mimicking cirrhosis. On microscopy, the liver parenchyma demonstrated numerous regenerative nodules with mildly thickened hepatocyte plates (Figure 21.1.2). The nodules were separated by loose connective tissue stroma admixed with prominent ductular reaction, which is likely to be ductular transformation of hepatocytes to a more duct-like phenotype due to the extensive injury. Necrosis was prominent both in central and periportal areas (Figures 21.1.3–21.1.5). Mild to moderate inflammatory infiltrates were present throughout the parenchyma and portal F I G U R E 2 1 . 1 . 3 Extensive necrosis near a larger hepatic (central) vein. Note the loose back ground tissue in the areas of hepatocyte dropout and necrosis. A small regenerative nodule is present (center) with thicker hepatic plates and acinar change and minimal fatty change. Ductular reaction is present in necrotic zones, associated with a mostly lymphocytic infiltrate and congestion. Lymphocytic infiltrates are present within the large vein consistent with a venulitis.
FIGURE 21. 1. 1 The liver has a nodular appearance secondary to regenerative changes (not cirrhosis).
areas. Trichrome stain confirmed that these ductular areas were not associated with dense scarring of established cirrhosis but instead showed the two-tone pattern of staining seen after necrosis (Figures 21.1.2, 21.1.6 and 21.1.7). In contrast, residual portal zones and central veins demonstrated intense darker
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FIGURE 21. 1. 4 Smaller hepatic (central) vein and perivenular zone
with extensive hepatocyte dropout, ductular reaction (transformation of hepatocytes to ductular pattern), mild inflammatory infiltrates, and a few residual hepatocytes with minimal fatty change.
FIGURE 21. 1. 5 Small portal zone with duct and artery containing mild mononuclear infiltrates. Surrounding areas show extensive hepatocyte dropout, with congestion and ductular reaction (transformation of hepatocytes to ductular pattern).
blue staining of established collagen fibers (Figures 21.1.6 and 21.1.7). Reticulin stain also demonstrated collapsed framework of subacute severe hepatitis rather than the more dense organized scar of cirrhosis (Figure 21.1.8). Copper stain (rubeanic acid) demonstrated patchy copper deposits, both in hepatocytes and Kupffer cells within the necrotic zones.
D I AG N OS I S
Severe hepatitis with massive necrosis, consistent with Wilson disease.
DISEASE
FIGURE 21.1.6 Trichrome stain at higher magnification demonstrates regenerative nodule on the left and extensive necrosis to the right of the residual portal zone (center). Note the two-tone staining pattern: established collagen in the portal zone is dark blue, and the necrosis is pale blue. Ductular reaction is prominent in necrotic zones.
F I G U R E 2 1 . 1 . 7 Trichrome stain demonstrates zones of previous hepatocyte necrosis and regenerative hepatocytes. Note the widened hepatic plates in the regenerative nodule (right). A residual central vein (upper center) and portal zone (lower center) are highlighted by the darker blue staining of the collagen.
DISCUSSIO N
Severe acute hepatitic presentation of WD can be confused with other more common etiologies, such as acute viral hepatitis, autoimmune hepatitis (AIH), idiosyncratic drug reactions, and idiopathic forms of acute severe hepatitis, the latter accounting for about 15% of acute hepatitis that progresses to liver failure. Although serum ceruloplasmin and copper staining were helpful in this case, serum ceruloplasmin may be elevated as an acute phase reactant, and copper stain may be negative due to extensive necrosis. The clinical observation of hemolysis can be key in alerting to the possibility of WD.
CASE
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:
FULMINANT
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DISEASE
303
A carefully done trichrome stain can help to differentiate the necrotic areas from background fibrosis, the latter evidence for previous chronic disease, a feature not seen in typical idiosyncratic drug reactions, hepatitis A, or idiopathic forms of acute hepatitis. Autoantibodies including antinuclear antibody (ANA), smooth muscle antibody (SMA), liver kidney microsomal-1 (LKM-1), and soluble liver antigen (SLA) are necessary to evaluate for AIH. A careful history is necessary to exclude unusual drug reactions, including any history of exposure to over-the-counter drugs, herbal agents, or other nutritional supplements, including ones used sporadically or that have recently been changed to a new “brand.” Travel history should be sought to exclude the possibility of hepatitis E.
FIGURE 21. 1. 8 Reticulin stain shows collapsed framework consist-
ent with acute/subacute process.
Case 21.2
Chronic Hepatitis Due to Wilson Disease LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
The patient described in Case 21.1 also had an identical twin sister, who was in a “normal state of health” at the time her twin presented with liver failure. However, after her twin’s death, the sister was also examined, was found to have mildly elevated transaminases, and liver biopsy was performed. Quantitative copper on that sample revealed a value of 812 μg/g. Serum ceruloplasmin was very low at 4 mg/dL.
interface activity (Figure 21.2.1). Fatty change of mild to moderate degree was also present, but there were no ballooned hepatocytes, significant inflammation, or centrizonal fibrosis to suggest steatohepatitis.
DIAGNO SIS
Mild chronic hepatitis, and early fibrosis (stage 1–2), consistent with early stage Wilson disease.
R E A S ON F OR R E F E R R A L
Evaluation for possible Wilson disease. PAT H OL OG I C F E AT U R E S
The twin sister’s liver biopsy showed mild chronic hepatitislike pattern with mild portal mononuclear infiltrate and mild
DISCUSSIO N
This case demonstrates the variability in presentation that can occur in WD, even in identical twins, where one would presume that the genetic defect is the same. Thus, there may be environmental factors or other modulators that influence the clinical presentation. The fatty change in this case can be mistaken for fatty liver disease (FLD); however, the patient did not have typical risk factors. Given the rising incidence of childhood obesity, however, it may become more difficult to use the clinical parameters alone to exclude FLD as etiology for fatty change, and many recommend the routine evaluation for WD using 1 or more of the recommended screening tests like serum ceruloplasmin, 24-hour urine copper, and/or quantitative copper values on liver tissue to help exclude this possibility.
FIGURE 21.2.1. Twin sister, liver biopsy. Note the mild portal hepati-
tis with interface activity and periportal fibrosis, as well as fatty change.
304
Case 21.3
Cirrhosis With Chronic Hepatitis Consistent With Wilson Disease LINDA D. FERRELL
C L I N IC A L P R E SE N TAT I ON
A 24-year-old woman presented with fatigue and was found to have elevated liver transaminases. Further workup revealed low serum ceruloplasmin and markedly elevated 24-hour urine copper, leading to diagnosis of WD. Over the next 2 years, the patient’s condition deteriorated, and it was found that she had not been compliant with her therapy for copper reduction. Transaminases at this time were elevated to 3 times normal, alkaline phosphatase 2 times normal, and bilirubin was over 30 mg/dL. She received liver transplantation. R E A SON F OR R E F E R R AL
To confirm the suspicion of WD and undergo transplantation for end-stage liver disease. PAT H OL OG I C F E AT U R E S
F I G U R E 2 1 . 3 . 2 Glycogenated nuclei can be seen in Wilson disease in any stage and were notable within hepatocytes in cirrhotic nodules in this case.
This case demonstrates end-stage cirrhosis due to WD (Figure 21.3.1). Typical features of WD are present, including copper deposits and glycogenated nuclei (Figure 21.3.2), Mallory-Denk bodies (Figures 21.3.3 and 21.3.4), and chronic inflammatory infiltrates with a chronic hepatitis pattern of injury (Figure 21.3.3). Copper stain (rubeanic acid) was focally positive in isolated nodules. Rubeanic acid stains the copper as dark green granules in hepatocytes (Figure 21.3.5).
F I G U R E 2 1 . 3 . 3 Giant (multinucleate) hepatocytes, moderate chronic inflammation, and mild focal fatty change are also present. Mallory-Denk bodies are also present (large cell bottom center).
DIAGNO SIS FIGURE 21. 3. 1 The cirrhosis of Wilson disease may have variable
amounts of inflammation and ductular reaction. Note mild degree of scattered fatty change.
305
Cirrhosis with moderate activity consistent with Wilson disease.
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F I G U R E 2 1 . 3 . 5 Rubeanic acid copper stain demonstrated patchy, focal positivity (green granules) in hepatocytes and some Kupffer cells. 21. 3. 4 Mallory-Denk bodies as darker eosinophilic, ropy, cytoplamic inclusions were present in some of the damaged hepatocytes.
FIGURE
D I SC U SSI ON
This case demonstrates chronic hepatitic form of WD with established cirrhosis and illustrates some of the helpful features of late stage WD, including the Mallory-Denk bodies and copper deposits. In this age group, other causes of chronic hepatitis such as AIH, viral hepatitis B or C, and alpha-1-antitrypsin
(AAT) deficiency should be considered. Viral and autoimmune markers, and periodic acid–Schiff diastase (PASd) and/ or immunostain for AAT can help exclude these etiologies. The pattern of portal-based inflammation with activity of this extent, in combination with the absence of ballooned hepatocytes, pericellular scarring, and clinical risk factors of metabolic syndrome or alcohol help to exclude late-stage chronic steatohepatitis.
22 Liver Transplant Pathology OYEDELE ADEYI
Although attempts to develop liver replacement regimens similar to renal dialysis in end-stage renal disease patients are ongoing, liver transplant remains the only treatment for endstage liver disease. Liver failure following chronic diseases or resulting from an acute fulminant injury are the usual indications for transplant. There are usually well-defined selection criteria that employ extensive clinical and psychosocial evaluations to confirm appropriateness of such a procedure. Most institutions have locally approved selection criteria for recruiting patients into the transplant system, often fashioned after the Milan or some other (eg, UCSF) criteria (1,2). In a field hampered by severe organ shortages, these criteria are useful for managing organ allocation and ensuring patients with measurable benefits are allocated the available resources. However, as summarized in Table 22.1, pretransplant selection is only one of several factors affecting outcome in transplanted patients (3). In broad terms other factors include operative complications, immunologic injury, infections, recurrent disease, neoplasms, and adverse reaction to medication. It is in managing the impact of these factors that the pathologist plays an important role. The scope of liver allograft pathology has recently been reviewed (4). Pathologists are called upon to guide treatment decisions by recognizing and grading the severity of the pathologic process(es), differentiating between 2 conditions requiring different therapies with potentially damaging outcome if incorrectly classified, determining the extent of injury by staging, as well as determining the rate of progression of a previously documented injury. Sometimes new diseases are identified in an allograft biopsy that call for new clinical parameters to be investigated and/or the course and type of immunosuppression to be altered. Recognizing morphologic pattern (or patterns when 2 or more processes overlap) is as important in liver allograft
biopsy as it is in the nontransplant biopsy. Interpretation of liver allograft biopsy therefore requires the understanding of nontransplant liver pathology as both involve pattern recognition, understanding of underlying clinical context, and ability to correlate morphology with clinical scenario. There are, however, certain instances that are unique to liver allografts and pose diagnostic dilemmas, especially when the contending differential diagnoses require diametrically opposing interventions, (eg, cellular rejection versus recurrent viral hepatitis). Some other sources of dilemma are: 1. Poor understanding of pathogenesis and/or natural history of a specific pattern of injury (eg, plasma-cell-rich hepatitis/zone 3 perivenulitis) 2. Defining the more prominent entity when 2 or more truly exist in the same biopsy 3. Determining the cause of cholestatic injury especially late in the graft when chronic rejection, stricture, and recurrent sclerosing cholangitis are in contention Figure 22.1 summarizes the timeline when some of the discussed problems encountered in liver transplant patients are likely to present and helps to understand the importance of overlaps. The aim of this chapter is to illustrate selected problem areas with clinical examples and suggest approaches to resolving these dilemmas. The first 2 examples are, however, not much of a dilemma but serve as the basis for understanding and discussing the subsequently illustrated problems.
TA B LE 22. 1 Factors affecting outcome in liver transplant recipients Donor factors
Recipient Factors
Management Factors
Age
Primary disease
Organ quality
Rejection episodes
Immunosuppression regimen
ABO blood group
ABO blood group
Surgery type
Cardiac death versus brain death
Immediate pretransplant clinical status, eg, fulminant failure
Surgeon
Warm and cold ischemia time
Neoplasms
Medications, eg, Interferon, Septra F I G U R E 2 2 . 1 This chart shows the timeline when the commonly encountered causes of liver allograft dysfunction are likely to emerge.
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References 1. De Carlis L, Belli LS, Romani F, et al. Selection criteria for liver transplantation: preliminary experience of Niguarda Hospital, Milan. Transplant Proc. 1989;21(1, pt 2):2415–2416. 2. Yao FY, Ferrell L, Bass NM, et al. Liver transplantation for hepatocellular carcinoma: expansion of the tumor size limits does not adversely impact survival. Hepatology. 2001;33(6):1394–1403.
PAT H O L O G Y
3. Busuttil RW, Farmer DG, Yersiz H, et al. Analysis of long-term outcomes of 3200 liver transplantations over two decades: a single-center experience. Ann Surg. 2005;241(6):905–916, discussion 916–908. 4. Adeyi O, Fischer SE, Guindi M. Liver allograft pathology: Approach to interpretation of needle biopsies with clinico-pathological correlation. J Clin Pathol. 2010;63(1):47–74.
Case 22.1
Acute Cellular Rejection OYEDELE ADEYI
4. Virtually quiescent lobule between zone 1 and zone 3 indicating that the inflammatory targets are in the portal area and hepatic vein endothelium (Figures 22.1.1 and 22.1.3).
C L I N IC AL I N F OR M AT I ON
A 52-year-old man transplanted for hepatitis C–induced endstage liver disease 2 weeks prior to biopsy. He achieved postoperative troughs of alanine aminotransferase (ALT) 35 U/L, aspartate transaminase (AST) 33 U/L, alkaline phosphatase (ALP) 115 U/L by 1 week posttransplant but now shows new rise in ALT to 97, AST 88, ALP 150; bilirubin remains unchanged.
DIAGNO SIS
Acute cellular rejection, rejection activity index (RAI) 7/9.
R E A SON F OR R E F E R R AL
Looks like rejection, but interface and parenchymal inflammation are present; is there hepatitis C as well? PAT H OL OG I C F E AT U R E S
Adequate needle biopsy shows inflammatory infiltrates restricted to portal tracts and perivenular areas of zone 3 (Figure 22.1.1). Close-up views show characteristic features of acute cellular rejection (ACR), namely: 1. Mixed infiltrates including lymphocytes (with activated/ blast forms), neutrophils, eosinophils, and few plasma cells. The infiltrates expand portal tracts and spill over into the hepatic plate that is interface activity (Figure 22.1.2) 2. Duct injury with inflammation within epithelial basement membrane (Figure 22.1.3) 3. Portal and hepatic vein phlebitis, characterized by inflammatory cells in the subendothelial space, resulting in lifting of the endothelial cells; the inflammation, though not always, but as exemplified by this case of severe rejection, has spilled into the perivenular lobule in zone 3 resulting in hepatocellular necrosis (Figure 22.1.4).
FIGURE 22. 1. 1 Acute cellular rejection low power view showing
portal and central distribution of inflammation. (H&E 20 ).
F I G U R E 2 2 . 1 . 2 Close-up view of two portal tracts from Figure 22.1 showing mixed infiltrate that includes activated lymphocytes, eosinophils, and neutrophils.
F I G U R E 2 2 . 1 . 3 Inflammation of bile duct is accompanied by evidence of duct epithelial injury, including irregular spacing and loss of polarity (H&E 200 ).
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TA BL E 2 2 . 1 . 1 Banff 1997 criteria for acute cellular rejection
in liver allografts Parameter Scored Portal inflammation (PI)
Bile duct injury/ inflammation FIGURE 22. 1. 4 Acute cellular rejection: a close-up view of one of
the terminal hepatic venules from Figure 22.1.1 shows phlebitis and perivenular inflammation; the latter results in hepatocellular necrosis around the venule and justifies a score of 3 out of 3 for phlebitis on the Banff scale (H&E 200 ). D I SC U SSI ON
This case highlights the characteristic features of ACR: it occurs within the first few weeks posttransplant, shows a steep rise in enzymes, the enzyme pattern could be hepatitic, cholestatic, or (as in this case) mixed. The histological features of duct, endothelial, and sometimes parenchymal injury help in understanding the reason for the range in the pattern of enzyme elevation and underlie the Banff scoring system for RAI used in assessing rejection severity (1). ACR is an immunologic injury implying there are specific targets in the liver. These targets are bile duct epithelium and vascular endothelium. Hence, the infiltrates, which are often mixed comprising small and activated lymphocytes, eosinophils, and neutrophils, are typically centered where these targets are located, that is portal tract and/or zone 3 around hepatic venules. When severe, portal and zone 3 infiltrates could spill into the zonal hepatocytes and should not be interpreted as hepatitis. ACR (with some exceptions discussed later) should not have significant lobular infiltrate away from the immediate vicinity of the portal tract or hepatic venule. When lobular inflammation is present, it should raise the questions of alternative or overlapping cause(s) of graft injury. Late-occurring, “atypical” cellular rejection is the exception, and this is illustrated later in this chapter. The 3 parameters graded in ACR are illustrated in Figures 22.1.1 and 22.1.4 and include portal infiltrates (PI), bile duct injury (DI), and subendothelial inflammation/endothelial injury (EI) (aka phlebitis, endotheliitis). Each of these parameters is scored using the Banff criteria summarized in Table 22.1.1
Venous phlebitis/ endothelial injury (EI)
Total (RAI)
Criteria
RAI Score
Inflammation in minority of portal tracts not expanding and mostly lymphocytic
1
Mixed lymphocytic inflammation in majority or all portal tracts, and expanding portal tracts
2
Mixed lymphocytic inflammation in majority or all portal tracts and expanding portal tracts with spillover to interface/periportal hepatocytes
3
Bile duct epithelium inflammation/mild injury in minority of portal tracts
1
PI of 2 or 3 with marked evidence of epithelial injury in few ducts
2
PI of 2 or 3 with marked evidence of epithelial injury in most ducts ⴙ/− outright duct necrosis in some ducts
3
Subendothelial lymphocytes in some but not the majority of portal and/or hepatic venules
1
Subendothelial lymphocytes in most portal and/or hepatic venules
2
EI of 2 with perivenular inflammation and hepatocellular dropout necrosis
3
Sum of scores in each of the three parameters
0–9
Abbreviation: RAI, rejection activity index.
to obtain an RAI of 0 to 3, which when added up would give a total RAI on a scale of 0 to 9. The example presented here was given a total score of 7 (PI 3 DI 1 EI 3). Few lymphocytes in the bile duct epithelium do not necessarily imply duct injury, as this is frequently seen in nonrejection-related portal inflammation including hepatitis C. Features for recognizing duct injury include inflammation as well as any or all of the following: increased nucleocytoplasmic ratio, irregular spacing in epithelium, cytoplasmic vacuolization, disordered polarity, or outright necrosis. Also, the occasional subendothelial lymphocyte could be seen outside of rejection; in ACR, subendothelial inflammation/phlebitis is characterized by endothelial lifting with or without reactive appearance to the nucleus or perivenular inflammation (Figure 22.1.4).
Reference 1. Banff schema for grading liver allograft rejection: an international consensus document. Hepatology. 1997;25(3):658–663.
Case 22.2
Recurrent Hepatitis C OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
This 57-year-old man was transplanted 17 months ago for hepatitis C–related end-stage liver disease. Baseline enzyme levels at 1 year posttransplant were ALT 33–40 U/L, AST 33 U/L, ALP 90–105 U/L, Bilirubin less than 1 mg/dL (17.1 μmol/L). In the last 3 to 6 months there has been a gradual rise in enzymes, and now enzyme levels are ALT 75, AST 69, ALP 100, and bilirubin is normal. R E A SON F OR R E F E R R AL
There is hepatitis but also some lymphocytes in the subendothelial space; is there some rejection as well? PAT H OL OG I C F E AT U R E S
Adequate biopsy shows mostly lymphocytic inflammation, but also with (very) few other cells that include neutrophils and plasma cells. The infiltrates are located mostly in the portal tracts but also patchily within the lobule, the latter associated with small foci of hepatocellular necrosis and occasional apoptoses (Figures 22.2.1 and 22.2.3). Although a portal vein shows occasional subendothelial lymphocytes, it is minimal and not associated with true phlebitis or endothelial injury.
F I G U R E 2 2 . 2 . 2 Higher magnification of one of the portal tracts in figure 22.2.1 showing predominantly lymphocytic infiltrates, and although the infiltrate extends to the subendothelium of the portal vein, the overall features do not support cellular rejection. Such changes are not infrequent in viral hepatitis, including in the non-transplant population (H&E 100 ).
FIGURE 22. 2. 1 Recurrent viral hepatitis C in a recently transplanted
F I G U R E 2 2 . 2 . 3 The lobule is mildly active as seen here, with clusters of lymphocytes and few apoptotic hepatocytes; hepatitis is mild going by the degree of lobular changes (H&E 200 ).
patient is illustrated at low magnification. There is predominantly portal inflammation but also scattered cells in the lobules (H&E 50 ).
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D I AG N OS I S
Recurrent viral hepatitis C posttransplant, mild activity; fibrosis stage 0 (Metavir); negative for ACR.
D I SC U SSI ON
This case illustrates histopathological features of recurrent viral hepatitis C posttransplant. Infection with hepatitis C virus (HCV) remains a major cause of hepatic and extrahepatic morbidity (1,2). Differentiating recurrent hepatitis C from ACR is therefore a common, and unfortunately sometimes difficult, task the pathologist is confronted with (3). In this case, however, the features despite the subendothelial lymphocytes are purely of hepatitis and consistent with recurrent HCV. Features indicative of hepatitis and not ACR are the mostly monotonous nature of infiltrates, the absence of duct epithelial or endothelial injury, and presence of lobular inflammation with single cell necrosis and apoptosis. These features are typical of HCV similar to what could be seen in the nontransplant setting, including the “passenger” lymphocytes in the subendothelial space. Occasional bile duct lymphocytes follow the same rule and are sometimes present in HCV biopsies but with no evidence of epithelial injury as described in the first case.
PAT H O L O G Y
Understanding the implication of making a diagnosis of ACR in HCV helps in forming a pathologic diagnosis. Transplant hepatologists are likely to employ steroid therapy or increase other forms of immunosuppression if the pathologist suggests there is significant ACR: an action that could be damaging to the graft (4). The features of rejection in the context of HCV patients should therefore be prominent and convincing to make it the primary diagnosis in a biopsy. In cases where ACR is being considered as overlapping with what is otherwise a hepatitic process, but in which the features suggestive of ACR are mild and less than RAI of 3, HCV should always be favored as the primary process. Nevertheless, in these cases the features indicative of coexisting (or indeterminate for) ACR should still be mentioned in the report to assist clinicians in making a decision on immunosuppression adjustment as part of recurrent HCV management.
References 1. Brown RS Jr, Gaglio PJ. Scope of worldwide hepatitis C problem. Liver Transpl. 2003;9(11):S10–S13. 2. Adeyi OA. Vascular and glomerular manifestations of viral hepatitis B and C: a review. Semin Diagn Pathol. 2009;26(2):116–121. 3. Demetris AJ, Eghtesad B, Marcos A, et al. Recurrent hepatitis C in liver allografts: prospective assessment of diagnostic accuracy, identification of pitfalls, and observations about pathogenesis. Am J Surg Pathol. 2004;28(5):658–669. 4. McCaughan GW, Zekry A. Impact of immunosuppression on immunopathogenesis of liver damage in hepatitis C virus-infected recipients following liver transplantation. Liver Transpl. 2003;9(11):S21–S27.
Case 22.3
Acute Cellular Rejection Versus Recurrent Hepatitis C OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
A 48-year-old man received a living donor liver 9 months prior due to hepatitis C cirrhosis and hepatocellular carcinoma. Since his last blood tests 5 weeks earlier, his liver enzymes have increased from ALT 65 to 112 U/L, AST 60 to 107 U/L, ALP 116 to 122 U/L, bilirubin is unchanged at 1.2 mg/dL (20.5 μmol/L). He is on cyclosporin (CyA) immunosuppression; he admitted missing “a few doses” a week ago but has not missed any since; serum level of CyA is within acceptable range. A prior biopsy performed at 6 months (ie, 3 months before the current biopsy) had shown recurrent viral hepatitis C. R E A SON F OR R E F E R R AL
There is recurrent viral hepatitis C, but this biopsy appears different from prior biopsy; is there rejection? F I G U R E 2 2 . 3 . 2 Higher magnification of Figure 22.3.1 shows
inflammation is both portal and lobular (H&E 50 ).
PAT H OL OG I C F E AT U R E S
There is a dense infiltrate on low power that at first appears limited to the portal tracts (Figure 22.3.1). Closer view, however, shows active lobular infiltrates with apoptotic hepatocytes (Figures 22.3.2 and 22.3.3). The portal infiltrate varies, being predominantly lymphocytic in some (Figure 22.3.2) and mixed in others (Figure 22.3.4) where the mixture includes activated lymphocytes and eosinophils. Duct injury and subendothelial inflammation is present (Figure 22.3.4).
F I G U R E 2 2 . 3 . 3 Active inflammation in the lobule typical of hepatitis is seen. This portion of the biopsy recapitulates the findings in an earlier biopsy in this patient (H&E 100 ).
FIGURE 22. 3. 1 Low power view shows what appears to be inflammation restricted to portal tracts in this case of co-existing cellular rejection and recurrent viral hepatitis C, but as one looks more closely (see Figures 22.3.2 and 22.3.3) lobular inflammation is also appreciated (H&E 25 ).
313
DIAGNO SIS
Acute cellular rejection superimposed on recurrent hepatitis C (coexisting ACR and HCV).
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FIGURE 22. 3. 4 Two of the portal tracts shown in Figure 22.3.1 are
illustrated showing a mixed pattern to the inflammation as well as injury to bile ducts and portal vein (H&E; upper panel 100 ; lower panel 200 ). D I SC U SSI ON
Although differentiating viral hepatitis C from ACR could be challenging in liver allograft biopsy, this case illustrates a not unusual occurrence of both entities in the same patient. Hepatitis with active lobular inflammation is usually not due to ACR, although, as illustrated later, this could occur in some late rejections. In this case, the patient had a prior
PAT H O L O G Y
biopsy documenting recurrent HCV without features of ACR. Comparing this biopsy with the previous one, there is a clear difference in that though hepatitis persists, the infiltrates in some portal tracts are heavier, more mixed, and associated with convincing duct epithelial injury. Two helpful practices in reviewing liver allograft biopsies are also highlighted by this case: one is to incorporate information gleaned from previous biopsies when available; the other is to consider the clinical scenario carefully, including the pattern of changes in liver enzymes, for example sudden and steep versus slow but persistent rise. Most ACR occur within 1 to 3 months posttransplant and rarely beyond the first year (see Figure 22.1.1 in Case 22.1). Cellular rejection beyond this period is usually (though not always) in the context of a recognizable factor, such as poor compliance and/or therapeutic dose reduction due to infections or neoplasms, such as posttransplant lymphoproliferative disease (PTLD) (1–3). The history of skipped CyA at 9 months posttransplant is therefore very important in this patient, although having resumed the serum levels were at therapeutic levels at presentation. As in nontransplant liver biopsies, pattern recognition is essential as it prompts one to recognize when 2 or more overlapping patterns coexist. When this is the case, the pathologist should try as much as possible to communicate to the clinician which entity is the more prominent. In this case, despite the risks associated with increased immunosuppression in the context of HCV, the pathologist has no choice than to communicate the obvious rejection features in this case. Because some of the portal infiltrate is clearly due to HCV, appropriately applying the Banff score could be difficult and potentially misleading. My approach is not to give a score but to have a verbal discussion with the hepatologist and give a descriptive comment on the relative significance of each lesion, that is bile duct injury; phlebitis, especially when associated with perivenular necrosis; and underlying hepatitis. In this case, both ACR and HCV are mild and communicated as such. The patient’s rejection resolved without any aggressive treatment, and he was encouraged to not “skip a few doses” again.
References 1. Wiesner RH. Advances in diagnosis, prevention, and management of hepatic allograft rejection. Clin Chem. 1994;40(11, pt 2): 2174–2185. 2. Anand AC, Hubscher SG, Gunson BK, McMaster P, Neuberger JM. Timing, significance, and prognosis of late acute liver allograft rejection. Transplantation. 1995;60(10):1098–1103. 3. D’Antiga L, Dhawan A, Portmann B, et al. Late cellular rejection in paediatric liver transplantation: aetiology and outcome. Transplantation. 2002;73(1):80–84.
Case 22.4
Late Cellular Rejection Versus Autoimmune Hepatitis Versus Recurrent Hepatitis C OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
The best way to illustrate this problem area is to present 4 patients with different background yet comparable histology. Patient I: A 62-year-old man transplanted 1 year earlier for hepatitis C cirrhosis had protocol biopsy with corresponding ALT 44 U/L; AST 52 U/L; ALP 140 U/L; normal bilirubin (Figures 22.4.1A; 22.4.2A; 22.4.3A). Patient II: A 43-year-old woman transplanted 5 years earlier for cirrhosis due to autoimmune hepatitis (AIH); her
baseline enzymes were ALT 13, AST 24, ALP 105, but these suddenly went up to ALT 288 U/L, AST 489 U/L, ALP 275 U/L, with normal bilirubin, prompting biopsy. This represents a third episode with similar presentation since transplant, each previous episode having responded well to steroid therapies (Figures 22.4.1B, 22.4.2B, and 22.4.3B). Patient III: A 19-year-old woman transplanted as a child for biliary atresia was biopsied because her ALT went up from a baseline of 33 to 261 U/L, AST from 26 to 168 U/L; ALP remained unchanged at 62 U/L (Figures 22.4.1C, 22.4.2C, and 22.4.3C).
FIGURE 22. 4. 1 Low power views of biopsies from four different patients with different background but similar histopathologic features that include hepatitic pattern of injury with portal and zone 3 accentuation of inflammation. Panels A–D, respectively, from patients I, II, III, and IV; (H&E 50 .)
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PAT H O L O G Y
v FIGURE 22. 4. 2 Higher magnification of representative portal tract from each of patients I, II, II, & IV (panels A–D, respectively) shows the infiltrate to contain many plasma cells, although to variable degree. In addition panel D from patient IV shows duct injury typical of acute cellular rejection (blue arrow), a feature not seen in panels A–C (H&E 100 ).
Patient IV: A 55-year-old man transplanted for alcohol cirrhosis 4 years earlier; he recently had immunosuppression (Tacrolimus-based) reduced because of an infection; subsequently, ALT and AST rose 2 to 3 times from his baseline of 45–52 U/L (Figures 22.4.1D, 22.4.2D, and 22.4.3D).
cell populations, are otherwise less mixed compared with typical cellular rejection discussed earlier. Only patient IV has associated bile duct epithelial injury (Figure 22.4.2D; blue arrow).
R E A S ON F OR R E F E R R A L
Biopsy in patient I was performed as a surveillance/protocol biopsy; the rest were performed to diagnose a cause for elevated liver enzymes, which had happened rather suddenly. PAT H OL OG I C F E AT U R E S
These 4 cases have hepatitic features including portal and lobular inflammation, as well as marked accentuation of inflammation around the hepatic veins and venules, resulting in perivenular hepatocellular dropout necroses. The infiltrates, although to varying degrees have significant plasma
DIAGNO SIS
For reasons discussed below, the respective diagnoses rendered were as follows: Patient I: hepatitis with zone 3 accentuation of inflammation, consistent with recurrent viral hepatitis C. Patient II: recurrent AIH. Patient III:immune-mediated injury—hepatitic/“atypical” acute cellular rejection versus de novo AIH (see comment). Patient IV: cellular rejection with hepatitic features, late occurring.
CASE
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H E PAT I T I S
317
FIGURE 22. 4. 3 The accentuation of inflammation in zone 3 around the central vein (cv) with hepatic vein phlebitis is seen in patients I–IV (panels A–D, respectively) (H&E 100 ).
D I S C U S S I ON
This area of liver allograft pathology remains a major topic for discussion, especially in more recent times. This pattern of injury has been given various names depending on the context, presumed pathogenesis, or personal preference. This appearance is similar to the features seen in AIH in the nontransplant setting, and, therefore, many experts believe this pattern has an immune-mediated basis. The fact that it has been reported as a feature of recurrent hepatitis C virus (HCV) supports its immunologically mediated nature of the injury, but also raises the problem of autoimmunity versus alloimmunity. The difficulty arising from these issues is significant for 2 main reasons: 1. What should be the right response-increased immunosuppression versus reduction in immunosuppression? 2. What is the natural history and prognosis? As illustrated in the 4 cases presented, this injury is best defined in 2 broad categories: viral hepatitis (infective) versus
nonviral hepatitis (noninfective). Whether or not the nonviral hepatitis causes represent late-onset cellular rejection, de novo, or recurrent AIH is important but not overly critical in terms of clinical intervention. Even so some experts would argue against the term “autoimmune” since there was no autoantigen in the allograft per se. It is becoming clear therefore that (at least some if not all of) these cases represent a form of rejection without significant duct injury and have been variously named hepatitic variant of ACR, plasma cell-rich ACR, late-occurring or atypical rejection with zone 3 perivenulitis, and so on. These descriptive terms highlight their differences from the typical, early occurring ACR(1,2). Apart from the morphological differences with typical ACR, these late occurring rejections are also more likely to be resistant to treatment and have a propensity to predict and/or progress to chronic rejection, fibrosis, and graft loss (2–4). The presence of these injuries in an HCV patient raises other problems that could hardly be solved on morphological grounds alone but should be presented as a possibility in
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the appropriate clinical context. For example, the biopsy from patient I was read as being consistent with recurrent HCV after correlation with viral load, the slow rise in enzymes, the timing posttransplant when recurrent HCV is the rule rather the exception, and absence of suggestive autoimmune serum markers. In summary, hepatitis with zone 3 inflammation (perivenulitis) with or without plasma-cell-rich infiltrate, with or without duct injury, tends to occur late in transplant and probably represents an “atypical” form of rejection that is likely to be relatively resistant to treatment compared with typical ACR. Current knowledge indicates progression to chronic rejection (CR) and/or significant fibrosis and therefore requires immunosuppressive treatment. Alternatively recurrent HCV could produce similar injury and should remain in contention to be supported by relevant clinical and biochemical data. A curious observation is that when these cases are due to HCV there is a tendency toward lower levels of transaminases expected for the degree of inflammation and zone 3 necrosis, as exemplified by patient I. Yet it seems that HCV-transplanted patients presenting this way have a significantly higher risk for poorer outcome
PAT H O L O G Y
(ie, death, graft loss, and fibrosis) than matched controls with more typical features of recurrent HCV (5).
References 1. Krasinskas AM, Demetris AJ, Poterucha JJ, Abraham SC. The prevalence and natural history of untreated isolated central perivenulitis in adult allograft livers. Liver Transpl. 2008;14(5):625–632. 2. Pappo O, Ramos H, Starzl TE, Fung JJ, Demetris AJ. Structural integrity and identification of causes of liver allograft dysfunction occurring more than 5 years after transplantation. Am J Surg Pathol. 1995;19(2): 192–206. 3. Fiel MI, Agarwal K, Stanca C, et al. Posttransplant plasma cell hepatitis (de novo autoimmune hepatitis) is a variant of rejection and may lead to a negative outcome in patients with hepatitis C virus. Liver Transpl. 2008;14(6):861–871. 4. Anand AC, Hubscher SG, Gunson BK, McMaster P, Neuberger JM. Timing, significance, and prognosis of late acute liver allograft rejection. Transplantation. 1995;60(10):1098–1103. 5. Ward SC, Schiano TD, Thung SN, Fiel MI. Plasma cell hepatitis in hepatitis C virus patients post-liver transplantation: case-control study showing poor outcome and predictive features in the liver explant. Liver Transpl. 2009;15(12):1826–1833.
Case 22.5
Fibrosing Cholestatic Hepatitis C Versus Biliary Obstruction Versus Adverse Reaction to Medication OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
PAT H O LO GIC FEAT UR ES
A 45-year-old man transplanted for hepatitis C (genotype 1b) cirrhosis; his best numbers posttransplant was at week 1: ALT 67 U/L, AST 47 U/L, ALP 96 U/L, bilirubin 7 mg/dL (120 μmol/L). The numbers began to rise and Septra which he was initially placed on was preemptively discontinued. However, enzyme rise continued and by the third week the following numbers were recorded: ALT 68; AST 77; ALP 189; bilirubin 14.7 mg/dL (252 μmol/L). He was biopsied because of the rising bilirubin on day 25 (Figures 22.5.1 and 22.5.2). By 20 weeks posttransplant, his liver enzyme numbers were ALT 45, AST 150, ALP and 129; 35.1 mg/dL (bilirubin 600 μmol/L), and he was rebiopsied (Figures 22.5.3 and 22.5.4).
The biopsy at the third week posttransplant (Figures 22.5.1 and 22.5.2) shows cholestasis, mild hepatocellular disarray, and swelling but otherwise preserved liver architecture with no significant inflammation or fibrosis. There are no features of biliary obstruction or duct necrosis or atrophy. However, isolated apoptotic hepatocytes are present, giving an overall nonspecific pattern of injury and raising the differential diagnoses of adverse reaction to medication (he was on Septra 1), early stages of cholestatic hepatitis C, and delayed recovery from ischemic/reperfusion injury. Septra had been withdrawn, and by the following week with worsening jaundice, antiviral therapy was commenced. Follow-up biopsy 17 weeks later (Figures 22.5.3 and 22.5.4) shows more cholestasis with centrizonal accentuation, (still) very minimal inflammation, progressive periportal and bridging fibrosis, mild ductular reaction, hepatocellular swelling and disarray, and single cell necrosis. Although there is some ductular reaction, it is not associated with other features
R E A SON F OR R E F E R R AL
Worsening jaundice despite adequate immunosuppression and negative magnetic resonance cholangiopancreatography (MRCP).
FIGURE 22. 5. 1 There is hepatocellular cholestasis 3 weeks posttransplant with no significant inflammation. Mild hepatocellular swelling is present but no fibrosis (see also Figure 22.5.2). Subsequent biopsy shown in Figures 22.5.3 and 22.5.4 showed diagnostic features of fibrosing cholestatic hepatitis (left panel: H&E 25 ; right panel: Masson’s Trichrome stain 25 ).
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FIGURE 22. 5. 2 Higher magnification of 3 weeks posttransplant biopsy showing cholestasis, absent fibrosis, hepatocellular swelling; these features had raised the possibilities of early features of cholestatic recurrent viral hepatitis C versus adverse reaction to Septra. Follow-up biopsy shown in Figures 22.5.3 and 22.5.4 showed diagnostic features of fibrosing cholestatic hepatitis (left panel: H&E 200 ; right panel: Masson’s Trichrome stain 200 ).
of biliary obstruction, namely portal edema, or increased copper accumulation (copper stain not shown), coupled with negative imaging of the biliary tree.
both hepatitis B and C patients who are immunocompromised for different reasons, including stem cell and solid organ transplantation and HIV infection (3–6). In addition to immunosuppression other clinicopathological parameters include
D I AG N OS I S
• High viral load (except in some human immunodeficiency virus [HIV] patients) • Periportal fibrosis • Swollen hepatocytes • Prominent cholestasis • Paucity of inflammation • / ductular reaction • Elevated bilirubin • Sometimes only modest elevation of transaminases • Rapidly progressive fibrosis and cholestasis to liver failure
Fibrosing cholestatic hepatitis C.
D I SC U SSI ON
Fibrosing cholestatic viral hepatitis (FCVH) was first described in 1991 by Davies et al in patients transplanted on account of chronic viral hepatitis B (2). It has since been recognized in
CASE
22.5:
POSTTRANSPLANT
C H O L E S TA S I S
WITH
OR
WITHOUT
FIBROSIS
321
FIGURE 22. 5. 3 Follow-up to the biopsy shown in Figures 22.5.1 and 22.5.2 at 20 weeks posttransplant shows typical features of fibrosing
cholestatic viral hepatitis: cholestasis, fibrosis, minimal inflammation, mild ductular proliferation, and hepatocellular swelling (left and right panels: Masson’s Trichrome stain 100 ).
All these features are identified in the illustrated case. This patient soon succumbed to liver failure, and autopsy showed fibrosis had progressed to full-blown cirrhosis, all within a span of 6 months. Stricturing/obstruction is a fairly common complication of liver transplant, and although MRCP is a very sensitive modality for diagnosing strictures, in our experience development of characteristic features seems to lag behind clinical and pathological parameters. The first biopsy showed no features of obstruction, although in the latter biopsy, periportal fibrosis and ductular reaction would ordinarily have raised some concerns. Arguing against obstruction is the low level of ALP for the degree of cholestasis and ductular reaction. Also, although imaging lags behind clinical parameters, by 5 months one would have expected there to be some features. When uncertain, a copper stain could be helpful (see Case 22.6), which was negative in this case.
The first biopsy at 3 weeks raised the usual differential diagnoses that include adverse drug reaction, particularly important in that the patient was on Septra. Septra is a commonly used prophylactic agent posttransplant. It is a known cause of cholestatic liver injury with or without ductopenia, although this complication is fortunately rare (3). The exclusion of a drug-induced liver injury in any context is a formidable challenge. The fact that this patient’s Septra was stopped in the first week posttransplant did not exclude it as the cause of cholestasis. As such the 3 weeks biopsy, though helpful in excluding biliary disease, could not have excluded Septra as the etiology, except that the modest elevation of liver enzymes would somehow be unusual. The follow-up biopsy showing rapidly progressive fibrosis and worsening cholestasis weeks after Septra withdrawal, and documented high viral load, however, point toward FCVH that failed antiviral therapy.
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FIGURE 22. 5. 4 Hematoxylin and eosin stain showing swollen hepatocytes and absent to very minimal inflammation in this case of fibrosing
cholestatic hepatitis recurrence at 20 weeks in this patient; note the absence of portal edema or other features of obstruction, which is a major consideration in the differential diagnosis (left and right panels: H&E 100 ).
References 1. Thies PW, Dull WL. Trimethoprim-sulfamethoxazole-induced cholestatic hepatitis. Inadvertent rechallenge. Arch Intern Med. 1984;144(8): 1691–1692. 2. Davies SE, Portmann BC, O’Grady JG, et al. Hepatic histological findings after transplantation for chronic hepatitis B virus infection, including a unique pattern of fibrosing cholestatic hepatitis. Hepatology. 1991; 13(1):150–157. 3. Cooksley WG, McIvor CA. Fibrosing cholestatic hepatitis and HBV after bone marrow transplantation. Biomed Pharmacother. 1995;49(3): 117–124.
4. Furuta K, Takahashi T, Aso K, Hoshino H, Sato K, Kakita A. Fibrosing cholestatic hepatitis in a liver transplant recipient with hepatitis C virus infection: a case report. Transplant Proc. 2003;35(1):389–391. 5. Rosenberg PM, Farrell JJ, Abraczinskas DR, Graeme-Cook FM, Dienstag JL, Chung RT. Rapidly progressive fibrosing cholestatic hepatitis— hepatitis C virus in HIV coinfection. Am J Gastroenterol. 2002;97(2): 478–483. 6. Suresh RL, Merican I, Chang KM, Yong SM, Purusothaman V. Cholestatic fibrosing hepatitis and hepatitis B after bone marrow transplantation. Med J Malaysia. 2001;56(4):508–511.
Case 22.6
Mechanical Biliary Obstruction Versus Chronic Rejection OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
A 46-year-old woman transplanted 13 years ago for AIH has “recently” elevated liver enzymes, although she was last followed up a year prior when her numbers were ALT 55 U/L, AST 54 U/L, ALP 161 U/L, and normal bilirubin. Her immunosuppression is deemed adequate. At the time of biopsy her liver enzymes were ALT 64, AST 70, and ALP 323, whereas serum bilirubin remained normal. Imaging studies show normal appearing liver and no evidence suggestive of obstruction. R E A SON F OR R E F E R R AL
Hepatologists think this could be chronic rejection partly because of negative imaging; biopsy shows some senescent bile ducts but it otherwise looks like obstruction; could chronic rejection be ruled out? PAT H OL OG I C F E AT U R E S
The biopsy (Figures 22.6.1–22.6.5) shows expanded portal tracts with mild inflammation, associated with ductular reaction, and increased copper at the expanded periportal areas. Routine stains show preserved and healthy-appearing ducts in most portal tracts, except in 1 or 2 portal tracts where senescent changes are seen, characterized by increased cytoplasmic eosinophilia, irregular spacing of duct epithelial cells, and distorted appearance of the duct shape (shown in Figure 22.6.5A; Figure 22.6.5B is another example of obstruction-induced senescence but in a different patient). One portal tract shows a duct with suggestive but not convincing periductal laminar fibrosis (Figure 22.6.4B).
F I G U R E 2 2 . 6 . 2 Higher magnification of one of the portal tracts in Figure 22.6.1, showing ductular proliferation in addition to portal widening (H&E 200 ).
F I G U R E 2 2 . 6 . 3 Positive rhodanine stain for periportal copper (arrows and inset) is helpful in identifying obstruction/stricture as this is typically absent in chronic rejection (rhodanine stain 100 ; inset 200 ).
DIAGNO SIS FIGURE 22. 6. 1 Low power view of a case of biliary stricture that
shows portal-centered mild inflammation with portal widening (H&E 25 ).
323
Biliary pattern changes consistent with obstruction/ stricture.
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FIGURE 22. 6. 4 Another helpful feature in distinguishing obstruction from chronic rejection is the absence of significant duct loss; as shown
here the ducts for the most parts are present and look normal (panels A&B). The laminar fibrosis in panel B is subtle at best, but when compared with a similar-sized nearby duct it is suggestive and also in keeping with the findings in the rest of the biopsy. Such findings could, however, be patchy, and its absence therefore does not rule out an obstructive process (H&E 200 ).
D I S C U S S I ON
Obstruction in liver allograft has features similar to nontransplant liver—portal expansion and edema, ductular reaction, mild, usually neutrophilic, inflammation and retention of copper in the periportal hepatocytes. These are all seen in this biopsy and support the diagnosis of biliary obstruction, despite negative imaging. Nevertheless, MRCP remains a very sensitive way of diagnosing posttransplant strictures, although its sensitivity for nonstricture- forming obstructions appears to be in the 60% range (1,2). We have seen examples of biopsies with histopathologic features of mechanical obstruction and initially negative MRCP studies but in which the obstructive nature was later confirmed either by follow-up MRCP or endoscopic retrograde cholangiopancreatography (ERCP). The suspicion for CR both clinically and histologically is reasonable, especially given the history of AIH as the primary disease 13 years posttransplant. Senescence of duct epithelial cells in majority of portal tracts and/or duct loss in at least 50% of portal tracts is the criteria for diagnosing CR (3). However, in this case only a minority of portal tracts show senescence (or atrophy) and in the context of an obstructive
process. One should bear in mind that senescent appearance could be seen in obstruction even in nontransplant patients and should therefore be interpreted with caution in the absence of significant (ie, up to 50%) ductopenia while evaluating for CR. It is important not to use senescent bile duct appearance in patients with features of obstruction as the sole criteria for diagnosing chronic rejection (4,5). In addition to not fulfilling the criteria for CR as related to the number of senescent bile ducts, the illustrated case has other features not characteristic of CR, including this degree and nature of inflammation, copper accumulation, and ductular reaction. Although ductular reaction could be seen as part of the features of CR reversal in patients treated early for CR, it is otherwise not a feature of (untreated) CR (4). The features in this biopsy therefore favor an obstruction, and follow-up studies confirmed the presence of multiple segmental (mostly intrahepatic) strictures. Many late occurring strictures are non-anastomotic, the exact pathogenesis is unclear, but are a well-documented complication of liver allografts, with reported cumulative incidence of 16% at 10 years in one large series (6).
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OBSTRUCTION
VERSUS
CHRONIC
REJECTION
325
FIGURE 22. 6. 5 Duct epithelial senescence, exemplified here in these ducts (arrows, panels A&B) with irregular epithelial spacing, loss of
polarity, nuclear atypia, and increased cytoplasmic eosinophilia should be interpreted with caution in cases with an obstructive process. In the absence of more than 50% ductopenia, epithelial senescence should not be the basis for diagnosing chronic rejection in patients with obstruction (H&E 200 ).
References 1. Aufort S, Molina E, Assenat E, et al. Value of MRCP for diagnosis of biliary complications after liver transplantation. J Radiol. 2008;89(2): 221–227. 2. Kitazono MT, Qayyum A, Yeh BM, Chard PS, Ostroff JW, Coakley FV. Magnetic resonance cholangiography of biliary strictures after liver transplantation: a prospective double-blind study. J Magn Reson Imaging. 2007;25(6):1168–1173. 3. Demetris A, Adams D, Bellamy C, et al. Update of the international banff schema for liver allograft rejection: working recommendations for
the histopathologic staging and reporting of chronic rejection. An international panel. Hepatology. 2000;31(3):792–799. 4. Demetris AJ. Distinguishing between recurrent primary sclerosing cholangitis and chronic rejection. Liver Transpl. 2006;12(11 suppl 2): S68–S72. 5. Demetris AJ, Adeyi O, Bellamy CO, et al. Liver biopsy interpretation for causes of late liver allograft dysfunction. Hepatology. 2006;44(2): 489–501. 6. Buis CI, Verdonk RC, Van der Jagt EJ, et al. Nonanastomotic biliary strictures after liver transplantation, part 1: Radiological features and risk factors for early vs. late presentation. Liver Transpl. 2007;13(5):708–718.
Case 22.7
Chronic Rejection Versus Recurrent Primary Sclerosing Cholangitis Versus Non-PSC Stricture OYEDELE ADEYI
C L I N I C AL I N F OR M AT I ON
A 36-year-old man was transplanted 27 months earlier for primary sclerosing cholangitis (PSC). This was his second graft having lost the first one to “chronic rejection and recurrent PSC” after 10 years. His retransplant ALP was always high between 260 U/L and 300 U/L. Four months prior to this biopsy, his ALT was 83 U/L, AST 62 U/L, ALP 277 U/L, and bilirubin 1.1 mg/dL (17.2 μmol/L); but these numbers gradually rose and at the time of biopsy were ALT 187, AST 206, ALP 500, bilirubin. 15.6 mg/dL (266 μmol/L). He had been on Tacrolimus-based immunosuppression with satisfactory levels, and there have been no recent changes in medication.
R E A S ON F OR R E F E R R A L
Explain reason for persistent mixed cholestatichepatitic pattern of injury; is there PSC recurrence or chronic rejection or other cause of obstruction?
PAT H OL OG I C F E AT U R E S
From Figures 22.7.1–22.7.3 similar features to those seen in the previous case can be appreciated: portal widening, ductular reaction, epithelial senescence (arrow in Figure 22.7.3), and periportal copper. The present case, however, shows more fibrosis. These features as discussed earlier favor an obstructive and stricturing process. In addition, however, there is ductopenia, albeit in less than 50% of sampled portal tracts.
DIAGNO SIS
Biliary pattern with ductular reaction, cholestasis, and ductopenia, most consistent with recurrent sclerosing cholangitis.
DISCUSSIO N
There is no evidence of an overlapping hepatitic process; the elevated transaminases in this patient are most probably due to hepatotoxicity resulting from intracellular retention of high amounts of bile salts and hydrophobic bile acid in this very cholestatic liver (1). Although it is important to correlate morphology with liver enzyme profile, certain exceptions, as in this case, should be borne in mind when elevated transaminases are not from an active hepatitic injury. The main question here is recurrent PSC versus CR, and it is not always possible to make a separation. PSC is a stricturing process and therefore produces similar findings to the previous case. However, unlike in the previous case there is higher degree of epithelial senescence and small bile duct loss albeit less than 50%, which brings CR as a valid differential diagnosis. Criteria for CR include senescence in the majority, or duct loss in greater than 50%, of portal tracts. Even if duct loss had been up to 50%, in this case it would still be difficult to diagnose CR, partly because PSC could also produce significant ductopenia, and partly because there are other features
FIGURE 22. 7. 1 Recurrent primary sclerosing cholangitis showing portal expansion and portal-centered fibrosis (left panel: H&E 25 ; right panel: Masson’s Trichrome stain 25 ).
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PSC
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FIGURE 22. 7. 2 Higher magnifications of Figure 22.7.1 in a case of primary sclerosing cholangitis (PSC) show ductular proliferation and
other features shared with non-PSC biliary obstruction earlier illustrated in Figures 22.6.1, 22.6.2 and 22.6.5 (right and left panels: Masson’s trichrome 100 ).
one would ordinarily not expect with CR. These include fibrosis, which is uncommon and usually a very late feature in CR. Also, ductular reaction or significant copper retention would be unusual findings in CR (2). CR is best viewed as a “serious problem with little noise.” In addition to the duct findings, other features to look for in CR include perivenular fibrosis, minimal to mild lymphoplasmacytic portal inflammation (unlike that mixed with neutrophils in PSC/strictures), and (hardly seen in needle biopsy, but when available) hepatic arterial intimal foam cell accumulation with or without concentric fibrointimal hyperplasia (2). In needle biopsies, employing cytokeratin 7 (CK7) immunostain to support routine stain findings should be considered. CK7 could often add new information, especially in cases where there is a question as to the exact degree of duct loss, in which case it might outline hitherto difficult to appreciate small portal tracts with absent ducts. Figure 22.7.4 compares the expected CK7 findings in this case of recurrent PSC with a biopsy from another patient with CR. Lastly most patients with CR have documented
prior episodes of ACR, suboptimum immunosuppression, or other clinical indicators in favor of an immunologic injury. In the case described, immunosuppression had been closely monitored especially in view of the patient’s prior history. Figure 22.7.5 is presented from a CR patient to further highlight important differences from PSC. A more challenging situation is trying to differentiate PSC from non-anastomotic strictures of other causes. The overlapping features between this and the previous case highlight why this differentiation would be a challenge. Generally speaking, “de novo” PSC though reported (3), is at best extremely rare to be practically nonexistent. Therefore, multiple stricturing occurring in a patient transplanted for non-PSC cause could hardly be regarded as PSC. Also, although some degree of ductopenia is possible in mechanical obstruction as in non-PSC strictures, they are less likely to be to the degree one would expect in PSC or CR. In summary differentiating PSC from CR is possible with careful evaluation for the features here discussed and
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FIGURE 22. 7. 3 Same case of PSC as in earlier figure shows bile duct epithelial senescence (left panel: H&E 100 ; right panel: H&E 200 ).
FIGURE 22. 7. 4 Cytokeratin 7 (CK7) staining pattern in the primary sclerosing cholangitis (PSC; left panel) shows prominent ductular proliferation with no visible duct. The right panel compares the CK7 pattern in a chronic rejection (CR) patient, where a very atrophic/ senescent duct is seen but not associated with ductular proliferation. CR characteristically lacks ductular proliferation, unless in the recovery phase (CK7 immunohistochemistry 100 ).
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REJECTION
VERSUS
RECURRENT
PSC
329
FIGURE 22. 7. 5 An example of chronic rejection (CR) is presented with features that help distinguish it from the obstructive/stricturing fea-
tures of PSC. As shown, CR features include duct loss, minimal fibrosis, absent ductular proliferation, negative rhodanine satin for copper, and (when available) graft arteriopathy including intimal thickening and accumulation of foamy macrophages (A and D, H&E 100 ; B, Masson’s Trichrome stain 100 ; C, rhodanine stain 100 ).
previously published (2). However, until new insights into the pathogenesis of late non-anastomotic strictures emerge, recurrent PSC should only be considered in patients with PSC as the original disease, and alternative cause(s) for strictures in other patients should be investigated.
References 1. Attili AF, Angelico M, Cantafora A, Alvaro D, Capocaccia L. Bile acidinduced liver toxicity: relation to the hydrophobic-hydrophilic balance of bile acids. Med Hypotheses. 1986;19(1):57–69.
2. Demetris AJ. Distinguishing between recurrent primary sclerosing cholangitis and chronic rejection. Liver Transpl. 2006;12(11 suppl 2): S68–S72. 3. McPartland KJ, Lewis WD, Gordon FD, et al. Post-liver transplant cholestatic disorder with biliary strictures: de novo versus recurrent primary sclerosing cholangitis. Pathol Int. 2009;59(5):312–316.
Case 22.8
Zone 3 (Centrilobular) Necrosis OYEDELE ADEYI
C L I N I C AL I N F OR M AT I ON
The cases of three patients are presented here to discuss this problem. Patient I: A 67-year-old man transplanted 8 months earlier for end-stage liver disease due to chronic hepatitis B. He was biopsied as a result of recent elevation of liver enzymes. He has had on and off problems with rejection, but his baseline prior to recent rise in enzymes was ALT 98 U/L, AST 56 U/L, and ALP 97 U/L; at the time of biopsy these were ALT 306, AST 184, and ALP 262.
Patient II: A 48-year-old man was transplanted 2 weeks prior to this biopsy for hepatitis B cirrhosis complicated by hepatocellular carcinoma. His transaminases very slowly reached a nadir of ALT 89 U/L and AST 43 U/L on day 9. The ALP, however, which was initially 71 U/L began to rise earlier than the ALT and AST. By day 14 posttransplant, the ALT was 1401 U/L, AST 3029 U/L, ALP 445 U/L, and total bilirubin 14 mg/dL (241 μmol/L). Due to worsening liver function, he was imaged and taken back to the operating room for exploration, at which time a biopsy was also performed.
FIGURE 22. 8. 1 Zone 3 necrosis around central veins (cv) in a patient recently treated for severe acute cellular rejection. The inflammatory
infiltrates previously documented (see Figure 22.8.2) have disappeared from zone 3 and portal tracts (pv) following treatment, but the resulting zone 3 necrosis is yet to heal (upper panels: 50 ; lower panels: 100 ; upper right panel: Masson’s Trichrome stain; others: H&E).
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3
(CENTRILOBULAR)
Patient III: A 54-year-old woman transplanted for primary biliary cirrhosis and developed biliary complications which kept her ALP high and for which she was stented. Her baseline liver enzymes were ALT 32 U/L, AST 29 U/L, ALP 924 U/L, and total bilirubin 1.3 mg/dL (23 μmol/L). However, by 15 weeks posttransplant, the ALT was 51, AST 64, ALP 841, and bilirubin 1.0 mg/dL (17.1 μmol/L). Repeated imaging showed normal liver with draining stent. A biopsy was performed. R E A SON F OR R E F E R R AL
Patient I: This patient has been treated for rejection, but his enzymes have not normalized; is there something else going on? Patient II: There is poor flow through the parenchyma with hepatic artery thrombus; assess for extent of liver damage. Patient III: Rule out rejection or other cause for slowly rising transaminases.
NECROSIS
331
PAT H O LO GIC FEAT UR ES
Patient I: Sections of needle biopsy (Figure 22.8.1) show a core with preserved architecture, and little inflammation, limited to occasional portal tracts. There is, however, significant necrosis around central veins (cv). Duct injury or phlebitis to suggest active rejection is not appreciated. The explanation for zone 3 necrosis becomes apparent after reviewing the most recent previous biopsy, obtained a week earlier, and after 2 days steroid bolus for presumed acute cellular rejection. The prior biopsy (Figure 22.8.2) shows features of severe acute cellular rejection (even after 2 days of steroid boluses). The degree of hepatic vein phlebitis with perivenular hepatocyte necrosis is severe justifying the maximum score on the Banff scale as described earlier in Case 22.1 and summarized in Table 22.1.1, Case 22.1. After steroids, this patient was further treated more aggressively for “steroid-resistant” rejection before the biopsy illustrated in Figure 22.8.1, with the result
FIGURE 22. 8. 2 Severe acute cellular rejection with zone 3 inflammation and necrosis were present in the pre-treatment biopsy preceding the one illustrated in Figure 22.8.1. Abbreviations: cv, central vein; pv, portal vein. (H&E; upper left panel 50 ; other panels 100 .)
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that the cellular infiltrate cleared but the necrosis was yet to heal/resolve.
DIAGNO SIS
Patient II: The wedge biopsy shown in Figure 22.8.3 shows geographic necrosis that appears to be bridging zone 3 (cv) areas in the left panel; the periportal areas are less necrotic. Higher magnifications in the right panels show some hemorrhage in addition to necrosis but no significant inflammation, sinusoidal dilatation, or fibrosis.
Patient I: Residual perivenular (zone 3) necrosis due to recent severe acute cellular rejection. Patient II: Severe ischemic necrosis secondary to hepatic artery thrombosis. Patient III: Zone 3 sinusoidal congestion and perivenular hepatocyte dropout consistent with outflow problems.
Patient III: Sections highlighted in Figure 22.8.4 show preserved alternation between portal (pv) and central (cv) veins with no fibrosis in the trichrome stain at the right lower panel. However, sinusoidal dilatation in zone 3 (cv) areas as well as perivenular hepatocellular necrosis are identified. Away from the central veins toward portal tracts, the sinusoidal dilatation and necrosis decrease.
DISCUSSIO N
The differential diagnosis of zone 3 necrosis is the same as in the nontransplant liver and includes ischemia/shock, drug toxicity (especially acetaminophen), outflow obstruction
FIGURE 22. 8. 3 Severe necrosis centered on zone 3 (central vein [cv]) with relative preservation of zone 1/periportal hepatocytes (portal vein [pv]). The necrosis is extensive in this patient with hepatic artery thrombosis (left and right upper panels: H&E; right lower panel: Masson’s Trichrome stain 100 ).
CASE
22.8:
ZONE
3
(CENTRILOBULAR)
NECROSIS
333
FIGURE 22. 8. 4 Zone 3 (central veins [cv]) necrosis, congestion, and sinusoidal dilatation is seen in this example of outflow obstruction posttransplant. These features are absent or minimal in zone 1 areas (portal veins [pv]) (left panels and right upper panel: H&E; right lower panel: Masson’s Trichrome stain; left panels: 25 ; right panels: 50 ).
(including cardiac causes), and alcohol-induced acute liver injury. In addition, however, (as summarized in Table 22.8.1), severe cellular rejection (typical and atypical forms) and preservation and reperfusion injury, both of which are not relevant in the native liver, should be considered when reviewing liver allograft biopsies with zone 3 necrosis. Although certain histologic parameters could point to a likely cause for zone 3/perivenular necrosis, knowledge of the clinical context including timing of event relative to transplant date, imaging results, recent therapeutic intervention, and, when available, review of previous biopsies are important in the evaluation of these biopsies. This way necrosis from a recent rejection (or other process) could be easily placed in the right context. Causes of ischemic-type necrosis posttransplant include thrombosis, outflow obstruction, preservation injury (comprising of “down-time,” and the cold and warm ischemic periods);
TA BL E 2 2 . 8 . 1 Causes of zone 3 necrosis in liver allografts Ischemia (including hepatic artery thrombosis, shock, for example, from sepsis or hypovolemia) Transport/preservation (ischemic) injury Reperfusion injury Outflow obstruction Severe acute cellular rejection Hepatitis with central perivenulitis Possible but rarely encountered: Drug or other toxic injury Alcohol
reperfusion injury, ironically caused by the re-establishment of vascular flow modulated by the release of reactive free radicals and pro-inflammatory cytokines (1,2); and ischemia resulting from poor vascular flow (either reduced flow into, or
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FIGURE 22.8.5 Zone 3 necrosis from preservation/reperfusion injury is milder than that seen in Figure 22.8.3, but the injured hepatocytes have
released fat into the sinusoids where they are partly engulfed by Kupffer cells (arrows). Lipopeliosis occurs in steatotic donor liver and could further comprise graft recovery (left panels: H&E; right panels: Masson’s Trichrome stain. Left upper panel 25 ; others 50 ).
obstructed flow out of, the graft). Ischemic and (as in acetaminophen toxicity) free-radical-induced liver injuries have a more pronounced effect on zone 3 hepatocytes due to metabolic zonation (3,4), and underlie the reasons for zone 3 predisposition to these injuries. The case of patient II is an example of a severe case of hepatic artery thrombosis. Hepatic artery thrombosis (HAT) could be early or late, although the outcome seems to be better in terms of graft loss in late than early cases. HAT remains a serious complication of liver transplant (5). The true incidence is uncertain, but overall it would seem to be less than 10% (probably approximately 4% in adults and 8% in children) (5). The definition of what should constitute early HAT also varies, but most cases occurred within the first few posttransplant days to weeks. The pathologist’s involvement in these cases is likely to be in reviewing intraoperative wedge biopsies (as in this illustration), or reviewing of failed graft, but occasional cases could also come as needle biopsy especially when Doppler evaluations have been inconclusive. Because bile ducts remain
absolutely dependent on hepatic arterial flow, ischemic duct injury is often a major issue; and in milder cases of HAT, parenchymal injury could be absent, the only findings being those of ischemic “cholangitis” associated with elevated ALP. However, in more catastrophic cases, differential enzyme rise is not always apparent. The features of ischemic necrosis are the same in the native and allograft liver and include zone 3 hepatocellular necrosis with or without hemorrhage. Sinusoidal dilatation seen in outflow obstruction cases are absent in ischemia. An important differential diagnosis is acetaminophen toxicity, but, fortunately, this complication is rare in the transplant population. Another differential diagnosis is severe rejection. Zone 3 necrosis with associated inflammation should raise the possibility of rejection or other entities discussed earlier in Case 22.4. A potential problem, however, arises when ischemic injury predisposes the graft to, or otherwise coexists with, cellular rejection, in which case the pathology review should be performed in the context of underlying clinical and radiologic factors, in order not to miss
CASE
22.8:
ZONE
3
(CENTRILOBULAR)
NECROSIS
335
FIGURE 22.8.6 Zone 3 injury without outright necrosis, characterized by hepatocellular swelling and intracellular cholestasis is seen in this example of preservation/reperfusion injury (left panels: H&E; right panels: Masson’s Trichrome stain; upper panels: 25 ; lower panels: 50 ).
the opportunity to flag the ischemia problem while emphasizing rejection. A useful clue is to weigh the severity of necrosis with the degree of inflammation in patients not yet treated for rejection. A significant problem could result when a patient had been treated for rejection before biopsy (the case of patient I), and in these cases matching the degree of inflammation with necrosis could be potentially misleading. Preservation and reperfusion injury (PRI) is not illustrated but is another differential diagnosis of hepatic artery thrombosis. PRI-induced zone 3 necrosis is usually (and fortunately) not as severe as the illustrated HAT case. The necrosis tends to be less pronounced and hardly bridging to produce the geographic pattern seen here. Figure 22.8.5 shows an example of a patient with reperfusion injury, as well as some other problems that could be associated. This is a patient who received cadaveric liver; the liver enzymes were observed to be unsatisfactorily creeping very slowly toward normalization prompting a biopsy. The zonal necrosis is less severe than in the patient with hepatic artery thrombosis, but the dead hepatocytes also
appear to have been steatotic, such that released fat was left freely floating in the sinusoids or within sinusoidal Kupffer cells (black arrows); hence, the term lipopeliosis. Lipopeliosis could further hamper the rate of recovery from reperfusion/preservation injury and should always be part of the pathology report whenever present. Also, some biopsies with preservation/reperfusion injury could show only subtle changes such as zone 3 hepatocellular swelling with or without cholestasis but no outright necrosis, as illustrated in Figure 22.8.6. In these cases, it is important to consider intra-abdominal or systemic sepsis and (again) drug reaction on the differential diagnosis list. Lastly outflow obstruction remains a major, although no longer frequent, posttransplant complication. The third illustrated case exemplifies this. Following this biopsy, additional imaging revealed a hepatic vein blockage hitherto undetected and was subsequently fixed. The absence of characteristic radiologic findings of hepatic vein blockage should not deter one from flagging a biopsy with features such as seen in this case and discussed in more detail in Case 22.10.
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References 1. Carden DL, Granger DN. Pathophysiology of ischaemia-reperfusion injury. J Pathol. 2000;190(3):255–266. 2. Teoh NC, Farrell GC. Hepatic ischemia reperfusion injury: pathogenic mechanisms and basis for hepatoprotection. J Gastroenterol Hepatol. 2003;18(8):891–902. 3. Sastre J, Rodriguez JV, Pallardo FV, et al. Effect of aging on metabolic zonation in rat liver: acinar distribution of GSH metabolism. Mech Ageing Dev. 1992;62(2):181–190.
PAT H O L O G Y
4. Gebhardt R. Metabolic zonation of the liver: regulation and implications for liver function. Pharmacol Ther. 1992;53(3):275–354. 5. Bekker J, Ploem S, de Jong KP. Early hepatic artery thrombosis after liver transplantation: a systematic review of the incidence, outcome and risk factors. Am J Transplant. 2009;9(4):746–757.
Case 22.9
Cytomegalovirus Hepatitis OYEDELE ADEYI
C L I N IC AL I N F OR M AT I ON
PAT H O LO GIC FEAT UR ES
A 42-year-old woman was transplanted 7 months prior to biopsy for fulminant hepatitic failure. Despite adequate Tacrolimus-based immunosuppression, her liver enzymes continued to rise; at the time of biopsy these were ALT 65 U/L, AST 313 U/L, and ALP 271 U/L.
Sections (Figures 22.9.1 and 22.9.2) show liver tissue with preserved architecture and only minimal lymphocytic inflammation limited to 1 or 2 portal tracts. Higher magnification shows preserved ducts and absence of phlebitis or other features of cellular rejection. However, in the sinusoid and in at least 1 portal vein endothelium, large cells with nonclassic but suggestive nuclear 6 cytoplasmic inclusions of the cytomegalovirus (CMV) type are observed. Also seen are few foci of small aggregates of neutrophils (neutrophilic microabscess— blue arrow in Figure 22.9.2). Ancillary immunohistochemistry
R E A SON F OR R E F E R R AL
Patient is adequately immunosuppressed but could there still be rejection?
FIGURE 22. 9. 1 Cytomegalovirus hepatitis in a liver allograft biopsy shows large cells with nuclear and cytoplasmic inclusions in sinusoidal and portal vein endothelia (black arrows). Note minimal portal inflammation a small cluster of lobular neutrophils (blue arrow) (all panels: H&E; left upper panel, 12.5 ; left lower panel, 25 ; right upper and lower panels, 50 ).
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FIGURE 22. 9. 2 Cytomegalovirus (CMV) hepatitis showing more sinusoidal cells with nuclear and cytoplasmic inclusions in the upper panels (arrows); the lower panels are immunohistochemistry stains for CMV in which occasional normal-sized cells also contain viral particles (upper panels: H&E, 50 ; lower panels: CMV immunohistochemistry, 25 ).
confirms CMV in many cells (sinusoidal, portal vein endothelium, and occasional hepatocytes).
D I AG N OS I S
Cytomegalovirus hepatitis. D I SC U SSI ON
Although the overall incidence appears to be falling compared with the earlier days of solid organ transplant, probably because of new immunosuppressives, antigenic monitoring, and use of prophylaxis or pre-emptive treatment by some programs, CMV infection nevertheless remains an important complication of organ transplantation. In liver transplant patients who received no prophylactic treatment, this complication when it occurs is usually in the first 3 months posttransplant, peaking at 4 weeks (1). It could, however, occur later after
discontinuation of treatment or as a de novo infection. CMV infection could be organ-specific or systemic, but the liver is the most commonly involved organ in liver transplant patients (2). Cholestatic enzyme elevation is characteristic, although the pattern could be mixed with significant transaminase elevation. Risk factors for developing posttransplant CMV hepatitis include seropositive donor and/or recipient; induction with lymphocyte depleting agents; mycophenolate-based immunosuppression; retransplantation; fulminant hepatic failure as the primary disease, hepatic artery thrombosis, and hepatitis C infection (1). Diagnosis employs blood sampling for antigenemia assays, nucleic acid amplification, or Hybrid Capture CMV DNA Assay, and liver biopsy. Liver biopsy depends on the identification of infected cells that are large (cytomegaly) and show characteristic cytoplasmic and nuclear inclusions of the Cowdry type A. It is important to note that because of the patients’ immunosuppressive states, inflammatory response could be modest or completely absent. Also, expecting “classic” inclusions seen in
CASE
22.9:
CYTOMEGALOVIRUS
pathology atlases could make for false negativity. The illustrated case shows few big cells but none could really be described as “classic” in the regular sense, and as shown by immunohistochemistry few cells also harbor the viral material without cytomegaly or demonstrable inclusions. Immunohistochemical and/or in situ hybridization methods are frequently helpful, being more sensitive and specific than routine histology, and it is possible to demonstrate nuclear staining in normal size cells by these special methods. In immunosuppressed patients with unexplained elevation of liver enzymes, ancillary staining for CMV should always be considered, even in the absence of characteristic inclusions and/or significant inflammation on routine stains. The illustrated patient had at least 3 risk factors including positive donor serology, fulminant hepatitis as the
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original disease, and exposure to immunosuppressive therapy. Although CMV hepatitis could be successfully treated the virus cannot be eliminated, and there is a risk for recurrence, overall reduced patient survival, biliary complications, and increased risk for acute and chronic rejections (1,3).
References 1. Sampathkumar P, Paya CV. Management of cytomegalovirus infection after liver transplantation. Liver Transpl. 2000;6(2):144–156. 2. Paya CV, Hermans PE, Wiesner RH, et al. Cytomegalovirus hepatitis in liver transplantation: prospective analysis of 93 consecutive orthotopic liver transplantations. J Infect Dis. 1989;160(5):752–758. 3. Razonable RR. Cytomegalovirus infection after liver transplantation: current concepts and challenges. World J Gastroenterol. 2008;14(31): 4849–4860.
Case 22.10
Graft Versus Host Disease OYEDELE ADEYI
C L I N I C AL I N F OR M AT I ON
R EA SO N FO R R EFER R A L
A 51-year-old man had nonmyeloablative stem cell transplant for chronic lymphocytic leukemia (CLL) after failing multiple cycles of chemotherapy. The graft failed at 3 months, and he was given donor leukocytes infusion. The following weeks, however, witnessed progressive rise in liver enzymes and worsening skin rash. Liver and skin biopsies were performed at a time when ALP was 808 U/L, AST 114 U/L, ALT 606, and total bilirubin of 17.2 mg/dL (294 μmol/L).
Increasing liver enzymes of mixed pattern: rule out graft versus host disease versus drug reaction or infiltrative disease. PAT H O LO GIC FEAT UR ES
The biopsy shows an adequate core of liver tissue with preserved architecture and very minimal portal lymphocytes (Figure 2.10.1). The only positive findings are absence of
F I G U R E 2 2 . 1 0 . 1 Chronic graft versus host disease in a patient who received bone marrow transplantation a little more than
3 months earlier. Liver biopsy shows minimal portal and no lobular inflammation, as well as absent bile ducts in the portal tracts (left panels: H&E; right panels: CK7 immunohistochemistry; left upper panel: 12.5 ; right upper and left lower panels: 25 ; right lower panel: 50 ).
340
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interlobular bile ducts in all but 1 of 11 sampled portal tracts and cholestasis. The absent bile ducts are further confirmed on deeper levels that include CK7 stain (Figure 22.10.1, right panels).
D I AG N OS I S
Consistent with chronic graft versus host disease (GVHD).
D I S C U S S I ON
GVHD affecting the liver is not an issue in liver transplant recipients. GVHD is a major consideration in bone marrow (BMT)/stem cell (SCT) transplant and small bowel transplant recipients, although it has been reported as rare events in other solid organ transplants including liver allograft recipients (1–3).
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341
The liver pathologist’s role mirrors what it is in other aspects of liver pathology: diagnose GVHD and confirm or exclude other pathological process(es) that could be responsible for abnormal liver enzyme. It is important to note that because BMT/SCT patients are on multiple medications including antibiotics, the diagnosis of (chronic) GVHD in this context should only be made definitively in the context of supporting clinical parameters (eg, extrahepatic features of GVHD, absence of potential drug etiology). This is necessary because the histopathological hallmarks of GVHD could be mirrored by some medications especially antimicrobials like the macrolide antibiotics, Bactrim® (Septra®), and some antifungals, among several others that BMT/SCT patients are almost as a rule exposed to (4–7). GVHD is either acute or chronic, depending on the timing posttransplant, 3 months being the commonly quoted timeline. Histologically acute GVHD shows more portal infiltrate and evidence of duct injury by infiltrating lymphocytes.
FIGURE 22. 10. 2 Chronic graft versus host disease in a patient who received bone marrow transplantation a little more than 3 months earlier. Liver biopsy shows no inflammation but significant cholestasis with a small focus of bile infarct (arrow) (all panels: H&E; left panels: 25 ; right panels: 50 ).
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Chronic GVHD occurs more than 3 months posttransplant, represents a different disease rather than progression of acute GVHD, and is characterized by no significant or very minimal infiltrate but significant loss of small bile ducts, (vanishing ducts), which is essentially “chronic ductopenic rejection in the native liver.” The illustrated case therefore, by virtue of timing and histopathological parameters is consistent with chronic GVHD. At the time of biopsy, this patient was also on fluconazole and vancomycin and other drugs with no known concern for hepatotoxicity. fluconazole could potentially produce hepatotoxicity, but the reported incidence is low (compared with other azoles in clinical use). Also, the concurrent skin biopsy showed features compatible with GVHD, such that the best interpretation in this context was chronic GVHD. An explanation for the ALT of 606 U/L was not immediately apparent, although it is likely due to secondary hepatocellular injury with focal bile infarcts from severe cholestasis, shown in Figure 22.10.2 (8).
References 1. Barton-Burke M, Dwinell DM, Kafkas L, et al. Graft-versus-host disease: a complex long-term side effect of hematopoietic stem cell transplant. Oncology (Williston Park). 2008;22(11 suppl Nurse Ed):31–45.
PAT H O L O G Y
2. Abu-Elmagd K, Bond G. The current status and future outlook of intestinal transplantation. Minerva Chir. 2002;57(5):543–560. 3. Kohler S, Pascher A, Junge G, et al. Graft versus host disease after liver transplantation—a single center experience and review of literature. Transpl Int. 2008;21(5):441–451. 4. Rosenberg PM, Farrell JJ, Abraczinskas DR, Graeme-Cook FM, Dienstag JL, Chung RT. Rapidly progressive fibrosing cholestatic hepatitis—hepatitis C virus in HIV coinfection. Am J Gastroenterol. 2002;97(2):478–483. 5. Adriaenssens B, Roskams T, Steger P, Van Steenbergen W. Hepatotoxicity related to itraconazole: report of three cases. Acta Clin Belg. 2001;56(6):364–369. 6. Altraif I, Lilly L, Wanless IR, Heathcote J. Cholestatic liver disease with ductopenia (vanishing bile duct syndrome) after administration of clindamycin and trimethoprim-sulfamethoxazole. Am J Gastroenterol. 1994;89(8):1230–1234. 7. Ramachandran R, Kakar S. Histological patterns in drug-induced liver disease. J Clin Pathol. 2009;62(6):481–492. 8. Attili AF, Angelico M, Cantafora A, Alvaro D, Capocaccia L. Bile acidinduced liver toxicity: relation to the hydrophobic-hydrophilic balance of bile acids. Med Hypotheses. 1986;19(1):57–69.
23 Benign Hepatocellular Lesions VALÉRIE PARADIS
I N T ROD U C T I ON
Benign hepatocellular lesions encompass 2 distinct groups of hepatocellular proliferations (focal nodular hyperplasias [FNH] and hepatocellular adenomas [HCA]) in terms of pathogenesis, clinical presentation, and behavior. Both groups of lesions are mostly observed in young women with normal liver, usually in the context of oral contraception (OC). Pathological diagnosis of benign hepatocellular proliferations has become more and more challenging for several reasons: (1) the increased detection of asymptomatic liver tumors by extensive use of abdominal imaging, (2) the necessity to obtain accurate diagnosis for subsequent adequate management, and (3) the requirement for tumor biopsy, especially in atypical lesions on imaging. FO C A L N OD U L A R H Y P E R P L A S I A
FNH accounts for the second most common benign liver process, following hemangioma. It is predominantly diagnosed in women of 30 to 50 years of age, not influenced by OC (1–3). FNH is considered as a hyperplastic focal reaction resulting from an arterial malformation (4). This hypothesis that suggests increased arterial blood flow hyperperfuses the local liver parenchyma, leading to secondary hepatocellular hyperplasia, has been reinforced by molecular data showing that FNH are polyclonal regenerative processes (5,6). The vast majority of FNH are asymptomatic and discovered incidentally during liver ultrasound examination. In addition, complications of FNH, such as rupture or bleeding, are exceptional, and no evidence of malignant transformation has been reported so far. Histologic Patterns
In most cases, FNH displays a typical morphological pattern for both radiologists and pathologists. Grossly, FNH is a well-circumscribed, unencapsulated, usually solitary mass, characterized by a central fibrous scar that radiates into the liver parenchyma. Histologically, FNH is composed of benignappearing hepatocytes arranged in nodules that are partly or completely delineated by fibrous septa originating from the central scar. In the fibrous septa, large and dystrophic vessels are observed, associated with ductular reaction and inflammatory cells in varied intensity. The hepatocytes are hyperplastic, arranged in liver plates of normal or slightly increased thickness with a well-preserved reticulin framework. Hepatocytes may be hydropic, related to cholestatic changes. Steatosis, usually of mild intensity, may also be observed. Besides the classic FNH, several variants are described with increased frequency, usually “atypical” on imaging, potentially leading to misdiagnosis. These variants include FNH without central fibrous scar, FNH with prominent steatosis,
and heterogeneous lesions displaying telangiectatic or adenomatous changes (7). On histological examination, FNH without macroscopic central fibrous scar is usually of small size and exhibits all the pathological features of classic FNH but with few, thin and short fibrous septa. Pathological diagnosis of FNH, even in its classic form, may be difficult on biopsy specimen where fibrous septa and thick abnormal arteries are usually missing (8). In addition to the presence of ductular reaction at the border between fibrous septa and hepatocellular component, immunostaining with glutamine synthetase showing focal positive hepatocellular areas usually centered around by hepatic veins, described as a map-like pattern, is highly consistent with the diagnosis of FNH (8,9). Given that FNH are regenerative lesions with only rare occurrence of complications, in cases of a definitive diagnosis, no follow-up or treatment for asymptomatic FNH is required, no matter the size and the number of lesions. However, surgical resection is indicated in doubtful or symptomatic cases, such as large FNH located in the left liver and pedunculated lesions. H EPATO CELLULA R A DENO MA S
HCA is a rare, benign liver neoplasm strongly associated with OC use in females and androgen steroid therapy in males (10,11). Its incidence is estimated to be 0.1 per year per 100 000 in non-OC users, and reaches 3 to 4 per 100 000 in long-term OC users (12). HCA can also occur spontaneously or be associated with underlying metabolic diseases, including type I glycogen storage disease, iron overload related to betathalassemia and diabetes mellitus (13). Pathologic Findings
HCAs are usually solitary, sometimes pedunculated, with a diameter that can reach 30 cm. Large subcapsular vessels are commonly found on macroscopic examination. On cut sections, the tumor is well delineated, sometimes encapsulated, of fleshy appearance ranging in color from white to brown. Heterogeneous areas of necrosis and/or hemorrhage may be observed, preferentially in tumors of large size. Histologically, HCA consists of a proliferation of benign hepatocytes arranged in a trabecular pattern, without any residual portal tracts. Small, thin, and unpaired vessels are usually found throughout the tumor. Hepatocytes may have intracellular fat or increased glycogen. A certain degree of cellular atypia can be detected, especially in patients who have taken steroids for many years. In that context, differential diagnosis with hepatocellular carcinoma (HCC) may be difficult.
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Compared with FNH, patients with HCA are more likely to present with symptoms, especially if they have large tumors. Moreover, potential serious complications may occur, including spontaneous bleeding and hemorrhage, especially for tumors larger than 5 cm in diameter (14,15). In addition, HCA, as monoclonal process, may progress to malignancy with a risk ranging from 4% to 10% (13,15,16). Recent studies confirmed that this risk is higher in male patients and in large HCA (15). It also recently appears that metabolic syndrome, the incidence of which is increasing worldwide, may favor development of HCC in a pre-existing HCA (17). Pathomolecular Classification of Hepatocellular Adenomas
Molecular comprehensive studies have recently gained further insights into the knowledge of HCA showing a great heterogeneity in that group of tumors, resulting in the description of 3 main subtypes associated with specific phenotypical and molecular features (18). The first group of HCA displays biallelic mutations of the TCF1 gene inactivating the hepatocyte nuclear factor 1 (HNF1 ) transcription factor and is phenotypically characterized by marked steatosis, absence of cytological abnormalities, and inflammatory infiltrates (18,19). Although, HNF1 mutations are somatic in most cases of these HCAs, patients with inherited mutation in 1 allele of HNF1 may develop maturity-onset diabetes of the young type 3 (MODY3) and are predisposed to have familial liver adenomatosis, classically defined by the presence of at least 10 HCA, when the second allele is inactivated in hepatocytes by somatic mutation or chromosome deletion (20). The second group of HCA displays -catenin–activating mutations and is characterized by increased risk for malignant transformation into HCC. These HCA are mostly encountered in male patients and frequently show significant cellular atypia and pseudo-glandular formation. The third group of HCA corresponds mainly to the initially called “telangiectatic form of FNH,” appearing as well-delineated, unencapsulated tumors showing significant areas of vascular changes (foci of sinusoidal dilation and/ or peliotic changes), without evident fibrous scar (21). The hepatocellular proliferation contains few and short fibrous septa around clusters of small vessels, sometimes accompanied by inflammatory infiltrates (mainly composed of lymphocytes and macrophages) and a relatively low degree of ductular reaction. Notably, significant steatosis may be observed inside and outside the lesion, with various degrees of intensity (22). Although commonly observed in women using OP contraception, telangiectatic/inflammatory (Tel/Infl) HCA are reported in patients with increased BMI and are associated with inflammatory syndrome (increased C reactive protein [CRP] or fibrinogen serum levels) (22). Interestingly, in approximately 60% of Tel/Infl HCA, IL6 signaling pathway has been shown to be activated in relation with mutations in the IL6ST gene that encodes the signaling coreceptor gp130 (23). As a matter of fact, the gain-of-function somatic mutations in gp130 may result in the inflammatory phenotype of HCA and explain activation of the acute inflammatory phase observed
LESIONS
in tumoral hepatocytes. Finally, a small group of HCA remain “unclassified” since they do not display any specific morphological or genotypical features. In contrast to FNH, and due to the potential risk for complications, surgical resection is required for HCA larger than 5 cm in diameter and all HCAs in males whatever their size. Small lesions with a low risk of complication could be initially observed after cessation of OC. Importantly, long-term follow-up of patients with unresected HCA showed a relative stability for most of them and even a significant regression in a small proportion of cases after interruption of OC (15,16). Immunophenotypical features of hepatocellular adenomas
Surrogate immunophenotypical markers related to the genetic abnormalities may be used in the classification of the 3 main subtypes of HCAs (24). Indeed, expression of liver fatty acid binding protein (LFABP), a protein positively regulated by HNF1 , is absent in steatotic HNF1 -mutated HCA, whereas it is highly expressed in non-tumoral liver. Tel/ Infl HCA display positive immunostaining with acute phase inflammatory proteins such as serum amyloid A (SAA) and CRP. Most of -catenin–mutated HCA present abnormal and nuclear staining of -catenin in tumoral hepatocytes, usually with a focal positivity restricted to few isolated tumoral hepatocytes. Immunostaining with glutamine synthetase, a
-catenin–targeted gene, showing a strong homogeneous or heterogeneous cytoplasmic staining, increases the sensibility for diagnosis of -catenin–mutated HCA. Lastly, -catenin mutations may be observed in some SAA- positive Tel/ Infl HCA, whereas gp130 activation (Tel/Infl subtype) and HNF1 inactivation (steatotic subtype) are mutually exclusive (23,24). Overall, although the diagnostic value of the different phenotypical markers is very good to excellent on paraffin sections, it is essential to compare their tissue expression in the tumor and its respective nontumoral liver in parallel. Finally, besides the 3 well-characterized subtypes, a fourth group of HCA includes the lesions without any specific morphological features nor the genetic abnormalities previously described. In surgical series of HCA, steatotic and Tel/Inf subtypes appear to be equally distributed, accounting for 85% of overall HCAs, when -catenin–mutated HCA are reported in 10% to 15% of cases. Table 23.1 summarizes the immunostaining pattern of the panel of markers used for HCA subtyping. Multiple Adenomas and Liver Adenomatosis
Review of the literature reporting patients with multiple HCA, including the so-called adenomatosis, does not support an arbitrary classification based on clinical and imaging characteristics (13,25,26). Patients with multiple HCA are predominantly females, but the use of OC appears to be less prevalent (25). Patients with glycogen storage disease type I are also at risk of developing multiple HCAs (27). Recent study confirmed that risk of complications, including bleeding and malignant transformation, is similar to that in patients with solitary HCA and is not influenced by the number of
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TA B LE 23. 1 Immunophenotypical characteristics of benign
hepatocellular tumors Tumor
-Catenin
Glutamine Synthetase
LFABP
SAA
Focal nodular hyperplasia
/Membranous
Perivascular
Steatotic HCA
/Membranous
Focal
Tel/Infl HCA
/Membranous
Focal
HCA with cellular atypia
Nuclear/ cytoplasmic
Diffuse
Unclassified HCA
/Membranous
Focal
Normal liver
/Membranous
Centrolobular
Abbreviations: HCA, hepatocellular adenoma; LFABP, liver fatty acid binding protein; SAA, serum amyloid A; Tel/Infl HCA, telangiectactic/ inflammatory hepatocellular adenoma.
tumors (13,15,26). Except for the number of lesions, no difference is observed between imaging features of adenomatosis and solitary HCA. Interestingly, on imaging, 3 main morphologic patterns of liver adenomatosis have been described: the steatotic form, the peliotic/telangiectatic form and the mixed form (28). To note, the proportion of steatotic HCA is higher and presence of microadenomatous foci in the “nontumoral liver” is more often observed in patients with liver adenomatosis (15). As proposed for patients with solitary HCA, surgical treatment should be restricted to HCA associated with higher risk for complications. C H A L L E N GE S I N B I OP SY D I AG N OS I S
The specific biologic behavior of the benign hepatocellular lesions requires an accurate diagnosis in order to define the appropriate management consisting of no follow-up or resection for FNHs and follow-up and/or ablation for HCAs according to their characteristics. Although diagnosis and HCA subtyping may be reached in most cases by clinical and imaging approaches in experienced centers, liver biopsy is required for atypical lesions (either FNH or HCA) and in HCAs without specific radiological characteristics (mainly the -catenin–mutated HCA and the “unclassified” subtypes of HCA). On biopsy, immunophenotypical markers may be useful, especially glutamine synthetase for diagnosis of FNH and the panel (LFABP/SAA or CRP/ -catenin) for HCA subtyping. At last, 1 major issue remains: the differential diagnosis between HCA and well-differentiated HCC, which may be very difficult on biopsy. In these situations, reticulin pattern and surrogate markers, including glypican-3, can be useful tools (29,30).
References 1. Edmondson HA. Tumors of the liver and intrahepatic bile ducts. In: Atlas of Tumor Pathology. Fascicle 25 First serie, Washington, DC: Armed Forces Institute of Pathology; 1958.
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2. International Working Party. Terminology of nodular hepatocellular lesions. Hepatology. 1995;22:983–993. 3. Ishak KG. Hepatic neoplasms associated with contraceptive and anabolic steroids. Carcinogenetic hormones. In: Lingeman CH ed. Recent Results in Cancer Research. New York, NY: Springer-Verlag; 1979:72–128. 4. Wanless IR, Mawdsley C, Adams R. On the pathogenesis of focal nodular hyperplasia. Hepatology. 1985;5:1194–1200. 5. Gaffey MJ, Iezzoni JC, Weiss LM. Clonal analysis of focal nodular hyperplasia of the liver. Am J Pathol. 1996;148:1089–1096. 6. Paradis V, Laurent A, Fléjou JF, Vidaud M, Bedossa P. Evidence for the polyclonal nature of focal nodular hyperplasia of the liver by the study of X chromosome inactivation. Hepatology. 1997;26:891–895. 7. Nguyen BN, Fléjou JF, Terris B, Belghiti J, Degott C. Focal nodular hyperplasia of the liver: a comprehensive pathologic study of 305 lesions and recognition of new histologic forms. Am J Surg Pathol. 1999;23: 1441–1454. 8. Makhlouf HR, Abdul-Al HM, Goodman ZD. Diagnosis of focal nodular hyperplasia of the liver by needle biopsy. Human Pathology. 2005;36: 1210–1216. 9. Bioulac-Sage P, Laumonier H, Rullier A, et al. Over-expression of glutamine synthetase in focal nodular hyperplasia: a novel easy diagnostic tool in surgical pathology. Liver Int. 2009;29:459–465. 10. Nime F, Pickren JW, Vana J, Aronoff BL, Baker HW, Murphy GP. The histology of liver tumors in oral contraceptive users observed during a national survey by the American College of Surgeons Commission on Cancer. Cancer. 1979;44:1481–1489. 11. Coombes GB, Reiser J, Paradinas FJ, Burn I. An androgen associated hepatic adenoma in a trans-sexual. Br J Surg. 1978;65:869–870. 12. Wittekind C. Hepatocellular carcinoma and cholangiocarcinoma. In: Hermanek P, Gospodarowicz MK, Henson DE, et al, eds. Prognostic Factors in Cancer. Berlin: Springer; 1995:88–93. 13. Barthelmes L, Tait IS. Liver cell adenomas and liver cell adenomatosis. HBP. 2005;7:186–196. 14. Terkivatan T, de Wilt JH, de Man RA, van Rijn RR, Tilanus HW, IJzermans JN. Treatment of ruptured hepatocellular adenoma. Br J Surg. 2001;88:207–209. 15. Dokmak S, Paradis V, Vilgrain V, et al. A single-center surgical experience of 122 patients with single and multiple hepatocellular adenomas. Gastroenterology. 2009;137:1698–1705. 16. Bioulac-Sage P, Laumonier H, Couchy G, et al. Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience. Hepatology. 2009;50:481–489. 17. Paradis V, Zalinski S, Chelbi E, et al. Hepatocellular carcinomas in patients with metabolic syndrome often develop without significant fibrosis: a pathological analysis. Hepatology. 2009;49:851–859. 18. Zucman-Rossi J, Jeannot E, Van Nhieu JT, et al. Genotype-phenotype correlation in hepatocellular adenoma: new classification and relationship with HCC. Hepatology. 2006; 43:515–524. 19. Bluteau O, Jeannot E, Bioulac-Sage P, et al. Bi-allellic inactivation of TCF1 in hepatic adenomas. Nat Genet. 2002;32:312–315. 20. Bacq Y, Jacquemin E, Balabaud C, et al. Familial liver adenomatosis associated with hepatocyte nuclear factor 1 alpha inactivation. Gastroenterology. 2003;125:1470–1475. 21. Wanless IR, Albrecht S, Bilbao J. Multiple focal nodular hyperplasia of the liver associated with vascular malformations of various organs and neoplasia of the brain. Mod Pathol. 1989;2:456–462. 22. Paradis V, Champault A, Ronot M, et al. Telangiectatic adenomas: an entity associated with increased body mass index and inflammation. Hepatology. 2007;46:140–146. 23. Rebouissou S, Amessou M, Thomas C, et al. Frequent in-frame somatic deletions activate gp130 in inflammatory hepatocellular tumors. Nature. 2009;457:2000–2004. 24. Bioulac-Sage P, Rebouissou S, Thomas C, et al. Hepatocellular adenoma subtype classification using molecular markers and immunohistochemistry. Hepatology. 2007;46:740–748.
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25. Flejou JF, Barges J, Menu Y, et al. Liver adenomatosis: an entity distinct from liver adenoma? Gastroenterology. 1985;89:1132–1138. 26. Ribeiro A, Burgart LJ, Nagorney DM, Gores GJ. Management of liver adenomatosis: results with a conservative surgical approach. Liver Transpl Surg. 1998;4:388–398. 27. Labrune P, Trioche P, Duvaltier I, Chevalier P, Odièvre M. Hepatocellular adenomas in glycogen storage disease type I and III: a series of 43 patients and review of the literature. J Ped Gastroenterol Nutr. 1997;24: 276–279.
LESIONS
28. Lewin M, Handra-Luca A, Arrivé L, et al. Liver adenomatosis: classification pf MR imaging features and comparison with pathologic findings. Radiology. 2006;241:433–440. 29. Wang XY, Degos F, Dubois S, et al. Glypican-3 expression in hepatocellular tumors: diagnostic value for preneoplastic lesions and hepatocellular carcinomas. Hum Pathol. 2006;37:1435–1441. 30. Shafizadeh N, Ferrell LD, Kakar S. Utility and limitations of glypican-3 expression for the diagnosis of hepatocellular carcinoma at both ends of the differentiation spectrum. Mod Pathol. 2008;21:1011–1018.
Case 23.1
Atypical Focal Nodular Hyperplasias on Imaging VALÉRIE PARADIS
C L I N IC AL I N F OR M AT I ON
Asymptomatic liver nodule discovered in the United States in a 42-year-old woman. Liver function tests were normal. On imaging, the nodule of 30 mm in diameter was hypervascular, partly steatotic, and occurred in a normal background liver. A biopsy was performed for differential diagnosis between FNH and HCA. PAT H OL OG I C F E AT U R E S
The biopsy of the nodule shows hepatocellular areas crossed by fibrous bands of various thickness (Figure 23.1.1). Fibrous septa contain multiple vascular channels with few ductules and inflammatory cells (Figure 23.1.2). Some dystrophic vessels with thickened wall are present (Figure 23.1.3). Hepatocellular proliferation is made of normal looking hepatocytes arranged in liver plates of normal thickness with presence of moderate steatosis (Figure 23.1.3). Glutamine synthetase immunostaining shows a typical patchy pattern with foci of positive- stained hepatocytes (Figure 23.1.4).
F I G U R E 2 3 . 1 . 2 Several small vessels are present in the fibrous septa, as well as scattered inflammatory cells. A few small ductules are present near the interface of the fibrous tissue and hepatocytes.
D I AG N OS I S
Steatotic focal nodular hyperplasias.
D I S C U S S I ON
The pathological features observed on the biopsy, especially the presence of fibrous bands with dystrophic vessels, are
F I G U R E 2 3 . 1 . 3 Focal thick-walled muscular vessel (higher magnifi-
cation of Figure 23.1.1) is present with dystrophic morphology; note muscle bundles extending into fibrous septa to the right of the vessel. Hepatocytes are steatotic but otherwise unremarkable. Ductular reaction is very scant.
FIGURE 23. 1. 1 Fibrous band with muscular vessel separates hepato-
cellular parechyma of the lesion. Hepatocytes are steatotic.
strongly concordant for the diagnosis of FNH. Such diagnosis could be difficult on biopsy, especially for pathologists with limited experience with the lesion, where thick abnormal arteries are usually missing (1). Presence of ductular reaction at the border between fibrous septa and hepatocellular component, which can be highlighted by immunostaining with cytokeratins 7 or 19, was shown to be the most consistent
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LESIONS
centered by hepatic veins, described as a map-like pattern, is highly suggestive of FNH (2). In spite of the presence of fibrous scar, this case was considered as atypical by radiologists, mainly because of the detection of significant steatosis on imaging modalities. Indeed, liver steatotic nodules are more often considered as HCA than FNH. However, diagnosis of FNH should not be excluded by the presence of intratumoral steatosis. Indeed, in a series of 100 consecutive needle biopsies of FNH, steatosis was observed in 25% of cases, with a moderate to severe intensity in 10% (1). Given that management of FNH and HCA are radically different, with abstention for FNH and resection for most HCA, the impact of the biopsy in the positive diagnosis of FNH is highly valuable and of clinical importance. FIGURE 23. 1. 4 Glutamine synthetase immunostain demonstrates a prominent, but patchy, pattern of staining in much of the lesion on the biopsy sample.
diagnostic histological feature for FNH (1). In addition, and as illustrated in this case, immunostaining with glutamine synthetase showing focal- positive hepatocellular areas usually
References 1. Makhlouf HR, Abdul-Al HM, Goodman ZD. Diagnosis of focal nodular hyperplasia of the liver by needle biopsy. Hum Pathol. 2005;36: 1210–1216. 2. Bioulac-Sage P, Laumonier H, Rullier A, et al. Over-expression of glutamine synthetase in focal nodular hyperplasia: a novel easy diagnostic tool in surgical pathology. Liver Int. 2009;29:459–465.
Case 23.2
Focal Nodular Hyperplasia Versus Inflammatory/Telangiectatic Hepatocellular Adenoma VALÉRIE PARADIS
C L I N IC AL I N F OR M AT I ON
A 36-year-old woman presented with a 6-cm nodule in the right liver. There were no symptoms, and liver function tests were normal. On imaging, lesion was atypical for classic FNH due to the absence of fibrous scar. The biopsy of the nodule was performed in order to exclude the possibility of an HCA. PAT H OL OG I C F E AT U R E S
The biopsy of the nodule shows a hepatocellular proliferation with few small vessels included and discrete sinusoidal dilatation (Figure 23.2.1). The hepatocellular proliferation is vaguely nodular with thin liver cell plates at the periphery, and focally steatotic (Figure 23.2.2). The vessels are thin, usually unpaired, slightly surrounded by extracellular matrix component (Figure 23.2.3). Very few foci of ductular reaction are visible (Figure 23.2.3). The tumoral hepatocytes are regular, arranged in normal thickness plates with very few lymphocytes observed (Figure 23.2.3). Glutamine synthetase immunostaining shows the typical patchy pattern (Figure 23.2.4) without any SAA staining (Figure 23.2.5).
F I G U R E 2 3 . 2 . 2 The lesion has a vague nodularity, with thinner
hepatic plates at the periphery of the “nodules.” Some hepatocytes contain fat.
D I AG N OS I S
FNH without fibrous scar.
F I G U R E 2 3 . 2 . 3 Higher magnification of Figure 23.2.5 showing “un-
paired” vessel (no accompanying bile duct). Note lack of ductular reaction at interface of fibrous tissue and hepatocytes.
DISCUSSIO N
FIGURE 23. 2. 1 Hepatocytic lesion with a focus of a few small ves-
sels without accompanying duct. Focal mild sinusoidal dilation is also present.
This case illustrates one variant of FNH that lacks the classic fibrous central scar. Indeed, presence of fibrous scar is a major diagnostic feature of FNH on imaging. Pathological analysis on the surgical specimen of FNH without a macroscopic central scar may be able to show several thin and short fibrous septa that are
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FIGURE 23. 2. 4 Glutamine synthetase immunostain. Prominent, but
patchy, pattern of staining as seen in previous case (Figure 23.2.4). Note cores on the left are nonlesional tissue with only limited perivenous positivity.
LESIONS
most of them, have been initially considered as atypical forms of FNH, so-called telangiectatic form of FNH (3). Interestingly, molecular studies, based on clonal analysis and gene expression analysis, demonstrated that these kinds of lesions were clonal processes with gene expression pattern similar to HCA (4). These results led to reconsideration of “telangiectatic form of FNH” as Tel/Infl HCA, a distinct subtype of HCA (4,5). Later on, immunohistochemical classification of the different subtypes of HCA, based on the correlation between genotype and phenotype, was developed (6,7). Tel/Infl HCA, which are morphologically characterized by intratumoral vascular changes and inflammatory foci, display overexpression of markers of the acute phase inflammatory reaction, including SAA and CRP (7). Interestingly, we observed a systemic biological inflammatory syndrome in patients with Tel/Infl HCA that has resolved after tumor resection (8). Therefore, in addition to glutamine synthetase, immunohistochemical analysis with inflammatory markers may be helpful, especially on biopsy samples, in the differential diagnosis between FNH and Tel/Infl HCA. In Tel/ Infl HCA, SAA immunostaining is restricted to the tumoral hepatocytes, with high specificity and sensitivity, even though focal staining has been described in non-tumoral liver in a few cases. Finally, this case perfectly illustrates the significant contribution of immunophenotyping in the diagnosis of atypical FNH.
References
FIGURE 23. 2. 5 Serum amyloid A immunostain. Negative for granular cytoplasmic staining to exclude Tel/Infl HCA.
usually lacking on biopsy samples. Nevertheless, and as discussed above, additional key features have to be carefully screened, such as the ductular reaction and the map-like pattern of glutamine synthetase immunostaining (1,2). The main differential diagnosis of FNH without macroscopic central fibrous scar, for radiologists, and pathologists as well, is the Tel/Infl subtype of HCA. Tel/Infl HCA, at least
1. Makhlouf HR, Abdul-Al HM, Goodman ZD. Diagnosis of focal nodular hyperplasia of the liver by needle biopsy. Hum Pathol. 2005;36: 1210–1216. 2. Bioulac-Sage P, Laumonier H, Rullier A, et al. Over-expression of glutamine synthetase in focal nodular hyperplasia: a novel easy diagnostic tool in surgical pathology. Liver Int. 2009;29:459–465. 3. Wanless IR, Albrecht S, Bilbao J. Multiple focal nodular hyperplasia of the liver associated with vascular malformations of various organs and neoplasia of the brain. Mod Pathol. 1989;2:456–462. 4. Paradis V, Benzekri A, Dargère D, et al. Telangiectatic focal nodular hyperplasia: a variant of hepatocellular adenoma. Gastroenterology. 2004;126:1323–1329. 5. Bioulac-Sage P, Rebouissou S, Sa Cunha A, et al. Clinical morphologic, and molecular features defining so-called telangiectatic focal nodular hyperplasias of the liver. Gastroenterology. 2005;128:1211–1218. 6. Zucman-Rossi J, Jeannot E, Van Nhieu JT, et al. Genotype-phenotype correlation in hepatocellular adenoma: new classification and relationship with HCC. Hepatology. 2006;43:515–524. 7. Bioulac-Sage P, Rebouissou S, Thomas C, et al. Hepatocellular adenoma subtype classification using molecular markers and immunohistochemistry. Hepatology. 2007;46:740–748. 8. Paradis V, Champault A, Ronot M, et al. Telangiectatic adenomas: an entity associated with increased body mass index and inflammation. Hepatology. 2007; 46:140–146.
Case 23.3
Hepatocellular Adenoma Subtyping: Inflammatory/Telangiectatic Versus Steatotic Adenoma VALÉRIE PARADIS
C L I N IC AL I N F OR M AT I ON
A 23-year-old woman presented with several liver nodules (>5 on imaging), one of which was 10 cm in diameter in the right lobe of an otherwise normal liver. Imaging features of all nodules was consistent with steatotic HCA. The largest nodule was biopsied before resection.
PAT H OL OG I C F E AT U R E S
The biopsy shows a very-well differentiated hepatocellular proliferation with some sinusoidal dilatation (Figure 23.3.1). Some mononuclear infiltrates are focally noted (Figure 23.3.2). The tumoral hepatocytes are regular with a trabecular pattern, without significant steatosis observed (Figure 23.3.2). SAA immunostaining demonstrates a cytoplasmic granular positivity of the tumoral hepatocytes (Figure 23.3.3). The liver proliferation also displays a positive staining with LFABP (cytoplasmic and nuclear) (Figure 23.3.4). Resection specimen (right hepatectomy) shows multiple nodules ranging from 1 to 10 cm. The largest nodule is unencapsulated, nodular shaped, yellowish with telangiectatic changes (Figure 23.3.5). On hematoxylin and eosin staining, the liver tumor is characterized by regular hepatocellular proliferation containing clusters of vascular channels surrounded by extracellular matrix with few inflammatory cells. Note the presence of steatotic hepatocytes (Figure 23.3.6).
F I G U R E 2 3 . 3 . 2 Focal mononuclear inflammation, a feature that is commonly present in this lesion.
F I G U R E 2 3 . 3 . 3 Serum amyloid A immunostain demonstrates posi-
tive staining as represented by relatively diffuse and prominent cytoplasmic granules in lesional hepatocytes.
DIAGNO SIS FIGURE 23. 3. 1 Biopsy sample of the lesion demonstrates relatively
normal-appearing hepatocytic plate architecture, but sinusoids are significantly dilated.
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Tel/Infl HCA in the context of liver adenomatosis.
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FIGURE 23. 3. 4 Liver fatty acid binding protein immunostain
demonstrates positivity in both cytoplasm and nuclei in lesional hepatocytes.
FIGURE 23. 3. 5 Resection specimen demonstrates a large pale, yellow tan lesion with somewhat irregular, but rounded, borders and mottled vascular/telangiectatic pattern.
D I SC U SSI ON
Liver adenomatosis was described as a separate entity characterized by the presence of multiple HCA (arbitrarily more than 10), observed both in men and women with no relationship to the use of OC (1). Later, it appeared that such classification was no longer relevant on the basis of demographics and clinical evolution, especially regarding rate of complications (2). Germline mutations of HNF1 were initially reported in cases of familial liver adenomatosis (3). Although a steatotic subtype of HCA is more prevalent in
LESIONS
F I G U R E 2 3 . 3 . 6 The resected tumor contains clusters of vascular channels in fibrous matrix with few inflammatory cells. Some fat is also present in tumoral hepatocytes.
patients with liver adenomatosis, other subtypes may be observed, especially Tel/Infl HCA, as illustrated in our case. Thus, imaging analysis of liver adenomatosis has described 3 different patterns: steatotic, peliotic (or telangiectatic), and mixed forms (4). Interestingly, the main pathological feature associated with the presence of multiple HCAs is the presence of microadenomas in the adjacent liver as observed in our case (5). Lastly, the rate of significant complications (hemorrhage and malignancy) is not related to the number of HCA but to its size and its pathological subtype with a lower risk for steatotic HCA. Although not present on the biopsy, significant intratumoral steatosis was observed both on macroscopy and histology of the surgical resection, highlighting that steatosis is not restricted to the steatotic LFABP-negative subtype of HCA. Therefore, significant steatosis (>10%) has been reported in at least half of Tel/Infl HCA, with moderate to severe intensity in about 30% of cases (6). In cases of Tel/Infl HCA, presence of intratumoral steatosis may be related to the clinical context of the patient since this HCA subtype is more prevalent in patients with increased body mass index and metabolic syndrome (6). On the other hand, the degree of steatosis may be highly variable in steatotic HNF1 -mutated HCA, ranging from less than 10% to more than 60% (7). Indeed, in the original study correlating genotype and phenotype of HCA, only 36% of HNF1 -mutated HCA displayed severe steatosis, as much as 60% (7). Lastly, this case also raises the major issue of biopsy sampling of benign hepatocellular tumors, especially for HCA subtyping. Indeed, whereas imaging diagnosis was steatotic HCA, no significant steatosis was observed on the biopsy of the tumoral nodule despite its representativity. Altogether, these limitations emphasize the importance of systematic immunohistochemistry for subtyping HCA on biopsy specimens.
CASE
23.3:
HCA
SUBTYPING:
INF/TEL
References 1. Flejou JF, Barges J, Menu Y, et al. Liver adenomatosis: an entity distinct from liver adenoma? Gastroenterology. 1985;89:1132–1138. 2. Veteläinen R, Erdogan D, de Graaf W, et al. Liver adenomatosis: reevaluation of aetiology and management. Liver Int. 2008;28:499–508. 3. Bacq Y, Jaquemin E, Balabaud C, et al. Familial liver adenomatosis associated with hepatocyte nuclear factor 1 alpha inactivation. Gastroenterology. 2003;125:1470–1475. 4. Lewin M, Handra-Luca A, Arrivé L, et al. Liver adenomatosis: classification pf MR imaging features and comparison with pathologic findings. Radiology. 2006;241:433–440.
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5. Dokmak S, Paradis V, Vilgrain V, et al. A single-center surgical experience of 122 patients with single and multiple hepatocellular adenomas. Gastroenterology. 2009;137:1698–1705. 6. Paradis V, Champault A, Ronot M, et al. Telangiectatic adenomas: an entity associated with increased body mass index and inflammation. Hepatology. 2007;46:140–146. 7. Zucman-Rossi J, Jeannot E, Van Nhieu JT, et al. Genotype-phenotype correlation in hepatocellular adenoma: new classification and relationship with HCC. Hepatology. 2006;43:515–324.
Case 23.4
Hepatocellular Adenoma Subtyping: Associated Liver Nodules VALÉRIE PARADIS
C L I N I C AL I N F OR M AT I ON
A 68-year-old woman presented with 3-fold increase in gamma glutamyl transpeptidase (GGT). Liver imaging revealed 3 nodules, including 2 centimetric lesions (segments II and IV) suggestive of FNH and 1 larger nodule (5 cm in its largest axis) appearing steatotic. Nontumoral liver was possibly slightly dysmorphic. Biopsy of the largest nodule and nontumoral liver was performed before resection.
PAT H OL OG I C F E AT U R E S
The biopsy demonstrates both nodule and adjacent nontumoral liver. The nodule corresponds to a well-differentiated hepatocellular proliferation mainly composed of steatotic hepatocytes (Figure 23.4.1). The steatotic proliferation contains small, unpaired arteries (Figure 23.4.2). The tumor is composed of more than 80% of steatotic hepatocytes, with large and small droplet patterns of steatosis (Figure 23.4.2). Nontumoral liver displays normal architecture without any steatosis (Figure 23.4.3). LFABP immunostaining demonstrates absent labeling of the hepatocellular proliferation compared with the positivity of the nontumoral hepatocytes (cytoplasmic and nuclear labeling) (Figure 23.4.4). Macroscopic view of the resected nodule shows a multinodular tan nodule of 5 cm in its largest axis (Figure 23.4.5). Hematoxylin and eosin (H&E) staining of the resected specimen confirms the diagnosis of steatotic HCA (Figure 23.4.6).
F I G U R E 2 3 . 4 . 2 Biopsy sample of lesion shows that small unpaired
arteries and hepatocytes contain both large and small droplet fat. Glycogenated nuclei are also present.
F I G U R E 2 3 . 4 . 3 Biopsy sample of nonlesional tissue (note portal
zone on right) shows no fat in hepatocytes.
DIAGNO SIS
Steatotic LFABP-negative HCA.
DISCUSSIO N FIGURE 23. 4. 1 Biopsy of the lesion demonstrates fatty hepatocytes.
This case illustrates a typical case of steatotic HNF1 -mutated HCA. This HCA subtype is the most frequently encountered
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HCA
SUBTYPING:
FIGURE 23. 4. 4 LFABP immunostain is negative in lesional hepatocytes (with fat) as compared with the positive nuclear and cytoplasmic staining of adjacent normal liver without fat.
FIGURE 23. 4. 5 Resection specimen demonstrates a multinodular
tan tumor.
with the Tel/Infl subtype, accounting for approximately 40% to 45% of HCA, respectively. As far as complications are concerned, it appears that steatotic HNF1 -mutated HCA are less prone to progress to hepatocellular carcinoma (HCC) compared with Tel/Infl and -catenin–activated subtypes (1,2). As a matter of fact, almost all of them occur in women, and, interestingly, it has been shown that HNF1 and gp130 mutations (characterizing Tel/Infl HCA) are mutually exclusive (3). Accordingly, a more conservative clinical approach would be
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F I G U R E 2 3 . 4 . 6 Resected tumor shows extensive fatty change.
considered for steatotic HNF1 -mutated HCA except for the very large tumors, as size remains one of the main risk factors for malignancy. Imaging and pathological diagnosis of steatotic HNF1 mutated HCA should be, in theory, the easiest to do, given that steatosis, a well-recognized feature, is the main morphological hallmark. Nevertheless, and as discussed above (Chapter 23.3), steatosis may be not so prominent. In these cases, immunophenotypical analysis is helpful, showing absence of staining in tumoral hepatocytes contrasting with nontumoral hepatocytes that display cytoplasmic and sometimes additional nuclear positivity for LFABP. Comparison of immunostaining between tumor and nontumoral counterpart is required. In the screening of patients with HCA, additional tumors of the liver may be detected. Among them, hemangiomas, the most frequent benign tumors of the liver and FNH are commonly reported. As illustrated in our case, the presence of steatotic HNF1 -mutated HCA and FNH is quite a frequent association as well, reaching 24% of cases (1).
References 1. Bioulac-Sage P, Laumonier H, Couchy G, et al. Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience. Hepatology. 2009;50:481–489. 2. Paradis V, Champault A, Ronot M, et al. Telangiectatic adenomas: an entity associated with increased body mass index and inflammation. Hepatology. 2007; 46:140–146. 3. Rebouissou S, Amessou M, Thomas C, et al. Frequent in-frame somatic deletions activate gp130 in inflammatory hepatocellular tumors. Nature. 2009;457:2000–2004.
Case 23.5
Hepatocellular Adenoma Subtyping: Inflammatory/Telangiectatic Adenoma VALÉRIE PARADIS
C L I N I C AL I N F OR M AT I ON
A 23-year-old woman on oral contraceptives for 8 years presented with back pain. Imaging revealed a liver nodule of 5 cm in segment VI with steatotic features suggestive of an HCA. Liver function tests were normal. A liver biopsy was performed followed by resection. PAT H OL OG I C F E AT U R E S
Biopsy of the nodule shows a well-differentiated hepatocellular proliferation with a vaguely nodular pattern, containing quite numerous thin vessels (Figure 23.5.1). Some areas demonstrate steatotic hepatocytes (Figure 23.5.2). In other places, hepatocellular proliferation is composed of clear hepatocytes arranged in liver plates slightly increased or with pseudoglandular formation (Figure 23.5.3). Presence of few inflammatory infiltrates throughout the nodule is noted (Figure 23.5.4). There is no significant cellular atypia. -catenin immunostaining demonstrates only a few tumoral hepatocytes with a nuclear positivity (Figure 23.5.5). Large areas of hepatocellular proliferation are strongly reactive with glutamine synthetase (Figure 23.5.6). SAA immunostaining shows very few positive tumoral hepatocytes (Figure 23.5.7). Macroscopic view of the resected nodule shows a 5 cm nonencapsulated yellowish nodule with few congestive changes (Figure 23.5.8). Pathological analysis of the surgical specimen clearly demonstrates that the hepatocellular proliferation contains the presence of small clusters of slightly dystrophic vessels surrounded by extracellular matrix and inflammatory infiltrates (Figure 23.5.9).
F I G U R E 2 3 . 5 . 2 Biopsy of the lesion at higher magnification high-
lights isolated unpaired vessels and fatty change of tumoral hepatocytes. No cellular atypia is present.
F I G U R E 2 3 . 5 . 3 Biopsy sample demonstrates that hepatic plates are mildly thickened and show focal pseudoglandular formation.
DIAGNO SIS FIGURE 23. 5. 1 Biopsy shows a hepatocellular proliferation with vaguely nodular pattern and numerous thin-walled vessels.
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Tel/Infl HCA with -catenin activation.
CASE
23.5:
HCA
SUBTYPING:
INF/TEL
ADENOMA
357
F I G U R E 2 3 . 5 . 6 -catenin immunostain of biopsy demonstrates a few
FIGURE 23. 5. 4 Biopsy sample. The lesion also contains a few inflammatory infiltrates. In addition, note again the small vascular channels.
positive nuclei.
FIGURE 23. 5. 5 Glutamine synthetase immunostain of biopsy shows
F I G U R E 2 3 . 5 . 7 Serum amyloid A immunostain shows only minimal, focal cytoplasmic staining of lesional hepatocytes.
large zone of strong positivity.
D I S C U S S I ON
Tel/Infl with steatotic HNF1 -mutated tumors represent the most prevalent subtypes of HCA. As already discussed, Tel/Infl HCA are predominantly observed in young women with a long history of OC use (1). In addition, this subtype is frequently observed in patients with increased body mass index that may explain presence of steatosis (at least >30%) in adjacent nontumoral liver in one-third of cases (1,2). Although diagnosis of HCA was confident on the biopsy, subtyping into Tel/Infl HCA is not so evident and could be suggested based on the vaguely nodular architecture of the proliferation associated with the presence of few inflammatory foci. Indeed, the clusters of vessels surrounded by extracellular matrix,
observed on the surgical specimen, were lacking on the biopsy sample. Additional immunohistochemical analysis searching for SAA staining in tumoral cells was of potential value in this case, showing focal positivity in one area. More importantly, surrogate histological features have to be taken into account, especially the presence of pseudoglandular formation. Indeed, this feature has been described in -catenin–activated liver tumors, including HCA and HCC as well (3,4). Therefore, and independently of the presence of cellular atypia, -catenin pattern has to be checked. Immunoprofiles of -catenin and glutamine synthetase were positive and so consistent with diagnosis of
-catenin–activated HCA. In fact, glutamine synthetase is useful to improve diagnostic accuracy of -catenin activation given that -catenin staining may be difficult to interpret (focal
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FIGURE 23. 5. 8 Resection sample reveals a white to yellow tan, vaguely nodular tumor with irregular mottled vascular pattern.
F I G U R E 2 3 . 5 . 9 Resected tumor shows slightly dystrophic vessels and
nuclear staining) and has much lower sensitivity compared with glutamine synthetase (2). Among Tel/Infl HCAs, a proportion may harbor
-catenin activation (5). Interestingly, no major differences appear between patients with Tel/Infl HCA according to the presence of -catenin activation, except for the presence of HCC (5). In the analysis of a series of HCC that developed on a pre-existing HCA, we observed that the Tel/Infl subtype was the more frequent (52%), and that approximately half of them displayed -catenin activation (personal data). Altogether, these data support that Tel/Infl subtype and presence of
-catenin activation are the main risk factors for progression to HCC.
References
inflammatory infiltrates scattered throughout the lesion.
1. Paradis V, Champault A, Ronot M, et al. Telangiectatic adenomas: an entity associated with increased body mass index and inflammation. Hepatology. 2007;46:140–146. 2. Bioulac-Sage P, Rebouissou S, Thomas C, et al. Hepatocellular adenoma subtype classification using molecular markers and immunohistochemistry. Hepatology. 2007;46:740–748. 3. Zucman-Rossi J, Jeannot E, Van Nhieu JT, et al. Genotype-phenotype correlation in hepatocellular adenoma: new classification and relationship with HCC. Hepatology. 2006;43:515–524. 4. Audard V, Grimber G, Elie C, et al. Cholestasis is a marker for hepatocellular carcinomas displaying beta-catenin mutations. J Pathol. 2007;212:345–352. 5. Bioulac-Sage P, Laumonnier H, Couchy G, et al. Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience. Hepatology. 2009;50:481–489.
Case 23.6
Hepatocellular Adenoma Subtyping: Adenoma With Atypical Features VALÉRIE PARADIS
C L I N IC AL I N F OR M AT I ON
A 52-year-old man referred for a unique nodule of 12 cm in diameter of the right lobe developed in a background normal liver. Alpha-fetoprotein (AFP) is normal. Right hepatectomy was performed. PAT H OL OG I C F E AT U R E S
Macroscopic analysis of the right hepatectomy identifies a well-limited, unencapsulated nodule of 12 cm in its largest axis. The nodule is lobulated, heterogeneous with cholestatic changes. Adjacent liver parenchyma was macroscopically normal (Figure 23.6.1). On HE staining, the hepatocellular proliferation displays a very well-differentiated trabecular pattern with pseudoglandular formation (Figure 23.6.2). The tumor contains numerous arteries, usually either thin and unpaired (Figure 23.6.3). Significant cellular atypia is focally observed with cholestasis as well (Figure 23.6.4). Reticulin staining shows a preserved reticulin framework (Figure 23.6.5).
-catenin immunostaining demonstrates aberrant nuclear positivity in some tumoral hepatocytes (Figure 23.6.6). SAA immunostaining was negative.
F I G U R E 2 3 . 6 . 2 Tumoral hepatocytes are arranged in thin trabecularlike pattern with focal pseudoglandular formation.
D I AG N OS I S
-catenin–activated HCA with cell atypia.
F I G U R E 2 3 . 6 . 3 Higher magnification of pseudoglandular formation.
Note the isolated unpaired artery.
DISCUSSIO N
FIGURE 23. 6. 1 Resection specimen demonstrates a mass with heterogeneous brown, hemorrhagic appearance in a background of normal liver.
This case reports a hepatocellular proliferation occurring in a male patient. Specific context, including androgen treatment, Fanconi’s anemia, or use of recreational steroids are considered as significant risk factors in men for developing hepatocellular tumors (1,2). More recently, several cases of HCC arising in a pre-existing HCA have been reported in patients with metabolic syndrome (3).
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FIGURE 23. 6. 4 Note significant nuclear atypia as compared with
F I G U R E 2 3 . 6 . 6 b-catenin immunostain shows nuclear positivity in
that seen in the previous cases. Cholestasis is also present.
some tumoral hepatocytes consistent with b-catenin–mutated variant of HCA.
FIGURE 23. 6. 5 Reticulin stain demonstrates intact framework, including around the pseudoglands.
morphological features on imaging, and the final diagnosis relies exclusively on the pathological analysis. Differential diagnosis between well-differentiated HCC and HCA with cellular atypia remains a major issue, especially on biopsy specimen. Additional features, including the reticulin pattern and surrogate immunophenotypical markers such as glypican-3, may be helpful for that purpose. Further molecular screening for chromosomal abnormalities has been recently shown to be helpful in the diagnosis of atypical hepatocellular neoplasms, defined as “HCA with focal atypical morphological features or unusual clinical settings, including HCA occurring in men” (5). Indeed, those atypical HCA share similar chromosomal alterations to HCC. Given all these considerations, a biopsy diagnosis has poor predictive value and due to the high potential for these HCA to transform to HCC, systematic resection should be considered in all cases, independent of their size.
References According to the genotype-phenotype classification of HCA, when morphologically characterized by presence of cellular atypia and pseudo-glandular formation, as illustrated in our case, HCA displayed -catenin mutations and were predominantly described in male patients (4). In this subgroup of tumors, several were considered borderline, difficult to classify between HCA and HCC or associated with HCC. The link between -catenin mutations and the higher risk for malignant transformation into HCC is now well established and reinforced by recent data showing -catenin activation in 64% of HCA with superimposed HCC (personal data). By contrast to the other subtypes (Tel/Infl and steatotic), -catenin–activated HCA do not present specific
1. Velazquez I, Alter BP. Androgens and liver tumors: Fanconi’s anemia and non-Fanconi’s conditions. Am J Hematol. 2004;77:257–267 2. Gorayski P, Thompson CH, Subhash HS, Thomas AC. Hepatocellular carcinoma associated with recreational anabolic steroid use. Br J Sports Med. 2008;42:74–75. 3. Paradis V, Zalinski S, Chelbi E, et al. Hepatocellular carcinomas in patients with metabolic syndrome often develop without significant fibrosis: a pathological analysis. Hepatology. 2009;49:851–859. 4. Zucman-Rossi J, Jeannot E, Van Nhieu JT, et al. Genotype-phenotype correlation in hepatocellular adenoma: new classification and relationship with HCC. Hepatology. 2006;43:515–524. 5. Kakar S, Chen X, Ho C, et al. Chromosomal abnormalities determined by comparative genomic hybridization are helpful in the diagnosis of atypical hepatocellular neoplasms. Histopathology. 2009;55:197–205.
24 Biliary Neoplasms KISHA MITCHELL AND DHANPAT JAIN
Most of the benign biliary tumors remain asymptomatic and are discovered incidentally. The malignant tumors also remain asymptomatic in the early stages leading to late detection and poor prognosis. Adenocarcinoma of the bile duct, also referred to as cholangiocarcinoma (CC), is the second most common primary epithelial malignancy of the liver after hepatocellular carcinoma (HCC), accounting for about 15% of all primary malignant hepatic neoplasms (1). Based on the location, it is classified into intrahepatic (so-called
peripheral CC), hilar (Klatskin tumor), and extra hepatic. Despite many common features, there are important differences with regard to etiopathogenesis and management such that the classification by the site is clinically important. Of these, extrahepatic CC constitutes about 40% of all tumors, whereas hilar and intrahepatic tumors constitute 30% each (2). Some use the term CC purely for the intrahepatic tumors, whereas others use this term to designate all bile duct adenocarcinomas.
FIGURE 24. 1 Mass-forming cholangiocarcinoma (CC): (A) solid, unencapsulated but well-defined white, intrahepatic mass. (B) Periductal,
infiltrating CC: The white tumor grows along bile ducts resulting in obstruction and dilatation of the distal bile ducts. The tumor extends into the parenchyma to form a fairly well-defined mass. (C) Periductal stricturing type CC involving the hilar bile ducts (Klatskin’s tumor). No mass is demonstrably present. On the left side, the bile cut is dilated distal to the ill-defined tumor that is present in the region of the suture. These patients often present with obstructive jaundice. (D) Intraductal papillary CC: fleshy polypoid masses within the biliary system. In this case, the tumor is entirely intraductal without parenchymal invasion.
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E P I D E M I OL OG Y
R ISK FACTO R S A ND ET IO LO GY
The incidence of CC is variable worldwide with highest incidence reported from Southeast Asia, Chile, and Japan, largely secondary to parasitic infections of the liver (3,4). In Thailand, CC occurs at an incidence rate of 88 per 100 000 in men and 37 per 100 000 in women (1). The parasitic infections associated with CC are Opisthorchis viverrini and Clonorchis sinensis, which are endemic in these parts of the world. Even in United States, the incidence of CC is increasing and has reportedly risen by 165% between 1975 and 1999 (4). CC typically occurs in the elderly, presenting most commonly in the seventh decade of life and is more common in men than women (M:F ratio is 1.5:1). In the United States, the highest incidence occurs in Hispanics and the lowest in African Americans (4). This increase in incidence has been similarly accompanied by an increase in mortality. In Italy, a 40-fold increase in mortality was reported between 1980 and 2003 (4). Overall, the prognosis of CC remains poor.
The vast majority of CCs (80–85%) arise in patients without any known risk factor or background of cirrhosis (4,5). Known risk factors include chronic biliary inflammation, liver disease, and congenital disorders (6). Primary sclerosing cholangitis (PSC) is the most consistent risk factor associated with CC in Western countries. Patients with PSC have a cumulative annual risk of 1.5% per year for CC after the development of jaundice (5). The majority of PSC-associated CC cases are diagnosed within a year following diagnosis of PSC, and 27% of patients are diagnosed following liver transplantation (7). Additional risk factors in the setting of PSC include older age at diagnosis (though PSC patients develop CC younger than the general population) (8), history of inflammatory bowel disease with dysplasia or malignancy, smoking, and alcohol use (4). Infestation with liver parasites (Opisthorchis viverrini, Clonorchis sinensis, and Schistosoma japonicum) is also a significant risk factor with increased prevalence in endemic areas
FIGURE 24. 2 (A) Well-differentiated, conspicuous gland-forming cholangiocarcinoma (CC) with focally cribriform glands. (B) Moderately differentiated CC with narrow tubules and ducts embedded in dense, collagenous stroma. (C) CC with extensive perineural infiltration. (D) Undifferentiated CC composed of bizarre cells without glandular differentiation.
CHAPTER
24:
BILIARY
(9). Presumably, the ensuing chronic inflammation following colonization by the parasite predisposes to risk of malignancy. Similarly, hepatolithiasis is also thought to result in increased risk of CC. Patients who have late resection (>20 years) of a choledochal cyst are also at increased risk of CC, as are patients who have abnormal pancreaticobiliary junctions and various other biliary malformations including Caroli disease. Exposure to toxic compounds such as Thorotrast (thorium dioxide) also predisposes to CC, although this agent has been out of use for decades and new cases attributed to it are unlikely to be encountered. Cirrhosis and, in particular, chronic hepatitis C virus (HCV) are also risk factors for CC with 10-fold and 4-fold higher risks reported respectively (5). PAT H OL OG Y
Though cirrhosis is a risk factor, CC most comonly arises in a noncirrhotic liver. Based on the gross appearance, it is often
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363
classified into 3 types (Figures 24.1A–D). The mass-forming type is the commonest and is represented by a gray-white, firm, solid intrahepatic mass (Figure 24.1A). The periductal infiltrating-type rarely forms a big mass. It spreads along portal tracts resulting in biliary strictures of involved ducts (Figures 24.1B and 24.1C). The intraductal-type is typically a polypoid mass that grows predominantly within the duct lumen (Figure 24.1D). Any combination of the three may be seen in a single case. Histologically, CC is an adenocarcinoma and may have many different histologic patterns with many recognized histologic subtypes (Figures 24.2 and 24.3) (2). CC may be very well differentiated (Figure 24.2A); however, the most common pattern is infiltrating, well to moderately differentiated with tubular or glandular structures dispersed within a very dense fibrotic stroma (desmoplasia) (Figure 24.2B), often with conspicuous perineural invasion (Figure 24.2C). The glandular component can also show cribriform, nesting, cord-like, or
FIGURE 24. 3 (A) Intraductal papillary cholangiocarcinoma (CC): The tumor is entirely within the lumen of the bile duct with a papillary
configuration. (B) Clear cell CC: extensive clear cytoplasmic change with small, often basally located nuclei; areas of gland formation are present. (C) von Meyenburg complex (VMC)-like pattern: dilated and angulated tubules with eosinophilic luminal material within a fibrotic stroma. (D) Oncocytic CC: abundant deeply eosinophilic cytoplasm and only mildly atypical nuclei.
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NEOPLASMS
Variant
Morphology
Typical
Tubular or papillary structures, often within desmoplastic stroma cribriforming mucin
Adenosquamous and squamous
Significant squamous component with keratin and/or intercellular bridges, often advanced stage at diagnosis
Mucinous
Abundant extracellular mucin with floating tumor clusters
Signet-ring cell
Predominant component is signet-ring cells within mucin lakes
immunohistochemistry. CC can be differentiated from HCC in most cases without significant difficulty, largely based solely on morphology or aided by a small panel of immunohistochemical markers. The greater difficulty often lies in differentiating CC from other metastatic carcinomas. Specific immunohistochemical markers for CC are lacking, and its separation from metastatic carcinomas requires the demonstration of a specific differentiation marker for other tumor types (eg, thyroid transcription factor, prostate specific antigen, gross cystic disease fluid protein, etc.). In practice, the tumor morphology and the clinical setting should dictate the choice of the immunohistochemical panel.
Sarcomatous
Predominant spindle cell component that is malignant fibrous histiocytoma or fibrosarcoma-like
T R EAT MENT A ND P RO GNO SIS
Lymphoepithelioma-like
Identical to extrahepatic variant with rich lymphoplasmacytic stroma
Clear cell
Predominantly abundant clear cytoplasm
Mucoepidermoid
Resembles salivary gland tumors with epidermoid, mucous secreting, and intermediate cells
TA B LE 24. 1 Variants of cholangiocarcinoma
Complete surgical resection offers the only chance of cure for these aggressive tumors, although the majority of cases at presentation are unresectable. Liver transplant for CC is offered only for a subset of patients that fulfill very strict criteria at limited centers and still remains controversial.
From Ref. 1.
papillary patterns. Poor differentiation is not uncommon, and some tumors may even be undifferentiated (Figure 24.2D). Other variants described in CC include mucinous, squamous, clear cell, papillary, oncocytic, or spindle/sarcomatoid (Figure 24.3A–D) (Table 24.1) (1). The immunophenotype of CC is not very distinctive. CC is positive for cytokeratins (CK) 7 and 19 and mucin core (MUC) proteins 1, 2, and 3 by immunohistochemistry. Positivity for CK20 may also be seen in a subset of CCs. They are also immunoreactive for MOC 31 and carcinoembryonic antigen (CEA). The positivity for polyclonal CEA (pCEA) tends to be cytoplasmic and surface, which is different from canalicular positivity of HCC. CC is negative for hepatocyte antigen (Hep Par 1), glypican-3, albumin, and AFP. DIF FE R E N T I A L D I AG N OSI S A N D P R AC T I C A L I SSUES
Most commonly, CC needs to be distinguished from benign biliary tumors on one hand and metastatic carcinoma and HCC on the other. The differentiation of CC from benign lesions is largely dependent on histomorphology, whereas differentiation from other malignant tumors often requires
References 1. Nakanuma Y, Curado M, Franceschi S, Gores G, Pradis V, Sripa B. Intrahepatic Cholangiocarcinoma. In: Bosman FT, Carneiro F, Hruban RH, Theise ND, editors. WHO Classification of tumors of the digestive system. Lyon: IARC Press; 2010. P217-224. 2. Goodman ZD. Neoplasms of the liver. Mod Pathol. 2007;(20 suppl 1): S49–S60. 3. Shaib Y, El-Serag HB. The epidemiology of cholangiocarcinoma. Semin Liver Dis. 2004;24(2):115–125. 4. Gatto M, Bragazzi MC, Semeraro R, et al. Cholangiocarcinoma: update and future perspectives. Dig Liver Dis. 2010;42(4):253–260. 5. Aljiffry M, Walsh MJ, Molinari M. Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990–2009. World J Gastroenterol. 2009;15(34):4240–4262. 6. Bosch FX, Ribes J, Diaz M, Cleries R. Primary liver cancer: worldwide incidence and trends. Gastroenterology. 2004;127(5 suppl 1):S5–S16. 7. Boberg KM, Bergquist A, Mitchell S, et al. Cholangiocarcinoma in primary sclerosing cholangitis: risk factors and clinical presentation. Scand J Gastroenterol. 2002;37(10):1205–1211. 8. Bergquist A, Broome U. Hepatobiliary and extra-hepatic malignancies in primary sclerosing cholangitis. Best Pract Res Clin Gastroenterol. 2001;15(4):643–656. 9. Poomphakwaen K, Promthet S, Kamsa-Ard S, et al. Risk factors for cholangiocarcinoma in Khon Kaen, Thailand: a nested case-control study. Asian Pac J Cancer Prev. 2009;10(2):251–258.
Case 24.1
Bile Duct Adenoma Versus Biliary Hamartoma KISHA MITCHELL AND DHANPAT JAIN
C L I N I C AL I N F OR M AT I ON
A 46-year-old woman was found to have a 1.5 cm white nodule in the right lobe of her liver during abdominal imaging undertaken for uterine fibroids. She had never used oral contraceptives and denied alcohol or other drug use.
PAT H OL OG I C F E AT U R E S
The liver biopsy showed a proliferation of small angulated and round ducts, densely hyalinized stroma, and scattered chronic inflammatory cells (Figures 24.1.1A,B). The ducts have bland cuboidal to low columnar biliary-type epithelium with minimal pleomorphism. No mitotic figures or necrosis were seen. Few benign lymphoid aggregates were seen at the periphery. Scant amount of adjacent benign liver parenchyma present appeared normal.
R E A S ON F OR R E F E R R A L
To distinguish between bile duct adenoma (BDA), VMC, welldifferentiated CC, and metastatic adenocarcinoma (MA).
FIGURE 24.1.1 (A) Core biopsy with variable architecture, some areas
are extensively hyalinized and sparsely cellular, others with a proliferation of small angulated and round ducts with less stroma. The poor definition of the rounded border renders distinction from carcinoma difficult. (B) High power view showing an area of relatively greater cellularity with minimal atypia of individual cells.
FIGURE 24. 1. 2 (A) Resection specimen with small tan nodule in right lobe of liver. (B) Well-circumscribed lesion with conspicuous zonal pattern due to marked cellularity peripherally and sclerosis centrally. (C) Zonal pattern of bile duct adenoma highlighted by Masson’s Trichrome stain.
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D I AG N OS I S
Bile duct adenoma.
D I SC U SSI ON
Differentiation from VMC is relatively easy, since the lesion lacks cystic dilatation of the glands, insipissated bile, and is relatively large for a VMC (1.5 cm). On the contrary, differentiation from a well-differentiated CC is extremely difficult. Lack of mitosis, significant nuclear atypia, and tumor type desmoplasia favors BDA, although none of these features by themselves is sufficiently specific to exclude a CC on needle biopsy. Since the possibility of well-differentiated CC could not be completely excluded, a wedge resection of the liver was subsequently undertaken (Figures 24.1.2A–C), which confirmed the diagnosis of BDA.
NEOPLASMS
BDAs rarely result in a needle biopsy; however, when a biopsy is undertaken as in this case, the diagnosis can be challenging. The lesions can show features that overlap with VMC on one hand and CC/MA on the other. BDAs are usually 0.5cm to 1.5cm in size, tend to be larger than VMC, but smaller than most CCs (1). They may occur in any area of the liver but, similar to VMCs, are most easily and frequently recognized during gross examination in the subcapsular location. The mean age of affected patients is 55 years (range 1–99 years), and there is no gender predilection. They appear as grey-white, tan, or yellow nodules that are round or oval in shape (Figure 24.1.2A). Though unencapsulated, they are typically well circumscribed (Figure 24.1.2B,C). Extension into the immediately adjacent portal tracts may impart an irregular outline on low magnification. The lesion consists of irregular and somewhat angulated ductular structures in variably collagenized stroma. In most lesions, especially those that are relatively large, the center of the lesion tends to be more
FIGURE 24. 1. 3 (A) Unencapsulated lesion that is distinctly demarcated from the adjacent parenchyma. (B) Central area of prominent hya-
linized sclerosis, devoid of ducts or ductules. (C) Peripheral area of increased cellularity with prominent ducts, less stroma, and no significant atypia. (D) Nodular lymphoid aggregate at periphery of bile duct adenoma.
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HAMARTOMA
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FIGUR E 24. 1. 4 (A) Cut surfaces of liver with multiple, inconspicu-
ous small white nodules (arrows), characteristic of VMC. (B) The nodules (arrows) are also poorly defined from the capsular surface but may be identified with careful observation. F I G U R E 2 4 . 1 . 5 (A) Needle core biopsy of liver with dilated duc-
tular proliferation of VMC, more prominent stroma than in the cellular areas of bile duct adenoma (see Figure 24.1.1). (B) High power highlighting luminal insipissated eosinophilic material.
FIGURE 24. 1. 6 (A) Circumscribed bile duct adenoma with surrounding lymphoid aggregates, occurring with a VMC (arrow). (B) VMC-like area of BDA with mildly dilated glands with luminal material.
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sclerotic with densely eosinophilic hyalinized collagen, and fewer and often compressed ductular structures lined by low cuboidal to flattened epithelium (Figure 24.1.3A–C). At the periphery, BDAs are more cellular with less stroma and the ductular structures are composed of cuboidal to low columnar epithelium. The interface between the lesion and adjacent hepatic parenchyma is well demarcated, a feature that is very helpful in distinguishing BDAs from CCs. BDA lacks infiltrative growth or an expansile growth pattern, and hence the adjacent hepatic parenchyma lacks features of compression or
NEOPLASMS
reactive changes. Rare examples of BDA with oncocytic or clear cells have also been described (2,3). Some lesions may show microcalcification, or even more rarely, noncaseating granulomas. Portal tracts with normal bile ducts can often be identified in the lesion. Variable lymphocytic infiltrate, sometimes forming nodular aggregates, can be seen at the periphery (Figure 24.1.3D). In contrast, VMC are usually smaller (<0.5 cm) (Figures 24.1.4A,B) and have fewer ducts with more abundant stroma (Figure 24.1.5A,B). The ductules are curvilinear, irregularly
FIGURE 24. 1. 7 (A) Needle biopsy of CC with similar morphology to bile duct adenoma (see Figure 24.1.1) at low power. Note, however, marked hyperchromasia and pleomorphism of cells, seen even at this power. (B) High power view of biopsy showing atypical cells in stroma; cytologic atypia is prominent within hyalinized and sclerotic stroma (see Figure 24.1.1).
CASE
24.1:
BILE
DUCT
ADENOMA
shaped or dilated, and often contain insipissated eosinophilic material and/or bile. The lining epithelial cells tend to be more cuboidal or flattened, and the lesion appears less cellular than a BDA. BDA and VMC may have some overlapping features and the distinction is based on somewhat arbitrary histologic criteria. VMC are considered a remnant of embryonic ductal plate, and have been associated with fibropolycystic disorders (ductal plate malformations) of the liver. More commonly, however, they occur as sporadic lesions in older individuals with peak incidence between the sixth and seventh decades of life. It is possible that these are acquired lesions rather than true hamartomas (see Chapter 8). The ductules in both lesions lack significant atypia, mitosis and an infiltrative growth pattern, and are typically uniform and bland, important features in differentiation from CCs. BDA has generally been considered a benign biliary neoplasm, although one study proposed it to be a benign proliferation of peribiliary glands and thus considered these lesions “peri-biliary gland hamartomas” (4). In this study, the glandular structures of BDA, unlike VMC, were found to be immunoreactive to “peri-biliary-gland–specific” antigens (D10 and 1F6), which do not react with bile duct epithelium. Interestingly, one of the antibodies (1F6) also stained canals of Herring and is possibly a marker of progenitor cells; however, no further studies have been published in this regard. Despite the apparent differences between VMC and BDA, the authors have seen cases where both lesions were present in the same patient (Figure 24.1.6A), as well as lesions with overlapping features (Figure 24.1.6B, also see Case 25.3). We believe that these lesions may represent a spectrum of benign biliary proliferations. Although the true nature of VMCs and BDAs has not been decisively clarified, the main clinical significance lies in their differentiation from CC or MA. It should also be recognized that they might be associated with CC in some cases (see Case 25.3). Both VMC and BDA are asymptomatic and are most often incidentally identified as tiny nodules or cysts during imaging studies, abdominal surgery, or at autopsy.
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BILIARY
HAMARTOMA
369
When identified during abdominal surgery, the major issue is distinction from a CC or metastasis, which often leads to an intra-operative frozen section consultation. As in this case, the other differential diagnosis for a BDA often is a well-differentiated CC, which can be very challenging on needle biopsies. In the largest series of BDA (n 152), about 35 were diagnosed as CC, and additional 20 were suspected to be malignant (1). The correct diagnosis of BDA was made in only 51 cases. In this study, both resection and biopsies were included, although it is not clear how many of the needle biopsies were among the misdiagnosed cases. The lack of mitosis, nuclear irregularity, and nuclear enlargement favor a benign lesion; however, some CC can be extremely well differentiated and could appear identical on needle biopsies, particularly in the setting of marked sclerosis (Figures 24.1.7A,B). The small size of the lesion (2 cm) favors BDA. The circumscribed, nonexpansile growth pattern can be extremely difficult to evaluate on needle biopsies. MA may also be small but is seldom a problem, other than in the intra-operative consultation setting. Most MAs have atypical cytologic and architectural features that render the distinction relatively simple. In addition, the clinical setting, presence of multiple lesions, knowledge of the morphology of the primary tumor, and sometimes the distinctive immunophenotype help to establish a diagnosis of metastasis. Among metastatic tumors, pancreatic ductal carcinomas are more often likely to cause diagnostic difficulties than other tumors due to their similarity with CC.
References 1. Allaire GS, Rabin L, Ishak KG, Sesterhenn IA. Bile duct adenoma. A study of 152 cases. Am J Surg Pathol. 1988;12(9):708–715. 2. Albores-Saavedra J, Hoang MP, Murakata LA, Sinkre P, Yaziji H. Atypical bile duct adenoma, clear cell type: a previously undescribed tumor of the liver. Am J Surg Pathol. 2001;25(7):956–960. 3. Arena V, Arena E, Stigliano E, Capelli A. Bile duct adenoma with oncocytic features. Histopathology. 2006;49(3):318–320. 4. Bhathal PS, Hughes NR, Goodman ZD. The so-called bile duct adenoma is a peribiliary gland hamartoma. Am J Surg Pathol. 1996;20(7):858–864.
Case 24.2
Intrahepatic Cholangiocarcinoma Versus Hepatocellular Carcinoma KISHA MITCHELL AND DHANPAT JAIN
C L I N I C A L F E AT U R E S
A 67-year-old man with a 15-year history of chronic hepatitis C and cirrhosis presented with a 3-week history of abdominal pain and weight loss. Laboratory investigation revealed a low serum albumin, prolonged prothrombin time (PT), normal liver enzymes, and mildly elevated serum alpha-fetoprotein (AFP). Abdominal computed tomography (CT) scan showed a 4.5 cm right lobe mass in a background of cirrhosis. The tumor demonstrated delayed enhancement without washout in the venous phase.
PAT H OL OG I C F E AT U R E S
The needle core biopsy showed moderately pleomorphic plump tumor cells arranged in nests, trabeculae and ill-defined glands, and no significant mitotic activity (Figures 24.2.1A,B). Focal areas suggested squamoid and even neuroendocrine differentiation. There was no mucin.
R E A SON F OR R E F F E R A L
In the absence of well-defined glandular features and in the clinical setting of hepatitis C cirrhosis, the tumor was suspected to be hepatocellular carcinoma (HCC) with a differential diagnosis of cholangiocarcinoma.
DIAGNO SIS
Intrahepatic cholangiocarcinoma.
DISCUSSIO N
Though the morphology of the tumor lacks the typical welldefined glandular architecture of a CC, it also lacks the distinctive features of HCC, and raises a concern for metastasis. This is a fairly common situation in clinical practice. Nesting and trabecular growth patterns are more common with HCC compared with CC; however, the tumor lacks the “hepatocytelike” appearance of cells or prominent eosinophilic nucleoli of HCC. Areas of nesting and trabecular growth pattern may be seen in CC, most often at the periphery of the tumor. The focally squamoid appearing areas favor CC and metastasis over HCC. The radiology findings also support CC. Most CCs are well to moderately differentiated. The tumor borders are irregular and have an infiltrative type pattern of growth into the surrounding liver, even if focal, and the tumor is often seen effacing adjacent portal tracts. Some foci of greater atypia are usually seen. In poorly differentiated tumors, single cells and small cords may be seen, often with abundant eosinophilic cytoplasm or markedly anaplastic morphology. In the appropriate clinical context (exclusion of primary tumors
FIGURE 24. 2. 1 (A) Needle biopsy with proliferating plump, atypical cells without distinct glandular differentiation. (B) Cells nesting in a
neuroendocrine-like fashion with somewhat squamoid appearance of cells.
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from other sites) and supportive immunohistochemical profile, this morphology should lead to the diagnosis of CC. In this case, a panel of immunohistochemical markers was used that included Hep Par 1, AFP, MOC 31, cytokeratin (CK) 7, CK19, CK5/6, p63, chromogranin, synaptophysin, and pCEA, which showed the tumor to be positive for MOC 31, CK7, CK19, and pCEA (cytoplasmic staining) (Figures 24.2.2A,B). This pattern, though excluding HCC, squamous cell carcinoma, and endocrine tumors, does not reliably differentiate between CC and MA from various sites. This is also a common problem in clinical practice. In the presence of cirrhosis and lack of evidence of tumor elsewhere, supported by negative tumor markers, imaging studies, negative past history, and negative positron emission tomography (PET) scan, a final diagnosis of CC was made. The possibility that this might represent a metastasis from an occult primary cannot be entirely excluded. Intrahepatic CC is morphologically indistinguishable from many extrahepatic adenocarcinomas, especially extrahepatic CC and pancreatic adenocarcinoma. The choice of immunohistochemical markers to differentiate CC from a metastatic carcinoma depends on the morphology and the clinical setting (gender, age, past medical history, chief complaints etc.). In this case, because of the solid nests and focal suggestion of squamoid differentiation, CK5/6, p63, and endocrine markers were employed, which were all negative. Based on the appropriate clinical context, additional markers may be added from a panel of estrogen receptor, progesterone receptor, gross cystic disease fluid protein, Her-2/neu, CDX2, villin, CK5/6, p63, TTF-1, prostate specific antigen, prostatic acid phosphatase, placental alkaline phosphatase, uroplakin, chromogranin, synaptophysin, AFP, CD10, melan A, inhibin, and S100, among others. The choice of immunohistochemical markers may vary depending on available resources and local experience. In tumors showing glandular differentiation, staining for mucin core polypeptides (Muc1–6) can be considered, although we have found this to be less useful in practice.
VS.
H E PAT O C E L L U L A R
CARCINOMA
371
A minority of CC may be partially or wholly composed of areas with variable morphology. In some CC, the glands may be large and cribriforming with extensive mucinous differentiation, although lacking the usual fibrous stroma. Mucinous carcinomas with intestinal or gastric phenotype have also been described, characterized wholly by tumor clusters floating within large mucin pools. Other prominent histologic variants of CC include papillary, CC with squamous differentiation, clear cell, spindle/sarcomatoid, mucoepidermoid, lymphoepithelioma-like, and anaplastic (1), and some variants tend to have predominant or exclusive intraductal growth. Papillary features comprised of typical columnar or cuboidal cells arranged around fibrovascular cores may be present and demonstrate mucin in the apical rim of the cytoplasm. The areas of squamous differentiation may or may not show overt keratinization and are not typically associated with squamous metaplasia in otherwise adjacent benign ducts. The clear cell variant is composed of medium-sized to large glands with basally arranged small nuclei and abundant clear cytoplasm (see Chapter 24, Figure 24.3B). The lymphoepithelioma-like variant shows EBV-coded RNAs similar to the identical tumors that occur in extrahepatic locations. The spindle cell or sarcomatoid component may resemble other true sarcomas such as fibrosarcoma. Two other situations can result in confusion in practice. First, in the setting of cirrhosis with increased serum AFP, biopsies of tumors that clearly appear glandular and stain like adenocarcinoma (CK7+, CK19+, Moc31+, and Hep Par 1-) may be mixed HCC-CC. Depending on the sampling, one may see either or both components in the biopsy. Occasionally, AFP and/or other hepatocytic markers might show some staining in the glandular component and support a mixed tumor. If dynamic imaging characteristics indicative of HCC and a significantly raised serum AFP (>200U) are present, these also suggest a component of HCC, and this should be included in the biopsy report.
FIGURE 24. 2. 2 (A) cytokeratin (CK) 7 positivity in CC (CK19 has a similar pattern). (B) Cytoplasmic polyclonal CEA positivity in CC.
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The second situation is that in which some HCCs show positivity for CK19 and CK7, markers that are typically associated with CC, though retaining other hepatocytic markers in varying combinations (HepPar-1, canalicular pCEA, and AFP). This phenotype may be seen in HCC arising in a liver with less fibrosis or without cirrhosis and is associated with poorer prognosis; thus, sharing many characteristics with CC (2). These tumors have now been reclassified by WHO as mixed HCC-CC with stem cell features. Differentiation of CC from a metastasis is often difficult since there is no specific marker for bile duct origin. The clinical situation, serum markers, imaging studies, and tumor morphology should be carefully evaluated to come up with likely
NEOPLASMS
primary sites. It is not necessary to throw the entire panel of immunohistochemical markers at all cases. Evaluation of the genotype of a tumor based on molecular techniques may eventually be helpful; however, the current data are insufficient to advocate their routine use.
References 1. Nakajima T, Kondo Y, Miyazaki M, Okui K. A histopathologic study of 102 cases of intrahepatic cholangiocarcinoma: histologic classification and modes of spreading. Hum Pathol. 1988;19(10):1228–1234. 2. Durnez A, Verslype C, Nevens F, et al. The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin. Histopathology. 2006;49(2):138–151.
Case 24.3
Cholangiocarcinoma in Association With Von Meyenburg Complexes KISHA MITCHELL AND DHANPAT JAIN
C L IN I C AL F E AT U R E S
R EA SO N FO R R EFER R A L
A 61-year-old woman presented with a 3-week history of abdominal pain and weight loss. On examination, she was jaundiced with a mildly enlarged liver. Laboratory investigation revealed minimal liver enzyme abnormalities, normal serum albumin, and normal PT. Serum CA 19-9 was moderately elevated, whereas serum AFP, CA 125, and carcinoembryonic antigen (CEA) were normal. Abdominal CT scan revealed multiple small hypodense lesions through the left lobe of the liver with a dominant 4 cm left lobe liver mass.
The tumor had features of CC; however, it was unclear whether the entire biliary proliferation was malignant.
DIAGNO SIS
Cholangiocarcinoma in association with VMC/bile duct hamartomas.
DISCUSSIO N PAT H OL OG I C F E AT U R E S
The left lobectomy showed a 4 cm adenocarcinoma in a noncirrhotic liver. The tumor was composed of variably sized but predominantly small atypical glands in a desmoplastic stroma. The tumor had an infiltrative and destructive growth pattern with replacement of hepatic parenchyma and normal portal structures (Figures 24.3.1A,B). Based on the histology, the features are typical of a well- to moderately differentiated intrahepatic CC. Multiple separate and adjacent nodules (0.2–1.5 cm) were seen, raising a concern for multifocal CC or intrahepatic metastasis. Some of these nodules were <0.5 cm and represented VMC, whereas others were larger, more cellular, and architecturally atypical (Figures 24.3.2A–D).
The histological features are typical of well-to moderately differentiated intrahepatic CC. Immunostains are not required in this setting. The issue in this case is the multiple separate and adjacent nodules (0.2–1.5 cm) that raise a concern for multifocal CC or intrahepatic metastasis. Some of these nodules are clearly VMC, whereas others are clearly more atypical (Figure 24.3.2A). The VMC shows irregular and branching ductular profiles, some of which are dilated with insipissated bile, in a sclerotic stroma (Figure 24.3.2B). Some of the larger lesions although still circumscribed are more cellular and show more compact glands with scant stroma (Figure 24.3.2C). Preserved portal structures are identified in some areas of the lesion, along with few aggregates of benign lymphocytes (Figure 24.3.2A). In some areas, there is minimal nuclear
FIGURE 24. 3. 1 (A) Heterogenous morphology of tumor with effacement of normal hepatic parenchyma. (B) Compact ductular proliferation
centrally with dilated atypical ducts at the periphery of the image; normal portal tracts are overrun by this proliferation.
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FIGURE 24. 3. 2 (A) Diverse morphology of tumor and adjacent nodules, VMC-like areas, typical CC-like areas, and sclerotic nodule with embedded atrophic ducts and lymphoid aggregates at the periphery. (B) Areas with typical dilated ducts of VMC with luminal material and without atypia. (C) VMC-like areas with complex architecture, increased cellularity, and some atypia. (D) Indistinguishable border between typical VMC area and carcinoma.
pleomorphism and no easily identifiable mitoses are seen. Some areas that resemble VMC blend imperceptibly with the tumor (Figure 24.3.2D) with one area showing features of both VMC and BDA (see Case 24.1, Figure 24.1.6B). Transformation of VMC to CC is a rare phenomenon, and only a few cases and a single case series have been reported in the literature (1–2). CC associated with VMC appears to have no distinctive clinical or morphologic features but raises some important diagnostic problems. First, VMC and intermediate lesions should be identified as benign lesions and not overinterpreted as CC or determined to represent its spread. Second, the risk of subsequent CC and need for close followup have not been resolved in this setting of multiple VMCs. It has been recently suggested that VMC may be the precursor to a subset of CC and that these various biliary proliferations in such cases represent neoplastic progression of VMC. Limited morphologic and molecular data exist that support the link between VMC and CC in such cases (3). The presence of
multiple VMCs and intermediate lesions in the background liver likely increases the risk of developing multiple tumors and a second CC. The natural history of such cases remains unknown and follow-up protocols have not been developed. At this point, it may suffice to say that careful monitoring may be warranted in these patients compared with those without any VMCs or other intermediate biliary proliferations.
References 1. Xu AM, Xian ZH, Zhang SH, Chen XF. Intrahepatic cholangiocarcinoma arising in multiple bile duct hamartomas: report of two cases and review of the literature. Eur J Gastroenterol Hepatol. 2009;21(5):580–584. 2. Jain D, Sarode VR, Abdul-Karim FW, Homer R, Robert ME. Evidence for the neoplastic transformation of Von-Meyenburg complexes. Am J Surg Pathol. 2000;24(8):1131–1139. 3. Jain D, Ahrens W, Finkelstein S. Molecular evidence for the neoplastic potential of hepatic Von-Meyenburg complexes. Appl Immunohistochem Mol Morphol. 2010;18(2):166–171.
Case 24.4
Diagnosis of Hilar/Extrahepatic Cholangiocarcinoma KISHA MITCHELL AND DHANPAT JAIN
C L IN I C AL F E AT U R E S
PAT H O LO GIC FEAT UR ES
A 36-year-old man with a 6-year history of primary sclerosing cholangitis (PSC) and a history of a total proctocolectomy for ulcerative colitis 3 years prior presented with progressively worsening jaundice, abdominal pain, and increased abdominal distension. Endoscopic retrograde cholangiopancreatography (ERCP) revealed a stricture in the common bile duct. Initial biopsies of the common bile duct were negative (Figures 24.4.1A–D). The brushing of the bile duct revealed atypical cells but was inconclusive for malignancy. Due to the strong clinical suspicion, repeat biopsies were performed and showed scanty atypical fragments (Figure 24.4.2).
Both biopsies were composed of tiny tissue fragments with crush artifacts. The initial biopsies had markedly inflamed, ulcerated fragments with fibrotic stroma, and minimal epithelium (Figures 24.2.1A–D). The subsequent biopsy fragments were also scant but relatively more cellular (Figures 24.2.2A,B). The epithelium was atypical with hyperchromatic nuclei, pleomorphism, and mitoses. The epithelium adherent to the tissues was scant. Few crushed cells and glandular structures were seen in the fibro-collagenous stroma that were suspicious for carcinoma.
FIGURE 24. 4. 1 (A) Three small biopsy fragments. (B) One ulcerated fragment with reactive granulation tissue–like areas. Prominent perpen-
dicularly oriented vessels are simulating glands. (C) No epithelium present on this fragment with reactive stromal changes. (D) High power of stroma without definite tumor cells.
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R E A S ON F OR R E F E R R A L
Definite categorization of scanty fragments of atypical epithelium with crushing artifact.
D I AG N OS I S
Hilar cholangiocarcinoma (Klatskin tumor).
D I SC U SSI ON
Bile duct biopsies are among the most difficult to interpret for many reasons. The tissue fragments are often small and artifacts are common. Bile duct carcinoma can appear deceptively bland, whereas reactive epithelium may be markedly atypical and look ominous. In addition, biopsies are often taken after biliary stents have been in place resulting in marked inflammation and reactive atypia (Figure 24.4.3). In some instances, the presence of normal peri-biliary glands in the wall may be confused with invasive glands. Lastly, the use of newer endoscopes though allowing for better visualization of biliary epithelium and more targeted biopsies, yields miniscule biopsy fragments. The implications of a positive diagnosis of malignancy are far reaching since it may result in a major surgical resection; alternatively, a delay in the diagnosis can lead to a resectable tumor becoming unresectable. The difficulty in interpretation of these bile duct biopsies cannot be overstated, and it is important to develop a practical approach that entails a review of not only the cytologic and architectural details but also the clinical context. The cytology of reactive epithelium can be very atypical, and prior history of local irritation, trauma, or inflammation (prior procedure, stent, or stone) can be helpful in setting a higher threshold for dysplasia or malignancy. Similarly, one should be extremely careful in diagnosing neoplasia in desquamated epithelium, which can show significant artifacts. The presence of nuclei twice the size of adjacent normal nuclei is suggestive of neoplastic change. Crowding of glands with back-to-back arrangement and cribriforming are also useful clues to neoplastic change. While looking at the glands deeper in the stroma, the arrangement of glands should be carefully evaluated as to whether the lobular architecture is preserved. Additional HE levels may often prove to be very helpful and should be used liberally. Occasionally, the use of CK7/CK19 to identify single cells embedded within desmoplastic stroma may be helpful. However, as far as is possible, these should be interpreted only after careful review of the HE stain (Figure 24.4.2C). Several molecular methods have been suggested to aid in the diagnosis of CC, but none can be advocated for routine clinical use. Diagnostic accuracy may often be improved by seeking a second opinion. If a malignant diagnosis remains uncertain and a major surgical resection is contemplated, repeat biopsies (sooner than later) should be suggested.
F I G U R E 2 4 . 4 . 2 (A) Crushed biopsy fragment with marked chronic inflammation and surface erosion with scant surface epithelium; there are no discernible epithelial cells in stroma. (B) Different fragment with non-neoplastic mucosal glands, detached epithelium, and marked inflammation. (C) Cytokeratin stain (AE1–AE3) highlighting single and small clusters of carcinoma cells.
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H I L A R / E X T R A H E PAT I C
CHOLANGIOCARCINOMA
377
include urothelial and colon carcinoma (1). Endocrine tumors of the extrahepatic bile ducts are also rare, however, are most commonly seen in the common bile duct and at the hilar region (2). Rarely granular cell tumors of the bile duct may result in strictures, and the epithelium overlying the lesion may mimic epithelial dysplasia or malignancy (3). Other nonneoplastic entities that may lead to bile duct strictures and atypia include autoimmune cholangiopathy and IgG4-related disease (4).
References
FIGURE 24. 4. 3 Markedly reactive bile duct epithelium from biopsy
of stented bile duct: acute and chronic inflammation with nuclear pseudostratification and crowding.
In addition to hilar cholangiocarcinoma, other entities should be entertained in evaluation of duct strictures or atypia/malignancy involving hilar bile ducts. Although rare, metastatic adenocarcinoma may involve the hilar bile ducts. Tumors that have been reported to cause intrabiliary metastasis
1. Hong SP, Park SW, Lee SJ, et al. Bile duct wall metastasis from micropapillary variant transitional cell carcinoma of the urinary bladder mimicking primary hilar cholangiocarcinoma. Gastrointest Endosc. 2002;56(5):756–760. 2. El Rassi ZS, Mohsine RM, Berger F, Thierry P, Partensky CC. Endocrine tumors of the extrahepatic bile ducts. Pathological and clinical aspects, surgical management and outcome. Hepatogastroenterology. 2004;51(59):1295–1300. 3. Eisen RN, Kirby WM, O,Quinn JL. Granular cell tumor of the biliary tree. A report of two cases and a review of the literature. Am J Surg Pathol. 1991;15(5):460–465. 4. Hamano H, Kawa S, Uehara T, Ochi Y, Takayama M, Komatsu K, et al. Immunoglobulin G4-related lymphoplasmacytic sclerosing cholangitis that mimics infiltrating hilar cholangiocarcinoma: part of a spectrum of autoimmune pancreatitis? Gastrointest Endosc. 2005;62(1):152–157.
Case 24.5
Bile Duct Cystadenoma/Carcinoma Versus Foregut Cyst KISHA MITCHELL AND DHANPAT JAIN
C L I N I C A L F E AT U R E S
DISCUSSIO N
A 25-year-old man underwent abdominal ultrasound for nonspecific abdominal complaints. The liver showed a 5 cm complex cystic lesion in the right lobe. The radiological differential diagnosis included solitary bile duct cyst, bile duct (hepatobiliary) cystadenoma, developmental cyst (ciliated foregut cyst), and a cystic CC. Due to the focal complexity seen on imaging, he underwent surgical resection of the cyst.
In practice, liver cysts are not uncommon and may be due to a variety of neoplastic and nonneoplastic lesions, including parasitic cysts, congenital development cysts (enteric duplication cyst or foregut ciliated cysts), cystadenomas and cystadenocarcinomas, mucinous adenocarcinoma, or metastasis with cystic degeneration. Radiologically, distinction between a hepatic foregut cyst and a biliary cystadenoma is not reliable. The histologic features seen here easily exclude a parasitic cyst (see Chapter 8). Since this cyst is epithelial in nature, the reasonable differential diagnosis in this case includes mucinous cystic neoplasm (adenoma or carcinoma) and ciliated foregut cyst. Further sampling showed a focal area of dense stroma that has “ovarian-stroma like” characteristics (Figure 24.5.3A), which strongly favored hepatobiliary cystic neoplasm. This was confirmed by the positive nuclear staining for estrogen receptor (ER) and progesterone receptor (PR) (Figure 24.5.3B). The presence of atypia in the epithelium raised a concern for carcinoma, and additional sections demonstrated a focus of invasive glands in the stroma (Figures 24.5.2A,B). The lack of cilia, subepithelial connective tissue, or smooth muscle argue against a ciliated foregut cyst. Hepatobiliary cystadenomas (HCA) have not been as well characterized as their pancreatic counterparts. These cystic neoplasms are rare, premalignant lesions that occur most commonly in women, although cases have also been described in men (1–2). Although long-term data regarding outcome are still lacking, they should be handled similar to pancreatic lesions. For practical purposes, the entire lesion should be examined when possible. HCA more commonly occurs in the right lobe of the liver and is most often multilocular. The
PAT H OL OG I C F E AT U R E S
The lesion was a complex multiloculated cyst containing mucinous material (Figure 24.5.1A). The cyst was lined by biliary type columnar to cuboidal epithelium that shows variable nuclear atypia (Figures 24.5.1A and 24.5.2A). The stroma was dense without definite muscle or ovarian stroma in the wall. Focally, the lining epithelium showed marked cytologic atypia that approached carcinoma in situ. R E A S ON F OR R E F E R R A L
Hepatobiliary cystadenoma was suspected but no definite ovarian stroma was seen. Some areas showed the marked atypia, raising concern for malignancy.
D I AG N OSI S
Focally invasive adenocarcinoma arising in a hepatobiliary cystadenoma.
FIGURE 24. 5. 1 (A) Multilocular cyst with adjacent hepatocytes (top right) (B) Bland, nonciliated columnar epithelium.
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379
FIGURE 24. 5. 2 (A) Hypercellular cyst lining with focally papillary configuration, marked reactive changes to stroma with prominent vessels
simulating glands. (B) Cytokeratin stain (AE1–AE3) highlighting small ducts infiltrating the stroma of the cyst wall.
FIGURE 24. 5. 3 (A) Hypercellular spindle cell stroma, beneath epithelium with unremarkable liver adjacent to cyst wall. (B) Nuclear estro-
gen receptor positivity in ovarian type stroma; this may be helpful in identifying stroma not seen on H&E stain.
cyst is typically lined by biliary type epithelium consisting of cuboidal cells with basally located nuclei and apical mucin. The atypia, though variable, may warrant a diagnosis of carcinoma in situ and can include marked pseudostratification of cells, hyperchromasia of nuclei, loss of polarity, and nuclear enlargement. The epithelium is often extensively denuded, with subjacent sclerotic and fibrotic changes of the stroma and compression of normal hepatic parenchyma. Extensive degenerative changes may be present (Figure 24.5.4). Occasionally, the bile ductules in the subjacent stroma may also appear atypical and should not be overinterpreted as malignant. The characteristic dense, hypercellular ovarian-type stroma may not be seen if the cyst is not adequately sampled and may be absent in some cases, more so in men and children. In some cases, staining for ER and PR may be helpful.
A variety of liver adenocarcinomas may appear cystic and are designated as “cystadenocarcinomas” (1). These include carcinomas that are predominantly cystic and are lined by overtly malignant epithelium with or without a minor solid component. In some cases, this may represent a variant of CC, and the important distinction is to exclude metastasis from other sites such as the ovary or pancreas (3–5). Others may represent invasive carcinomas arising in or from a hepatic cystadenoma, where the distinction is relatively simple when the background of cystadenoma, often with dysplasia or carcinoma in situ, can be identified. In cases composed entirely of malignant epithelium, clinical correlation to exclude an alternate primary site by imaging or other investigative modalities is imperative. In contrast, hepatic foregut cysts are most commonly unilocular (6). Although relatively few cases have been
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FIGURE 24. 5. 4 Epithelial denudation of hepatobiliary cystadeno-
F I G U R E 2 4 . 5 . 5 Hepatic foregut cyst lined by prominently ciliated
mas with stromal fibrosis and degenerative changes, including cholesterol clefts.
columnar epithelium with subepithelial connective tissue.
reported, there has been a slight male predominance (6–8). Hepatic foregut cysts are most commonly asymptomatic, occasionally presenting with obstructive jaundice or abdominal pain. These cysts appear to be most common in or around segment IV of the liver (8). These cysts do not communicate with the biliary duct system and typically contain thick, mucinous liquid. Histologically, the cyst has a ciliated columnar/cuboidal epithelial lining (Figure 24.5.5) with subepithelial connective tissue surrounded by a muscle layer. Goblet cells may be present within the epithelium. Rarely, squamous metaplasia may also be present (9). Though malignant transformation is exceedingly rare, squamous cell carcinoma has been reported. Surgical excision is the suggested therapy, particularly if associated with abdominal pain (10–13).
4. Lee JH, Kim KS, Chung CW, Park YN, Kim BR. Hepatic resection of metastatic tumor from serous cystadenocarcinoma of the ovary. J Korean Med Sci. 2002;17(3):415–418. 5. Tang Y, Yamashita Y, Ogata I, et al. Metastatic liver tumor from cystic ovarian carcinomas: CT and MRI appearance. Radiat Med. 1999;17(4):265–270. 6. Vick DJ, Goodman ZD, Deavers MT, Cain J, Ishak KG. Ciliated hepatic foregut cyst: a study of six cases and review of the literature. Am J Surg Pathol. 1999;23(6):671–677. 7. Wheeler DA, Edmondson HA. Ciliated hepatic foregut cyst. Am J Surg Pathol. 1984;8(6):467–470. 8. Sharma S, Dean AG, Corn A, et al. Ciliated hepatic foregut cyst: an increasingly diagnosed condition. Hepatobiliary Pancreat Dis Int. 2008;7(6):581–589. 9. Ben Mena N, Zalinski S, Svrcek M, et al. Ciliated hepatic foregut cyst with extensive squamous metaplasia: report of a case. Virchows Arch. 2006;449(6):730–733. 10. de Lajarte-Thirouard AS, Rioux-Leclercq N, Boudjema K, Gandon Y, Ramee MP, Turlin B. Squamous cell carcinoma arising in a hepatic foregut cyst. Pathol Res Pract. 2002;198(10):697–700. 11. Furlanetto A, Dei Tos AP. Squamous cell carcinoma arising in a ciliated hepatic foregut cyst. Virchows Arch. 2002;441(3):296–298. 12. Vick DJ, Goodman ZD, Ishak KG. Squamous cell carcinoma arising in a ciliated hepatic foregut cyst. Arch Pathol Lab Med. 1999;123(11):1115–1117. 13. Zhang X, Wang Z, Dong Y. Squamous cell carcinoma arising in a ciliated hepatic foregut cyst: case report and literature review. Pathol Res Pract. 2009;205(7):498–501.
References 1. Devaney K, Goodman ZD, Ishak KG. Hepatobiliary cystadenoma and cystadenocarcinoma. A light microscopic and immunohistochemical study of 70 patients. Am J Surg Pathol. 1994;18(11):1078–1091. 2. Yu FC, Chen JH, Yang KC, Wu CC, Chou YY. Hepatobiliary cystadenoma: a report of two cases. J Gastrointestin Liver Dis. 2008;17(2): 203–206. 3. Hiatt JR, Furnas H, Tompkins RK. Serous adenocarcinoma of the ovary presenting as a large liver cyst. West J Med. 1986;144(5):609–610.
Case 24.6
Biliary Adenofibroma VIKRAM DESHPANDE AND GREGORY Y. LAUWERS
C L I N IC AL I N F OR M AT I ON
A 47-year-old woman presented with right upper quadrant pain. A CT scan revealed a 16 cm solid and cystic mass in the left hepatic lobe. The patient underwent enucleation of a large well-circumscribed tumor located in segments 4, 5, and 8. The tumor was only partially resected. PAT H OL OG I C F E AT U R E S
The tumor had a smooth tan-white surface. Cross sectioning revealed a honeycomb cut surface with multiple cysts that were delineated by thin fibrous septae. Approximately a third of the tumor showed a more solid appearance. Microscopically, the tumor was composed of tubules and acini of varying sizes embedded in a fibrotic stroma. The larger cysts measured up to 0.5 cm. The tubules, glands, and cysts were lined by a single layer of flat to cuboidal nonmucin producing cells without cilia. Apocrine-like snouts were occasionally observed. The cells showed centrally located round to oval nuclei and inconspicuous nucleoli. Mitoses and atypia were virtually absent. On immunohistochemistry, the glandular epithelium was strongly positive for cytokeratin 7 and 19.
D I AG N OS I S
Biliary adenofibroma.
D I S C U S S I ON
Biliary adenofibroma is a rare benign hepatic neoplasm. There have been only 2 prior descriptions of this entity (1,2). This tumor is well circumscribed and is composed of tubules and cysts embedded in a fibrotic stroma. The tubules are frequently cystically dilated and focally assume complex configurations. The cells lining the glands and cysts resemble biliary epithelium and lack stratification. Atypia and mitotic activity are characteristically absent. The lumina may contain bile. The stroma is typically hypocellular and shows fibroblasts and scattered inflammatory cells. This tumor should be distinguished from other hepatic neoplasms including bile duct adenoma, biliary hamartoma, biliary cystadenoma and cholangiocarcinoma. It is critical to distinguish a biliary adenofibroma from a cholangiocarcinoma. Although the case described herein lacked evidence of atypia and epithelial tufting, moderate nuclear atypia and mitotic activity have been described in a biliary adenofibroma (2). Furthermore, cholangiocarcinomas may show,
generally only focally, acini lined by bland biliary-type epithelium. Furthermore, the hypocellular sclerotic stroma is similar to that seen in biliary adenofibroma. Nonetheless, a more exhaustive review of cholangiocarcinoma will reveal cellular atypia, including atypical nuclei and mitotic activity. Difficulties in distinguishing biliary adenofibroma from cholangiocarcinoma are most likely to arise when evaluating needle biopsy material. Bile duct adenoma is a solitary (and only occasionally multiple) well-circumscribed aggregate of small caliber ducts (3). In contrast to a biliary adenofibroma, bile duct adenoma is an incidental lesion that typically measures only a few millimeters, although examples as large as 2 cm have been described. In addition, bile duct adenomas generally show a more tubular and less cystic appearance. A needle biopsy from a biliary adenofibroma may be mistaken for a bile duct adenoma; however, the presence of a large solid cystic mass on imaging would essentially exclude the diagnosis of a bile duct adenoma. Based on their small size (generally <5 mm) a bile duct hamartoma (von Meyenburg complex) is unlikely to be confused with a biliary adenofibroma. Histologically, however, the maze of dilated ducts may resemble a biliary adenofibroma. Rarely, bile duct hamartomas have been shown to undergo adenomatous neoplastic transformation, and these lesions could conceivably be confused with a biliary adenofibroma (4). The macroscopic features may mimic a biliary cystadenoma. However, these lesions are characterized by multiloculated cysts, many larger than several centimeters (5). In contrast, the cysts of a biliary adenofibroma measure less than 1 cm. Furthermore, unlike biliary adenofibroma, these lesions are lined by mucinous epithelium and like their pancreatic counterpart show ovarian-type of stroma. Of note, there have been no well-documented examples of malignancy arising in a biliary adenofibroma. The solitary case report of biliary adenofibroma with malignant transformation lacked histology images and as such the accuracy of this diagnosis cannot be validated (6). Nonetheless, following resection, biliary adenofibroma warrants close clinical followup (Figures 24.6.1–24.6.6).
F I G U R E 2 4 . 6 . 1 Biopsy from a biliary adenofibroma shows well-
formed tubules and glands embedded in a fibrotic stroma. A biliary hamartoma and biliary adenoma may show similar morphology.
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FIGURE 24. 6. 2 On low power, a biliary adenofibroma demonstrates
F I G U R E 2 4 . 6 . 5 Tubular profiles lined by a single layer of cuboidal
a complex maze of tubules and cysts.
epithelium. The cells lack atypia.
FIGURE 24. 6. 3 Tubules and cysts lined by a single layer of biliary-
type epithelium. F I G U R E 2 4 . 6 . 6 Cyst lined by cuboidal to columnar epithelium,
some demonstrating apical snouts.
References
FIGURE 24. 6. 4 The neoplasm showed both small caliber ducts and
larger cysts.
1. Varnholt H, Vauthey JN, Dal Cin P, et al. Biliary adenofibroma: a rare neoplasm of bile duct origin with an indolent behavior. Am J Surg Pathol. 2003;27:693–698. 2. Tsui WM, Loo KT, Chow LT, Tse CC. Biliary adenofibroma. A heretofore unrecognized benign biliary tumor of the liver. Am J Surg Pathol. 1993;17:186–192. 3. Allaire GS, Rabin L, Ishak KG, Sesterhenn IA. Bile duct adenoma. A study of 152 cases. Am J Surg Pathol. 1988;12:708–715. 4. Jain D, Sarode VR, Abdul-Karim FW, Homer R, Robert ME. Evidence for the neoplastic transformation of Von-Meyenburg complexes. Am J Surg Pathol. 2000;24:1131–1139. 5. Devaney K, Goodman ZD, Ishak KG. Hepatobiliary cystadenoma and cystadenocarcinoma. A light microscopic and immunohistochemical study of 70 patients. Am J Surg Pathol. 1994;18:1078–1091. 6. Akin O, Coskun M. Biliary adenofibroma with malignant transformation and pulmonary metastases: CT findings. AJR Am J Roentgenol. 2002;179:280–281.
Case 24.7
Biliary Papillomatosis/Intraductal Cholangiocarcinoma WILSON M. S. TSUI
Intraductal papillary neoplasm (IPN) of the bile ducts is characterized by dilated intrahepatic bile ducts filled with a noninvasive papillary or villous biliary neoplasm covering delicate fibrovascular stalks. The nomenclature has been aligned with that of the pancreatic tumors and includes lesions previously named biliary papillomatosis and mucin hypersecreting bile duct tumor (1–3). The dilated bile ducts are fusiform or cystic (unilobular or multilocular) (Figure 24.7.1). The papillae range from microscopic folds of neoplastic epithelium to grossly visible finger-like projections. The papillae may be simple and villous-like, or complex and branching (Figure 24.7.2). The lesion can be focal (localized), multifocal, or diffuse. Similar neoplasia can develop in the hilar and
extrahepatic bile ducts and synchronous and dyssynchronous IPN can develop in the intrahepatic and extrahepatic biliary tree, gallbladder, and major pancreatic ducts. About one-third of IPN secrete mucin in the duct lumen (mucin secreting biliary tumor), not as commonly mucinous secreting as the intraductal papillary mucinous neoplasm (IPMN) of the pancreas. On the basis of morphologic characteristics and mucin expression (Table 24.7.1), 4 subtypes of IPN are currently defined: pancreatobiliary, intestinal, gastric, and oncocytic (4,5). Mixed lines of differentiation can be seen in an individual IPN. Apart from mucin glycoproteins, biliary ductal markers including CK 7, CK 19, CA19-9, B72.3, and CEA are strongly expressed in most IPN. 1. The pancreatobiliary type is the most common and consists of thin, branching papillae. The neoplastic cells are cuboidal, with round, hyperchromatic nuclei, prominent nucleoli, moderately amphophilic cytoplasm, and have a less mucinous appearance (Figure 24.7.3). Some cases have overlapping features with intraductal oncocytic papillary neoplasms. TA BL E 2 4 . 7 . 1 Mucin expression in different subtypes of IPN Subtype
Positive
Negative
Pancreatobiliary
MUC1, MUC5AC, MUC6
MUC2
Intestinal
MUC2, MUC5AC
MUC1, MUC6
Gastric
MUC5AC
MUC1, MUC2, MUC6
Oncocytic
MUC5AC, MUC1( ), MUC6
MUC2
FIGURE 24. 7. 1 Gross specimen showing dilated bile ducts filled
with papillary tumor. Background liver with coincidental hepatitis B cirrhosis.
FIGURE 24. 7. 2 Dilated bile ducts packed with long and branching
papillae lined by columnar cells and supported by delicate fibrovascular stroma.
F I G U R E 2 4 . 7 . 3 Pancreatobiliary-type IPN showing thin branching
papillae, cuboidal cells, round nuclei, and amphophilic cytoplasm.
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2. Intestinal-type IPNs are characterized by tall papillae lined by columnar cells with pseudostratified, cigar-shaped nuclei and basophilic cytoplasm with variable amount of apical mucin (Figure 24.7.4). The picture is highly reminiscent of colonic villous adenomas. Some examples are composed predominantly of goblet-like cells with micropapillary features. 3. Gastric-type IPNs are composed of innocuous, tall columnar cells with basally oriented nuclei and abundant pale mucinous cytoplasm, reminiscent of gastric foveolar epithelium (Figure 24.7.5). The peripheral portion of the lesion often forms pyloric-like glands. The gastric type generally shows low-grade dysplasia. 4. The oncocytic-type IPN usually has complex and arborizing papillae with delicate stroma. The papillae are lined by 2 to 5 layers of cuboidal cells with abundant eosinophilic granular cytoplasm (Figure 24.7.6). The nuclei are round, large, and fairly uniform, and typically contain single, prominent, eccentrically located nucleoli. Goblet
NEOPLASMS
F I G U R E 2 4 . 7 . 6 Oncocytic-type IPN featuring cells with abundant
eosinophilic granular cytoplasm and high-grade nuclei.
cells may be interspersed among the oncocytic cells. The neoplastic cells often form intraepithelial lumina, which may produce a cribriform pattern and even fuse to form a solid growth pattern.
FIGURE 24. 7. 4 Intestinal-type IPN with tall columnar cells, elon-
gated crowded hyperchromatic nuclei, basophilic cytoplasm, scattered goblet-like cells, and Paneth cells.
IPN of the bile ducts are classifiable as IPN-low grade and IPN-high grade based on the highest degree of architectural and cytological atypia. IPNs with low-grade dysplasia are characterized by a single layer of cells, well polarized to pseudostratified nuclei, mild to moderate nuclear enlargement and pleomorphism, and infrequent mitoses. The papillae maintain identifiable stromal cores. IPNs with high-grade dysplasia (carcinoma in situ) are characterized by severe architectural and cytological atypia, with the formation of irregular branching papillae and, sometimes, cribriform growth. The epithelial cells lack polarity, and the nuclei are stratified, hyperchromatic, and pleomorphic. Mitoses are frequent and can be found near the luminal surface. The high-grade lesion corresponds to intraductal growth type of cholangiocarcinoma or intraductal papillary carcinoma. IPNs are not infrequently associated with invasive carcinoma (IPN with an associated invasive intrahepatic cholangiocarcinoma [ICC]). As in pancreas, the pancreatobiliary type of bile duct IPN is usually associated with a tubular adenocarcinoma (MUC1), whereas the intestinal type is associated with colloid carcinoma (MUC2). DIFFER ENT IA L DIAGNO SIS
FIGURE 24. 7. 5 Gastric-type IPN with tall columnar cells, basally oriented nuclei, and abundant pale mucinous cytoplasm, reminiscent of gastric foveolar epithelium.
IPN is distinct from biliary intraepithelial neoplasia (BilIN), which is a microscopic lesion that is not usually macroscopically detectable. BilINs are characterized by abnormal epithelial cells with multilayering of nuclei and micropapillary projections into the duct lumen. The abnormal cells have increased nuclear:cytoplasmic ratio, partial loss of nuclear polarity, and nuclear hyperchromasia. They are divisible into BilIN-1, -2, and -3 according to degree of atypia (6). BilIN-3,
CASE
24.7:
BILIARY
PA P I L L O M AT O S I S / I N T R A D U C TA L
corresponding to high-grade dysplasia, is usually accompanied by invasive carcinoma. As expected, there are overlapping cases between IPN and BilIN when the micropapillae are more florid and forming macropapillae, and this distinction line is not easily drawn. Extensive intraductal spread of BilINs along the intrahepatic bile ducts without grossly visible tumor lesions has been reported (7). IPN with cystic luminal dilatation and mucin hypersecretion should be distinguished from biliary mucinous cystic neoplasm (biliary cystadenoma/cystadenocarcinoma) (8). The presence of ovarian-type stroma and female gender are supportive of biliary mucinous cystic neoplasm, whereas luminal communication with the bile ducts and absence of ovariantype stroma favor IPN. Hyperplastic polyp of intrahepatic bile ducts is exceedingly rare and morphologically similar to gastric hyperplastic polyp. It harbours cystically dilated glands of varying sizes, lined by gastric foveolar type of mucin-secreting columnar epithelium. The fibrovascular stroma is expanded, edematous, and filled with inflammatory cells and often contains thin smooth muscle fascicles. A similar lesion in pancreas has been regarded as an intraductal tubular adenoma (pyloric glandtype) and is possibly related to gastric type IPMN (9).
CC
385
Reason for Referral
To determine the presence of any associated invasive carcinoma. Pathologic Features
Resected specimen revealed papillary tumors filling up the dilated left intrahepatic bile ducts. The involved bile ducts contained branching papillary fronds covered by mucussecreting columnar epithelium and supported by delicate fibrovascular stalks. The epithelial layer was adenomatous with moderate degree of dysplasia, and apical mucin secretion was present (Figure 24.7.7). There were some small ducts lined by dysplastic epithelium with surrounding stromal edema (Figure 24.7.8); these foci were regarded as suspicious for invasive carcinoma by the referring pathologist. In addition, there were dilated ducts containing small brownish stones and a background of atrophic liver. These ducts exhibited features of chronic proliferative cholangitis characteristic of hepatolithiasis.
DIAGNO SIS C A S E I L L U S T R AT I ON Clinical Information
Intraductal papillary neoplasm, intestinal type, low grade, arising in hepatolithiasis, no invasive carcinoma.
A 71-year-old man was found to have liver lesions during investigation for epigastric pain. There was a history of choledochoenterostomy 35 years ago. CT revealed markedly dilated intrahepatic bile ducts in the atrophic left lobe. After failure of ERCP, left duct percutaneous transhepatic cholangiography (PTC) was performed and revealed irregular left ducts and a long irregular narrow segment in proximal part suggesting a malignant obstruction. Fine needle aspiration biopsy from the left lobe showed biliary papillomatosis; left hemihepatectomy and right hepatico-jejunostomy was performed.
The main determinant of outcome for surgically resected IPN is the presence or absence of an associated invasive carcinoma, defined by invasion through the basement membrane. Invasive carcinoma, if present, produces irregular, heterogenous thickening of the duct walls, fibrotic foci in endoluminal papillary-nodular vegetations, or gelatinous stromal masses. The latter appearance is characteristic of colloid carcinoma.
FIGURE 24. 7. 7 Periodic acid Schiff stain with diastase showing
F I G U R E 2 4 . 7 . 8 Three small ducts with micropapillae lined by mod-
long branching papillae lined by intestinal type tall columnar cells with apical mucin secretion.
erately dysplastic epithelium similar to Figure 24.7.7 and showing transition to mild dysplasia in 1 duct.
DISCUSSIO N
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Small invasive carcinomas may be macroscopically undetectable, and thorough histologic sampling is needed to rule out invasion. The distinction from pseudo-invasion is critically important. In particular, benign mucin spillage into the stroma that presumably occurs due to rupture of an involved duct can mimic an invasive colloid carcinoma. Mucin spillage is characterized by stromal dissection by acellular mucin and is usually associated with a brisk inflammatory reaction (less common in colloid carcinoma). Any mucin in the stroma, however, should be evaluated carefully as suspicious for invasion. Similarly, IPN extending along small ducts may create the impression of early invasion (Figure 24.7.8). The lobular architecture, smooth contours of the units, and morphologic similarity to the larger lesions are the main features that help distinguish these from invasive carcinoma. Patients with IPN usually present in middle- to old age with a male/female ratio of 2:1. The condition is characterized by recurrent bouts of cholangitis and obstructive jaundice. Other complications include hemobilia, choledocholithiasis, and carcinomatous transformation. Patients may die from complications before malignant change takes place. Occasional cases have been associated with ulcerative colitis, hepatolithiasis, Caroli disease, choledochal cyst, and polyposis coli (10). Preoperative diagnosis is difficult, but possible, by means of endoscopic retrograde cholangiopathy (ERCP) and endoscopic biopsy for extrahepatic cases and PTC and fine needle aspiration cytology (FNAC) for intrahepatic tumors (11). Although invasive carcinoma is absent in this case, noninvasive IPN is regarded as having borderline or low-grade malignant potential due to its tendency to recur, multicentricity, ability to undergo malignant transformation, and significant morbidity and mortality due to complications such as recurrent bouts of cholangitis and obstructive jaundice. The management is difficult, because of its multicentricity and propensity to grow and spread along the biliary tree. Curettage and drainage may relieve obstruction temporarily and is invariably followed by recurrence. Laser therapy via choledochoscopy is advocated and enables complete removal of the tumor. In rare
NEOPLASMS
cases with restriction to 1 lobe of the liver, cure has been successful by radical surgery. However, even after resection with adequate clear margins, recurrences can occur in the remaining intrahepatic ducts. Hepatic transplantation has also been proposed as an alternative approach to therapy. Even then, the lesion may possibly recur in the extrahepatic ducts.
References 1. Bosmann FT, Carneiro F, Hruban RH, Theise ND. WHO Classification of Tumours of the Digestive System. Lyon, France: IARC Press; 2010. 2. Nakanuma Y, Sasaki M, Ishikawa A, Tsui W, Chen TC, Huang SF. Biliary papillary neoplasm of the liver. Histol Histopathol. 2002;17:851–861. 3. Kloppel G, Kosmahl M. Is the intraductal papillary mucinous neoplasia of the biliary tract a counterpart of pancreatic papillary mucinous neoplasm? J Hepatol. 2006;44:249–250. 4. Shibahara H, Tamada S, Goto M, et al. Pathologic features of mucinproducing bile duct tumors: 2 histopathologic categories as counterparts of pancreatic intraductal papillary-mucinous neoplasms. Am J Surg Pathol. 2004;28:327–338. 5. Tanaka M, Fukushima N, Noda N, Shibahara J, Kokudo N, Fukayama M. Intraductal oncocytic papillary neoplasm of the bile duct: clinicopathologic and immunohistochemical characteristics of 6 cases. Hum Pathol. 2009;30:543–552. 6. Zen Y, Adsay NV, Bardadin K, et al. Biliary intraepithelial neoplasia: an international interobserver agreement study and proposal for diagnostic criteria. Mod Pathol. 2007;20:701–709. 7. Aishima S, Nishihara Y, Tsujita E, et al. Biliary neoplasia with extensive intraductal spread associated with liver cirrhosis: a hitherto unreported variant of biliary intraepithelial neoplasia. Hum.Pathol. 2008;39: 939–947. 8. Zen Y, Fujii T, Itatsu K, et al. Biliary cystic tumors with bile duct communication: a cystic variant of intraductal papillary neoplasm of the bile duct. Mod Pathol. 2006;19:1243–1254. 9. Chetty R, Serra S. Intraductal tubular adenoma (pyloric gland-type) of the pancreas: a reappraisal and possible relationship with gastrictype intraductal papillary mucinous neoplasm. Histopathology. 2009;55: 270–276. 10. Chen TC, Nakanuma Y, Zen Y, et al. Intraductal papillary neoplasia of the liver associated with hepatolithiasis. Hepatology. 2001;34:651–658. 11. Tsui WM, Lam PW, Mak CK, Pay KH. Fine needle aspiration cytologic diagnosis of intrahepatic biliary papillomatosis (intraductal papillary tumor): report of three cases and comparative study with cholangiocarcinoma. Diagn Cytopathol. 2000;22:293–298.
25 Hepatocellular Carcinoma PRODROMOS HYTIROGLOU
B R I E F O U T L I N E OF E P I D E M I OL OG Y A ND R I S K FAC TOR S
Hepatocellular carcinoma (HCC) is the most common primary malignant neoplasm of the liver, representing the fifth most common malignancy worldwide and the third most frequent cause of cancer-related mortality (1,2). This tumor is more common in men than women, with a ratio of 2.7:1 (2). The incidence of HCC varies significantly in different geographic areas, reflecting the prevalence of various risk factors, such as chronic hepatitis B or C virus infection and dietary aflatoxin exposure (Table 25.1). It is high in eastern Asia and sub-Saharan Africa, intermediate in countries of the Mediterranean region, and low in northern Europe, the Americas, and Australia. Hepatitis B virus (HBV) infects over 350 million people worldwide, and thus represents the most widespread risk factor for HCC. This virus is implicated in hepatocarcinogenesis in several ways, including (1) nonrandom viral integration in the host genome, targeting genes involved in cell signaling, and potentially providing growth advantage to infected cells; (2) function of the viral X protein as a gene transactivator; and (3) hepatocellular proliferation, due to cell loss and regeneration, especially after cirrhosis is established (3–6). Therefore, in patients with chronic hepatitis B, HCC may arise in either cirrhotic or noncirrhotic background. On the other hand, in patients with chronic hepatitis C, HCC is rare in the absence of cirrhosis because the hepatitis C virus (HCV) lacks a direct carcinogenic role; however, once cirrhosis has developed, the risk of HCC is in the range of 1% to 4% per year (7,8). Aflatoxins are mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus, which contaminate grain, particularly peanuts, stored in warm and humid conditions in tropical and subtropical regions. There are at least 13 different types of aflatoxin, with aflatoxin B1 considered as a most potent hepatocarcinogen (2). TA B LE 25. 1 Most common risk factors for hepatocellular
carcinoma Cirrhosis
In Western countries, the great majority of HCCs are found in cirrhotic livers, with most patients being in the sixth decade of life or older. By contrast, in large parts of Asia and Africa, where vertical transmission of HBV is common, this neoplasm often develops in younger patients with chronic HBV infection but without cirrhosis. The most common etiologies of cirrhosis in patients with HCC are chronic hepatitis B, chronic hepatitis C, and alcoholic liver disease. HCC is the leading cause of death in cirrhotic patients with chronic viral hepatitis (9). Despite the widespread use of vaccination against HBV in western countries, the incidence of HCC is on the rise, mostly due to HCV infection (10,11). Lastly, it is of note that a minority of HCCs arise in patients without predisposing factors. This is the rule for fibrolamellar carcinoma, a special type of HCC occurring in young individuals. However, cases of HCC of the usual type (also called classic HCC) may also occur in patients without a known history of chronic liver disease, especially in old age. T ER MINO LO GY O F H EPATO CELLULA R NO DU LES A ND P R EC A NCERO US LESIO NS
There is a variety of hepatic nodular lesions that are predominantly composed of either hepatocytes or neoplastic cells with hepatocytic features. A standardized terminology of these lesions was introduced by an International Working Party (IWP) in 1995 and was updated by an International Consensus Group for Hepatocellular Neoplasia (ICGHN) in 2009 (12,13). When such nodules are larger than a few millimeters in diameter, they may be detected on imaging studies of cirrhotic and noncirrhotic livers and may undergo guided needle biopsy. The differential diagnosis in this setting can be aided by clinical and imaging information; however, the final diagnosis usually rests with the pathologist’s ability to adequately assess sets of subtle and overlapping histologic features that characterize such lesions. The diagnostic considerations vary significantly between noncirrhotic and cirrhotic livers (Table 25.2). The precancerous lesions of HCC have become the subject of detailed clinicopathologic and molecular studies over the past 3 decades, which have revealed
Chronic hepatitis B virus infection
1. Cytologic changes indicative of dysplasia. Cells with dysplastic features often form groups, which were termed “dysplastic foci” by the IWP (12). By definition, dysplastic foci measure less than 1mm in diameter, thus representing incidental findings on microscopic examination. 2. Nodular lesions with cytologic and/or structural atypia indicative of precancerous change, which have been termed “dysplastic nodules” (12). Dysplastic nodules may be
Chronic hepatitis C virus infection Aflatoxin exposure Metabolic disorders (hereditary hemochromatosis, tyrosinemia, alpha-1-antitrypsin deficiency, nonalcoholic fatty liver disease) Alcohol Tobacco
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TA B LE 25. 2 Hepatocellular nodular lesions that may be detected
on imaging studies Noncirrhotic Liver Benign Focal nodular hyperplasia Hepatocellular adenoma Large regenerative nodule Nodular regenerative hyperplasia Lobar or segmental hyperplasia Focal fatty change Malignant Hepatocellular carcinoma Cirrhotic Liver Benign Large regenerative nodule Focal nodular hyperplasia-like nodule Precancerous Low-grade dysplastic nodule High-grade dysplastic nodule Malignant Hepatocellular carcinoma Note: The histologic features of focal nodular hyperplasia-like nodule are similar to those of focal nodular hyperplasia arising in noncirrhotic liver (14,15). This lesion has drawn attention because it can mimic hepatocellular carcinoma on imaging studies.
detected on gross examination or imaging studies, raising issues of differential diagnosis with HCC and other nodular lesions. With rare exceptions, these precancerous lesions are detected in livers with cirrhosis and are often multiple, because hepatocarcinogenesis in diseased livers is a multifocal process. Dysplastic foci and dysplastic nodules consist of expanding cell populations with genomic and epigenetic changes that provide a survival advantage over the surrounding hepatocytes and make possible the acquisition of additional molecular changes, ultimately leading to malignancy (16,17). On the other hand, little is known about the precancerous changes occurring in the noncirrhotic human liver. Some HCCs arise in hepatocellular adenomas (18), but the great majority appears to be unrelated to preexisting adenomas. Recent studies from France have identified a subset of hepatocellular adenomas with β-catenin gene mutations, occurring in both sexes, which are likely to progress to HCC (19–21) (Chapter 23).
H I S TOL OG I C F E AT U R E S O F PR E C AN C E ROU S L E S I ON S
F I G U R E 2 5 . 1 Example of small cell change of hepatocytes in a cirrhotic nodule ( 400).
nucleocytoplasmic ratio, mild nuclear pleomorphism and hyperchromasia, and cytoplasmic basophilia (Figure 25.1). There is significant cytologic similarity between small cell change and early HCC. Furthermore, molecular studies have provided convincing evidence of the precancerous nature of small cell change (23,24). However, it should be kept in mind that small-sized hepatocytes are often seen in cirrhotic livers, as a result of regeneration (25). Therefore, in the absence of cytologic atypia, small cell size alone is not sufficient evidence of precancerous change. Other cytologic changes that may be of precancerous nature certainly exist but are not as well-documented as small cell change. For instance, at least some foci of resistance to hemosiderin accumulation in livers with hereditary hemochromatosis (the so-called iron-free foci) are considered to represent precancerous lesions (26). Another candidate lesion is “large cell change” of hepatocytes (12). This cytologic change was originally described as “liver cell dysplasia” (27) and is characterized by cellular and nuclear enlargement, nuclear pleomorphism, frequent nuclear hyperchromasia, and multinucleation (Figure 25.2). The nucleocytoplasmic ratio is preserved. Although large cell change has been found to be related to cholestasis and hepatocellular senescence (28,29), it nonetheless represents a documented risk factor for HCC in patients with chronic viral hepatitis and cirrhosis (30,31). Recent findings suggest that large cell change of hepatocytes is a biologically heterogeneous lesion, with cases in the setting of HBV cirrhosis being precancerous (32,33).
Dysplastic Foci
Dysplastic Nodules
The dysplastic foci usually consist of expansile groups of crowded, small, atypical hepatocytes. This cytologic change was originally called “small cell dysplasia” (22), but was subsequently termed “small cell change” of hepatocytes by the IWP (12). Small cell change is characterized by increased
The dysplastic nodules usually measure less than 1.5 cm in diameter and differ from the surrounding cirrhotic nodules in terms of size, color, texture, or degree of bulging at the cut surface of the liver. The diagnosis is made by histologic examination (12,13,16,17,34–40). The ample molecular
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EA R LY V ER SUS CLA SSIC H EPATO CELLULA R C A R CINO MA
FIGURE 25. 2 Example of large cell change of hepatocytes in a cir-
rhotic nodule. Cholestasis is also present ( 200).
evidence for the precancerous nature of these lesions has been reviewed recently (17). The dysplastic nodules were classified by the IWP (12) into low-grade and high-grade ones, the latter differing from the former in the degree of cytologic and structural atypia but lacking clear-cut features of HCC. These lesions have been shown to evolve to HCC over time (41,42). Therefore, on microscopic examination of dysplastic nodules, focal HCC may occasionally be found (43). Both low- and high-grade dysplastic nodules may contain portal tracts, as well as small, isolated arteries coursing outside of portal tracts, called “unpaired” or “nontriadal” arteries (44–46). The portal tracts are often present in small numbers and may be scarred. The unpaired arteries of dysplastic nodules are less well developed than those of classic HCC, both in number and in size. The cellularity of these lesions is often increased, as compared with the adjacent hepatic parenchyma; this feature is most pronounced in high-grade dysplastic nodules (13). Dysplastic nodules may contain cell populations with clone-like features, such as iron or copper deposition, or fat accumulation in a liver without significant steatosis (47,48). Increased cellularity, clone-like cell populations, and unpaired arteries are useful histologic features, distinguishing dysplastic nodules from large regenerative nodules of cirrhotic livers (13,17). The latter can reach sizes similar to those of dysplastic nodules and contain portal tracts that are often abundant, but no unpaired arteries. However, in practice, the distinction between low-grade dysplastic nodules and large regenerative nodules has been found to be difficult or impossible. On the other hand, high-grade dysplastic nodules can be distinguished from both regenerative nodules and low-grade dysplastic nodules on the basis of cytologic and structural atypia (Figure 25.3). The histologic features that are useful in this distinction are summarized in Table 25.3.
Several studies from Japan over the past 20 years (35,49,50) have found that there are 2 types of “small HCC” (defined by the IWP as HCC measuring less than 2 cm): (1) a type with gross and histologic features similar to those of larger examples of classic HCC; and (2) a well-differentiated type with indistinct margins (vaguely nodular type) (Figure 25.4A). The latter was called “early HCC,” a term that has now been endorsed by the ICGHN (13). This low-grade, early-stage tumor was not recognized as an entity earlier, because it has great histologic similarity to high-grade dysplastic nodule. Early HCCs are usually composed of small neoplastic cells with hepatocytic features, which are arranged in thin plates and pseudoglandular structures. Both portal tracts and unpaired arteries may be seen within the lesion. The feature that definitely distinguishes early HCC from high-grade dysplastic nodule is the presence of stromal invasion (13,40,51,52) (Figure 25.4B). In the absence of detectable stromal invasion, immunohistochemical stains may be of assistance, as discussed in Case 25.3. Early HCC has been shown to evolve over time to classic HCC (35,40). In contrast to early HCC, classic HCC, whether small or large, usually is distinctly nodular on gross examination. On microscopic examination, the nodule may be surrounded by a fibrous pseudocapsule. The grade of differentiation of the neoplastic cells is variable. In daily diagnostic practice, HCC is graded as well-, moderately, or poorly differentiated; different grades in different parts of the tumor are common. The mitotic rate varies significantly among different tumors and among different areas of the same tumor. The pattern of growth may be trabecular, pseudoacinar, or diffuse; the trabeculae usually are over 3 cells in thickness and have an endothelial lining. Unpaired arteries are identified with ease and are generally larger than those of dysplastic nodules and early HCC. Bile production and fat accumulation may be seen both in early and in classic HCC. Portal tracts are not present in classic HCC; however, at the tumor margin, entrapped portal tracts may be seen among the invading neoplastic cells. Vascular invasion is commonly seen in classic HCC. Occasional tumors may exhibit clear cell features (clear cell variant) or marked pleomorphism (pleomorphic cell variant). Lastly, special types of HCC include fibrolamellar carcinoma, scirrhous carcinoma, lymphoepithelioma-like carcinoma, sarcomatoid carcinoma, and undifferentiated carcinoma. DIAGNO SIS O F H EPATO CELLULA R C A R CINOMA IN T H E CIR R H OT IC LIV ER
HCC has traditionally been considered to be a neoplasm with poor prognosis because most cases are diagnosed at advanced stages, often in a background of cirrhosis. The clinical manifestations of advanced HCC are variable and include decompensation of cirrhosis (with jaundice, ascites, encephalopathy, or ruptured esophageal varices); tumor-related symptoms (such as abdominal pain, malaise, anorexia, and weight loss); acute
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A
D
B
C
E
FIGUR E 25. 3 Characteristic areas from a high-grade dysplastic nodule measuring 1.4 cm. (A) Cell plates with thickness of 1 to 3 cells; focally increased nucleocytoplasmic ratio. (B) Small cell change of hepatocytes. (C) Scarred portal tract. (D,E) Unpaired arteries (A–C: 200; D,E: 400).
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TA B LE 25. 3 Evidence of atypia in high-grade dysplastic nodules Cytologic Atypia Small cell change of hepatocytes Nuclear hyperchromasia Mild nuclear contour irregularities Increased nucleocytoplasmic ratio Cytoplasmic basophilia Cytoplasmic clear cell change Resistance to iron accumulation Occasional mitotic figures Structural Atypia Cell plates up to 3 cells in thickness Occasional pseudoglandular structures (in the absence of cholestasis) Expansile foci (subnodules), often differing from the remaining nodule due to increased cytologic atypia or cell proliferation rate
A
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391
abdominal catastrophe due to hemorrhage; cholestasis; fever; paraneoplastic phenomena; and metastatic complications (1,2). The development of surveillance programs for cirrhotic patients in recent years is now changing this grim outlook, and HCCs are increasingly detected in early, curable stages. Surveillance programs presently rely on regular ultrasonographic examination every 6 months (1,2), whereas there is active research to identify clinically useful serologic markers. Alpha-fetoprotein, an oncofetal protein that is often elevated in the serum of patients with HCC, has been found to be of limited utility for tumor surveillance due to low sensitivity and specificity. HCC arising in cirrhosis has recently been made an exception to the rule that histologic proof is the cornerstone of every diagnosis of malignancy (53,54). Documentation by biopsy is no longer recommended for (1) tumors larger than 2cm, displaying typical features of HCC (ie, enhanced contrast uptake in the arterial phase, followed by contrast “washout” in the portal venous and late venous phases) on a dynamic imaging study, such as contrast enhanced ultrasonography, computed tomography, or magnetic resonance imaging; and (2) tumors measuring 1 to 2 cm, displaying typical features of HCC on 2 different dynamic imaging studies. The recommendation for nodules less than 1cm in diameter is follow-up with repeat ultrasonography at short (ie, 3- to 4-month) intervals. Therefore, guided liver biopsy is now mostly used for lesions with equivocal imaging features measuring over 1cm. The differential diagnosis in this setting basically includes: (1) large regenerative nodule, (2) focal nodular hyperplasia-like nodule, (3) dysplastic nodule, (4) early HCC, and (5) classic HCC. The first 2 types of lesions lack cytologic and structural atypia, as opposed to dysplastic nodule, early HCC, and classic HCC. Among the lesions characterized by atypia, the differential diagnosis is based on careful assessment of the histologic features discussed in the previous paragraphs. This is often easier when paired biopsies (both from the lesion and from the parenchyma away from the lesion) are available for comparative examination. Furthermore, adequacy of sampling is a very important parameter to be kept in mind, as the histologic features may vary among different areas of the lesion in question.
References
B FIGURE 25. 4 Early hepatocellular carcinoma measuring 1.5 cm: (A)
On gross examination, the contour of the lesion appears indistinct. (B) Focal stromal invasion is present at the margin of the lesion ( 200).
1. Bruix J, Branco FS, Ayuso C. Hepatocellular carcinoma. In: Schiff ER, Sorrell MF, Maddrey WC, eds. Schiff’s Diseases of the Liver. 10th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006 [e-edition]. 2. Roberts LR, Gores GJ. Hepatocellular carcinoma. In: Yamada T, ed. Textbook of Gastroenterology. Vol 2. 5th ed. Oxford, UK: Blackwell; 2009:2386–2411. 3. Paterlini-Brechot P, Saigo K, Murakami Y, et al. Hepatitis B virus-related insertional mutagenesis occurs frequently in human liver cancers and recurrently targets human telomerase gene. Oncogene. 2003;22(25): 3911–3916. 4. Locarnini S. Molecular virology of hepatitis B virus. Semin Liver Dis. 2004;(24 suppl):1, 3–10. 5. Wen YM. Structural and functional analysis of full-length hepatitis B virus genomes in patients: implications in pathogenesis. J Gastroenterol Hepatol. 2004;19(5):485–489.
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6. Murakami Y, Saigo K, Takashima H, et al. Large scaled analysis of hepatitis B virus (HBV) DNA integration in HBV related hepatocellular carcinomas. Gut. 2005;54(8):1162–1168. 7. Degos F, Christidis C, Ganne-Carrie N, et al. Hepatitis C virus related cirrhosis: time to occurrence of hepatocellular carcinoma and death. Gut. 2000;47(1):131–136. 8. El-Serag HB. Hepatocellular carcinoma and hepatitis C in the United States. Hepatology. 2002;36(5 suppl 1):S74-S83. 9. Benvegnu L, Gios M, Boccato S, Alberti A. Natural history of compensated viral cirrhosis: a prospective study on the incidence and hierarchy of major complications. Gut. 2004;53(5):744–749. 10. Hassan MM, Frome A, Patt YZ, El-Serag HB. Rising prevalence of hepatitis C virus infection among patients recently diagnosed with hepatocellular carcinoma in the United States. J Clin Gastroenterol. 2002;35(3):266–269. 11. Blonski W, Reddy KR. Hepatitis C virus infection and hepatocellular carcinoma. Clin Liver Dis. 2008;12(3):661–674. 12. Terminology of nodular hepatocellular lesions. International working party. Hepatology. 1995;22(3):983–993. 13. International Consensus Group for Hepatocellular Neoplasia. Pathologic diagnosis of early hepatocellular carcinoma: a report of the international consensus group for hepatocellular neoplasia. Hepatology. 2009;49(2):658–664. 14. Quaglia A, Tibballs J, Grasso A, et al. Focal nodular hyperplasia-like areas in cirrhosis. Histopathology. 2003;42(1):14–21. 15. Libbrecht L, Cassiman D, Verslype C, et al. Clinicopathological features of focal nodular hyperplasia-like nodules in 130 cirrhotic explant livers. Am J Gastroenterol. 2006;101(10):2341–2346. 16. Hytiroglou P. Morphological changes of early human hepatocarcinogenesis. Semin Liver Dis. 2004;24(1):65–75. 17. Hytiroglou P, Park YN, Krinsky G, Theise ND. Hepatic precancerous lesions and small hepatocellular carcinoma. Gastroenterol Clin North Am. 2007;36(4):867–887. 18. Ferrell LD. Hepatocellular carcinoma arising in a focus of multilobular adenoma. A case report. Am J Surg Pathol. 1993;17(5):525–529. 19. Bioulac-Sage P, Balabaud C, Bedossa P, et al. Pathological diagnosis of liver cell adenoma and focal nodular hyperplasia: Bordeaux update. J Hepatol. 2007;46(3):521–527. 20. Rebouissou S, Bioulac-Sage P, Zucman-Rossi J. Molecular pathogenesis of focal nodular hyperplasia and hepatocellular adenoma. J Hepatol. 2008;48(1):163–170. 21. Bioulac-Sage P, Laumonier H, Couchy G, et al. Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience. Hepatology. 2009;50(2):481–489. 22. Watanabe S, Okita K, Harada T, et al. Morphologic studies of the liver cell dysplasia. Cancer. 1983;51(12):2197–2205. 23. Marchio A, Terris B, Meddeb M, et al. Chromosomal abnormalities in liver cell dysplasia detected by comparative genomic hybridisation. Mol Pathol. 2001;54(4):270–274. 24. Plentz RR, Park YN, Lechel A, et al. Telomere shortening and p21checkpoint inactivation characterize multistep hepatocarcinogenesis in humans. Hepatology. 2007;45(4):968–976. 25. Nakanuma Y, Hirata K. Unusual hepatocellular lesions in primary biliary cirrhosis resembling but unrelated to hepatocellular carcinoma. Virchows Arch A Path Anat. 1993;422(1):17–23. 26. Deugnier YD, Charalambous P, Le Quilleuc D, et al. Preneoplastic significance of hepatic iron-free foci in genetic haemochromatosis: a study of 185 patients. Hepatology. 1993;18(6):1363–1369. 27. Anthony PP, Vogel CL, Barker LE. Liver cell dysplasia: a premalignant condition. J Clin Path. 1973;26(3):217–223. 28. Natarajan S, Theise ND, Thung SN, Antonio L, Paronetto F, Hytiroglou P. Large-cell change of hepatocytes in cirrhosis may represent a reaction to prolonged cholestasis. Am J Surg Pathol. 1997;21(3):312–318. 29. Lee RG, Tsamandas AC, Demetris AJ. Large cell change (liver cell dysplasia) and hepatocellular carcinoma in cirrhosis: matched case–control
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50. Kojiro M, Nakashima O. Histopathologic evaluation of hepatocellular carcinoma with special reference to small early stage tumors. Semin Liver Dis. 1999;19(3):287–296. 51. Kondo F, Kondo Y, Nagato Y, Tomizawa M, Wada K. Interstitial tumor cell invasion in small hepatocellular carcinoma. Evaluation in microscopic and low magnification view. J Gastroenterol Hepatol. 1994;9(6):604–612. 52. Nakano M, Saito A, Yamamoto M, Doi M, Takasaki K. Stromal and blood vessel wall invasion in well-differentiated hepatocellular carcinoma. Liver. 1997;17(1):41–46.
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53. Bruix J, Sherman M, Llovet JM, et al. Clinical management of hepatocellular carcinoma. Conclusions of the Barcelona-2000 EASL conference. J Hepatol. 2001;35(3):421–430. 54. Bruix J, Sherman M, Practice Guidelines Committee, American Association for the Study of Liver Diseases . Management of hepatocellular carcinoma. Hepatology. 2005;42(5):1208–1236.
Case 25.1
Well-Differentiated Hepatocellular Carcinoma PRODROMOS HYTIROGLOU
C L I N I C AL I N F OR M AT I ON
A 54-year-old man without a known history of liver disease presented to a local physician because of an upper abdominal lump that had appeared recently. The patient did not have any other symptoms. Imaging studies revealed a 9 cm nodular lesion with evidence of hemorrhage in hepatic segment V; in addition, the liver parenchyma appeared diffusely macronodular. Serologic studies provided evidence of HCV infection. Serum alpha-fetoprotein levels were within normal range. R E A S ON F OR R E F E R R A L
The case was referred to establish the nature of the tumor as either hepatocellular adenoma or well-differentiated HCC.
A PAT H OL OG I C F E AT U R E S
The biopsy material is entirely composed of neoplastic tissue with areas of hemorrhagic necrosis (Figures 25.1.1A,B). No portal tracts are present. The tumor cells simulate hepatocytes and are arranged in plates and pseudoglandular structures (Figures 25.1.2 and 25.1.3). An endothelial lining is hardly discernible along the cell plates. Scattered unpaired arteries are seen. The neoplastic cells have round nuclei, with mild size variation and hyperchromasia, as well as increased nucleocytoplasmic ratio. Nuclear contour irregularities and pleomorphism are not seen. There are no mitotic figures. On searching carefully, occasional bile plugs are found (Figure 25.1.4). A thick fibrous capsule is present at the edge of one of the biopsy cores (Figure 25.1.5). Reticulin stain shows a poor fiber network (Figure 25.1.6). Immunohistochemical stain for CD34 antigen shows diffuse expression along the cell plates and reveals that some plates exceed 3 cells in thickness (Figure 25.1.7).
B F I G U R E 2 5 . 1 . 1 Representative areas of the biopsy specimen show-
ing a neoplasm with hepatocytic features (A,B) and hemorrhagic necrosis (B) (A,B: 100). D I AG N OS I S
Well-differentiated HCC.
3. There are scattered isolated arteries among the tumor cells.
D I SC U SSI ON
The pathologic features of this case are clearly those of a hepatocellular neoplasm, because 1. The tumor cells resemble hepatocytes, cytologically and functionally (they produce bile); furthermore, they are arranged in plates and pseudoglandular structures. 2. There are no portal tracts and no bile ductules in the lesion.
On the basis of these histologic features, the differential diagnosis is narrowed between 2 entities: hepatocellular adenoma and well-differentiated HCC. Several clinical features in this case are in favor of the diagnosis of HCC rather than hepatocellular adenoma, including male gender, age over 50 years, history of HCV infection, as well as imaging findings suggestive of cirrhosis. Although the duration of HCV infection is not known, cirrhosis usually develops 20 to 30 years after the onset. However, even if there was no clinical information in this case, the diagnosis of
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FIGURE 25. 1. 2 The tumor cells are arranged in plates and pseudoglandular structures. An unpaired artery is seen on the upper left. Two vascular structures reminiscent of terminal hepatic venules are seen on the right ( 200).
F I G U R E 2 5 . 1 . 4 Focally, bile plugs are noticed in pseudoglandular structures (arrows) ( 400).
FIGURE 25. 1. 3 Two unpaired arteries are present among neoplastic
F I G U R E 2 5 . 1 . 5 Portion of a thick fibrous capsule at the tumor edge
cells with mild nuclear size variation and increased nucleocytoplasmic ratio ( 400).
( 100).
well-differentiated HCC could have been made on the basis of a set of histologic features, including
liver disease, most often in patients already known to have cirrhosis. The presence of cirrhosis practically rules out the possibility of adenoma; however, in many cases, such as the one presented here, there may be no histologic documentation of cirrhosis. Most importantly, the pathologist’s diagnosis must rely on histologic criteria rather than clinical and radiologic features. Both architectural and cytologic features are helpful in distinguishing between hepatocellular adenoma and welldifferentiated HCC (see Table 25.1.1) (1–4). As a rule, the distinction is made on the basis of a set of features rather than a single feature; however, well-developed trabecular architecture, with cell plates exceeding 3 cells in thickness, is an unequivocal feature of HCC. The thickness of the plates may be
1. 2. 3. 4.
Cell plates exceeding 3 cells in thickness; Presence of abundant pseudoglandular structures; Cytologic atypia; and Paucity of reticulin fibers.
Distinction between hepatocellular adenoma and welldifferentiated HCC is often difficult and sometimes impossible (1–3). Clinical information is helpful, because there are significant differences in the epidemiology of these 2 tumors. In Western countries, most cases of hepatocellular adenoma occur in women of reproductive age on oral contraceptives, whereas HCC usually develops in a background of chronic
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FIGURE 25. 1. 6 Reticulin stain reveals paucity of fibers ( 200).
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F I G U R E 2 5 . 1 . 7 CD34 immunostain demonstrates variable thickness
of the tumor cell plates ( 200). TA B LE 25. 1. 1 Useful features in the differential diagnosis of well-differentiated hepatocellular carcinoma from hepatocellular adenoma
and high-grade dysplastic nodule Hepatocellular Adenoma
Well-Differentiated Hepatocellular Carcinoma
High-Grade Dysplastic Nodule
Thickness of cell plates
1-2 cells
Variable
1-3 cells
Trabecular architecture
Absent
Absent or present
Absent
Pseudoglandular structures
Absent or few
Absent or present
Absent or few
Reticulin fibers
Aresent
Decreased
Present
Invasive growth
Absent
Present
Absent
Nuclear hyperchromasia
Uncommon
Commonly present
Commonly present
Nuclear contour irregularities
Uncommon
Commonly present
Absent or mild
Nuclear pleomorphism
Uncommon
Commonly present
Absent
Cytoplasmic basophilia
Absent
Commonly present
Commonly present
Nucleocytoplasmic ratio
Usually normal
Often increased
Often increased
Mitotic figures
Absent or rare
Absent or present
Absent or few
Absent
Present or absent
Present; rarely absent
Alpha-fetoprotein
Absent
Absent or present
Absent
Glypican-3
Absent
Absent or present
Absent; occasionally present
Features Tumor architecture
Cytologic features
Nonlesional hepatic parenchyma Evidence of cirrhosis Positive immunohistochemical staining
Note: Complete assessment of these features requires adequate sampling, and may not be possible in biopsy material. Additional immunohistochemical stains that are helpful in distinguishing high-grade dysplastic nodule from well-differentiated hepatocellular carcinoma are discussed in Case 25.3.
difficult to assess on HE-stained sections, because both these tumors may have areas of compressed vascularity simulating a diffuse (compact) pattern of growth. Immunohistochemical stains for CD34 antigen are often useful in assessing plate thickness, since most HCCs and some hepatocellular
adenomas display extensive positivity of the endothelial cells lining the cell plates. An invasive pattern of tumor cell growth is a definite feature of carcinoma and excludes hepatocellular adenoma. Extensive pseudoglandular structures and paucity of reticulin
CASE
25.1:
W E L L - D I F F E R E N T I AT E D
fibers also are in favor of HCC rather than adenoma (2). Hemorrhage and necrosis may be found in both hepatocellular adenoma and HCC (1,3). A fibrous pseudocapsule is sometimes present in hepatocellular adenomas but represents the exception rather than the rule. A thick pseudocapsule, as seen in the present case, is in favor of HCC. Most hepatocellular adenomas lack cytologic atypia; however, both atypia and pseudoglandular structures may occasionally be found, especially in tumors associated with anabolic steroid use and in those with β-catenin gene mutations (1,3). The latter occur with similar frequency in women and men and may potentially progress to HCC (5,6). Presence of mitotic figures in a hepatocellular adenoma-like tumor should raise suspicion of HCC. Immunohistochemical stains can be of help in distinguishing HCC from hepatocellular adenoma, because positive immunostaining for glypican-3 or alpha-fetoprotein represents strong evidence for HCC (7–9); however, well-differentiated HCCs are often negative for these markers. Detection of chromosomal abnormalities holds promise as a diagnostic adjunct for the distinction between these 2 neoplasms (10). Other hepatocellular nodules that may need to be distinguished from well-differentiated HCC in noncirrhotic livers are shown in Chapter 25, Table 25.2. Large regenerative nodule, nodular regenerative hyperplasia, lobar or segmental hyperplasia, and focal fatty change are lesions that contain portal tracts, as opposed to both hepatocellular adenoma and HCC. These lesions, as well as focal nodular hyperplasia, may display reactive cytologic changes but no definite cytologic atypia. Focal nodular hyperplasia lacks portal tracts; however, bile ductules (ductular reaction) are usually present in the scar and fibrous septa that characterize this lesion. Detection of ductular reaction and abnormally structured arteries are useful clues for the diagnosis of focal nodular hyperplasia, as discussed in more detail in Chapter 23. In cirrhotic liver biopsies, distinction between welldifferentiated HCC and high-grade dysplastic nodule may often be problematic. Useful features for this differential diagnosis are summarized in Table 25.1.1; helpful immunohistochemical stains are further discussed in Case 25.3. Lastly, it should be noted that
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focal areas of nodularity, with histologic features indistinguishable from focal nodular hyperplasia, may occasionally be found in cirrhotic livers (11,12). The importance of these lesions, which have been called “focal nodular hyperplasia-like nodules,” lies with the fact that they can mimic HCC on imaging studies.
References 1. Bioulac-Sage P, Balabaud C, Bedossa P, et al. Pathological diagnosis of liver cell adenoma and focal nodular hyperplasia: Bordeaux update. J Hepatol. 2007;46(3):521–527. 2. Hytiroglou P, Theise ND. Differential diagnosis of hepatocellular nodular lesions. Semin Diagn Pathol. 1998;15(4):285–299. 3. Ishak KG, Goodman ZD, Stocker JT. Tumors of the Liver and Intrahepatic Bile Ducts. Atlas of Tumor Pathology. 3rd series. Fascicle 31. Washington, DC: Armed Forces Institute of Pathology; 2001. 4. Goodman ZD, Terraciano LM. Tumours and tumour-like lesions of the liver. In: Burt AD, Portmann BC, Ferrell LD, eds. MacSween’s Pathology of the Liver. 5th ed. Philadelphia, PA: Churchill Livingstone; 2007: 761–814. 5. Rebouissou S, Bioulac-Sage P, Zucman-Rossi J. Molecular pathogenesis of focal nodular hyperplasia and hepatocellular adenoma. J Hepatol. 2008;48(1):163–170. 6. Bioulac-Sage P, Laumonier H, Couchy G, et al. Hepatocellular adenoma management and phenotypic classification: the Bordeaux experience. Hepatology. 2009;50(2):481–489. 7. Coston WM, Loera S, Lau SK, et al. Distinction of hepatocellular carcinoma from benign hepatic mimickers using glypican-3 and CD34 immunohistochemistry. Am J Surg Pathol. 2008;32(3):433–444. 8. Shafizadeh N, Ferrell LD, Kakar S. Utility and limitations of glypican-3 expression for the diagnosis of hepatocellular carcinoma at both ends of the differentiation spectrum. Mod Pathol. 2008;21(8):1011–1018. 9. Wang HL, Anatelli F, Zhai QJ, Adley B, Chuang ST, Yang XJ. Glypican-3 as a useful diagnostic marker that distinguishes hepatocellular carcinoma from benign hepatocellular mass lesions. Arch Pathol Lab Med. 2008;132(11):1723–1728. 10. Kakar S, Chen X, Ho C, et al. Chromosomal abnormalities determined by comparative genomic hybridization are helpful in the diagnosis of atypical hepatocellular neoplasms. Histopathology. 2009;55(2):197–205. 11. Quaglia A, Tibballs J, Grasso A, et al. Focal nodular hyperplasia-like areas in cirrhosis. Histopathology. 2003;42(1):14–21. 12. Libbrecht L, Cassiman D, Verslype C, et al. Clinicopathological features of focal nodular hyperplasia-like nodules in 130 cirrhotic explant livers. Am J Gastroenterol. 2006;101(10):2341–2346.
Case 25.2
Poorly Differentiated Hepatocellular Carcinoma PRODROMOS HYTIROGLOU
C L I N I C AL I N F OR M AT I ON
A 66-year-old man without a history of chronic liver disease complained of right upper abdominal pain of approximately 2 months’ duration. Radiologic workup revealed multiple mass lesions in the liver and lungs. Serum laboratory work was remarkable for elevated alpha-fetoprotein (104.8 ng/mL; upper limit of normal: 12.0 ng/mL) and CA19-9 (124 U/mL; upper limit of normal: 37 U/mL). A liver biopsy was performed.
R E A S ON F OR R E F E R R A L
The question in this case was whether the tumor represented poorly differentiated HCC or another type of primary or metastatic neoplasm.
A
PAT H OL OG I C F E AT U R E S
The biopsy cores consist of hepatic parenchyma with extensive replacement by a malignant neoplasm. The tumor cells are mostly arranged diffusely and in trabeculae (Figure 25.2.1A); however, in some areas, they are arranged in groups and tubular structures surrounded by fibrous tissue (Figure 25.2.1B). The neoplastic cells are large, with polygonal, roundish or columnar shape, hyperchromatic nuclei, high nucleocytoplasmic ratio, and eosinophilic cytoplasm (Figure 25.2.2A,B). The mitotic rate is high; aberrant mitotic figures are easily found. Foci of necrosis are present (Figure 25.2.1A). Focal parenchymal collapse and occasional groups of tumor cells within portal venules are also seen (Figure 25.2.3). Masson’s Trichrome stain shows poor collagenization of the fibrous tissue (Figure 25.2.4). Histochemical stains for mucin (periodic acid-Schiff diastase [PAS-d], mucicarmine) are negative. On immunohistochemical stains, the tumor cells are positive for cytokeratin 8/18 and glypican-3 (Figure 25.2.5). There is also focal membranous positivity for carcinoembryonic antigen with a “canalicular” pattern (polyclonal antibody for carcinoembryonic antigen [pCEA]) (Figure 25.2.6A). There is no staining of the neoplastic cells for cytokeratin 7 (Figure 25.2.6B), cytokeratin 19 and cytokeratin 20, carbamoyl synthetase-1, alpha-fetoprotein, CD10, CA19-9, and thyroid transcription factor-1.
D I AG N OS I S
Poorly differentiated HCC .
B F I G U R E 2 5 . 2 . 1 Representative areas of the tumor. The neoplastic
cells are arranged diffusely and in trabeculae (A) there are foci of necrosis. In other areas (B) there are neoplastic cell groups and tubular structures within fibrous tissue (A: 100; B: 200).
DISCUSSIO N
Although the overall histologic features of this poorly differentiated carcinoma were suggestive of HCC, the presence of multiple tumors in both liver and lungs, in the absence of a known history of chronic liver disease, raised the possibility of metastatic carcinoma in the liver, or in both liver and lungs. Furthermore, the presence of groups and tubules of neoplastic cells in fibrous tissue entertained the possibilities of poorly differentiated cholangiocarcinoma and combined
398
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P O O R LY
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399
A F I G U R E 2 5 . 2 . 3 Tumor growing within a small portal vein branch.
The portal tract is surrounded by parenchymal collapse with ductular reaction ( 200).
B FIGURE 25. 2. 2 On high power magnification, this poorly differ-
entiated neoplasm exhibits areas with features suggestive of both hepatocellular carcinoma (A) and adenocarcinoma (B) In the latter, there is ductular reaction among the infiltrating neoplastic cells (A,B: 400).
hepatocellular and cholangiocarcinoma. Therefore, a consultation was sought. Immunohistochemical stains were then performed, which provided further support for the diagnosis of HCC. As a rule, HCC is a cellular neoplasm with very little fibrous tissue. As opposed to cholangiocarcinoma and other adenocarcinomas, desmoplasia is not a feature of HCC, except for the rare scirrhous type (see Chapter 26). However, when HCC replaces cirrhotic parenchyma, the histologic appearances may simulate carcinomas with desmoplastic response. Even a loose fibroconnective stroma, such as that of the present case, is relatively uncommon in HCC and raises the possibility of tumor cell differentiation other than hepatocellular. Nevertheless, a loose fibroconnective stroma may also be due to parenchymal collapse, occurring over small or large areas of the liver as a result of vascular compromise. In
F I G U R E 2 5 . 2 . 4 Masson’s Trichrome stain revealing paucity of collagen fibers in the fibrous tissue ( 200).
our case, the presence of vascular invasion by neoplastic cells is consistent with this possibility. Furthermore, parenchymal collapse may induce ductular reaction, which, in turn, may account for elevated serum CA19–9 (1). Poorly differentiated HCCs display a great variety of histologic features. The most common growth patterns are trabecular and diffuse; areas of necrosis are commonly found. The tumor cells may be polygonal, rounded, or columnar; often, a mixture of cell shapes is seen. The nuclei are hyperchromatic and the nucleoli are usually prominent. The histologic features may be suggestive of a variety of metastatic poorly differentiated neoplasms, including adenocarcinomas from various organs, renal cell carcinoma, adrenocortical carcinoma, neuroendocrine carcinomas, and malignant
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A
CARCINOMA
B
FIGURE 25. 2. 5 The neoplastic cells exhibit positive immunostaining for glypican-3, which is more pronounced in the areas of diffuse (A) rather than grouped (B) arrangement (A,B: 400).
melanoma. Occasionally, the tumor cells are highly pleomorphic (pleomorphic cell variant), spindly (sarcomatoid HCC), or undifferentiated. A known history of chronic liver disease predisposing to HCC, such as chronic hepatitis B, hereditary hemochromatosis, or cirrhosis is useful clinical information but does not represent proof that any hepatic tumor is primary. On the other hand, lack of history of chronic liver disease does not rule out the possibility of HCC. Although bile production by the tumor cells is definite proof of HCC, this feature is uncommonly found in poorly differentiated tumors. Other features that are suggestive of hepatocellular differentiation, such as fat, Mallory bodies, eosinophilic globules, and “pale” bodies are also uncommon. On the other hand, mucin production by tumor cells, seen on histochemical stains such as PAS-d and mucicarmine is evidence that the tumor in question is an adenocarcinoma (either primary, ie, cholangiocarcinoma, or metastatic), or a combined hepatocellular and cholangiocarcinoma. Immunohistochemical features in favor of HCC include cytoplasmic staining of tumor cells for carbamoyl
synthetase-1 (recognized by the HepPar-1 antibody) and glypican-3, as well as a canalicular pattern of staining with pCEA and CD10. However, it should be kept in mind that poorly differentiated HCCs are often negative for carbamoyl synthetase-1, whereas a variety of metastatic carcinomas may occasionally be positive (2,3). Glypican-3 is positive in approximately 80% of HCCs, more often in poorly differentiated than well-differentiated ones, but it is also positive in malignant melanoma and nonseminomatous germ cell tumors (3). Poorly differentiated HCCs are often negative for pCEA and CD10. Alpha-fetoprotein is specific for HCC, if germ cell tumors can be excluded, but the sensitivity is low (30%–50%). Lastly, HCCs of patients with chronic hepatitis B may express hepatitis B surface antigen (HBsAg), a most specific, but uncommon finding. Therefore, in most cases of diagnostic doubt, a battery of immunohistochemical stains, rather than a single stain, will be required to confirm the diagnosis of poorly differentiated HCC and to rule out metastatic neoplasms. In addition to the stains discussed in the previous paragraph, a variety of stains
CASE
25.2:
P O O R LY
D I F F E R E N T I AT E D
A
H E PAT O C E L L U L A R
CARCINOMA
401
B
FIGURE 25. 2. 6 (A) On immunohistochemical stain with polyclonal antibody for carcinoembryonic antigen, the tumor cells show focal “canalicular-type” positivity. (B) The tumor cells are negative for cytokeratin 7, whereas the reactive ductules are positive (A: ×400; B: 200).
that are usually negative in HCC, but positive in HCC mimics, may be useful on different occasions (3,4). Examples include cytokeratin 7 (positive in a large variety of adenocarcinomas and urothelial carcinoma), cytokeratin 20 (positive in adenocarcinomas of gut origin and urothelial carcinoma), MOC-31 (positive in adenocarcinomas and neuroendocrine carcinomas), markers of renal cell carcinoma and adrenocortical carcinoma (discussed in Chapter 26), neuroendocrine markers (chromogranin, synaptophysin and others), thyroid transcription factor-1 (positive in carcinomas of the thyroid and in most neuroendocrine carcinomas and adenocarcinomas of the lung), prostate-specific antigen and prostatic acid phosphatase, hormone receptors (mostly expressed in carcinomas of the breast and the endometrium), and melanoma markers (such as S-100 protein, Melan-A, and HMB-45). It should also be kept in mind that aberrant immunohistochemical marker expression is commonly seen in poorly differentiated neoplasms, especially when focal rather than diffuse positivity is present. Distinction between poorly differentiated HCC and poorly differentiated cholangiocarcinoma may sometimes be
difficult, especially in needle biopsy specimens, because (1) HCC infiltrating cirrhotic parenchyma may give the wrong impression of a tumor with desmoplasia, (2) cholangiocarcinoma may display a trabecular pattern of growth, and (3) both neoplasms may have pseudoglandular structures. In contrast to HCC, cholangiocarcinoma may contain cytoplasmic mucin and usually expresses cytokeratin 7, CEA (cytoplasmic staining with both polyclonal and monoclonal antibodies), and MOC-31. On the other hand, immunopositivity for carbamoyl synthetase-1, alpha-fetoprotein, or glypican-3 is in favor of HCC. Epithelial membrane antigen is usually positive in cholangiocarcinoma and usually negative in HCC; however, among HCCs, positivity is mostly seen in poorly differentiated tumors (4). Cytokeratin 19 is positive in most cholangiocarcinomas and in a minority of HCCs. In the latter, cytokeratin 19 expression is considered to represent a marker of adverse prognosis (5). When examining a tumor with features suggestive of both HCC and cholangiocarcinoma, the possibility of combined hepatocellular and cholangiocarcinoma should be considered.
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Oncofetal proteins such as alpha-fetoprotein, CEA, and CA19–9, are commonly used in clinical tumor diagnosis and follow-up. This information is sometimes provided to the pathologist as an aid for differential diagnosis; however, it should be kept in mind that there are significant limitations in the sensitivity and the specificity of these proteins when used as tumor markers. For instance, elevated serum CA19–9 is often found in benign disorders of the biliary tree and pancreas. Even ductular reactions following parenchymal collapse, as seen in the present case, may cause serum CA19–9 elevation, unrelated to the nature or even the presence of a neoplasm (1).
2.
3.
4.
5.
References 1. Halme L, Karkkainen P, Isoniemi H, Makisalo H, von Bogulawski K, Hockerstedt K. Carbohydrate 19-9 antigen as a marker of non-malignant
CARCINOMA
hepatocytic ductular transformation in patients with acute liver failure. A comparison with alpha-fetoprotein and carcinoembryonic antigen. Scand J Gastroenterol. 1999;34(4):426–4431. Minervini MI, Demetris AJ, Lee RG, Carr BI, Madariaga J, Nalesnik MA. Utilization of hepatocyte-specific antibody in the immunocytochemical evaluation of liver tumors. Mod Pathol. 1997;10(7):686–692. Kakar S, Gown AM, Goodman ZD, Ferrell LD. Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms. Arch Pathol Lab Med. 2007;131(11):1648–1654. Goldstein NS, Bosler DS. Immunohistochemistry of the gastrointestinal tract, pancreas, bile ducts, gallbladder and liver. In: Dabbs DJ, ed. Diagnostic Immunohistochemistry. 2nd ed. Philadelphia,PA: Churchill Livingstone; 2006:442–508. Durnez A, Verslype C, Nevens F, et al. The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin. Histopathology. 2006;49(2): 138–151.
Case 25.3
Early Hepatocellular Carcinoma PRODROMOS HYTIROGLOU
C L I N IC AL I N F OR M AT I ON
A 60-year-old man underwent liver transplantation for cirrhosis due to chronic hepatitis B. On serial sectioning of the explanted cirrhotic liver, a 1.3 cm nodular lesion was found, which had a tan-brown cut surface and indistinct margins. R E A SON F OR R E F E R R AL
The differential diagnosis on referral was between dysplastic nodule and early HCC. PAT H OL OG I C F E AT U R E S
The nodule is composed of small neoplastic cells with hepatocytic features, which are arranged in thin (1- to 2-cell thick) plates with an inconspicuous endothelial lining (Figure 25.3.1). Occasional pseudoglandular structures are present (Figure 25.3.2). As compared with the adjacent hepatocytes, the tumor cells have increased nucleocytoplasmic ratio, nuclear hyperchromasia, mild nuclear contour irregularities, and mild cytoplasmic basophilia. Such differences are best appreciated at the border of the lesion, where there are cell plates, replaced in part by neoplastic cells (Figure 25.3.3). Focal steatosis is present in the lesion (Figure 25.3.4). Occasional unpaired arteries are found (Figure 25.3.5). On examination of multiple sections, focal areas of stromal invasion are identified (Figure 25.3.6). Cytokeratin 7 stain confirms that the invasive growth of the neoplastic cells is not accompanied by ductular reaction (Figure 25.3.7).
F I G U R E 2 5 . 3 . 2 Cytologic atypia is evident on high power magnifi-
cation ( 400).
F I G U R E 2 5 . 3 . 3 At the border of the lesion, the neoplastic cells
merge imperceptibly with the adjacent hepatocytes ( 200).
DIAGNO SIS
Early hepatocellular carcinoma.
DISCUSSIO N FIGURE 25. 3. 1 The most impressive histologic feature of this lesion
on low power magnification is the high cellularity ( 100).
Early HCC is a low-grade, early stage HCC, sharing many histologic features with high-grade dysplastic nodule. Although clinicopathologic studies from Japan over the past 2 decades
403
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FIGURE 25. 3. 4 Focal fat accumulation in neoplastic cells ( 200).
CARCINOMA
F I G U R E 2 5 . 3 . 6 A focus of stromal invasion: the neoplastic cells are arranged in groups and cords within fibrous tissue. No ductular reaction is present ( 200).
FIGURE 25. 3. 5 Unpaired artery surrounded by neoplastic cells
( 400).
have indicated that early HCC differs from high-grade dysplastic nodule (1,2), international recognition of this lesion was only recently acknowledged (3). The majority of early HCCs are smaller than 1.5 cm in diameter (4). On gross examination, these lesions usually appear vaguely (“indistinctly”) nodular. Histologically, they are composed of well-differentiated cells. The most characteristic feature of early HCC on low power examination is the high cellularity, as compared with the adjacent hepatic parenchyma. This is because the neoplastic cells are usually relatively small, with increased nucleocytoplasmic ratio. They are arranged in thin plates (often described as “irregular thin trabeculae”) and a variable number of pseudoglandular structures. Nuclear hyperchromasia and nuclear contour irregularities are present. Mitotic figures are absent or few. Usually, there is no substantial paucity of reticulin fibers. As the lesion grows, the neoplastic cells replace the hepatocytes of the adjacent cell plates; therefore, the border of
F I G U R E 2 5 . 3 . 7 Cytokeratin 7 immunostain in a focus of stromal invasion: preexisting bile ducts and rare tumor cells are positive. No ductular reaction is present ( 200).
the lesion is indistinct both grossly and microscopically. This replacing pattern of growth may result in entrapment of portal tracts within the lesion. However, unpaired arteries are also found in early HCC. Fatty change is common (40%) and has been attributed to the relatively poor arterial supply of these small tumors (5). Sometimes, in addition to the characteristic welldifferentiated cell population of early HCC, small HCCs (defined by the IWP as HCCs measuring less than 2cm in diameter) are found on microscopic examination to contain areas with neoplastic cell populations, which may be well- or moderately differentiated. These emerging cell clones replace over time the original cell population, and early HCC evolves to classic HCC (4). On the other hand, some tumors with characteristic histologic features of early HCC measure over
CASE
25.3:
E A R LY
H E PAT O C E L L U L A R
2 cm in diameter, indicating that the rate of emergence of different neoplastic clones in low-grade, early stage HCC varies significantly among lesions. Early HCC shares with high-grade dysplastic nodule all the features indicative of atypia shown in Chapter 25 Table 25.3; therefore, definite evidence that a lesion is early HCC rather than high-grade dysplastic nodule rests with the identification of stromal invasion. Stromal invasion may involve portal tracts or fibrous septa; the invading neoplastic cells are arranged in groups or cords, unaccompanied by ductular reaction (4,6,7). Because the foci of stromal invasion may be small, examination of multiple levels of the tissue blocks may be required to unequivocally identify invasion. Obviously, assessment of these nodular lesions is best performed when the lesions are entirely embedded. Due to the well-differentiated nature of early HCC, distinction between invading neoplastic cells and hepatocytes that are entrapped in fibrous tissue may sometimes be very difficult. However, as opposed to invading cells, entrapped hepatocytes are usually associated with ductular reaction, which can be highlighted with immunohistochemical stains for cytokeratin 7 or cytokeratin 19 (7). In the absence of identifiable invasion, histologic distinction between early HCC and high-grade dysplastic nodule may be impossible. Nevertheless, recent gene expression studies have provided immunohistochemically assessable markers that can be useful in such distinction (8–10). For example, it has been reported that positive immunostaining for any 2 of a set of 3 proteins, including glypican-3, heat shock protein-70, and glutamine synthetase, is a feature of HCC (either early or classic), whereas occasional high-grade dysplastic nodules may be positive for any one (but not more than one) of these markers (11,12). It is emphasized that the findings of these immunohistochemical stains should always be interpreted in association with the histologic features because cases of HCC may be negative for 2, or even 3, of these markers. Sampling issues in biopsy material also are of obvious importance. As molecular research on the precancerous and early cancerous lesions is progressing, there is hope that additional markers with clinical utility will be discovered. In the present case, the diagnosis of early HCC was made without need for these 3 immunohistochemical stains. However, the stains were performed at a later date for teaching purposes, and the lesion was found to be focally positive for glutamine synthetase and heat shock protein-70 (Figure 25.3.8A,B), and negative for glypican-3. From a practical point of view, identification of a nodular lesion in a cirrhotic liver as HCC, including early HCC, is an indication for treatment by ablation (most commonly performed, nowadays, with percutaneous radiofrequency application, rather than ethanol injection) or surgical resection (13). The diagnosis of HCC is also taken into account when assigning priority to cirrhotic patients for liver transplantation. On the other hand, the diagnosis of precancerous hepatocellular lesions is an indication for increased HCC surveillance. Nevertheless, it has been recommended that highgrade dysplastic nodules should be ablated, due to the high risk of evolution to HCC (14).
CARCINOMA
405
A
B F I G U R E 2 5 . 3 . 8 (A) Focal immunopositivity of the tumor cells for glutamine synthetase. (B) Focal immunopositivity of the tumor cells for heat shock protein-70. (Stain performed by courtesy of Professor M. Sakamoto, Keio University School of Medicine, Tokyo, Japan) (A,B: 200).
References 1. Sakamoto M, Hirohashi S, Shimosato Y. Early stages of multistep hepatocarcinogenesis: adenomatous hyperplasia and early hepatocellular carcinoma. Hum Pathol. 1991;22(2):172–178. 2. Kojiro M, Nakashima O. Histopathologic evaluation of hepatocellular carcinoma with special reference to small early stage tumors. Semin Liver Dis. 1999;19(3):287–296. 3. International Consensus Group for Hepatocellular Neoplasia. Pathologic diagnosis of early hepatocellular carcinoma: a report of the International Consensus Group for Hepatocellular Neoplasia. Hepatology. 2009;49(2):658–664. 4. Kojiro M. Pathology of Hepatocellular Carcinoma. Malden, MA: Blackwell; 2006. 5. Kutami R, Nakashima Y, Nakashima O, Shiota K, Kojiro M. Pathomorphologic study on the mechanism of fatty change in small hepatocellular carcinoma of humans. J Hepatol. 2000;33(2):282–289. 6. Kondo F. Histological features of early hepatocellular carcinomas and their developmental process: for daily practical clinical application: hepatocellular carcinoma. Hepatol Int. 2009;3(1):283–293.
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7. Park YN, Kojiro M, Di Tommaso L, et al. Ductular reaction is helpful in defining early stromal invasion, small hepatocellular carcinomas, and dysplastic nodules. Cancer. 2007;109(5):915–923. 8. Chuma M, Sakamoto M, Yamazaki K, et al. Expression profiling in multistage hepatocarcinogenesis: identification of HSP70 as a molecular marker of early hepatocellular carcinoma. Hepatology. 2003;37(1):198–207. 9. Capurro M, Wanless IR, Sherman M, et al. Glypican-3: a novel serum and histochemical marker for hepatocellular carcinoma. Gastroenterology. 2003;125(1):89–97. 10. Osada T, Sakamoto M, Nagawa H, et al. Acquisition of glutamine synthetase expression in human hepatocarcinogenesis: relation to disease recurrence and possible regulation by ubiquitin-dependent proteolysis. Cancer. 1999;85(4):819–831.
CARCINOMA
11. Di Tommaso L, Franchi G, Park YN, et al. Diagnostic value of HSP70, glypican 3, and glutamine synthetase in hepatocellular nodules in cirrhosis. Hepatology. 2007;45(3)725–734. 12. Di Tommaso L, Destro A, Seok JY, et al. The application of markers (HSP70, GPC3 and GS) in liver biopsies is useful for detection of hepatocellular carcinoma. J Hepatol. 2009;50(4):746–754. 13. Bruix J, Sherman M, Practice Guidelines Committee, American Association for the Study of Liver Diseases. Management of hepatocellular carcinoma. Hepatology. 2005;42(5):1208–1236. 14. Hytiroglou P, Park YN, Krinsky G, Theise ND. Hepatic precancerous lesions and small hepatocellular carcinoma. Gastroenterol Clin N Am. 2007;36(4):867–887.
26 Hepatocellular Carcinoma Variants SHRIRAM JAKATE AND DEBORAH GIUSTO
Hepatocellular carcinomas (HCCs) occurring in prototypical clinical settings and displaying classical histological features can be relatively easily diagnosed. These tumors usually appear in patients with preexistent cirrhosis, create masses with recognizable radiographic imaging characteristics, and often elevate the serum alpha fetoprotein (AFP). Microscopically, the tumor cells simulate hepatocytes and show multilayered trabecular cords, high nuclear/cytoplasmic ratios, prominent nucleoli, faintly granular eosinophilic cytoplasm, and bile canaliculi. Tumors digressing from these familiar patterns may be broadly described as variants of HCC (1–3), provided hepatocellular origin can be immunohistochemically established and metastatic and other primary tumors excluded. These variants may be grouped as follows: (1) histological mimicry to metastatic and other primary tumors, (2) combination with primary intrahepatic cholangiocarcinoma, (3) diffuse multifocality with cirrhosis-like nodularity, (4) variety of prominent cytoplasmic contents, (5) altered appearances due to extremes of grade, vascular permeation, pedunculation, and therapeutic ablation.
or combined phenotype may be relevant for optimizing the treatment and estimating the prognosis, which may be overall poorer than HCC.
M I M I C RY TO M E TASTAT I C A N D OT H E R P R I M ARY T U M OR S
HCC may display a spectrum of prominent cytoplasmic contents including Mallory-Denk bodies, hyaline bodies, pale bodies, AFP, hepatitis B surface antigen (HBsAg), lipid, iron, and copper. Often these are discordant in quality and/or quantity in HCC and the surrounding nonneoplastic liver or serum. Given this discordance, the HCC cytoplasmic contents are best not utilized for assessment of potential etiology of chronic liver disease and cirrhosis. In addition, such contents should also not be used for making the diagnosis of HCC instead of a hepatocellular nonneoplastic process or benign tumor.
Suspicion that a liver tumor is metastatic and not HCC may be present clinically due to any of the following: lack of clinically known chronic liver disease or cirrhosis, multiplicity of tumor masses, history of primary tumor in another organ, normal AFP, and atypical radiographic findings. Histologically, well-formed glandular or acinar pattern instead of trabecular pattern is the commonest variation leading to a preliminary diagnosis of adenocarcinoma, either primary intrahepatic cholangiocarcinoma or metastasis from gastrointestinal tract, lung, breast, pancreas, or other organs. Alternatively, trabecular pattern may be maintained, but clear cytoplasm may mimic renal cell carcinoma, and compact cords with monomorphic and hyperchromatic nuclei may raise the possibility of metastatic neuroendocrine carcinoma. C O M BI NE D H E PATOC E L L U L A R A N D C H OL A N G I OC AR C I N OM A
Both primary intrahepatic cholangiocarcinoma and HCC may arise subsequent to chronic liver disease and cirrhosis. Although their morphological features may sometimes overlap, the 2 primary liver tumors are generally phenotypically and immunohistochemically distinct. Occasionally, there is combination of the 2 tumors. Identifying this mixed
MULT IFO C A L H CC W IT H CIR R H O SIS- LIKE NO DULA R IT Y
Rarely, a random liver biopsy in a patient with cirrhosis may unexpectedly yield multifocal HCC with small cirrhosis-like nodules. There is usually no clinically or radiographically recognizable mass, and the serum AFP levels may be normal or only mildly elevated. Such tumors are likely to be quite extensive throughout the liver. This variant is often clinically unsuspected and incidentally encountered in a random liver biopsy, explanted native liver, or after autopsy and may show distinctive gross, microscopic, and immunohistochemical features. H CC W IT H A VA R IET Y O F P RO MINENT CY TO P LA SMIC CO NT ENT S
A LT ER ED A P P EA R A NCE O F H CC DUE TO GRADE, VA SCULA R P ER MEAT IO N, P EDUNCULAT ION, A ND T H ER A P EUT IC A BLAT IO N
Most easily diagnosable HCC is moderately differentiated. Well-differentiated HCC shows minimal architectural and cytological alterations and creates difficulties in distinguishing the lesion from macroregenerative nodule or hepatocellular adenoma. Conversely, poorly differentiated HCC may show a solid pattern and bizarre pleomorphic cells including giant cells. Vascular invasion is more common in larger and less well-differentiated tumors. Occasionally, HCC extends like a column in the portal and hepatic veins and rarely into the right atrium. Pedunculated HCC, a rare form of HCC protruding extrahepatically from the right lobe may mimic a growth in right adrenal or para-adrenal tissue. After therapeutic ablation of
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classical HCC, the tumor may undergo variable degrees of loss of viability ranging from severe necrosis to apparent cytological preservation but lack of expected immunophenotypical characteristics.
References 1. Hirohashi S, Ishak KG, Kojiro M, et al. Hepatocellular carcinoma. In: Hamilton SR, Aaltonen LA, eds. Tumors of the Digestive System. Lyon: IARC Press; 2000:159–172. World Health Organization Classification of Tumors.
CARCINOMA
VA R I A N T S
2. Ishak KG, Goodman ZD, Stocker JT. Tumors of the liver and intrahepatic bile ducts. Atlas of tumor pathology, third series, fascicle 31. Washington, DC: Armed Forces Institute of pathology, American Registry of Pathology; 2001. 3. Wee A. Diagnostic utility of immunohistochemistry in hepatocellular carcinoma, its variants and their mimics. Appl Immunohistochem Mol Morphol. 2006;14:266–272.
Case 26.1
Pseudoglandular Hepatocellular Carcinoma versus Cholangiocarcinoma and Metastatic Adenocarcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 52-year-old man presented with dull right upper quadrant abdominal pain for several weeks. Hemoglobin and liver function tests were within normal limits. Abdominal ultrasound showed a solitary 3.5 cm hyperechoic mass in the medial segment of the left hepatic lobe. Subsequently, computed tomography (CT) was performed which showed a hypodense mass. The imaging characteristics were of a solid neoplastic mass rather than a hemangioma or a cyst. The patient was otherwise healthy and had no known neoplasm elsewhere. There was no history of weight loss, liver disease, or alcohol abuse. Serum AFP was moderately elevated (162 ng/mL). CT guided needle biopsies were obtained from the mass.
R E A SON F OR R E F E R R AL
The needle biopsies have recovered tumor and adjacent liver tissue. The tumor appears to be an adenocarcinoma with glands showing variably distended lumina and greenish yellow content. There are no clear cells and no obvious trabecular pattern is seen. On routine hematoxylin and eosin stain, it is difficult to determine if this is a variant of HCC, cholangiocarcinoma, or metastatic adenocarcinoma.
F I G U R E 2 6 . 1 . 1 Hepatocellular carcinoma showing pseudoglandular pattern with focally distended lumina (arrows) filled with bile-like material.
PAT H OL OG I C F E AT U R E S
Microscopically, the tumor shows prominent glandular pattern. There are small densely crowded glands lined by cells with central vesicular nuclei, small nucleoli, and ample eosinophilic cytoplasm reminiscent of neoplastic hepatocytes. The glands show focally distended lumina filled with bile-like material (Figure 26.1.1). Immunostains show the following results: positive for cytokeratin (CK) 8/18, Hep Par 1 (Figure 26.1.2), Glypican-3, and p-CEA which shows strong staining of the glandular lumina suggestive of dilated bile canaliculi (Figure 26.1.3). The tumor cells are negative for CK7, CK20, synaptophysin, caudal drosophila homeobox analogue (CDX-2), thyroid transcription factor 1 (TTF-1), and prostate specific antigen (PSA). The adjacent liver shows cirrhotic nodules and no biliary epithelial dysplasia or periductal fibrosis.
D I AG N OS I S
Pseudoglandular variant of hepatocellular carcinoma.
F I G U R E 2 6 . 1 . 2 Pseudoglandular hepatocellular carcinoma showing strong positivity for hepatocyte antigen.
DISCUSSIO N
Pure pseudoglandular variant of HCC is quite uncommon (<5%), but pseudoglandular pattern is often seen admixed with conventional trabecular pattern (1). Usually pseudoglandular pattern is seen in well and moderately differentiated HCC. It has no unique prognostic or therapeutic relevance but creates challenges in the differential diagnoses such 409
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FIGURE 26. 1. 3 Pseudoglandular hepatocellular carcinoma showing luminal lining stained by polyclonal carcinoembryonic antigen (long arrow) consistent with distended bile canaliculi and pericanalicular staining (short arrow).
F I G U R E 2 6 . 1 . 4 Outer aspect of pseudoglandular structures showing
as pseudoglandular variant of HCC, primary intrahepatic cholangiocarcinoma, or metastatic adenocarcinoma from an unknown primary. The diagnosis of pseudoglandular variant of HCC can be established through its identity as HCC. Clinically, the majority of HCC occur in the setting of cirrhosis, show elevated serum AFP, and distinctive findings on imaging studies. Morphologically, individual tumor cells resemble neoplastic hepatocytes, and the glandular pattern is created through distended bile canaliculi and/or focal necrosis within the usual trabecular pattern (2). Portions within the tumor may also show conventional HCC-type trabecular pattern, and adjacent nonneoplastic liver may show cirrhosis. Immunohistochemically, general hepatocellular origin is distinguished by high level of specificity for hepatocyte antigen (Hep Par 1), peri-canalicular polyclonal carcinoembryonic antigen (p-CEA) as well as peri-canalicular cell membrane metallopeptidase, neprilysin (CD10) positivity (3,4). Since pseudoglands may represent distended biliary canaliculi, there may be strong staining of the luminal lining by p-CEA. Glypican-3 (a heparan sulfate proteoglycan that acts as an oncofetal protein) is usually positive in moderately and poorly differentiated malignant hepatocytes. HCC induces capillarization of the sinusoids leading to strong expression of CD34 and Vimentin in endothelial cells. In the pseudoglandular variant, such staining is present on the outer border of the glands, opposite of the luminal p-CEA (Figure 26.1.4). The diagnosis of intrahepatic cholangiocarcinoma is more challenging than HCC, since this tumor can share morphological and immunohistochemical features with metastatic adenocarcinoma, particularly pancreatic. Presence of risk factors such as primary sclerosing cholangitis, cirrhosis, or biliary epithelial dysplasia and lack of known primary, exclusion of pancreatic mass on imaging and positive immunostaining for CK7, CK19,
TA BL E 2 6 . 1 . 1 Immunohistochemical profile of HCC, cholangi-
strong staining with CD34 positive endothelial cells.
ocarcinoma, and metastatic adenocarcinoma Diagnosis
Typical Immunohistochemical Profile
Pseudoglandular hepatocellular carcinoma
Positive: Hep Par 1, GPC-3, CK8/18, p-CEA (luminal lining), CD34 (outer border of glands) Negative: CK7, CK19, CK20
Intrahepatic cholangiocarcinoma
Positive: CK7, CK19, CK20/, p-CEA cytoplasmic Negative: Hep Par 1, p-CEA pericanalicular, GPC-3
Adenocarcinoma from unknown primary
Lung: CK7, CK20, TTF-1 Colorectal: CK20, CK7, CDX-2 Breast: CK7, CK20, ER, Mammaglobin, GCDFP-15 Pancreas: CK7, CK19, CK20/, p-CEA cytoplasmic Ovary: CK7, CK20, ER, WT-1 Thyroid: CK7, CK20, TTF-1, Thyroglobulin Prostate: CK7, CK20, PSA, PAP Kidney: CK7, CK20, PAX-2, RCC, CD10
Abbreviations: CDX-2, caudal drosophila homeobox analogue 2; CK, cytokeratin; ER, estrogen receptor; GCDFP-15, gross cystic disease fluid protein -15; GPC-3, glypican 3; HCC, hepatocellular carcinoma; Hep Par 1, (hepatocyte antigen); PAP, prostatic acid phosphatase; p-CEA, polyclonal carcinoembryonic antigen; PAX-2, paired Homeobox-2; PSA, prostate specific antigen; RCC, renal carcinoma marker; TTF-1, thyroid transcription factor 1; WT-1, Wilms tumor gene product.
and cytoplasmic p-CEA are helpful in favoring the diagnosis of cholangiocarcinoma. Liver is one of the commonest locations for carcinoma of unknown primary, most of which are adenocarcinomas. Immunomarkers based on organ or tissue of origin for potential primary sites may be helpful when faced with unknown primary (Table 26.1.1).
CASE
26.1:
PHC
References 1. Ishak KG, Goodman ZD, Stocker JT. Tumors of the liver and intrahepatic bile ducts. Atlas of tumor pathology, third series, fascicle 31. Armed Forces Institute of pathology. American Registry of Pathology, 2001. 2. Kondo Y, Nakajima T. Pseudoglandular hepatocellular carcinoma: a morphogenetic study. Cancer. 1987;60:1032–1037.
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3. Kakar S, Gown AM, Goodman ZD, Ferrell LD. Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms. Arch Pathol Lab Med. 2007;131:1648–1654. 4. Gokden M, Shinde A. Recent immunohistochemical markers in the differential diagnosis of primary and metastatic carcinomas of the liver. Diagn Cytopathol. 2005;33:166–172.
Case 26.2
Hepatocellular Versus Neuroendocrine Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N I C AL I N F OR M AT I ON
A 59-year-old woman presented with recent rectal bleeding and dull abdominal pain for 3 months. On colonoscopy no abnormality was detected in the colon or 10 cm of terminal ileum. Upper endoscopy showed unremarkable esophagus, stomach, and duodenum. On ultrasound, there were two 3.3 cm and 2 cm well-circumscribed, ultrasonographically identical hypoechoic masses in the right lobe of the liver. Liver function tests showed no abnormalities and the AFP level and platelets were normal. There was no known neoplasia anywhere else. Ultrasound-guided needle biopsy was performed on the larger mass.
Immunohistochemically, the tumor cells are negative for Hep Par 1 and Glypican-3 and strongly positive for CK7 (Figure 26.2.2), synaptophysin, chromogranin (Figure 26.2.3), and CDX-2 (Figure 26.2.4). TTF-1 and ER are negative.
DIAGNO SIS
Well-differentiated neuroendocrine carcinoma. Potentially metastasis from ileum based on immunohistochemistry.
R E A S ON F OR R E F E R R A L
The tumor shows a trabecular HCC-like pattern of uniform cells. The liver tissue away from the tumor shows no hepatitis or cirrhosis. Both multiplicity (clinically 2 nodules) and lack of cirrhosis are suggestive of metastasis, but there is no known primary. The case is referred with the suspicion of welldifferentiated hepatocellular carcinoma in a noncirrhotic liver. PAT H OL OG I C F E AT U R E S
The tumor shows a characteristic architectural pattern of trabeculation and stratified-appearing neoplastic cell layers reminiscent of hepatocellular origin. However, the tumor cell nuclei are not vesicular, and the nuclear chromatin is coarse (Figure 26.2.1). The cytoplasm shows granular texture. F I G U R E 2 6 . 2 . 2 Tumor cells are strongly positive for cytokeratin 7.
FIGURE 26. 2. 1 Uniform cells with trabecular pattern reminiscent of hepatocellular carcinoma, but the nuclei are not vesicular and show coarse chromatin.
F I G U R E 2 6 . 2 . 3 Tumor cells are positive for chromogranin.
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VERSUS
NEUROENDOCRINE
CARCINOMA
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TA BL E 2 6 . 2 . 1 Immunohistochemical pattern and potential clinical
setting of primary HCC and metastatic welldifferentiated neuroendocrine tumor and potential primary site Immunohistochemical Pattern
Potential Clinical Setting
Primary HCC
Positive: Hep Par 1, GPC-3, p-CEA (pericanalicular) Negative: Synaptophysin, Chromogranin, CK7
Cirrhosis, solitary more than multiple liver masses
Metastatic welldifferentiated neuroendocrine tumor
Positive: Synaptophysin, Chromogranin, CK7 Negative: Hep Par 1, GPC-3, p-CEA (pericanalicular)
Noncirrhotic, multiple more than solitary liver masses
Potential primary site
Ileum (CDX-2 positive)
Carcinoid syndrome Ileal/mesenteric mass on imaging
Pancreas (CDX-2 /)
Pancreatic mass on imaging Functional hormonal secretion/
Lung (TTF-1 positive)
Respiratory symptoms Lung mass on imaging
Breast (ER, mammaglobin positive)
Abnormal mammogram Breast mass
Tumor
FIGURE 26. 2. 4 Tumor cells show strong nuclear staining with caudal
drosophila homeobox analogue 2.
D I S C U S S I ON
Primary well-differentiated neuroendocrine carcinoma of the liver is extremely rare (1), and the overwhelming majority of cases are metastatic, with the most common primary sites being pancreas (pancreatic endocrine tumor or islet cell tumor) and ileum. Other sites are uncommon and include lung, breast, appendix, rectum, stomach, duodenum, and jejunum. Well-differentiated neuroendocrine carcinoma mimics hepatocellular carcinoma both cytologically and architecturally. The cells of well-differentiated neuroendocrine carcinoma are uniform with central nuclei and substantial cytoplasm, much like hepatocytes. Architecturally, trabeculae with stratified cell plates and glandular structures may be seen in both. Immunohistochemical studies (2) and the clinical profile are crucial in the differentiation between the 2 tumors and if metastatic, estimating the potential primary site (Table 26.2.1).
Abbreviations: CDX-2, caudal drosophila homeobox analogue 2; CK, cytokeratin; GPC-3, glypican 3; ER, estrogen receptor; Hep Par 1, (hepatocyte antigen); p-CEA, polyclonal carcinoembryonic antigen; TTF-1, thyroid transcription factor 1.
References 1. Iimuro Y, Deguchi Y, Ueda Y, et al. Primary hepatic carcinoid tumor with metachronous lymph node metastasis after long-term follow up. J Gastroenterol Hepatol. 2002;17:1119–1124. 2. Srivastava A, Hornick JL. Immunohistochemical staining for CDX-2, PDX-1, NESP-55 and TTF-1 can help distinguish gastrointestinal carcinoid tumors from pancreatic endocrine and pulmonary carcinoid tumors. Am J Surg Pathol. 2009;33:626–632.
Case 26.3
Hepatocellular Carcinoma, Clear Cell Variant SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N I C AL I N F OR M AT I ON
A 50-year-old woman presented with weakness, weight loss, and abdominal pain for 3 months. CT scan showed a 4.0 cm liver mass, with no evidence of cirrhosis. In addition, masses were identified in the right kidney, right adrenal gland, and right lung. A needle biopsy of the liver mass was performed. R E A S ON F OR R E F E R R A L
The case was referred in order to distinguish clear cell hepatocellular carcinoma from metastatic carcinoma with clear cells. PAT H OL OG I C F E AT U R E S
The biopsy shows a neoplastic proliferation of large polygonal cells, separated by a rich vascular stroma with prominent sinusoid-like vessels. The majority of tumor cells show clear cytoplasm with no glandular differentiation (Figure 26.3.1). Immunohistochemistry revealed that the tumor cells expressed pan-cytokeratin, paired homeobox-2 ([PAX-2] nuclear pattern, Figure 26.3.2), and MOC31 (membranous pattern) and were negative for Hep Par 1, S100, HMB-45, inhibin, chromogranin, and synaptophysin (Figure 26.3.3).
F I G U R E 2 6 . 3 . 2 Tumor cells show strong nuclear reactivity with
paired homeobox-2.
D I AG N OS I S
Metastatic renal cell carcinoma.
F I G U R E 2 6 . 3 . 3 Clear cell tumor negative for synaptophysin.
DISCUSSIO N
FIGURE 26. 3. 1 Tumor showing trabecular pattern and clear cells.
The principal differential diagnoses of clear cell tumors in the liver include clear cell HCC, metastatic renal cell carcinoma, balloon cell melanoma, metastatic adrenocortical carcinoma, neuroendocrine carcinoma with clear cell features and epithelioid angiomyolipoma (AML) (Table 26.3.1). The presence of bile and Mallory hyaline can establish the diagnosis of HCC based on HE sections, but immunohistochemistry is required in most cases. Expression of Hep Par 1 with negative MOC 31 in the appropriate clinical and 414
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CARCINOMA,
CLEAR
CELL
VA R I A N T
415
TA B LE 26. 3. 1 Differential diagnosis of clear cell neoplasms
in the liver Diagnosis
Typical Immunohistochemical Profile
Clear cell hepatocellular carcinoma
Positive: Hep Par 1, p-CEA, GPC-3 Negative: MOC31, PAX-2 Variable: CD10, CD56
Renal cell carcinoma clear cell type
Positive: PAX-2, MOC31 Negative: Hep Par 1, p-CEA, GPC-3 Less useful: CD10, vimentin
Balloon cell melanoma
Positive: S-100, HMB-45, Melan A, GPC-3 Negative: Hep Par 1, p-CEA
Clear cell neuroendocrine tumors
Positive: CG, Syn, MOC31 Negative: Hep Par 1, p-CEA
Adrenocortical carcinoma
Positive: Inhibin, Melan A, calretinin Negative: Hep Par 1, PAX-2, cytokeratin
Angiomyolipoma
Positive: HMB-45, SMA Negative: Hep Par 1, S-100 cytokeratin
Abbreviations: CEA, carcinoembryonic antigen; CG, chromogranin; GPC, Glypican; Hep Par 1, hepatocyte antigen; p-CEA, polyclonal carcinoembryonic antigen; PAX-2, paired Homeobox-2; SMA, smooth muscle actin; Syn, synaptophysin.
morphological setting confirms the diagnosis of HCC (1). Hep Par 1 has high sensitivity for HCC and is expressed in nearly all cases of clear cell HCC. Hep Par 1 is negative in the other clear cell neoplasm mentioned above. If the staining with Hep Par 1 is weak or absent, but suspicion of HCC persists based on clinical and imaging findings, other markers of hepatocellular differentiation can be sought such as p-CEA or GPC-3. p-CEA shows a canalicular pattern of staining, which is considered pathognomonic of HCC (Figure 26.3.4). In contrast, most adenocarcinomas show luminal or cytoplasmic pattern of staining with p-CEA. Both Hep Par 1 and p-CEA have low sensitivity for poorly differentiated HCC (around 50%). GPC-3 can be helpful in this situation as it has higher sensitivity for poorly differentiated HCC. AFP has low sensitivity for diagnosis of HCC (<30%) and is less useful since better antibodies are available. MOC31, a cell surface glycoprotein is negative in more than 90% of HCC, whereas majority of adenocarcinomas are positive. This antibody along with one or more hepatocellular markers is extremely useful for the diagnosis of HCC. The absence of Hep Par 1 and expression of MOC31 in this case does not support HCC. Melanomas can undergo clear cell change (balloon cell melanoma) due to degeneration of premelanosomes or accumulation of lipid or glycogen. Liver metastasis from these tumors can mimic clear cell HCC morphologically. Melanocytic markers like S-100, HMB-45, and Melan A are negative in hepatocellular tumors, whereas melanomas do not express Hep Par 1 or polyclonal CEA. GPC-3 is not helpful in this differential diagnosis, as it can be expressed in melanomas. The lack of S-100 and HMB-45 in this tumor does not support melanoma.
F I G U R E 2 6 . 3 . 4 HCC showing characteristic pericanalicular staining (arrows) with p-CEA.
This patient has an adrenal mass and adrenocortical carcinomas often have clear cells that can mimic clear cell HCC. The expression of inhibin, Melan A, and calretinin in adrenocortical carcinoma distinguishes it from HCC. Inhibin is expressed in around 70% of adrenocortical carcinomas and Melan A in 50% to 60%. The sensitivity can be improved to more than 80% by a combination of both antibodies. Adrenocortical carcinomas express synaptophysin but are negative for chromogranin. Most adrenocortical carcinomas are negative for pan-cytokeratin, as well as hepatocyte markers like Hep Par 1 and p-CEA. The expression of pan-cytokeratin and absence of inhibin and melan A is not in keeping with adrenocortical origin. Neuroendocrine carcinomas (carcinoids) are almost always metastatic but can rarely arise as a primary lesion in the liver. Neuroendocrine carcinomas can have clear cells and may be comprised of polygonal tumor cells in acinar or trabecular patterns similar to HCC. Stromal hyalinization, if present, favors a neuroendocrine tumor. The majority of neuroendocrine carcinomas express one or more neuroendocrine markers (chromogranin, synaptophysin) as well as MOC31. CD56, a less specific neuroendocrine marker, is not helpful as it can be positive in HCC as well. Hep Par 1 is consistently negative in neuroendocrine neoplasms. This tumor does not show any neuroendocrine features on morphology or immunohistochemistry. The epithelioid variant of AML can have clear cells and is difficult to distinguish from HCC on morphologic grounds alone. Most AMLs in the liver are not associated with tuberous sclerosis and often lack fat. Once the diagnosis is suspected, immunohistochemical confirmation is easy because of their characteristic staining profile. AMLs strongly coexpress smooth muscle markers like smooth muscle actin and melanoma markers (eg, HMB-45, Melan A). S-100 is typically negative. Cytokeratin, Hep Par 1, and p-CEA are not expressed in AML. Clear cell renal cell carcinoma is also a highly vascular neoplasm composed of polygonal cells and can be
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indistinguishable from clear cell HCC on morphologic grounds. Expression of hepatocellular markers Hep Par 1 and p-CEA (canalicular pattern) is not observed in renal cell carcinoma. PAX-2, a renal-restricted nuclear transcription factor, is expressed in 70% to 80% of metastatic clear cell renal cell carcinomas, and less commonly in other subtypes of renal cell carcinoma. Higher grades of clear cell carcinoma can have decreased expression. PAX-2 is negative in HCC. Unlike HCC, MOC31 is positive in 60% to 70% of renal cell carcinomas. Other markers like renal cell carcinoma (RCC) antibody and vimentin have a lower sensitivity and are less useful. CD10 has a different expression pattern in RCC and HCC (membranous and canalicular respectively), but the utility of CD10 is limited in view of the availability of better antibodies. The nuclear expression of PAX-2 and lack of hepatocellular and other differentiation on immunohistochemistry confirm the diagnosis of metastatic renal cell carcinoma. Carcinomas from a wide variety of sites can exhibit clear cell features, including those originating in the bile duct, prostate, endometrium, vagina, cervix, ovary, salivary
CARCINOMA
VA R I A N T S
gland, and thyroid. The clinical presentation and pattern of immunoreactivity with cytokeratins (like CK7/CK20) and lineage specific markers such as TTF-1, PSA, and so on can help to confirm the diagnosis. Other tumors with clear cells include squamous cell carcinoma, germ cell tumors like seminoma, and sarcomas like epithelioid leiomyosarcoma and gastrointestinal stromal tumors. If there are no morphological clues to the site of origin, a suggested approach is to obtain Hep Par 1, MOC-31, and PAX-2 along with several unstained slides. In most instances, the diagnosis can be established with this limited panel. If any doubt persists or if there is any discrepancy based on the clinical presentation, additional stains listed in Table 26.3.1 can be sought depending on the clinical situation.
Reference 1. Kakar S, Gown AM, Goodman ZD, Ferrell LD, et al. Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms. Arch Pathol Lab Med. 2007;131:1648–1654.
Case 26.4
Scirrhous Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 65-year-old male with several years’ history of hepatitis C and well-compensated cirrhosis was screened for HCC. The AFP level was elevated at 265 ng/mL. Ultrasonography showed a subcapsular hypoechoic 2.7 cm mass in the right lobe. Contrast enhanced CT showed heterogeneous enhancement in the early phase and prolonged enhancement in the late phase consistent with cholangiocarcinoma. To avoid the risk of seeding, no fine needle aspirate core needle biopsy was performed. Instead, the tumor was locally resected with free margins and the clinical and radiological diagnosis of cholangiocarcinoma. R E A SON F OR R E F E R R AL
The tumor does not have the definite glandular pattern expected for cholangiocarcinoma. The tumor also has a very dense stroma. The differential diagnoses considered histologically are poorly differentiated cholangiocarcinoma without gland formation, hepatocellular carcinoma with dense stroma, and fibrolamellar carcinoma. PAT H OL OG I C F E AT U R E S
F I G U R E 2 6 . 4 . 2 Scirrhous variant of hepatocellular carcinoma showing dense fibrous stroma and cords and pseudoglandular structures.
and unlike the larger deeply eosinophilic polygonal cells with large vesicular nuclei and prominent nucleoli that are seen in fibrolamellar carcinoma. Immunohistochemically, the tumor cells are negative for CK7 and CK19 and positive for Hep Par 1.
Grossly, the resected tumor shows cirrhotic liver with unencapsulated yellowish-white solid tumor and ragged edges (Figure 26.4.1). Histologically, there is dense fibrous stroma and cords and pseudoglandular structures of malignant cells resembling conventional hepatocellular carcinoma (Figure 26.4.2)
DIAGNO SIS
Scirrhous hepatocellular carcinoma.
DISCUSSIO N
FIGURE 26. 4. 1 Cut surface of the resected liver showing subcapsular
fibrotic tumor.
This variant is subclassified by the WHO as hepatocellular carcinoma with marked fibrosis along the sinusoid-like blood spaces with varying degrees of atrophy of tumor trabeculae (1). Such fibrosis needs to be differentiated from nonspecific fibrotic changes that commonly occur after post-therapeutic ablation in any hepatocellular carcinoma. By virtue of its mimicry to cholangiocarcinoma on imaging, this tumor is commonly radiographically mistaken for cholangiocarcinoma (2). On gross and microscopic examination due to the dense fibrosis, this variant may be confused with fibrolamellar carcinoma. However, the histological features are neither those of cholangiocarcinoma nor fibrolamellar carcinoma. Apart from the dense fibrosis that occupies a major portion of the tumor, the individual tumor cells are cytologically similar to the conventional hepatocellular carcinoma with trabecular and/or pseudoglandular patterns. The clinicopathological features of scirrhous hepatocellular carcinoma, conventional
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TA B LE 26. 4. 1 Comparison between scirrhous hepatocellular carcinoma, conventional hepatocellular carcinoma, intrahepatic
cholangiocarcinoma, and fibrolamellar carcinoma Scirrhous Hepatocellular Carcinoma (S-HCC)
Conventional Hepatocellular Carcinoma (HCC)
Intrahepatic Cholangiocarcinoma (ICC)
Fibrolamellar Carcinoma (FLC)
Incidence (percentage of primary liver carcinoma)
<1–4%
70–90%
10–15%
<1–2%
Approximate average age (in the USA) and gender bias
Similar to HCC
60.5 (M:F 4:1)
64 (M F)
About 35 (M F)
Underlying chronic liver disease and cirrhosis
Cirrhosis in the majority of cases similar to HCC
Cirrhosis in the majority of cases
More often noncirrhotic but may have underlying fibrosing biliary disease
Often none
Gross pathology
Often subcapsular unencapsulated and lobulated whitish mass mimicking ICC
Often encapsulated variegated mass with necrosis
Unencapsulated graywhite solid mass
Well-circumscribed pale mass often with prominent central scar
Microscopic features
Dense fibrotic stroma and HCC-like malignant cells
Malignant hepatocytes with multilayered cell plates
Malignant adenocarcinoma cells with glandular structures
Dense fibrotic stroma and polygonal cells with large nucleoli
hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and fibrolamellar carcinoma are given in the Table 26.4.1. Immunohistochemically, this variant may sometimes show CK7 positivity with or without Hep Par 1 positivity (3). In one study, better prognosis is reported (4).
References 1. Hirohashi S, Ishak KG, Kojiro M, et al. Hepatocellular carcinoma. In: Hamilton SR, Aaltonen LA, eds. Tumors of the Digestive System. Lyon: IARC Press; 2000. p. 159–172. World Health Organization Classification of Tumors.
2. Kurogi M, Nakashima O, Miyaaki H, Fujimoto M, Kojiro M, et al. Clinicopathological study of scirrhous hepatocellular carcinoma. J Gastroenterol Hepatol. 2006;21:1470–1477. 3. Matsuura S, Aishima S, Taguchi K, et al. “Scirrhous” type hepatocellular carcinomas: a special reference to expression of cytokeratin 7 and hepatocyte paraffin 1. Histopathol. 2005;47:382–390. 4. Sugiki T, Yamamoto M, Taka K, Nakano M, et al. Specific characteristics of scirrhous hepatocellular carcinoma. Hepatogastroenterol. 2009;93:1086–1089.
Case 26.5
Combined Hepatocellular-Cholangiocarcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 58-year-old Chinese woman presented with a 5-week history of fever, weight loss, and decreased appetite. Physical examination was unremarkable except for a low-grade fever of 38.0ºC. Her medical history included Hepatitis B infection. Serological studies showed a moderate increase in both serum AFP and CA 19-9. Ultrasonography showed a single 4.3 cm hypoechoic mass with a central hyperechoic area in the right lobe. A contrast enhanced CT scan showed an irregular tumor with different density and enhancement patterns. Angiographically, this mass was hypovascular. An extended right hepatectomy was performed.
Glypican 3 and negative or weakly and focally positive for CK7 (Figure 26.5.3). The surrounding liver is noncirrhotic but shows bridging fibrosis and moderately active hepatitis B virus (HBV) hepatitis.
DIAGNO SIS
Combined hepatocellular and cholangiocarcinoma.
R E A SON F OR R E F E R R AL
The tumor shows both the trabecular and glandular structures. The differential diagnoses considered are cholangiocarcinoma (CC), HCC, and combined HCC and CC (cHCC-CC).
PAT H OL OG I C F E AT U R E S
Grossly, the resected tumor reveals a solid, unencapsulated white mass with irregular margins within a noncirrhotic liver (Figure 26.5.1). Histologically, the tumor is composed of 2 components: 1 suggestive of HCC with trabecular growth with bile production and another suggestive of CC showing small glandular formation within fibrous stroma and composed of small cuboidal cells with round nuclei resembling biliary epithelium (Figure 26.5.2). The glandular component is positive for cytokeratin AE1/AE3, CAM 5.2, CK7, and CK19 and negative for Glypican 3 and Hep Par 1 and also focally positive for cytoplasmic mucicarmine. The hepatocellular component is positive for Hep Par 1 and
FIGURE 26. 5. 1 Gross appearance of combined HCC and CC show-
ing unencapsulated irregular white mass.
F I G U R E 2 6 . 5 . 2 Intimately combined hepatocellular carcinoma-like trabecular (long arrow) and cholangiocarcinoma-like glandular (short arrow) patterns.
FIGURE 26.5.3 Combined HCC and CC variant showing stronger CK7 staining in the glandular CC (short arrow) component and weaker or absent reactivity in the trabecular HCC (long arrow) component.
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D I SC U SSI ON
Combined hepatocellular-cholangiocarcinoma is a rare primary hepatic malignancy with histological features of both HCC and CC. The WHO definition of cHCC-CC is a tumor containing unequivocal elements of both hepatocellular and cholangiocarcinoma that are intimately admixed and accounts for less than 1% of all primary liver carcinomas (1). The existence of such combined tumors has been recognized for several decades. Allen and Lisa reported and reviewed this tumor in 1949 and classified it into 3 types (2). Goodman et al (1985) reported a larger series with another classification (3). The 2 classification schemes are given in Table 26.5.1. The clinicopathological characteristics of cHCC-CC identified so far include multifocal disease, less capsular formation, frequent microvascular and portal or hepatic vein invasion, and more frequent lymph node metastasis. Multiple studies have shown that serum AFP, CA19-9, and CEA can each be normal or TA B LE 26. 5. 1 Pathological classification schemes of combined
hepatocellular and cholangiocarcinoma Allen
Goodman
Type I
HCC and CC are present at different sites within the same liver (double tumor)
Type I
“Collision tumor,” or an apparently coincidental occurrence of HCC and CC within the same liver
Type II
HCC and CC are present at adjacent sites and mingle with continued growth (combined type)
Type II
“Transitional tumor,” in which there is transition from elements of HCC to elements typical of CC
Type III
HCC and CC are combined within the same tumor (mixed type)
Type III
“Fibrolamellar type,” which resembles the fibrolamellar subtype of HCC but which contains mucin-producing pseudoglands
Abbreviations: CC, cholangiocarcinoma; HCC, hepatocellular carcinoma.
CARCINOMA
VA R I A N T S
elevated in cHCC-CC. Although tumor markers are not specific, a simultaneous increase in CA19-9 and AFP plus a liver mass on imaging studies may strongly suggest cHCC-CC. There is controversy in the literature regarding behavior and clinicopathological similarity of cHCC-CC to HCC and CC. Some reports indicate its closer similarity to CC and prognosis worse than HCC (4,5), whereas others document its similarity to HCC and better prognosis (6). There is also controversy among liver pathologists as to the exact criteria for definite diagnosis of the CC component within a cHCC-CC. Some advocate that mucin production, either intraglandular or intracellular, must be present for a definitive diagnosis of CC, whereas others advocate that a significant degree of CK19 staining of gland-like structures with or without mucin production is indicative of CC. No consensus to date has been established on this definition, but there is evidence that a significant proportion of CK19 positivity within HCC does often portend a poorer prognosis (7,8).
References 1. Hirohashi S, Ishak KG, Kojiro M, et al. Tumors of the digestive system. In: Hamilton SR, Aaltonen LA, eds. World Health Organization Classification of Tumors. Lyon, France: IARC Press; 2000:158–172. 2. Allen RA, Lisa JR. Combined liver cell and bile duct carcinoma. Am J Pathol. 1949;25:647–655. 3. Goodman ZD, Ishak KG, Langloss JM, et al. Combined hepatocellularcholangiocarcinoma. A histologic and immunohistochemical study. Cancer. 1985;55:124–135. 4. Jarnagin WR, Weber S, Tickoo SK, et al. Combined hepatocellular and cholangiocarcinoma. Demographic, clinical, and prognostic factors. Cancer. 2002;94:2040–2046. 5. Kim KH, Lee SG, Park EH, et al. Surgical treatments and prognoses of patients with combined hepatocellular carcinoma and cholangiocarcinoma. Ann Surg Oncol. 2009;16:623–629. 6. Kassahun WT, Hauss J. Management of combined hepatocellular and cholangiocarcinoma. Int J Clin Pract. 2008;62:1271–1278. 7. Uenishi T, Kubo S, Yamamoto T, et al. Cytokeratin 19 expression in hepatocellular carcinoma predicts early postoperative recurrence. Cancer Sci. 2003;94(10):851–857. 8. Zhuang PY, Zhang JB, Zhu XD, et al. Two pathologic types of hepatocellular carcinoma with lymph node metastasis with distinct prognosis on the basis of CK19 expression in tumor. Cancer. 2008; 112(12): 2740–2748.
Case 26.6
Diffuse Cirrhosis-Like Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 42-year-old male patient with known hepatitis C virus (HCV) hepatitis was being evaluated for post-therapeutic grading and staging. His prior liver biopsy, performed 5 years ago, had shown moderate hepatitis and periportal fibrosis without bridging fibrosis or cirrhotic nodularity. Clinically, the patient was asymptomatic and without weight loss, hepatomegaly, or ascites. Liver function tests showed mildly elevated aspartate transaminase (AST) and alanine aminotransferase (ALT) (<100 U/L) and normal bilirubin and alkaline phosphatase. A random needle biopsy was performed transcutaneously and 3 long needle cores were obtained.
The tumor cells are distinctly abnormal and show high nuclear/ cytoplasmic ratios, stratified cell plates, and invasion of small vessels. Many tumor cells show ballooning and Mallory-Denk bodies. The immunohistochemical profile in many ways is similar to conventional HCC, namely CD34 sinusoidal strong reactivity accentuating the neoplastic cell plate stratification, and HepPar-1 and Glypican-3 positivity. AFP is negative. Unlike the conventional HCC, the CD10 staining is also membranous and cytoplasmic (Figure 26.6.2) along with the usual pericanalicular pattern and the MIB-1 proliferative activity is quite low at 5%.
R E A SON F OR R E F E R R AL
DIAGNO SIS
All 3 needle cores show small nodules of moderately differentiated HCC intermixed with cirrhotic nodules. However, this is an unexpected finding since these are random, un-targeted biopsies from a liver that is not clinically known to contain tumor. In addition, after the biopsy result, a dynamic triple phase CT of the liver is performed that shows no enhancing mass lesion and the serum AFP level is normal (<20 ng/mL).
Diffuse cirrhosis-like hepatocellular carcinoma (CL-HCC). Clinically and radiographically undetected variant mimicking cirrhosis.
PAT H OL OG I C F E AT U R E S
The liver biopsy needle cores show scattered small cirrhosis-like nodules of well and moderately differentiated hepatocellular carcinoma among nonneoplastic cirrhotic nodules. Many tumor nodules show a thin sclerotic rim (Figure 26.6.1).
FIGURE 26. 6. 1 Small cirrhosis-like hepatocellular carcinoma nod-
ule showing well-differentiated HCC and sclerotic rim around the tumor nodule.
DISCUSSIO N
This variant is characterized by its diffuse and extensive occupation of the liver in the form of small nodules mimicking cirrhosis and evading clinical and radiographic detection (1). Serum AFP may not be elevated and no discrete mass may be seen even on dynamic imaging (CT or magnetic resonance [MR]) due to the relatively small sizes of individual tumor nodules. Often patients do not manifest the clinical features of
F I G U R E 2 6 . 6 . 2 Cirrhosis-like hepatocellular carcinoma tumor nodule (left) showing strong membranous and cytoplasmic CD10 staining in addition to the pericanalicular staining also seen in the nonneoplastic liver (right).
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HCC such as weight loss, ascites, or hepatomegaly. CL-HCC is quite rare and usually discovered unexpectedly. On gross examination of the cut surface of liver, pale and/or cholestatic (Figure 26.6.3) small cirrhosis-like tumor nodules stand out as distinct from adjacent nonneoplastic cirrhotic nodules. Histologically, these are likely to show well or moderately differentiated hepatocellular carcinoma nodules often surrounded by slender sclerotic rims. The tumor cells frequently show ballooning, Mallory-Denk bodies, and cholestasis. Although cytological characteristics of this variant are not different from
FIGURE 26. 6. 3 Cut surface of an explanted liver showing cirrhosis-
like hepatocellular carcinoma with extensive pale tumor nodules (long arrows), fewer cholestatic tumor nodules (short arrows) and nonneoplastic cirrhotic nodules (rectangle).
CARCINOMA
VA R I A N T S
conventional HCC, the extensive small nodularity diffusely throughout the liver and some immunohistochemical features such as cytoplasmic and membranous CD10 reactivity (in addition to the pericanalicular staining pattern) and lower MIB1 proliferative activity (<15%) are distinct. This variant may be unexpectedly discovered in explanted liver, autopsy, or in a random needle biopsy (as in this case). When random needle biopsies, particularly multiple needle cores from different areas and without a radiographic mass, show cirrhotic liver admixed with multiple tumor nodules, CL-HCC variant should be histologically suspected. In these cases, the liver is likely to harbor extensive tumor mass. Given the implications of such tumor burden, it is necessary to ensure that all cytological criteria for HCC including elevated nuclear/cytoplasmic ratios and stratified cell plates are met convincingly and there is immunohistochemical support in the form of Glypican-3 and endothelial sinusoidal CD34 reactivity. Occasionally, this variant may also be associated with a conventional HCC showing a dominant mass. CL-HCC so far, given the small number of reported cases, does not appear to show any predilection to any specific cause of cirrhosis or any identifiable bias toward gender or age. Sufficient follow-up data is not available to determine prognosis after orthotopic liver transplantation (OLT) or rate of recurrence of HCC in the graft.
Reference 1. Jakate S, Yabes A, Giusto D, et al. Diffuse cirrhosis-like hepatocellular carcinoma: a clinically and radiographically undetected variant mimicking cirrhosis. Am J Surg Pathol. 2010;34:935–941.
Case 26.7
Spectrum of Cytoplasmic Contents in Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 62-year-old female patient was diagnosed with cryptogenic cirrhosis. Extensive investigations failed to provide the etiological basis for the liver disease. The viral and autoimmune markers and iron and copper studies were negative and A1AT phenotype was normal. During screening, she was noted to have a solitary 3 cm tumor in the right lobe. Dynamic CT showed characteristic features of HCC. Since her liver function was steadily deteriorating, she was selected to undergo orthotopic liver transplantation without preoperative therapy for HCC. R E A SON F OR R E F E R R AL
The tumor is a well-circumscribed, moderately differentiated HCC that shows prominent ballooning with numerous Mallory-Denk bodies (MB) and intracellular hyaline bodies (IHB) in the neoplastic cells. The surrounding cirrhotic liver shows no morphological clues regarding the etiology of cirrhosis. In particular, the nonneoplastic liver does not share features present in HCC such as ballooning, MB or IHB. Can the potential etiology of cirrhosis be speculated based upon the cytoplasmic contents of HCC?
F I G U R E 2 6 . 7 . 1 Moderately differentiated hepatocellular carcinoma
showing ballooned cells and several irregular eosinophilic Mallory-Denk bodies (arrows) in the cytoplasm.
PAT H OL OG I C F E AT U R E S
The hepatocellular carcinoma is moderately differentiated with the usual features such as stratified cell plates and high nuclear/cytoplasmic ratios. In addition, many tumor cells show cytoplasmic distention or ballooning with irregularly shaped dense eosinophilic MB (Figure 26.7.1). Fewer neoplastic cells show well-circumscribed globular homogeneous eosinophilic IHB (Figure 26.7.2), and rare tumor cells show both or hybrid inclusions. Immunohistochemically, MB stain positively with keratin 8/18 but not IHB, but ubiquitin is positive for both. Neither inclusion stains for A1AT. No such inclusions are seen in the surrounding liver, which shows rather bland cirrhosis with mild portal and periportal chronic inflammation and no steatosis, cholestasis, or granulomas.
F I G U R E 2 6 . 7 . 2 Hepatocellular carcinoma cells showing cytoplasmic round or oval homogeneous eosinophilic hyaline bodies with surrounding halo (arrows).
DISCUSSIO N D I AG N OS I S
Moderately differentiated hepatocellular carcinoma with nonspecific intracellular Mallory-Denk bodies and hyaline bodies in cryptogenic cirrhosis.
Hepatocellular carcinoma may manifest a wide variety of cytoplasmic contents that range from aggregated proteins, lipids, and trace elements. Most of these cytoplasmic inclusions are epiphenomena of cellular injury and altered metabolism and carry no prognostic significance. Although such cytoplasmic
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FIGURE 26. 7. 3 Hepatocellular carcinoma cells showing pale bod-
ies reminiscent of hepatitis B surface antigen-like ground-glass cells (arrows).
contents may occur in both neoplastic and nonneoplastic hepatocytes, there is well-known quantitative and qualitative discordance between the 2. This precludes linking such inclusions in HCC to etiology of cirrhosis when similar inclusions are absent in the nonneoplastic liver. Cytoplasmic inclusions seen in HCC include the following: (1) MB (irregular dark eosinophilic inclusions in ballooned cells composed of aggregates of keratin 8, ubiquitin, heat shock proteins, and the adapter and stress protein p62) in approximately 16% of HCC (1). (2) IHB (round to oval homogeneous dark eosinophilic inclusions surrounded by clear halo, also containing p62 protein but lacking keratin) in about 9% of HCC (1). (3) Pale bodies (Figure 26.7.3, homogeneous pale eosinophilic inclusion occupying most of the cytoplasm and mimicking HBsAg-containing ground-glass change and consisting of fibrinogen and negative for periodic acid-Schiff [PAS]), hepatitis B surface antigen [HBsAg], alpha fetoprotein [AFP], A1AT) in about 6% of HCC (2). (4) AFP is not visible as cytoplasmic inclusion but identified by
CARCINOMA
VA R I A N T S
Macrovesicular steatosis in well-differentiated hepatocellular carcinoma cells.
FIGURE 26.7.4
immunohistochemical staining. It does not correlate well with serum AFP levels, shows patchy staining and low reactivity at both ends of the histological grade spectrum. (5) Steatosis, usually macrovesicular, may occur in HCC (Figure 26.7.4) corresponding with or independent of steatosis in the surrounding liver. (6) Iron content is often lower in HCC than surrounding liver (3), a possible explanation being malignant cells utilize more iron and deplete the iron content. (7) Copper content is higher in HCC than surrounding liver in most studies.
References 1. Denk H, Stumptner C, Fuchsbichler A, et al. Are the Mallory bodies and intracellular hyalin bodies in neoplastic and non-neoplastic hepatocytes related? J Pathol. 2006;208:653–661. 2. Moon WS, Yu HC, Chung MJ, et al. Pale bodies in hepatocellular carcinoma. J Korean Med Sci. 2000;15:516–520. 3. Gurusamy K. Trace element concentration in primary liver cancers— a systematic review. Biol Trace Elem Res. 2007;118:191–206.
Case 26.8
Poor Differentiation and Vascular Invasion in Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO C L I N IC AL I N F OR M AT I ON
A male patient aged 49 years with known alcohol (EtOH)related cirrhosis complained of recent weight loss. On screening, his AFP was significantly elevated (461 ng/mL) and CT showed a solitary 1.8 cm mass in the posterior right lobe. Dynamic CT showed vascular features typical for HCC. His liver function was gradually deteriorating, and he was scheduled to undergo OLT on a priority basis with the presumption of HCC.
focal pericanalicular pattern and are negative for Hep Par 1, CK7, and CK20. The surrounding liver shows active EtOH hepatitis with steatosis, ballooning, Mallory-Denk bodies and neutrophils. There is microvascular invasion of intracapsular portal vein branches (Figure 26.8.2). In addition, macrovascular tumor embolization is seen in the main portal vein branch in the hilar area (Figure 26.8.3).
DIAGNO SIS
R E A SON F OR R E F E R R AL
Poorly differentiated hepatocellular carcinoma with microvascular and macrovascular invasion.
The explanted liver is slightly enlarged, pale, and shows expected EtOH-related micronodular cirrhosis. The 1.8 cm right lobe tumor nodule shows an encapsulated necrotic and hemorrhagic poorly differentiated tumor. There is intracapsular vascular invasion. Several centimeters away from the tumor, in the hilar area, a branch of portal vein shows intraluminal tumor embolus. Consultation is sought to address 2 different questions: first, the tumor is poorly differentiated and needs discrimination between primary HCC and metastasis and second, the impact of vascular invasion on HCC staging and outcome.
PAT H OL OG I C F E AT U R E S
The tumor is poorly differentiated with a solid sheet-like pattern but a focally trabecular pattern is visible. The cells show quite high nuclear/cytoplasmic ratios with frequent pleomorphism (Figure 26.8.1). Immunohistochemically, the tumor cells are positive for CK8/18, Glypican 3, and p-CEA with
FIGURE 26.8.2 Intratumoral microvascular invasion in a branch of vein.
FIGURE 26. 8. 1 Poorly differentiated HCC showing highly pleomorphic cells and vague trabeculae.
F I G U R E 2 6 . 8 . 3 Cut surface of the liver showing tumor embolus in the portal vein at the hilum.
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The tumor is poorly differentiated, but it is occurring in a clinical setting (cirrhosis, raised AFP, CT findings) that is typical for HCC. With such background, not only is primary carcinoma more common but also metastases are less likely to occur. According to the World Health Organization criteria, HCC is classified into well-differentiated, moderately differentiated, poorly differentiated, and undifferentiated types (1). Most well-differentiated HCC tend to be early stage (<2 cm) with thin trabecular pattern, whereas moderately differentiated tumors are larger (generally >3 cm) and show thicker (3 or more cells) trabeculae. Poorly differentiated HCC are solid with pleomorphic cells and barely visible trabeculae. Rarely, the tumor may show predominantly giant cells (Figure 26.8.4). Unlike our case, poorly differentiated HCC is extremely rare in small, less than 2 cm HCC. Immunohistochemically, Hep Par 1 may be negative in poorly differentiated HCC (2). However,
CARCINOMA
VA R I A N T S
the tumor cells show Glypican 3 and CK8/18 positivity, at least focal p-CEA pericanalicular pattern and negative staining for CK7 and CK20. Most metastatic carcinomas are CK7 and/or CK20 positive (renal, prostatic, and adrenal carcinomas are notable exceptions). For similar stage, poor differentiation of HCC portends worse outcome than well or moderate differentiation (3,4). Vascular invasion is a potential source of intrahepatic metastasis and recurrence, a strong prognostic factor (4) and a crucial component of staging. Microvascular invasion implies invasion of small branches of portal or hepatic veins within and around the tumor, which is seen microscopically and not radiographically. Macrovascular invasion suggests tumor invasion of the major branches of portal or hepatic veins, that is generally visible radiographically and on gross examination. Rarely, HCC may show macrovascular invasion extending into the portal or hepatic veins (and rarely as far as the right atrium) as a long column of tumor. According to the TNM classification, a less than 2 cm tumor without metastasis is T1 (and stage I). However, a tumor of the same size with microvascular invasion is T2 (and stage II) and with macrovascular invasion, T4 (and stage IV). Thus, vascular invasion in this case has worsened the stage from potentially I to IV with drastic worsening of prognosis and outcome.
References
FIGURE 26. 8. 4 Poorly differentiated HCC showing predominantly
giant cells.
1. Hirohashi S, Ishak KG, Kojiro M, et al. Hepatocellular carcinoma. In: Hamilton SR, Aaltonen LA, eds. Tumors of the Digestive System. Lyon: IARC Press; 2000:159–172. World Health Organization Classification of Tumors. 2. Kakar S, Gown AM, Goodman ZD, Ferrell LD, et al. Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms. Arch Pathol Lab Med. 2007;131:1648–1654. 3. Dudek K, Kornasiewicz O, Remiszewski P, et al. Impact of tumor characteristic on the outcome of liver transplantation in patients with hepatocellular carcinoma. Transplant Proc. 2009;8:3135–3137. 4. D’Amico F, Schwartz M, Vitale A, et al. Predicting recurrence after liver transplantation in patients with hepatocellular carcinoma exceeding the up-to-seven criteria. Liver Transpl. 2009;10:1278–1287.
Case 26.9
Pedunculated Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N IC AL I N F OR M AT I ON
A 47-year-old woman with a history of hepatitis B complained of left upper abdominal pain. On CT, a 10 cm mass was seen between the posterior aspect of the liver and the right adrenal. Radiographically, it was unclear whether this mass originated from the liver or the adrenal gland. On dynamic CT, the mass showed arterial enhancement that faded in the portal venous phase—features suggestive of hepatocellular carcinoma. The AFP was 133 ng/mL. Clinically, there was no cirrhosis and no history of tumor elsewhere. The liver function tests (LFTs) showed mildly elevated transaminases and normal bilirubin and alkaline phosphatase. Exploratory laparotomy was performed and the exophytic mass appeared to originate from the posterior and inferior surface of the right lobe. The mass was pressing on the right adrenal but did not invade the gland. No other masses were noted in the liver radiographically or intraoperatively. The mass was resected with about 3 cm of underlying noncirrhotic liver (Figure 26.9.1). R E A SON F OR R E F E R R AL
Histologically, the tumor shows features of HCC, but the extrahepatic and pedunculated gross appearance is unusual. Metastasis is also a consideration, since the underlying liver is noncirrhotic. PAT H OL OG I C F E AT U R E S
The tumor shows all the expected morphological features of HCC. There are trabeculae and pseudoglands with distended bile canaliculi. In addition, many cells show ballooning,
steatosis, and cholestasis. Immunohistochemically, as expected, the tumor cells are positive for Hep Par 1, CK 8/18, and pericanalicular p-CEA and negative for CK7 and CK20. The underlying liver shows HBV hepatitis with mild activity and Stage 3 bridging fibrosis without cirrhotic nodularity.
DIAGNO SIS
Pedunculated hepatocellular carcinoma.
DISCUSSIO N
Pedunculated variant of HCC is rare (<1%) and is usually located on the posterior and inferior surfaces of the right lobe. Multiple suggested origins of such extrahepatic growth include an accessory lobe, Riedel’s lobe (a tongue-like process) and heterotopic liver (1). In addition, an aging-related phenomenon called “adrenohepatic fusion” may occur where the inferior surface of the right hepatic lobe fuses with the right adrenal, sharing vascular networks and disintegrating the intervening fibrous capsules between the 2 organs (2). When HCC arises in this fused area, it may become difficult on gross, radiographic, or intraoperative examination to differentiate between pedunculated HCC, HCC metastasis to right adrenal or primary adrenal cortical carcinoma mimicking pedunculated HCC. This dilemma may be escalated due to some microscopic (clear cells and trabeculae) and immunophenotypical (negative CK7 and CK20) similarities between the 2 tumors. However, Hep Par 1, Glypican 3 and pericanalicular p-CEA positivity for HCC and inhibin and D2-40 positivity for adrenal epithelial cells may help in the discrimination. Pedunculated HCC occurs in the same clinical setting as conventional HCC such as cirrhosis and chronic liver disease, and grading and staging is similar. However, the exophytic growth and a narrow base in pedunculated HCC provide the opportunity for easier respectability. This results in good prognosis and better survival, especially if there is no vascular invasion (3).
References
FIGURE 26. 9. 1 Resected exophytic pedunculated HCC with underlying nonneoplastic liver at the base of the pedicle.
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1. Arakawa H, Kage M, Isomura T, et al. Pathomorphological studies on hepatocellular carcinoma (HCC)—7 cases of HCC with an extrahepatic tumor growth, so-called “pedunculated hepatoma.” Acta Hepatol Jpn. 1982;23:942–948. 2. Honma K. Adreno-hepatic fusion. An autopsy study. Zentralbl Pathol. 1991;137:117–122. 3. Yeh CN, Lee WC, Jeng LB, Chen MF. Pedunculated hepatocellular carcinoma: clinicopathologic study of 18 surgically resected cases. World J Surg. 2002;26:1133–1138.
Case 26.10
Ablated Hepatocellular Carcinoma SHRIRAM JAKATE AND DEBORAH GIUSTO
C L I N I C AL I N F OR M AT I ON
A 65-year-old man with a long history of nonalcoholic steatohepatitis (NASH) and known cirrhosis developed recent weight loss, ascites, hepatomegaly, and decompensation of the liver function with low albumin. The AFP level was 602 ng/mL. Contrast-enhanced CT showed 5 discrete liver masses ranging from 1.2 to 5 cm, all in the right lobe and all with typical features of hepatocellular carcinoma (early arterial hypervascularity and portal venous phase washout). Given the elevated AFP, characteristic imaging results and the risk of seeding, no tissue diagnosis of any tumor mass was considered necessary. Although all the tumor nodules were in one (right) lobe, the patient did not initially qualify for transplantation since there were more than 3 tumor nodules and the largest was more than 3 cm. Ablation of the tumor nodules was attempted via transarterial chemoembolization (TACE) of doxorubicin-coated (DC) beads with the hope of downstaging and improving survival. One month after the last ablation therapy and after verifying ablation on dynamic CT scan (now hypovascular), orthotopic liver transplant was performed.
F I G U R E 2 6 . 1 0 . 1 Gross image of the cut surface showing 2 of 5 tumor
nodules with variable ablation and dark tiny chemotherapeutic beads in the tumor nodules and the adjacent artery.
R E A S ON F OR R E F E R R A L
The tumor nodules show variable degrees of necrosis with some nodules entirely devoid of any viable cells. It is difficult to say whether these areas histologically represent pre-therapeutic hepatocellular carcinoma and if these necrotic nodules should be incorporated as tumor nodules for staging purposes.
PAT H OL OG I C F E AT U R E S
Gross photograph of the cut surface of the explanted liver shows 2 of 5 tumor nodules with variable necrosis and visible tiny dark chemotherapeutic beads within the tumor and in the branches of the feeding arteries (Figure 26.10.1). Histologically, the nodules are encapsulated and many areas show complete ablation with no viable cells. Immunostaining in these areas is not attempted since both positive and negative staining results are not considered reliable due to ablation-related tissue changes. The small spherical chemotherapeutic beads are also identified within and away from the tumor. Some tumor nodules are partially ablated (Figure 26.10.2) and show residual moderately differentiated hepatocellular carcinoma at the edge. The ablated nodules cannot be histologically graded but all nodules should be regarded as hepatocellular carcinoma for the following reasons: (1) large encapsulated masses developing in cirrhotic liver; (2) characteristic findings on imaging;
F I G U R E 2 6 . 1 0 . 2 Section showing partially ablated (top) moder-
ately differentiated HCC with intravascular chemotherapeutic beads (arrow).
(3) markedly raised AFP level; (4) residual hepatocellular carcinoma in partially ablated masses. The downstaging is based more upon the radiographic reduction of size rather than viability on histology. In this case, though necrotic, the tumor nodules still maintain the size and the original stage (T3).
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CARCINOMA
429
D I AG N OS I S
Multiple nodules of hepatocellular carcinoma variably ablated by chemotherapeutic beads (TACE).
D I S C U S S I ON
The modern screening techniques detect hepatocellular carcinomas with great accuracy and offer reliable presurgical staging. Ablation therapies play an important role in nonsurgical or presurgical management and may achieve palliation, local resectability, improved survival, and qualification for transplantation by downstaging. Various image-guided ablation techniques are practiced, including ethanol injection, thermal therapies such as radiofrequency ablation (RFA, Figure 26.10.3), microwave coagulation therapy (MCT) and laser ablation (LA), and TACE with a drug such as doxorubicin (1,2) or transarterial embolization with radionuclide Yttrium-90 microspheres. These ablation therapies produce variably necrotic nodules on gross and microscopic examination. Successful ablation may leave no viable tumor for pathological assessment. However, a skeletal network showing stratified cell plates may still be visible. Immunostaining is not recommended due to the necrotic changes and questionable reliability of staining results. Pathological evaluation of resected or explanted liver should include comment on degree of ablation as feedback for therapeutic success, grading
F I G U R E 2 6 . 1 0 . 3 Gross image of the cut surface showing a tumor
nodule that has undergone total necrosis after radiofrequency ablation therapy.
of residual viable tumor, vascular permeation of tumor away from the ablated mass, and the status of the surrounding liver.
References 1. Lammer J, Malagari K, Vogl T, et al. Perspective randomized study of doxorubicin-eluting-bead embolization in the treatment of hepatocellular carcinoma: results of the PRECISION V study. Cadiovasc Intervent Radiol. 2010;33:41–52. 2. Shiina S. Image-guided percutaneous ablation therapies for hepatocellular carcinoma. J Gastroenterol. 2009;44(suppl 19):122–131.
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27 Metastatic Tumors: Illustration of Immunohistochemical Workup RAGESHREE RAMACHANDRAN AND SANJAY KAKAR
It can be challenging to distinguish hepatocellular carcinoma (HCC) from metastatic neoplasms, especially on core needle or fine needle biopsies when limited material is available. Metastatic carcinomas are more common than primary liver tumors. Many studies have shown that metastatic carcinomas are rare or less common in cirrhotic liver (1,2). However, metastases have been well documented in cirrhotic liver, and this possibility cannot be discounted in an individual case. In view of the limited tissue available on biopsy, judicious use of immunohistochemistry is essential for reaching the diagnosis. In some cases, the presence of bile, cytoplasmic fat, and/or Mallory-Denk bodies supports hepatocellular differentiation, and immunohistochemistry is not necessary. This chapter discusses the pros and cons of commonly used markers and suggests an algorithm for the use of these markers to establish the diagnosis. A . C O M MON LY U SE D M AR K E R S
Hep Par 1 (hepatocyte antigen) is a monoclonal antibody developed using formalin-fixed tissue from failed liver allografts. Normal staining pattern is diffuse, with cytoplasmic granular positivity in both normal and neoplastic hepatocytes (3–8). It is usually negative or only focally positive in adenocarcinomas (biliary tree, pancreas, colorectum, breast, urinary bladder, prostate) and in polygonal cell tumors (neuroendocrine tumors, renal cell carcinoma [RCC], adrenocortical carcinoma [ACC], melanoma, and epithelioid angiomyolipoma [AML]). Advantages: Sensitivity and specificity are more than 80% (4–8), and it is useful in evaluating fine needle aspiration biopsies (9). Disadvantages: It cannot be used to distinguish benign and malignant hepatocellular tumors. Staining can be patchy in 10% to 20% of cases (Figure 27.1). Hep Par 1 may be negative in poorly differentiated and scirrhous HCC (sensitivity 50% or less). Some adenocarcinomas (eg, lung, stomach, esophagus) can show strong positive staining (8) (Figure 27.2). Some gastrointestinal (GI) and pancreatic carcinomas have hepatoid features and are positive for Hep Par 1. Glypican-3 (GPC-3) is a membrane-anchored heparan sulfate proteoglycan and is normally expressed in fetal liver and placenta but not in normal adult liver. GPC-3 is expressed in the majority of HCCs but not in normal liver or benign tumors such as hepatic adenoma (10–12). GPC-3 can show diffuse cytoplasmic, membranous, or Golgi-pattern in HCC (Figure 27.3). This marker is also sensitive and specific for the HCC component of combined HCC/cholangiocarcinoma (13).
F I G U R E 2 7 . 1 Patchy staining with Hep Par 1 is seen in 10% to 20% of hepatocellular carcinoma and can yield false negative results on needle biopsy.
FIGURE 27.2 Metastatic gastric adenocarcinoma showing cytoplasmic staining with Hep Par 1.
Advantages: GPC-3 has higher sensitivity for poorly differentiated HCC compared with Hep Par 1 (56%, 83%, and 89% of well-, moderately, and poorly differentiated HCC (14). It is useful in distinguishing benign and malignant tumors, since it is negative in nonneoplastic liver and benign tumors.
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also shows cytoplasmic positivity in adenocarcinomas but with lower sensitivity (~60%). HCC is negative with mCEA. Advantages: Canalicular staining is specific for HCC, and sensitivity is more than 80% for well- and moderately differentiated HCC. Disadvantages: Interpreting pCEA can be difficult in some cases, as some adenocarcinomas show luminal staining that can mimic canalicular staining of HCC. In addition, some HCCs show cytoplasmic staining and sensitivity for poorly differentiated HCC is only 25% to 50% (3).
FIGURE 27. 3 Glypican-3 can show diffuse cytoplasmic, membranous, or dot-like/Golgi-pattern of staining in hepatocellular carcinoma.
FIGURE 27. 4 Canalicular pattern of staining with pCEA in hepatocellular carcinoma.
MOC31 (epithelial cell adhesion molecule or EPCAM) is directed against a cell surface glycoprotein and was originally used to distinguish metastatic adenocarcinoma from mesothelioma. It is expressed in more than 90% of cholangiocarcinoma and metastatic adenocarcinoma (including colorectum, pancreas, stomach, lung, breast, and ovary) (6,18,19). It is also expressed in most neuroendocrine tumors, urothelial carcinomas, and RCCs (20,21). Advantages: The diffuse membranous staining pattern is easy to interpret. It is positive in most adenocarcinomas, RCC, urothelial carcinoma, and neuroendocrine tumors. The majority of HCCs are negative or weakly positive (6,18,19). Disadvantages: MOC31 expression has been observed in 4% to 10% of HCC (6,22), though it initially was described as negative in HCC (18). Less useful antibodies: CD10 and villin yield a canalicular pattern similar to pCEA (6,17). Their addition does not add to the sensitivity in diagnosis. Alpha fetoprotein (AFP) has poor sensitivity (30%–50%) and is prone to high background staining (5,8,17). Thyroid transcription factor 1 (TTF-1) shows cytoplasmic staining in ~70% of HCCs in contrast to the nuclear staining in lung and thyroid. The pattern of staining is similar to that of Hep Par 1, but it can vary with the antibody clone (23–25). TTF-1 does not add to the diagnostic yield in HCC (3). The sinusoids in HCC undergo capillarization and express CD34 (Figure 27.5); sinusoids in normal liver
Disadvantages: Results vary regarding expression in highgrade dysplastic nodules (75% in 1 series, 43% in 1 series, negative in most cases in other studies) (3,14). GPC-3 is expressed by melanoma (around 5% of cases) and nonseminomatous germ cell tumors, including yolk sac tumor and choriocarcinoma. Staining can be negative in welldifferentiated HCC and the fibrolamellar variant. Occasionally, cirrhotic nodules and active hepatitic disease in nonneoplastic liver can show GPC-3 reactivity (15). Polyclonal carcinoembryonic antigen (pCEA) is a glycoprotein in the glycocalyx of fetal epithelium; it is also found in small amounts in normal adult cells. Cytoplasmic, membranous and/or luminal staining with pCEA is seen in more than 90% of adenocarcinomas. HCC shows a distinct canalicular staining pattern in 60%–90% of cases (Figure 27.4) that is not seen in adenocarcinomas (6,16,17). Monoclonal CEA (mCEA)
F I G U R E 2 7 . 5 Diffuse sinusoidal pattern of staining with CD34 in hepatocellular carcinoma.
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M E TA S TAT I C
are negative (26). CD34 may also demonstrate endothelial “wrapping” in areas of widened plate architecture. In view of limited sensitivity and specificity, it has a limited role since better antibodies are available (3).
TUMORS
433
In these situations, additional evidence of hepatocellular differentiation can be sought by using pCEA or GPC-3.
2. Hep Par 1 Negative, MOC31 Diffuse Positive
Keratins: Most HCCs (~85%) are negative for CK7 and CK 20 (27–29). CK19 is expressed in more than 85% of cholangiocarcinomas, whereas most HCCs are negative or show patchy staining (28). CK7 and CK19 tend to be more strongly expressed in poorly differentiated HCC (30). B . I M M U N O H I S TOC H E M I C A L A L G OR I T H MS FO R D I AG N OSI S OF H C C
The use of Hep Par 1 and MOC31 will distinguish HCC from adenocarcinoma in the majority of cases. Based on the results of these 2 stains, the case can be grouped into 1 of the following 4 categories (Table 27.1). Further use of immunohistochemical stains, if necessary, can be based on these categories. 1. Hep Par 1 Diffuse Positive, MOC31 Negative
This pattern established the diagnosis of HCC in most situations. Further workup is necessary only if a. Clinical information or morphological features are not typical b. Staining patterns are focal or not clear
TA B LE 27. 1 Differential diagnosis of liver tumors based
on Hep Par 1 and MOC31 expression Expression Pattern
Leading Consideration(s)
Other Possibilities
Hep Par 1 diffuse, MOC31
HCC
Hep Par 1, MOC31
Metastatic adenocarcinoma Polygonal cell tumors: Neuroendocrine tumor Renal cell carcinoma
Hep Par-negative HCC with aberrant MOC31
Hep Par 1, MOC31
Adenocarcinomas with aberrant Hep Par 1: lung, gastroesophageal
Hepatoid carcinoma HCC with aberrant MOC31
Hep Par 1, MOC31
Keratin Hep Par 1-negative HCC MOC31-negative adenocarcinoma (rare) Polygonal cell tumors: Neuroendocrine tumor Renal cell carcinoma
Keratin Melanoma Adrenocortical carcinoma Epithelioid angiomyolipoma Sarcomas with epithelioid morphology
HCC is unlikely, and the differential diagnosis includes cholangiocarcinoma, metastatic adenocarcinoma, or metastatic polygonal cell tumors like neuroendocrine carcinoma and RCC. Further immunohistochemistry is guided by clinical information and can include markers helpful in establishing site of origin such as CK7 and CK20, TTF-1 (lung), Caudal type (Drosophilia) homeobox gene -2 (CDX-2) (colorectum), prostate-specific antigen (prostate), estrogen receptor (ER) and progesterone receptor (PR) (breast and endometrium) (31). Markers for RCC and neuroendocrine tumors can be considered in the appropriate morphological and/or clinical setting. Around 10% of HCCs can be MOC31-positive, and a combined pattern of Hep Par 1 negative and MOC31-positive can be observed in 2% to 3% of HCC. Further pursuit of hepatocellular differentiation with pCEA and/or GPC-3 is dictated by the clinical context and morphology.
3. Hep Par 1 Positive, MOC31 Positive
This profile is uncommon and is seen in 2 situations: a. HCC with aberrant MOC31 reactivity b. Adenocarcinomas with aberrant Hep Par 1 expression, most commonly from stomach, esophagus, and lung Further staining with hepatocellular markers (pCEA and/or GPC-3), cytokeratins (CK7, CK19), or site-specific markers (TTF-1) is necessary for these cases.
4. Hep Par 1 Negative, MOC31 Negative
Abbreviations: HCC, hepatocellular carcinoma; Hep Par 1, hepatocyte antigen.
This is the broadest of the categories and has the following possibilities: a. HCCs lacking Hep Par 1 expression: Additional markers for hepatocellular differentiation such as pCEA and GPC-3 have to be obtained. b. Adenocarcinomas lacking MOC31 expression: This is the least likely possibility in this group as almost all adenocarcinomas express MOC31. Other adenocarcinoma markers such as CK7, CK19, and cytoplasmic pCEA can be helpful. Although some HCCs express CK7 and CK19 focally, diffuse and strong staining favors adenocarcinomas. Other epithelial markers such as Ber-Ep4 (epithelialspecific membrane antigen) and B72.3 (tumor-associated glycoprotein-72) are less useful due to lower sensitivity and their expression in 20% to 30% of HCCs (16,17,22). c. Polygonal cell tumors other than HCC: RCC, neuroendocrine tumor, melanoma, ACC, AML, and sarcomas with epithelioid morphology.
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TUMORS
Pancytokeratin staining (AE1/AE3) can be very useful in dividing this category into 2 groups:
(HMB-45, Melan-A, microphthalmia-associated factor) are positive (40). S-100 is negative in AML (8).
1. Pancytokeratin-positive: HCC, rare MOC31 negative adenocarcinoma, RCC, neuroendocrine tumor. 2. Pancytokeratin-negative: Melanoma, ACC, AML, sarcomas with epithelioid morphology.
Scirrhous and poorly differentiated HCC: Hep Par 1 has low sensitivity for the diagnosis of these variants (around 50%), whereas MOC31 expression may be more common (unpublished observations). In these situations and other challenging situations (eg, small biopsy, mismatch between clinical and morphological features), it may be prudent to include other hepatocellular markers like GPC-3 and pCEA in the panel of immunohistochemical markers in addition to Hep Par 1 and MOC31 (41). Based on our experience, a panel of 4 antibodies (2 hepatocellular, 2 adenocarcinoma markers) including Hep Par 1, GPC-3 (or pCEA), MOC31, and CK19 is highly effective in distinguishing HCC from metastatic adenocarcinoma. GPC-3 is preferred over pCEA due to higher sensitivity in poorly differentiated HCC. MOC31 is a firstchoice adenocarcinoma marker because of its high sensitivity for neuroendocrine carcinoma and renal cell carcinoma in addition to metastatic adenocarcinoma. CK19 is preferred as the second adenocarcinoma marker over others like CK7 because it is the least likely to be expressed in HCC among the adenocarcinoma markers.
C . HC C V E R S U S M E TA S TA S I S: SP E C I F I C SI T UAT IO NS
Neuroendocrine tumor: The tumor cells in neuroendocrine carcinoma can show abundant eosinophilic cytoplasm and round nuclei, mimicking hepatocytes. Acinar or trabecular patterns mimicking HCC can be seen. Prominent vascular/ capillary network and/or stromal hyalinization favors neuroendocrine tumor. They are usually metastatic but, rarely, can be primary to the liver (32). These tumors are Hep Par 1negative, MOC31-positive. Staining for chromogranin, synaptophysin, and CD56 can help identify neuroendocrine differentiation, although some HCCs express CD56. In addition, some HCCs are focally positive for synaptophysin and chromogranin (33). Renal cell carcinoma: Clear cell RCCs are highly vascular tumors and can closely mimic clear cell HCC. In some RCC cases, clear cells may not be a prominent component of the tumor. MOC31 is expressed by most RCCs. Hep Par 1 and pCEA are negative. The combination of paired homeobox 2 (PAX-2), a renal transcription factor, and RCC antigen yields high sensitivity and specificity for diagnosis of metastatic renal carcinoma (34,35). The canalicular pattern of CD10 in HCC can be confused with membranous CD10 in RCC (3). Melanoma: Metastatic melanoma can lack pigment and can be morphologically indistinguishable from HCC. Expression of S-100 and melanocytic markers (such as HMB-45) and absence of hepatocellular markers (such as Hep Par 1, canalicular pCEA) help in identifying melanoma. Melanoma is negative for Hep Par 1 and pCEA. GPC-3 is reported to be expressed in a small minority of primary melanomas (5%) and in no metastatic melanomas (36) even though an earlier study found expression in more than 80% of cases (37). Adrenocortical carcinoma: These tumors fall under the Hep Par 1 and MOC31 negative category. Other hepatocellular markers like GPC-3 and pCEA are also negative. Most ACCs are negative for pancytokeratin, and express inhibin and Melan-A (sensitivity 70% and 50%–60%, respectively, combined sensitivity, 80%). HCC is negative for these 2 markers (38,39). Epithelioid variant of angiomyolipoma: Hepatic AML is often epithelioid and monotypic, characterized by lack of angio- and lipomatous elements. Epithelioid AML can bear a close resemblance to well-differentiated HCC. Bile and Mallory-Denk hyaline are not seen in AML. Hep Par 1, pCEA, GPC-3, and keratin are not expressed, whereas smooth muscle markers such as smooth muscle actin and melanocytic markers
References 1. Strohmeyer T, Schultz W. The distribution of metastases of different primary tumors in the liver. Liver. 1986;6:184–187. 2. Vanbockrijck M, Klöppel G. Incidence and morphology of liver metastasis from extrahepatic malignancies to cirrhotic livers. Zentralbl Pathol. 1992;138:91–96. 3. Kakar S, Gown AM, Goodman ZD, Ferrell LD. Best practices in diagnostic immunohistochemistry: hepatocellular carcinoma versus metastatic neoplasms. Arch Pathol Lab Med. 2007;131:1648–1654. 4. Wennerberg AE, Nalesnik MA, Coleman WB. Hepatocyte paraffin 1: a monoclonal antibody that reacts with hepatocytes and can be used for differential diagnosis of hepatic tumors. Am J Pathol. 1993;143: 1050–1054. 5. Minervini M, Demetris A, Lee R, Carr BI, Madariaga J, Nalesnik MA. Utilization of hepatocyte-specific antibody in the immunocytochemical evaluation of liver tumors. Mod Pathol. 1997;10:686–692. 6. Morrison C, Marsh W Jr, Frankel WL. A comparison of CD10 to pCEA, MOC-31 and hepatocyte for the distinction of malignant tumors in the liver. Mod Pathol. 2002;15:1279–1287. 7. Fan Z, van de Rijn M, Montgomery K, Rouse RV. Hep Par 1 antibody stain for the differential diagnosis of hepatocellular carcinoma: 676 tumors tested using tissue microarrays and conventional tissue sections. Mod Pathol. 2003;16:137–144. 8. Kakar S, Muir T, Murphy LM, Lloyd RV, Burgart LJ. Immunoreactivity of Hep Par 1 in hepatic and extrahepatic tumors and its correlation with albumin in situ hybridization in hepatocellular carcinoma. Am J Clin Pathol. 2003;119:361–366. 9. Wang L, Vuolo M, Suhrland MJ, Schlesinger K. HepPar1, MOC-31, pCEA, mCEA and CD10 for distinguishing hepatocellular carcinoma vs. metastatic adenocarcinoma in liver fine needle aspirates. Acta Cytol. 2006;50:257–262. 10. Yamauchi N, Watanabe A, Hishinuma M, et al. The glypican 3 oncofetal protein is a promising diagnostic marker for hepatocellular carcinoma. Mod Pathol. 2005;18:1591–1598. 11. Libbrecht L, Severi T, Cassiman D, et al. Glypican-3 expression distinguishes small hepatocellular carcinomas from cirrhosis, dysplastic
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23.
24.
25.
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nodules, and focal nodular hyperplasia-like nodules. Am J Surg Pathol. 2006;30:1405–1411. Wang XY, Degos F, Dubois S, et al. Glypican-3 expression in hepatocellular tumors: diagnostic value for preneoplastic lesions and hepatocellular carcinomas. Hum Pathol. 2006;37:1435–1441. Shirakawa H, Kuronuma T, Nishimura Y, et al. Glypican-3 is a useful diagnostic marker for a component of hepatocellular carcinoma in human liver cancer. Int J Oncol. 2009;34:649–656. Shafizadeh N, Ferrell LD, Kakar S. Utility and limitations of glypican-3 expression for the diagnosis of hepatocellular carcinoma at both ends of the differentiation spectrum. Mod Pathol. 2008;21: 1011–1018. Abdul-Al HM, Makhlouf HR, Wang G, Goodman ZD. Glypican-3 expression in benign liver tissue with active hepatitis C: implications for the diagnosis of hepatocellular carcinoma. Hum Pathol. 2008;39: 209–212. Ma CK, Zarbo RJ, Frierson HF Jr, Lee MW. Comparative immunohistochemical study of primary and metastatic carcinomas of the liver. Am J Clin Pathol. 1993;99:551–557. Lau SK, Prakash S, Geller SA, Alsabeh R. Comparative immunohistochemical profile of hepatocellular carcinoma, cholangiocarcinoma, and metastatic adenocarcinoma. Hum Pathol. 2002;33:1175–1181. Niemann TH, Hughes JH, De Young BR. MOC-31 aids in the differentiation of metastatic adenocarcinoma from hepatocellular carcinoma. Cancer. 1999;87:295–298. Proca DM, Niemann TH, Porcell AI, DeYoung BR. MOC31 immunoreactivity in primary and metastatic carcinoma of the liver. Report of findings and review of other utilized markers. Appl Immunohistochem Mol Morphol. 2000;8:120–125. Ordóñez NG. The diagnostic utility of immunohistochemistry in distinguishing between mesothelioma and renal cell carcinoma: a comparative study. Hum Pathol. 2004;35:697–710. Ordóñez NG. Value of the MOC-31 monoclonal antibody in differentiating epithelial pleural mesothelioma from lung adenocarcinoma. Hum Pathol. 1998;29:166–169. Ramachandran R, Browne LW, Mehdi I, et al. Evidence-based immunohistochemical panel for the distinction of hepatocellular carcinoma and metastatic carcinoma. Mod Pathol. 2010;23:370A. Wieczorek TJ, Pinkus JL, Glickman JN, Pinkus GS. Comparison of thyroid transcription factor-1 and hepatocyte antigen immunohistochemical analysis in the differential diagnosis of hepatocellular carcinoma, metastatic adenocarcinoma, renal cell carcinoma, and adrenal cortical carcinoma. Am J Clin Pathol. 2002;118:911–921. Pan CC, Chen PC, Tsay SH, Chiang H. Cytoplasmic immunoreactivity for thyroid transcription factor-1 in hepatocellular carcinoma: a comparative immunohistochemical analysis of four commercial antibodies using a tissue array technique. Am J Clin Pathol. 2004;121:343–349. Lei JY, Bourne PA, diSant’Agnese PA, Huang J. Cytoplasmic staining of TTF-1 in the differential diagnosis of hepatocellular carcinoma vs cholangiocarcinoma and metastatic carcinoma of the liver. Am J Clin Pathol. 2006;125:519–525.
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26. Kong C, Appenzeller M, Ferrell L. Utility of CD34 reactivity in evaluating focal nodular hepatocellular lesions sampled by fine needle aspiration biopsy. Acta Cytol. 2000;44:218–222. 27. Wang N, Zee S, Zarbo R, et al. Coordinate expression of cytokeratins 7 and 20 defines unique subsets of carcinomas. Appl Immunohistochem. 1995;3:99–107. 28. Maeda T, Kajiyama K, Adachi E, et al. The expression of cytokeratins 7, 19, 20 in primary and metastatic carcinomas of the liver. Mod Pathol. 1996;9:901–909. 29. Chu P, Wu E, Weiss L. Cytokeratin 7 and cytokeratin 20 expression in epithelial neoplasms: a survey of 435 cases. Mod Pathol. 2000;13: 962–972. 30. Durnez A, Verslype C, Nevens F, et al. The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin. Histopathology. 2006;49: 138–151. 31. Nash JW, Morrison C, Frankel WL. The utility of estrogen receptor and progesterone receptor immunohistochemistry in the distinction of metastatic breast carcinoma from other tumors in the liver. Arch Pathol Lab Med. 2003;127:1591–1595. 32. Sano K, Kosuge T, Yamamota J, et al. Primary hepatic carcinoid tumors confirmed with long-term follow-up after resection. Hepatogastroenterology. 1999;46:2547–2550. 33. Wang J, Dhillon A, Sankey E, et al. Neuroendocrine differentiation in primary neoplasms of the liver. J Pathol. 1991;163:61–67. 34. Gokden N, Gokden M, Phan DC, et al. The utility of PAX-2 in distinguishing metastatic clear cell renal cell carcinoma from its morphologic mimics: an immunohistochemical study with comparison to renal cell carcinoma marker. Am J Surg Pathol. 2008;32:1462–1467. 35. Ozcan A, Zhai Q, Javed R, et al. PAX-2 is a helpful marker for diagnosing metastatic renal cell carcinoma: comparison with the renal cell carcinoma marker antigen and kidney-specific cadherin. Arch Pathol Lab Med. 2010;134:1121–1129. 36. Kandil D, Leiman G, Allegretta M, Evans M. Glypican-3 protein expression in primary and metastatic melanoma: a combined immunohistochemistry and immunocytochemistry study. Cancer Cytopathol. 2009;117:271–278. 37. Nakatsura T, Kageshita T, Ito S, et al. Identification of glypican-3 as a novel tumor marker for melanoma. Clin Cancer Res. 2004;10: 6612–6621. 38. Renshaw A, Granter S. A comparison of A103 and inhibin reactivity in adrenal cortical tumors: distinction from hepatocellular carcinoma and renal tumors. Mod Pathol. 1998;11:1160–1164. 39. Tsui W, Colombari R, Portmann BC, F, et al. Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphological variants. Am J Surg Pathol. 1999;23:34–48. 40. Ghorab Z, Jorda M, Ganjei P, Nadji M. Melan A (A103) is expressed in adrenocortical neoplasms but not in renal cell and hepatocellular carcinomas. Appl Immunohistochem Mol Morphol. 2003;11:330–333. 41. Matsuura S, Aishima S, Taguchi K, et al. “Scirrhous” type hepatocellular carcinomas: a special reference to expression of cytokeratin 7 and hepatocyte paraffin 1. Histopathology. 2005;47:382–390.
Case 27.1
Hepatocellular Carcinoma Versus Metastatic Adenocarcinoma RAGESHREE RAMACHANDRAN AND SANJAY KAKAR
C L I N I C AL I N F OR M AT I ON
A 65-year-old woman with chronic hepatitis C underwent lumpectomy and axillary node dissection for ductal adenocarcinoma of the breast. Two years later, a follow-up CT scan revealed a 4 cm liver mass and a 3 cm mass in the right lower lobe of the lung. There was no evidence of cirrhosis. R E A S ON F OR R E F E R R A L
Establish the diagnosis of liver mass, HCC versus metastatic carcinoma. PAT H OL OG I C F E AT U R E S
The biopsy shows neoplastic cells arranged in trabeculae, small nests, and occasional acini (Figure 27.1.1). The tumor cells have a high N:C ratio and enlarged, pleomorphic, and hyperchromatic nuclei with irregular nuclear borders and occasional small but conspicuous nucleoli. The nonneoplastic liver shows nonspecific changes including large droplet fat, glycogenated nuclei, and mild inflammation. Immunohistochemistry shows that the neoplastic cells express MOC31, ER, and mammaglobin (Figures 27.1.2–27.1.4) and are negative for Hep Par 1.
F I G U R E 2 7 . 1 . 2 The tumor cells show diffuse and strong membra-
nous expression of MOC31.
D I AG N OS I S
Metastatic adenocarcinoma consistent with breast primary.
F I G U R E 2 7 . 1 . 3 Estrogen receptor shows strong nuclear positivity in
the tumor cells. DISCUSSIO N
FIGURE 27. 1. 1 Tumor cells are arranged in trabeculae and small
nests.
Based on the clinical information, HCC, metastatic breast carcinoma, and metastatic lung cancer were the leading possibilities. The two-stain immunohistochemical approach was adopted with Hep Par 1 and MOC31. The Hep Par 1 negative and MOC31-positive profile indicated that HCC was unlikely, and metastatic adenocarcinoma was the likely diagnosis (Figures 27.1–27.5). Negative GPC-3 also made HCC unlikely (Figures 27.1–27.5, 27.1.1). There was focal
436
CASE
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HCC
VS.
M E TA S TAT I C
ADENOCARCINOMA
437
also stain for mammaglobin (1). In the setting of breast carcinoma metastatic to the lung and pleura, specificity has been reported as more than 98% for mammaglobin and more than 91% for GCDFP-15 (3). However, primary lung carcinomas have been reported to express GCDFP-15, with reported expression ranging from 5% to 15% (3–6). Therefore, the combined use of ER/mammaglobin or GATA-3/mammaglobin is recommended (7).
References
FIGURE 27. 1. 4 Strong cytoplasmic staining in tumor cells with
mammaglobin.
loss of reticulin in the nonneoplastic liver, likely due to mass effect from adjacent tumor (Figures 27.1–27.5, 27.1.1, 27.1.2). Additional immunohistochemical markers (ER, mammaglobin, GCDFP-15, and TTF-1) were selected in view of the history and radiologic findings. The tumor cells expressed mammaglobin and ER, and they were negative for GCDFP-15 and TTF-1 (Figures 27.1–27.5, 27.1.1, 27.1.2.). These results established the diagnosis of metastatic breast adenocarcinoma. Mammaglobin is more sensitive than GCDFP-15 for breast carcinoma (55% vs 23% in biopsies and 87% vs 46% in fluid specimens) (1,2). However, 8% of nonbreast tumors
1. Bhargava R, Beriwal S, Dabbs DJ. Mammaglobin vs GCDFP-15: an immunohistologic validation survey for sensitivity and specificity. Am J Clin Pathol. 2007;127:103–113. 2. Yan Z, Gidley J, Horton D, Roberson J, Eltoum IE, Chhieng DC. Diagnostic utility of mammaglobin and GCDFP-15 in the identification of metastatic breast carcinoma in fluid specimens. Diagn Cytopathol. 2009;7:475–478. 3. Takeda Y, Tsuta K, Shibuki Y, et al. Analysis of expression patterns of breast cancer-specific markers (mammaglobin and gross cystic disease fluid protein 15) in lung and pleural tumors. Arch Pathol Lab Med. 2008;132:239–243. 4. Borst MJ, Ingold JA. Metastatic patterns of invasive lobular versus invasive ductal carcinoma of the breast. Surgery. 1993;114:637–641. 5. Striebel JM, Dacic S, Yousem SA. Gross cystic disease fluid protein— (GCDFP-15): expression in primary lung adenocarcinoma. Am J Surg Pathol. 2008;32:426–432. 6. Wang LJ, Greaves WO, Sabo E, et al. GCDFP-15 positive and TTF-1 negative primary lung neoplasms: a tissue microarray study of 381 primary lung tumors. Appl Immunohistochem Mol Morphol. 2009;17: 505–511. 7. Yang M, Nonaka D. A study of immunohistochemical differential expression in pulmonary and mammary carcinomas. Mod Pathol. 2010;23: 654–661.
Case 27.2
Hepatocellular Carcinoma Versus Metastatic Polygonal Cell Tumor RAGESHREE RAMACHANDRAN AND SANJAY KAKAR
C L I N I C AL I N F OR M AT I ON
A 55-year-old woman was found to have hepatomegaly on routine examination. CT scan showed necrotic liver masses in the left and right lobes and a 1.2 cm lower lung nodule. Liverassociated enzymes were normal. R E A S ON F OR R E F E R R A L
Metastatic tumor was favored, but the morphology and immunohistochemical findings did not clearly establish the type of tumor. PAT H OL OG I C F E AT U R E S
The liver biopsy shows a tumor composed of diffuse sheets of polygonal to slightly elongated cells (Figures 27.2.1 and 27.2.2). There is mild nuclear atypia and a few prominent intranuclear inclusions. Many medium-sized arterioles without accompanying bile ducts are present. There is no significant mitotic activity or necrosis. No normal liver parenchyma is present in the biopsy. The diagnosis was established after 2 rounds of immunohistochemistry (see discussion).
D I AG N OS I S
Metastatic epithelioid gastrointestinal stromal tumor.
FIGURES 27. 2. 1 Polygonal to elongated tumor cells arranged in sheets; the morphology and unpaired arterioles raised the possibility of hepatocellular carcinoma.
F I G U R E 2 7 . 2 . 2 Closer view of the polygonal tumor cells; cytologic
atypia is minimal.
DISCUSSIO N
The presence of unpaired arterioles and polygonal cells raised the possibility of HCC even though typical features like small cell change and trabecular growth pattern were not seen. The two-stain panel of Hep Par 1 and MOC31 was used and showed that the tumor is negative for both markers. The possibilities at this point included Hep Par 1negative HCC, MOC31-negative adenocarcinoma (unlikely), and polygonal cell tumors. Pancytokeratin stain can be very helpful for further workup for cases that fall in the Hep Par 1-/ MOC 31-negative category. In view of these possibilities, hepatocellular markers (GPC-3, pCEA), CK19 (to exclude the unlikely possibility of MOC31-negative adenocarcinoma), and pancytokeratin were obtained. The tumor was negative for GPC-3, pCEA, and CK19 arguing against HCC or metastatic adenocarcinoma. Pancytokeratin was also negative, excluding polygonal cell tumors like renal cell carcinoma and neuroendocrine carcinoma. The considerations at this point included cytokeratin-negative polygonal cell tumors like melanoma, adrenocortical carcinoma, angiomyolipoma, and sarcomas with epithelioid morphology. For further evaluation, S-100 (for melanoma), Melan-A (for melanoma, angiomyolipoma, and adrenocortical carcinoma), smooth muscle actin (for angiomyolipoma), vimentin, and CD117 (for mesenchymal tumor) were obtained. The tumor was negative for S-100, Melan-A, and smooth muscle actin, and showed strong expression of vimentin and CD117 (Figures 27.2.3 and 27.2.4). The morphology and staining
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HCC
VS.
M E TA S TAT I C
P O LY G O N A L
CELL
TUMOR
439
FIGURE 27. 2. 3 Immunohistochemistry for CD117 shows strong expression in tumor cells.
F I G U R E 2 7 . 2 . 4 Immunohistochemistry for vimentin shows strong expression in tumor cells.
pattern established the diagnosis of metastatic gastrointestinal stromal tumor (GIST). Upon further probing into the clinical information, we learned that the patient had undergone resection of a gastric epithelioid leiomyosarcoma 22 years ago. Many tumors earlier classified as gastric leiomyosarcomas are now likely to be categorized as GISTs based on CD117 positivity (1).
Reference 1. Miettinen M, Lasota J. Gastrointestinal stromal tumors: review on morphology, molecular pathology, prognosis, and differential diagnosis. Arch Pathol Lab Med. 2006;130:1466–1478.
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28 Hepatoblastoma SARANGARAJAN RANGANATHAN
I N T ROD U C T I ON
TA BL E 2 8 . 1 Conditions associated with hepatoblastoma
Liver cancers are an uncommon group of tumors in childhood. Hepatoblastomas (HB) constitute the largest group and account for 1% of all pediatric malignancies (1). Hepatocellular carcinomas (HCC) in children on the other hand are uncommon and usually associated with an underlying metabolic or infectious etiology discussed later. HCC in children are more common in the second decade and can be of the fibrolamellar type. Other tumors of the liver in childhood include hemangiomas and angiosarcomas, mesenchymal hamartomas, undifferentiated embryonal sarcomas, embryonal rhabdomyosarcoma, germ cell tumors, rare cases of primitive neuroectodermal tumor, and malignant rhabdoid tumors (1,2).
Chromosome (Gene)
Disease/Syndrome Familial adenomatous polyposis coli syndrome (APC)
5q21.22
Beckwith-Wiedemann syndrome
11p15.5
Li-Fraumeni syndrome
17p13 (p53)
Trisomy 18
18
Glycogen storage diseases types I–IV Hemihypertrophy Simpson-Golabi-Behmel syndrome
Xq26:Xp22 (Glypican 3)
E P I D E M I OL OG Y
HBs are primarily reported in children, although occasional examples have been documented in adults. Most cases occur in the first 4 years of life (1.9% according to the SEER data), and they constitute 2.1% of all pediatric cancers in the 1- to 19-year age group (3). They can be congenital (4). The mean age at diagnosis was 19 months in a large Pediatric Oncology Group (POG) study (2). The male to female ratio is 3:2. There is an increased incidence reported in low birth weight infants though the exact etiology for this is unknown (5,6). The overall incidence of HB has been increasing over the years, but this may be due to early detection and better imaging modalities (7).
It determines the zonal involvement of segments of the liver to evaluate the feasibility of surgery. It also evaluates the vascular invasion and extrahepatic extension of the tumor. One of the goals of the current Children’s Oncology Group (COG) study is to compare the PRETEXT staging with the conventional staging used by COG. An ultrasound-directed liver biopsy is the usual method of diagnosis. The role of the pathologist is to make sure that tissue is received fresh after an intra-procedural evaluation. Tissue should be set aside for special studies and for any ongoing COG study in which the patient may agree to participate in subsequently.
C L IN I C AL F E AT U R E S
The most common clinical presentation is with an enlarged liver mass. Other symptoms such as anorexia, weight loss, nausea, vomiting, and abdominal pain may also be noted. Most HBs are associated with thrombocytosis and elevated alphafetoprotein (AFP) level, usually in millions (8). Other liver parameters may be normal or increased if there is obstruction to bile flow by the tumor or by lymph nodes at hilum. They occur in the setting of several syndromes as listed in Table 28.1.
PAT H O LO GY
Since the original description by Ishak and Gluntz in 1967 (9), the histopathology of HB has been the subject of several seminal publications over the years (1,10–13). GRO SS
D I AG N OSI S
The classic presentation of a child is with an abdominal mass with elevated AFP level. Imaging is used to determine the location of tumor and is the most important modality for the PRETEXT (Pretreatment assessment of extent of disease) classification of the tumor prior to any treatment.
HBs are usually solid tumors that have a variegated morphology. Surgical specimens may be obtained either before or after treatment. In untreated primary tumors, the right lobe is more often involved than the left. The lesion may be solitary or multifocal. If solitary and restricted to 1 lobe, segmental resection is usually performed. The cut surface is heterogeneous with areas of hemorrhage and necrosis, more often evident after chemotherapy. Areas of calcification and even ossification 441
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:
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may be noted. It is important to look for gross vascular invasion and make sure the margins are free of tumor (14). The background liver is usually normal. H I S TOL OG Y
HBs are embryonic tumors of the liver, and the morphologic features may correspond to various stages of normal liver development. They are morphologically classified into epithelial, mixed epithelial and mesenchymal, and HB with heterologous elements. Each subtype has unique histologic features (Table 28.2) and may predict survival. Epithelial HB: The epithelial subtype is the most common and constitutes more than 95% of tumors, either by itself or in combination with other patterns. The salient
TA B LE 28. 2 Histologic subtypes and components seen
in hepatoblastoma Epithelial Fetal—pure fetal pattern Crowded fetal (fetal pattern with mitoses >2 per 10 high power fields) Embryonal (isolated or mixed with fetal component) Macrotrabecular (either fetal or embryonal pattern or HCC-like) Small cell undifferentiated (also called anaplastic) Mesenchymal (either alone or mixed with epithelial elements) Osteoid Rhabdomyomatous areas Primitive spindle cell areas
morphologic and immunohistochemical characteristics are listed in Tables 28.3 and 28.4 respectively. Pure fetal HB: This term reflects the resemblance to fetal liver and is composed of cords (usually 2-cell thick) and trabeculae of polygonal cells with abundant eosinophilic to amphophilic to clear cytoplasm and a small centrally placed nucleus with no nucleolus or atypia. The cells are smaller than normal hepatocytes and have a low nuclear-cytoplasmic ratio of 1:2 to 1:4. The entire tumor (100%) needs to be made up of these uniform appearing cells with rare mitoses (<2/10 hpf) (Figure 28.1). Crowded fetal HB (fetal with mitoses): As the name suggests, the cells are more crowded and closely packed with more frequent mitoses (2/10 hpf). Nuclear-cytoplasmic ratio is higher, the nuclei are round, and the cytoplasm is more eosinophilic. They are intermixed with areas that resemble the pure fetal pattern. These areas appear to bridge and merge into embryonal foci and may sometimes be difficult to differentiate. Extramedullary hematopoiesis may be seen (Figure 28.2). Embryonal HB: This morphology corresponds to the embryonic stage of liver development. The cells here have high nuclear-cytoplasmic ratio, scant cytoplasm with indistinct borders, and a large nucleus with a prominent nucleolus. The nucleus is frequently angulated or oval in shape and is larger than that seen in fetal HB. The cell density is increased due to crowding. Mitoses are frequent. Extramedullary hematopoiesis may be a prominent feature, more so than the fetal patterns, but does not help in the distinction (Figures 28.3 and 28.4). Small cell HB: This is the most primitive form of the tumor and is highlighted by small blue cell morphology with high nuclear-cytoplasmic ratio, pale vesicular to hyperchromatic nucleus, scant cytoplasm, and indistinct cell borders. The cells can show a rhabdoid phenotype with eccentric nucleus and eosinophilic cytoplasmic globules. Mitotic rate may
Hepatoblastoma with other minor or major elements Squamous and mucinous epithelial cysts Immature neuroepithelium (teratoid) Melanin pigment and retinal epithelium (teratoid) Ductular component (cholangioblastic) Abbreviation: HCC, hepatocellular carcinomas.
TA B LE 28. 3 Comparison of salient histologic features of HB subtypes Characteristic
Pure Fetal
Crowded Fetal
Embryonal
Small Cell
Low power pattern
“Light and dark” areas
More dark cells with few “light” cells
Dark appearance
Pale areas, sometimes dark islands
Cytoplasm
Abundant—clear to granular pink
Usually granular, eosinophilic
Scant, eosinophilic to amphophilic
Absent except for “rhabdoid” cells with eccentric eosinophilic cytoplasm
Nucleus
Pale, stippled fine chromatin
Pale, stippled chromatin to coarse chromatin
Coarse chromatin
Coarse
Nucleolus
Absent
Absent
Present, prominent
Absent/present, prominent in rhabdoid
Mitoses
Rare <2/10 hpf
More often >2/10 hpf
Frequent
Frequent or scant
N:C ratio
Low 1:3–1:4
Low 1:2–1:3
High 1:1
High 2:1, except rhabdoid
EMH
Present, rare
Present often
Present
Absent/rare
Anaplasia
Absent
Present in foci
Rare
Rhabdoid foci
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TA B LE 28. 4 Immunohistochemical profile of hepatoblastoma subtypesa
Stain
Pure Fetal
Crowded Fetal
Embryonal
Small Cell
Neuroepithelial (Teratoid)
Mesenchymal
-cat
M or N /
M, C, N /
C or N
N
−
N or C /
GPC3
fine C
coarse, diffuse C
diffuse C
−
−
−
GS
C
C
− to
−
−
−
HepPar-1
/
−
−
−
CD34/31
endo
endo
endo
−
−
−
CK AE1/3
/−
/−
−
CK7
−
−
−
−
−
−
CK19
/−
/−
/−
/
−
−
Vim
−
−
−
INI1
−
−
−
/
−
−
Ki67
/
/
Cyclin D1
−/
/
/
−
−/
Abbreviations: b-cat, b-catenin; CK, cytokeratin; C, cytoplasmic; endo, endothelial; GS, glutamine synthetase; Hep Par-1, hepatocyte antigen; M, membranous; N, nuclear; “−,” Negative; “1,” positive with grading of intensity and density; Vim, vimentin. a Data based on literature and personal experience (not all data are published at this time). The staining pattern reported is the usual pattern and is seen in more than 90% of examples. Outliers are possible and need to be considered in rare instances.
FIGURE 28. 1 Fetal hepatoblastoma composed of small polygonal cells with abundant clear to eosinophilic cytoplasm and no nuclear pleomorphism or mitoses.
F I G U R E 2 8 . 2 Crowded fetal pattern with mitoses (3 in this field).
be high, but some tumors show scant mitoses. This pattern has been variably called small cell anaplastic HB or small cell undifferentiated HB. It is interesting to note a zonal relationship among HB components with small cells aggregating in the center of embryonal area that transition at the periphery into crowded fetal/fetal areas. This is more often seen in resection specimens, especially if they have not been treated before. By nomenclature, a tumor should contain at least 70% small cell component to be considered a pure small cell HB. However,
smaller components of this morphology also need to be recognized as they may portend a poor outcome. Immunohistochemically, the tumor cells are negative for Hep Par-1, AFP, glutamine synthetase (GS), and GPC3 but express cytokeratin and vimentin. Integrase interactor 1 (INI1) may be lost in some of these tumors, especially those with rhabdoid phenotype. Cytokeratin 19 may highlight scattered cells. Strong and diffuse nuclear staining with b-catenin is a typical feature of this variant.
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Mixed HB: This subtype comprises of epithelial and mesenchymal elements seen by imaging or on histology. The most common mesenchymal elements are bone and less often cartilage. Muscle especially skeletal muscle, fat, and primitive spindle cell mesenchyme may also be seen. The mesenchymal component is an integral part of the tumor and not due to differentiation as a result of chemotherapy. It shows similar staining as the epithelial component including nuclear b-catenin staining in the primitive mesenchyme and cells bordering bony elements (so-called osteoblasts). The mesenchymal component is negative for GPC3 suggesting an early transformation of primitive hepatoblasts to mesenchyme.
FIGURE 28. 3 Embryonal hepatoblastoma showing sheets of tumor cells with ovoid to angulated nuclei, crowding, hyperchromasia, prominent nucleoli, and frequent mitoses.
FIGURE 28. 4 Hepatoblastoma showing transition from fetal (left)
to crowded fetal (middle) to embryonal (upper right).
Macrotrabecular HB: This pattern is one of the most difficult ones to recognize due to its morphologic overlap with hepatocellular carcinoma (HCC). This pattern is recognized by the presence of trabeculae and cords that are greater than 10 cells thick. Morphologically, these cells can show fetal or embryonal morphology, and are associated with other areas of more typical HB, but can be the only pattern on a biopsy. Other epithelial components: Ductular differentiation may sometimes be seen at the periphery of areas of other epithelial subtypes, especially fetal HB. The ductular elements can be highlighted by a cytokeratin stain (CK19, CK 7). The tumor is called cholangioblastic HB when ductular elements are a prominent feature (15). They need to be differentiated from ductular reaction noted at the periphery of the tumor, especially after chemotherapy or as a compression effect.
Teratoid HB (HB with heterologous elements): This term is used for mixed HBs with neural/neuroectodermal differentiation represented by mature brain, primitive neuroepithelial components forming tubules and rosettes as well as melanin and retinal pigment (16). Squamous and mucinous glands may also be present but can also be seen without neural elements in pure epithelial HB. Rarely glandular elements with subnuclear and supranuclear vacuoles can raise consideration for primary yolk sac tumor of the liver, but these are interspersed with other areas of typical HB. Spindle cell mesenchyme with rhabdomyomatous areas, cartilage, and bone are also frequently seen in this subtype. Treatment and outcome: The COG staging system is being currently used (Table 28.5), and attempts are underway to correlate it with the European PRETEXT staging. Although COG staging system is for primary resection prior to any chemotherapy, PRETEXT staging is based on segmental involvement of the liver again prior to chemotherapy, but can be done postchemotherapy retrospectively and compared with postchemotherapy, preoperative images (also called POSTTEXT: posttreatment assessment of extent of disease). The PRETEXT system is determined by the contiguous segments that are free of tumor. In 2005, this system was improved upon to include other factors such as caudate lobe involvement, vascular invasion, tumor rupture, extrahepatic tumor spread, lymph nodes, and distant metastases with the aim to improve its correlation with prognosis. At this time there appears to be poor correlation between the 2 staging systems (PRETEXT and COG) in lower stage tumors or in stage IV tumors but good correlation with stage III tumors (2,17). Further prospective studies are being done to improve this correlation so that there is a universal uniformity to staging of HB and all other childhood liver tumors.
TA BL E 2 8 . 5 Children’s Oncology Group Staging System
for hepatoblastoma (pretreatment staging) Stage I: Total gross resection at surgery (primary resection) Stage II: Total gross resection at surgery with microscopic residual disease at margin on pathology Stage III: Biopsy diagnosis only; or gross resection with nodal involvement, tumor rupture, or incomplete surgical resection Stage IV: Distant metastases at diagnosis
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The first line of treatment is surgical resection for tumors restricted to the liver without vascular invasion. For higher stage tumors or for a small proportion of stage I tumors where primary resection/segmental resection is not possible, chemotherapy followed by surgery is the preferred treatment. Current COG trials are using a combination therapy either cisplatin/ doxorubicin or cisplatin/5FU/vincristine, with evaluation for surgery after 2 cycles and along with transplant consult for higher stage tumors. Based on the current COG protocol, all tumors that are stage I and have pure fetal histology are treated by surgery alone. All other histological variants (nonpure fetal) and higher stage tumors are treated with a combination of surgery and chemotherapy in either order depending on tumor resectability at diagnosis. This approach is based on the premise that almost all pure fetal HBs are stage I at diagnosis and have a 5-year event free survival of 100%. The event free survival reported in 1 recent COG study for stage I (nonpure fetal) is about 97%, stage II is 100%, stage III is 70.2%, and stage IV is 39.3% (18,19). The current COG protocol advocates rapid pathological review of any biopsy/primary resection of stage I and II tumors to recognize the pure fetal HB that would need surgery alone with no adjuvant chemotherapy. It is also important to recognize small cell component as it has now been shown to decrease event free survival, and hence the new protocol incorporates this finding into therapy (20). Prognostic factors: The single most important determinant in predicting prognosis is the stage of the tumor with stage IV being associated with a uniformly poor prognosis; AFP level less than 100 is associated with a worse prognosis. Among histological subtypes, the small cell undifferentiated and macrotrabecular HB have an adverse outcome compared with fetal HB. Other unfavorable prognostic factors include multiple lobes involvement, vascular invasion, slow decline in AFP following therapy, aneuploidy, nuclear b-catenin staining, low p27/kip1 expression, and high cyclin D1 expression (2,13,18, 20–23). Molecular genetics of HB: The most common gene implicated in the pathogenesis of HB is b-catenin, a component of the Wnt signaling pathway (24–26). b-catenin gene mutations have been described in up to 80% of HB. The Wnt pathway involves a complex interplay of several factors that result in the phosphorylation and degradation of the b-catenin complex in the cytoplasm. Mutations in the genes involved in the Wnt signaling pathway can result in accumulation of b-catenin in the cytoplasm and its translocation to the nucleus, where it upregulates target genes such as cyclin D1 and c-myc resulting in tumorigenesis. Similar mechanisms are in play in familial syndromes such as familial adenomatous polyposis wherein adenomatous polyposis coli (APC) gene mutations result in b-catenin activation. More recent studies suggest origin of HB from progenitor stem cells that either differentiate or are arrested in the proliferative phase giving rise to the 2 major patterns of HB that have been referred to as C1 and C2 subtypes. The C1 subtype is more differentiated and corresponds to the fetal subtype, whereas C2 is more
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proliferative and corresponds to the embryonal phenotype (27). This has also been shown to be true by gene expression analysis (28). Gene expression analyses have shown distinct genetic signatures for these tumors with variation between fetal and embryonal subtypes as well as upregulation of markers of the NOTCH pathway such as DLK1 and upregulation of GPC3 (29,30). The multiple variants of this tumor suggest origin from a precursor cell that is undifferentiated and has the capability of undergoing epithelial-mesenchymal transition in response to specific signals (31,32). It is likely that the small cell undifferentiated HB represents the least differentiated subtype and arises from hepatoblast progenitor cell due to its ability to express epithelial and mesenchymal markers and lack of differentiation markers (33). Several cytogenetic defects have been described in HB, the most frequent of which is aberrations of the 1q12–q21 locus. Others include t(1;4), Xp and Xq gains, trisomies 2, 8, and 20 (2,34).
References 1. Weinberg AG, Finegold MJ. Primary hepatic tumors in childhood. In Finegold MJ, ed. Pathology of neoplasia in children and adolescents: major problems in pathology. Philadelphia, PA: WB Saunders;1986:333–372. 2. Lopez-Terrada D, Finegold MJ. Tumors of the liver. In: Suchy FJ, Sokol RJ, Balisteri WF, eds. Liver Disease in Children. 3rd ed. Cambridge University Press. New York, USA;2007:943–974. 3. SEER website, National Cancer Institute. http://seer.cancer.gov. Accessed March 30, 2010. 4. Isaacs H Jr. Neoplasms in infants: a report of 265 cases. Pathol Annu. 1983;18:165–214. 5. Ikeda H, Hachitanda Y, Tanimura M, Maruyama K, Koizumi T, Tsuchida Y. Development of unfavorable hepatoblastoma in children of very low birth weight. Results of a surgical and pathologic review. Cancer. 1998;82:1789–1796. 6. Buckley ID, Sather H, Ruccione K, et al. A case-control study of risk factors for hepatoblastoma: a report from the Children’s Cancer Study Group. Cancer. 1989;64:1169–1176. 7. Darbari A, Sabin KM, Shapiro CN, Schwartz KB. Epidemiology of primary hepatic malignancies in US children. Hepatol. 2003;38: 560–566. 8. Shafford EA, Pritchard J. Extreme thrombocytosis as a diagnostic clue to hepatoblastoma. Arch Dic Child. 1993;69:171. 9. Ishak KG, Gluntz PR. Hepatoblastoma and hepatocarcinoma in infancy and childhood. Cancer. 1967;20:396–422. 10. Kasai M, Watanabe I. Histologic classification of liver cell carcinoma in infancy and childhood and its clinical evaluation. Cancer. 1970;25: 551–563. 11. Gonzalez-Crussi F, Upton MP, Maurer HS. Hepatoblastoma: attempt at characterization of histologic subtypes. Am J Surg Pathol. 1982;6: 599–612. 12. Rowland JM. Hepatoblastoma: assessment of criteria for histologic classification. Med Pediatr Oncol. 2002;39:478–483. 13. Haas JE, Muczynski KA, Krailo M, et al. Histopathology and prognosis in childhood hepatoblastoma and hepatocarcinoma. Cancer. 1989;64:1082–1095. 14. Finegold MJ, Lopez-Terrada DH, Bowen J, Washington MK, Qualman SJ. College of American Pathologists. Protocol for the examination of specimens from pediatric patients with hepatoblastoma. Arch Pathol Lab Med. 2007;131:520–529. 15. Zimmerman A. Hepatoblastoma with cholangioblastic features (cholangioblastic hepatoblastoma) and other liver tumors with bimodal differentiation in young patients. Med Pediatr Oncol. 2002;39:487–491.
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16. Manivel C, Wick MR, Abenoza P, Dehner LP. Teratoid hepatoblastoma. The nosologic dilemma of solid embryonic neoplasms of childhood. Cancer. 1986;57(11):2168–2174. 17. Douglass EC, Reynolds M, Finegold MJ, Cantor AB, Glicksman A. Cisplatin, vincristine, and fluorouracil therapy for hepatoblastoma: a Pediatric Oncology Group Study. J Clin Oncol. 1993;11:96–99. 18. Meyers RL, Rowland JR, Krailo M, Chen Z, Katzenstein HM, Malogolowkin MH. Predictive power of pretreatment prognostic factors in children with hepatoblastoma: a report from the Children’s Oncology Group. Pediatr Blood Cancer. 2009;53:1016–1022. 19. Finegold MJ. Chemotherapy for suspected hepatoblastoma without efforts at surgical resection is a bad practice. Med Pediatr Oncol. 2002;39:484–486. 20. Haas JE, Feusner JH, Finegold MJ. Small cell undifferentiated histology in hepatoblastoma may be unfavorable. Cancer. 2001;92: 3130–3134. 21. Conran RM, Hitchcock CL, Waclawiw MA, Stocker JT, Ishak KG. Hepatoblastoma: the prognostic significance of histologic subtype. Pediatr Pathol. 1992;12:167–183. 22. Trobaugh-Lotrario AD, Tomlinson GE, Finegold MJ, Gore L, Feusner JH. Small cell undifferentiated variant of hepatoblastoma: adverse clinical and molecular features similar to rhabdoid tumors. Pediatr Blood Cancer. 2009;52:328–334. 23. Park WS, Oh RR, Park JY, et al. Nuclear localization of b-catenin is an important prognostic factor in hepatoblastoma. J Pathol. 2001;193; 483–490. 24. Buendia MA. Genetic alterations in hepatoblastoma and hepatocellular carcinoma: common and distinctive aspects. Med Pediatr Oncol. 2002;39:530–535. 25. Cairo S, Armengol C, De reynies A, et al. Hepatic stem-like phenotype and interplay of Wnt/b-catenin and Myc signaling in aggressive childhood liver cancer. Cancer Cell. 2008;14:471–484.
26. Ranganathan S, Tan X, Monga SP. Beta-Catenin and met deregulation in childhood hepatoblastomas. Pediatr Dev Pathol. 2005;8: 435–447. 27. Armengol C, Cairo S, Fabre M, Buendia MA. Wnt signaling and hepatocarcinogenesis: the hepatoblastoma model. Int J Biochem Cell Biol. 2009, July 29. [Epub ahead of print]. 28. Adesina AM, Lopez-Terrada D, Wong KK, et al. Gene expression profiling reveals signatures characterizing histologic subtypes of hepatoblastoma and global deregulation in cell growth and survival pathways. Hum Pathol. 2009;40(6):843–853. 29. López-Terrada D, Gunaratne PH, Adesina AM, et al. Histologic subtypes of hepatoblastoma are characterized by differential canonical Wnt and Notch pathway activation in DLK precursors. Hum Pathol. 2009;40(6):783–794. 30. Luo JH, Ren B, Keryanov S, et al. Transcriptomic and genomic analysis of human hepatocellular carcinomas and hepatoblastomas. Hepatology. 2006;44:1012–1024. 31. Lee JS, Heo J, Libbrecht L, et al. A novel prognostic subtype of human hepatocellular carcinoma derived from hepatic progenitor cells. Nature Med. 2006;12:410–416. 32. Zimmermann A. The emerging family of hepatoblastoma tumours: from ontogenesis to oncogenesis. Eur J Cancer. 2005;41:1503–1514. 33. Ruck P, Xiao JC, Kaiserling E. Small epithelial cells and the histogenesis of hepatoblastoma. Electron microscopic, immunoelectron microscopic and immunohistochemical findings. Am J Pathol. 1996;148:321–329. 34. Tomlinson GE, Douglass EC, Pollock BH, Finegold MJ, Schneider NR. Cytogenetic evaluation of a large series of hepatoblastomas: numerical abnormalities with recurring aberrations involving 1q12–q21. Genes Chromosome Cancer. 2005;44:177–184.
Case 28.1
Biopsy Diagnosis of Hepatoblastoma SARANGARAJAN RANGANATHAN
C L I N IC AL I N F OR M AT I ON
A 17-month-old child, 28-week premie, with short gut syndrome secondary to necrotizing enterocolitis and prolonged total parenteral nutrition (TPN) presented with fever and abdominal distension. The total bilirubin was 1.7 mg/dL, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were 127 and 68 IU/L respectively and alkaline phosphatase was 378 IU/L. Computed tomography (CT) showed diffuse heterogeneous signal in the liver. AFP level was 280 000 ng/ml. An ultrasound guided biopsy was performed. R E A SON F OR R E F E R R AL
To categorize the tumor seen on liver biopsy. PAT H OL OG I C F E AT U R E S
The biopsy predominantly showed normal liver. A minute portion at the edge showed small polygonal cells with enlarged nuclei, indistinct cell borders, occasional large nucleus, and prominent nucleolus. The nuclear cytoplasmic ratio was increased, many crushed cells were seen, and there were no mitoses. Immunohistochemistry for b-catenin showed membranous and cytoplasmic staining in tumor cells with no definite nuclear staining. GPC3 stain was negative in normal liver and showed coarse granular staining in many tumor cells (Figures 28.1.1–28.1.5).
F I G U R E 2 8 . 1 . 2 The tumor is composed of polygonal cells with indistinct cell borders and hyperchromatic round to oval nuclei with inconspicuous nucleoli.
D I AG N OS I S
Hepatoblastoma, epithelial subtype.
F I G U R E 2 8 . 1 . 3 Reticulin stain highlights decreased and irregular reticulin in the tumor as opposed to normal liver, which has an intact reticulin framework.
DISCUSSIO N Differential diagnosis of epithelial and mesenchymal HB
FIGURE 28. 1. 1 Compressed liver parenchyma with a small sleeve of tumor at one edge.
The main source of difficulty in a liver biopsy is recognizing normal infantile liver with extramedullary hematopoiesis from neoplastic tissue. Normal liver cells show well-defined lobular configuration with portal areas and central veins. The hepatocytes are arranged in 1 to 2 cell thick plates with no variation in morphology. The cells are large polygonal and show
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FIGURE 28. 1. 4 GPC3 stain shows granular diffuse cytoplasmic staining of tumor cells. The normal liver is negative.
FIGURE 28. 1. 5 -catenin stain shows membranous staining of normal liver and cytoplasmic staining in tumor cells.
a small central nucleus with nuclear cytoplasmic ratio of 1:6 to 1:8. Immunohistochemistry shows membranous b-catenin staining (hepatocytes and bile ducts) with negative GPC3 and CK19. GS is expressed in pericentral 1 to 2 cell thick zone of hepatocytes with negative staining in the rest of the lobule. This can be contrasted with the fetal areas especially in a pure fetal hepatoblastoma that shows alternating light and dark cell zones due to cytoplasmic clearing or eosinophilia. The cells are arranged in trabeculae that may vary from 2 to 4 cells thick. Mitosis is rare or absent in the pure fetal category. Most fetal HB show membranous b-catenin staining similar to normal liver, with only rare tumor cells showing nuclear staining, although rare cases of fetal HB with extensive nuclear staining may be encountered. GPC3 stain shows a pericanalicular pattern of staining in the fetal areas with slightly more intense staining in the eosinophilic cells as opposed to clear cells. GS
stain shows diffuse cytoplasmic staining in all fetal areas. This panel will help to identify neoplastic tissue from normal liver. Hep Par 1 stain will be positive in both normal and tumor tissue and does not help in the differential diagnosis. AFP stain is helpful if the levels are elevated but is difficult to interpret due to strong background staining. Endothelial markers such as CD31 and CD34 have been tried but can be variable in the background liver depending on the underlying pathology. The pattern of staining in the crowded fetal areas is the same as the fetal areas except for slightly more intense staining with GPC3 and GS. The crowded fetal is thought to represent a less differentiated form of HB and is characterized by increased mitoses of more than 2/10 hpf. Any areas of presumed fetal HB that show increased mitoses would take the tumor out of the category of pure fetal HB. The crowded fetal areas can be differentiated from embryonal areas by the presence of polygonal cells with only a mild increase in nuclear cytoplasmic ratio, distinct cell borders, and abundant amphophilic cytoplasm. The embryonal pattern creates diagnostic difficulty if it is the only constituent seen on biopsy. Primitive angulated cells with increased nuclear cytoplasmic ratio raises the possibility of metastatic Wilms tumor (WT) and neural tumors such as neuroblastoma or primitive neuroectodermal tumor. Origin from the kidney on imaging helps in diagnosis of WT. Histologically, WT shows considerable histologic overlap with HB. Unlike the diffuse staining for GPC3 in most HBs, only an occasional WT will show intense staining. b-catenin staining shows nuclear staining in embryonal HB, whereas WT is usually negative for nuclear b-catenin. In neuroblastoma, the imaging often demonstrates an adrenal tumor. On immunohistochemistry, it expresses PGP 9.5, and is negative for GPC3 (personal experience) and b-catenin. The presence of mesenchymal elements also helps in the diagnosis of HB on a biopsy. Rare examples of HB that have a dominant primitive mesenchymal component with spindle cells raise the differential diagnosis of other primary or metastatic spindle cell tumors including embryonal rhabdomyosarcoma, synovial sarcoma, and nested spindle and epithelial stromal tumor. Embryonal rhabdomyosarcoma, however, is a tumor of the biliary tree and rarely involves the liver parenchyma. It is strongly positive for desmin, muscle-specific actin, and myogenin, the latter not being a feature of HB. The presence of classic areas of HB or other components of mesenchyme such as bone and cartilage also help in this distinction. Nested spindle and epithelial stromal tumor of the liver shows epithelial, ductular, and osteoid components associated with a spindle cell component that stains for cytokeratin, vimentin, and hormones such as adrenocorticotropic hormone (ACTH) (35) but is negative for GPC3 (personal experience) and nuclear b-catenin. Classic areas of epithelial HB are not seen. The nested tumor affects older children who may present with Cushing syndrome. The illustrated case highlights the difficulty in biopsy diagnosis as only a small sample of tumor may be obtained if the borders are indistinct. It may be difficult to confidently subtype these tumors. It is best to report such minute portions of tumor as hepatoblastoma not otherwise specified (NOS) and enumerate the different areas that can be identified.
Case 28.2
Macrotrabecular Hepatoblastoma Versus Hepatocellular Carcinoma SARANGARAJAN RANGANATHAN
C L I N IC AL I N F OR M AT I ON
A 3-year-old male with no known prior liver disease presented with a right upper quadrant mass. Imaging revealed a large tumor in the right lobe with normal background liver. The viral serologies were negative and metabolic screen was normal. R E A SON F OR R E F E R R AL
Macrotrabecular variant of HB versus hepatocellular carcinoma. PAT H OL OG I C F E AT U R E S
The biopsy shows a tumor comprised of polygonal cells arranged in broad trabeculae that are up to 10 to 20 cells thick. There is moderate nuclear pleomorphism and frequent mitoses. The individual cells have scant eosinophilic cytoplasm, distinct cell borders, centrally placed hyperchromatic nuclei and conspicuous nucleoli. Staining for GPC3 is positive in the tumor cells, whereas a beta-catenin stain shows membranous, focal cytoplasmic staining and rare nuclear staining (Figures 28.2.1–28.2.3).
F I G U R E 2 8 . 2 . 2 GPC3 stain shows intense cytoplasmic staining in tumor cells suggestive of an embryonal pattern of hepatoblastoma with macrotrabecular arrangement.
D I AG N OS I S
Macrotrabecular hepatoblastoma.
F I G U R E 2 8 . 2 . 3 -catenin stain showing membranous, cytoplasmic, and nuclear staining in tumor cells.
DISCUSSIO N
FIGURE 28. 2. 1 Clusters of small tumor cells arranged in broad
trabeculae that range from 8 to 10 cells thick in places. The cells are small with increased N:C ratio and occasional nucleoli. No anaplasia is noted.
It is challenging to distinguish macrotrabecular HB from HCC arising in normal liver. Both patterns show broad trabeculae of polygonal cells with abundant cytoplasm and increased nuclear cytoplasmic ratio with variably conspicuous nucleoli. Diligent search in resection specimens always reveal areas of classic fetal or embryonal areas and/or mesenchymal elements.
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Most macrotrabecular HB show cytological features of fetal or embryonal patterns and hence have less pleomorphism with cells resembling classic HB in terms of cytoplasmic staining and nuclear cytoplasmic ratio. In contrast, most HCC show a wide range of nuclear pleomorphism, including intranuclear inclusions and atypical mitoses, a feature not usually seen in HB (Figures 28.2.4 and 28.2.5), although occasional HB can have anaplastic features (Figure 28.2.6). The finding of globules of alpha-1-antitrypsin is more likely to represent HCC than HB. Finding of areas resembling cholangiocarcinoma may also favor a HCC or mixed HCC-cholangiocarcinoma. Nuclear b-catenin staining is more often seen in HB (70%) than HCC (10–15%). Glypican 3 stain is more consistently positive in the macrotrabecular HB than in
FIGURE 28.2.6 Fetal hepatoblastoma (HB) with marked nuclear ana-
plasia, but the trabeculae are only 3–4 cell thick (anaplastic fetal HB).
FIGURE 28. 2. 4 Hepatocellular carcinoma showing with clear cytoplasm, moderate nuclear pleomorphism, and several cells thick trabeculae.
F I G U R E 2 8 . 2 . 7 GPC3 stain showing strong cytoplasmic staining of
tumor shown in Figure 28.2.5.
FIGURE 28. 2. 5 Hepatocellular carcinoma showing large cells with bubbly vacuolated to eosinophilic cytoplasm, large pleomorphic nuclei, and prominent intranuclear inclusions.
well-differentiated HCC (50% or less) (Figure 28.2.7). Glutamine synthetase is also more consistently expressed in HB. AFP staining is not helpful as both HB and HCC can be positive. HCC in children, though less frequent than HB, can be seen in the first 2 decades (1–5), including the fibrolamellar variant of HCC (6). The latter is characterized by the presence of large cells with eosinophilic cytoplasm, prominent nucleoli, and lamellar pattern of fibrosis. Although previously thought to have a favorable prognosis, it has now been shown that these tumors behave in the same aggressive fashion as conventional HCC, can recur and metastasize, and have a poor 5-year survival (7). The main modality of treatment is surgery with conventional chemotherapy having very little role to play at this time. Intraarterial chemotherapy has
CASE
28.2:
MACROTRABECULAR
been attempted prior to surgery. The characteristic histologic appearance of this entity seldom poses a diagnostic dilemma and can be easily differentiated from HB. Conventional HCC in the first decade often occurs in cirrhotic livers in the setting of metabolic conditions or congenital transmission of hepatitis viruses. The livers in most instances show cirrhosis. The various metabolic conditions associated with the development of HCC include tyrosinemia (early detection and treatment has decreased this incidence), hemochromatosis, glycogen storage disease, alpha-1-antitrypsin deficiency, and progressive intrahepatic familial cholestasis. The background liver frequently shows adenomas and dysplastic nodules in addition to cirrhosis. The tumor itself resembles its adult counterpart and shows abundant cytoplasmic vacuolation or eosinophilia with evidence of bile production in some cases. Eosinophilic globules of AFP or alpha-1-antitrypsin may be seen. The clue to the diagnosis is nuclear pleomorphism and lack of areas with typical features of HB. Staining for Hep Par 1 and GPC3 may be positive, the latter being more common in the moderately and poorly differentiated tumors. Although there is some morphologic overlap, gene expression analysis shows distinct separation of HCC and HB in some studies. Some HCC show a phenotype suggestive of origin from a common precursor hepatoblast, the same precursor that gives rise to the HB (8). Further molecular analysis and newer techniques such as comparative genomic hybridization may help delineate the few difficult tumors that can be impossible to differentiate
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morphologically. There are rare tumors that have features of both HB and HCC, and these will require more study to understand their biology.
References 1. Weinberg AG, Finegold MJ. Primary hepatic tumors in childhood. In: Finegold MJ, ed. Pathology of Neoplasia in Children and Adolescents: Major Problems in Pathology. Philadelphia, WB: Saunders; 1986: 333–372. 2. Lopez-Terrada D, Finegold MJ. Tumors of the liver. In: Suchy FJ, Sokol RJ, Balisteri WF, eds. Liver Disease in Children. 3rd ed. Cambridge University Press. New York, USA; 2007:943–974. 3. SEER website, National Cancer Institute. http://seer.cancer.gov. Accessed March 30, 2010. 4. Darbari A, Sabin KM, Shapiro CN, Schwartz KB. Epidemiology of primary hepatic malignancies in US children. Hepatol. 2003;38: 560–566. 5. Katzenstein HM, Krailo MD, Malogolowkin MH, et al. Hepatocellular carcinoma in children and adolescents: results from the Pediatric Oncology Group and the Children’s Cancer Group intergroup study. J Clin Oncol. 2002;20:2789–2797. 6. Katzenstein HM, Krailo MD, Malogolowkin MH, et al. Fibrolamellar hepatocellular carcinoma in children and adolescents. Cancer. 2003;97:2006–2012. 7. Kakar S, Burgart LJ, Batts KP, Garcia J, Jain D, Ferrell LD. Clinicopathologic features and survival in fibrolamellar carcinoma: comparison with conventional hepatocellular carcinoma with and without cirrhosis. Mod Pathol. 2005;18:1417–1423. 8. Lee JS, Heo J, Libbrecht L, et al. A novel prognostic subtype of human hepatocellular carcinoma derived from hepatic progenitor cells. Nat Med. 2006;12:410–416.
Case 28.3
Small Cell Hepatoblastoma Versus Other Small Round Cell Tumors SARANGARAJAN RANGANATHAN
C L I N I C AL I N F OR M AT I ON
A 1-year-old child presented with poor appetite and no weight gain. Ultrasound and CT scan showed a large right lobe liver mass associated with absent portal vein flow on the right side. AFP level was normal (<100 ng/mL). The mass was determined to be surgically unresectable. Biopsy was performed followed by chemotherapy and subsequent surgical resection. R E A S ON F OR R E F E R R A L
To determine if this represented a small cell HB or embryonal HB in the postchemotherapy resection. PAT H OL OG I C F E AT U R E S
The sections showed a monotonous appearing tumor with small round blue cells arranged in sheets with no areas of differentiation. There were no areas of classic HB of fetal or embryonal type although other areas showed mesenchymal elements. The cells were small, round, and had high nuclear cytoplasmic ratio with scant cytoplasm. Occasional cells had an eccentric nucleus with inconspicuous nucleolus and more eosinophilic cytoplasm but no cytoplasmic inclusions were noted. Immunohistochemically, the cells variably stained for vimentin and cytokeratin with rare foci of CD99 staining in a membrane fashion. The GPC3 stain was negative, whereas a CK19 stain showed scattered clusters of positive cells. INI-1 stain showed no loss of nuclear staining in tumor cells (Figures 28.3.1–28.3.4).
F I G U R E 2 8 . 3 . 2 Tumor cells have round to oval hyperchromatic nuclei with overlapping, high N:C ratio, scant cytoplasm, and mitoses.
F I G U R E 2 8 . 3 . 3 INI1 stain showing no loss of staining in the nuclei
of tumor cells.
DIAGNO SIS
Small cell undifferentiated hepatoblastoma.
DISCUSSIO N FIGURE 28. 3. 1 Sheets of small round blue cells with scant cyto-
plasm and large nucleus with variable nucleolus.
It is difficult to establish a diagnosis of small cell HB, especially when a biopsy or resection offers no other classic areas of HB (1–4). In a typical epithelial hepatoblastoma, there appears to
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CELL
FIGURE 28. 3. 4 GPC3 stain is negative in tumor cells.
be a zonation, with fetal hepatocytes surroundings islands and zones of embryonal or crowded fetal pattern of HB. The center of these aggregates show clusters of small undifferentiated cells consistent with small cell HB. This zonal pattern is lost in many cases and some tumors may be entirely composed of small round blue cells posing a diagnostic challenge that needs adjunct techniques for confirmation. Immunohistochemistry may provide helpful clues when the tumors are mixed with the small cell undifferentiated (SCU) areas not reacting with GPC3 or Hepar stains but show strong nuclear b-catenin staining. Although the INI-1 stain is preserved in most examples of SCU hepatoblastomas similar to other subtypes and areas of conventional HB, rare instances of pure SCU show loss of INI-1 staining and mutations in INI-1 gene as described below. The most likely small round cell tumors to involve the liver are metastatic neuroblastoma (NB), metastatic WT and Ewing’s sarcoma/primitive neuroectodermal tumor (EWS/ PNET). These can usually be differentiated by imaging, morphology and immunohistochemistry. Rare cases of stage 4S NB can present with liver nodules, which may be single or multiple, and these invariably show rosettes and neuropil in the background and stain uniformly for PGP 9.5. NBs are also negative for b-catenin and are weak or negative for GPC3. INI1 staining is intact. WT invariably has a primary in the kidney, though in rare cases the tumor may spread by contiguity. They are triphasic and may show blastemal tubules and mesenchyme: features that aid in the diagnosis. Rarely, a WT may be predominantly blastemal, and in these cases may pose some diagnostic difficulty; but the presence of a renal mass as well as the larger cells of blastema with more angulated and ovoid nuclei help in the differential. WT can be variably positive for cytokeratin, vimentin, and GPC3 but is usually negative for nuclear b-catenin. PNETs are unusual as primary liver tumors with only isolated reports in the literature. They can be confused with small cell HB, but staining for CD99 and fluorescence in situ hybridization for the EWS break apart probe will confirm the diagnosis (Figure 28.3.5).
H E PAT O B L A S T O M A
453
F I G U R E 2 8 . 3 . 5 Ewing’s sarcoma (EWS)/primitive neuroectodermal tumor involving the liver. The cells are small, round, and show clear to vacuolated scant cytoplasm. EWS translocation was detected in this case.
F I G U R E 2 8 . 3 . 6 Malignant rhabdoid tumor involving the liver. The
cells show abundant eccentric cytoplasm with eosinophilic globules and large vesicular nuclei with prominent nucleoli.
Malignant rhabdoid tumor (MRT) can occur in the liver and prove to be a diagnostic challenge (5). This is a highly aggressive tumor characterized by classic cytogenetics that show deletion of the INI1/BAF47 gene on chromosome 22 and morphologically is made up of small to large cells with abundant cytoplasm, variably prominent nucleoli, and eosinophilic cytoplasmic globules (Figures 28.3.6 and 28.3.7). They stain strongly for cytokeratin, vimentin, and epithelial membrane antigen and show uniform loss of INI1 staining in the nuclei. Molecular and chromosomal analysis of small cell HB shows that a subset has the same deletion and mutation as the MRT and show diffuse loss of INI1 expression. Such HBs also behave aggressively and respond poorly to conventional HB
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References
FIGURE 28. 3. 7 INI1 stain shows loss of nuclear staining in the tumor shown in the previous image. The background endothelial and stromal cells retain the INI1.
therapy (6,7). Recent data suggests that these patients may benefit from therapy used in MRT. This makes it imperative to attempt cytogenetic studies where possible for pediatric liver tumors to exclude the mimics and enable use of appropriate treatment options.
1. Weinberg AG, Finegold MJ. Primary hepatic tumors in childhood. In: Finegold MJ, ed. Pathology of Neoplasia in Children and Adolescents: Major Problems in Pathology. Philadelphia, PA: WB Saunders; 1986:333–372. 2. Lopez-Terrada D, Finegold MJ. Tumors of the liver. In: Suchy FJ, Sokol RJ, Balisteri WF, eds. Liver Disease in Children. 3rd ed. Cambridge University Press; 2007:943–974. 3. Haas JE, Feusner JH, Finegold MJ. Small cell undifferentiated histology in hepatoblastoma may be unfavorable. Cancer. 2001;92: 3130–3134. 4. Gonzalez-Crussi F. Undifferentiated small cell (“anaplastic”) hepatoblastoma. Pediatr Pathol. 1991;11:155–162. 5. Wagner LM, Garrett JK, Ballard ET, et al. Malignant rhabdoid tumor mimicking hepatoblastoma: a case report and literature review. Pediatr Dev Pathol. 2007;10:409–415. 6. Trobaugh-Lotrario AD, Tomlinson GE, Finegold MJ, Gore L, Feusner JH. Small cell undifferentiated variant of hepatoblastoma adverse clinical and molecular features similar to rhabdoid tumors. Pediatr Blood Cancer. 2009;52:328–334. 7. Russo P, Biegel JA. SMARCB1/INI1 alterations and hepatoblastoma: another extrarenal rhabdoid tumor revealed? Pediatr Blood Cancer. 2009;52:312–313.
Case 28.4
Teratoid Hepatoblastoma Versus Malignant Teratoma/Yolk Sac Tumor SARANGARAJAN RANGANATHAN
C L I N IC AL I N F OR M AT I ON
A 1-year-old child presented with a liver mass. Ultrasound showed a large liver mass that was heterogeneous and CT scan showed areas of calcification and cystic degeneration. AFP level was in the millions. A biopsy was performed and showed epithelial HB. Following chemotherapy a resection was performed. R E A SON F OR R E F E R R AL
Does this represent a teratoid hepatoblastoma or primary hepatic teratoma with yolk sac components? PAT H OL OG I C F E AT U R E S
The resection showed a variegated tumor with neuroepithelial, glandular, and mesenchymal elements. The neuroepithelium consisted of rosettes with no mature glial elements. The glandular component resembled intestinal type epithelium and occasional foci of smaller glands with supra-and infra-nuclear vacuoles. There were rare foci resembling fetal HB. Other components noted included keratin, melanin pigment, and spindle cell mesenchyme. Calcification and ossification were present.
represent a component of yolk sac tumor (YST). The latter component is usually in the form of primitive glandular elements that are in close proximity and found within islands of primitive neuroepithelial component rather than the large intestinal glands that represent a differentiated end of the epithelial component of teratoma. The classic YST appearance of reticular myxoid areas or glandular component with “piano-key” appearance of cells is seen in many cases of primary hepatic YST but is almost never seen in a teratoid HB. Rare small glands resembling the “piano-keys” have been seen by the author but its significance remains to be elucidated. Teratomas usually show a membranous pattern of staining with b-catenin with no staining of the mesenchymal component. In contrast, the mesenchymal component of a HB shows intense nuclear b-catenin staining. The osteoblasts lining the bony trabeculae also show nuclear -catenin in HB. GPC3 stain highlights the epithelial component of HB but does not stain the mesenchyme (3). In comparison, YST shows positive staining for GPC3 in the smaller glands and myxoid areas rather than the large intestinal type gland, which probably are mature. The liver portion in teratoma is also positive for GPC3 confirming its fetal nature. Glutamine synthetase staining is positive in fetal and to some extent embryonal HB but has not been tested in YST. The neuroepithelium does not stain with any of the above stains. CK7 stain may be seen in HB and almost always in YST (Figures 28.4.1–28.4.6).
D I AG N OS I S
Teratoid hepatoblastoma.
D I S C U S S I ON
Teratoid HB is the most uncommon variant of HB and highlights the pluripotency of the stem cell giving rise to HB. In addition to epithelial elements and mesenchyme, the stem cell precursor has the ability to differentiate into the primitive neuroectodermal derivatives including retinal pigment and ependymal rosettes (1,2). Choroid plexus may rarely be noted. The only clue to the diagnosis may be the small components of fetal or embryonal HB. Although all these components are an integral part of a teratoma, the liver seen in a teratoma is usually more mature looking despite having foci of extramedullary hematopoiesis (EMH) and resembles more often the mature end of the spectrum of fetal liver. It stains with GPC3 in a pattern similar to fetal HB. The fetal liver in a teratoma represents one of the multiple lines of differentiations and does not necessarily constitute evidence of immaturity or
F I G U R E 2 8 . 4 . 1 Treated hepatoblastoma showing extension across the portal veins into the left lobe and extensive areas of necrosis.
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FIGURE 28. 4. 2 Primitive neural tissue with neuroepithelial rosettes
in teratoid hepatoblastoma.
FIGURE 28. 4. 3 Teratoid hepatoblastoma with large intestinal type glands with cytoplasmic vacuolation and mucinous material in the lumen. Note the loose myxoid areas around the gland that may mimic yolk sac tumor.
F I G U R E 2 8 . 4 . 5 Teratoid hepatoblastoma with glandular elements surrounded by scattered cells with melanin pigment.
F I G U R E 2 8 . 4 . 6 Teratoid hepatoblastoma showing keratin with giant
cell reaction surrounded by fetal hepatoblasts.
References 1. Manivel C, Wick MR, Abenoza P, Dehner LP. Teratoid hepatoblastoma. The nosologic dilemma of solid embryonic neoplasms of childhood. Cancer. 1986;57(11):2168–2174. 2. Moll A, Krenauer A, Bierbach U, et al. Mixed hepatoblastoma and teratoma of the liver in a 3-year-old child: a unique combination and clinical challenge. Diagn Pathol. 2009;12:37. 3. Zynger DL, Gupta A, Luan C, Chou PM, Yang GY, Yang XJ. Expression of glypican 3 in hepatoblastoma: an immunohistochemical study of 65 cases. Hum Pathol. 2008;39:224–230.
FIGURE 28. 4. 4 Mesenchymal component in hepatoblastoma with
ossification and primitive spindle cell mesenchyme.
29 Vascular Tumors
Case 29.1
Cavernous Hemangioma Variants LINDA D. FERRELL
Cavernous hemangioma is the most common primary tumor of the liver and typically is not a problematic diagnosis. However, there are variations in both the intratumoral changes likely due to intratumoral thrombosis and ischemic changes, as well as underrecognized extratumoral manifestations of this lesion that can cause considerable diagnostic problems, often in the setting of needle core biopsy when the sample is limited. The typical pathology of cavernous hemangioma consists of a circumscribed tumor composed of vascular channels lined by endothelium. However, the vascular structures do not have the morphology of true vessels, but, instead, the walls of the vascular spaces consist of predominantly fibrous tissue (Figure 29.1.1) with only minimal smooth muscle and elastic fiber components present in an unorganized pattern (1). This lesion has no known risk of malignant transformation but can present clinically due to hemorrhagic complications requiring resection, which tend to be the larger lesions and are often referred to as “giant cavernous hemangiomas” (2). Intratumoral alterations probably due to ongoing thrombosis, ischemia, and scarring can lead to considerable alteration of the morphology that is often overlooked due to the obvious nature of the tumor. The intratumoral thrombi (Figure 29.1.2) can form “ball-like” scars (Figure 29.1.3) along the vascular walls. These tumors can also undergo extensive sclerosis (Figure 29.1.4) (3) likely
F I G U R E 2 9 . 1 . 2 Foci of organizing thrombus are frequent in large cavernous hemangiomas and likely lead to the histologic findings of focally thickened walls or ball-like structures within the cavernous hemangioma.
F I G U R E 2 9 . 1 . 3 The three round, ball-like foci from left to right FIGURE 29. 1. 1 Typical cavernous hemangioma: vascular structures
are thin-walled, lined by a single layer of endothelium overlying a fibrous wall and have scant smooth muscle or elastic fibers.
demonstrate various stages organizing thrombus, from late stage organization of hemorrhagic debris, to a more myxoid early scar, and finally to a more dense hyaline ball.
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FIGURE 29. 1. 4 Extensive sclerosis with small vessel proliferation,
F I G U R E 2 9 . 1 . 5 Cavernous hemangioma-like vessels are present
increased stromal cellularity, and mild inflammatory changes.
in the liver parenchyma outside of the main tumor. These vascular structures have the same morphologic components of the vascular structures seen in the cavernous hemangioma.
due to chronic ischemic changes and organization of intratumoral hemorrhage and thrombosis. The scarred zones can vary in amount of collagen present from a loose, edematous stroma to dense collagen deposits. Small vessels with well-defined muscular walls can be seen in these scarred areas; such vessels are not a component of the routine cavernous hemangioma without scar formation. In addition, irregularity of tumor border and the presence of cavernous hemangioma-like structures in the liver tissue adjacent to the cavernous hemangioma have also been underappreciated; yet, these changes are relatively common in the setting of giant cavernous hemangiomas (1). Thus, such findings can lead to difficulties in the histologic diagnosis, especially in the setting of small biopsy samples that do not include the classic vascular channels.
hemangioma (Figure 29.1.5). These HLVs were located in variable positions in the liver parenchyma as well as near or within the confines of portal zones, which retained the usual hepatic artery, portal vein, and bile duct. Histochemical stains of both the giant hemangioma and the HLV had similar staining patterns with scant smooth muscle and elastic fibers, negative staining for estrogen or progesterone receptors, and a very low proliferative rate (<5%) on MIB-1 staining.
DIAGNO SIS
Cavernous hemangioma with HLV in adjacent liver.
C L I N I C AL I N F OR M AT I ON
This 38-year-old woman was referred for excision of a 23 cm cavernous hemangioma, which was discovered after the patient complained of abdominal pain following a bicycle accident. On gross examination, small punctuate hemorrhagic zones were present outside the confines of the cavernous hemangioma. The patient was alive and well 8 years after resection with no evidence of recurrence. R E A S ON F OR R E F E R R A L
The referring pathologist recognized the nature of the cavernous hemangioma but was concerned about the possibility of transformation to angiosarcoma due to the increased number of extratumoral vascular spaces in the adjacent liver. PAT H OL OG I C F E AT U R E S
The primary lesion had the typical appearance of cavernous hemangioma (Figure 29.1.1) in 70% of the lesion, but about 30% of the tumor consisted of a large laminated thrombus with variable degrees of organization (Figures 29.1.2–29.1.4). Small clusters of cavernous hemangioma-like vessels (HLV) were present in the nontumoral liver adjacent to the cavernous
DISCUSSIO N
HLVs associated with cavernous hemangioma occur more commonly in women than in men (16 women and 3 men) (1). On follow-up after resection, no recurrence, metastatic, or postsurgical hemorrhagic complications were noted. Thus, despite the prominence of HLV, there is no clear evidence that the patient is at significant risk for future complications. HLVs have been noted to involve the entire liver. In addition, rare cases of cavernous hemangioma-like lesions in other organs have been observed in combination with giant hepatic cavernous hemangioma (personal observation).
References 1. Kim GE, Thung SN, Tsui WM, Ferrell LD. Hepatic cavernous hemangioma: underrecognized associated histologic features. Liver Int. 2006;26:334–338. 2. Adams YG, Huvos AG, Fortner JG. Giant hemangiomas of the liver. Ann Surg. 1970;172:239–245. 3. Makhlouf HR, Ishak K. Sclerosed hemangioma and sclerosing cavernous hemangioma of the liver: a comparative clinicopathologic and immunohistochemical study with emphasis on the role of mast cells in their histogenesis. Liver. 2002;22:70–78.
Case 29.2
Epithelioid Hemangioendothelioma HALA R. MAKHLOUF AND ZACHARY D. GOODMAN
C L I N IC AL I N F OR M AT I ON
A 30-year-old man presented with abdominal discomfort. Computed tomography (CT) revealed ascites, thickened omentum and peritoneum, and multiple hypodense lesions with calcifications in the right hepatic lobe. Laboratory studies showed elevated alkaline phosphatase 1265, gamma glutamyl transpeptidase (GGT) 1123, aspartate transaminase (AST) 196, alanine aminotransferase (ALT) 280, and bilirubin 15. R E A SON F OR R E F E R R AL
To differentiate an epithelioid and spindle cell tumor from primary or metastatic carcinoma. PAT H OL OG I C F E AT U R E S
The right hepatic lobectomy specimen was almost completely replaced by white firm fibrous tissue and multiple confluent nodules of fleshy, hemorrhagic tumor with areas of calcification. Microscopic examination showed invasion of the sinusoids, terminal hepatic venules, and portal vein branches by neoplastic cells which lined the sinusoids (Figure 29.2.1). Groups of cells and individual cells formed vascular lumina, some of which contained erythrocytes (Figure 29.2.2). Some small vessels contained tumor cells with an epithelioid appearance, and similar cells were present in the more cellular parts of the specimen (Figure 29.2.3). The Masson’s Trichrome stain
F I G U R E 2 9 . 2 . 2 Intracellular vascular lumina resemble signet rings.
F I G U R E 2 9 . 2 . 3 A terminal hepatic venule infiltrated by tumor.
demonstrated the invasion and occlusion of small veins by the tumor. (Figure 29.2.4). The tumor cells were immunoreactive for CD31, demonstrating endothelial differentiation (Figure 29.2.5).
DIAGNO SIS FIGURE 29. 2. 1 Epithelioid tumor cells infiltrating the sinusoids and
disrupting the liver cell plates; some tumor cells contain intracellular lumina.
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Epithelioid hemangioendothelioma.
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FIGURE 29. 2. 4 The Masson’s Trichrome stain demonstrates the out-
lines of small veins that have been invaded and occluded by tumor.
TUMORS
weight loss, hepatomegaly, jaundice, or a mass lesion. Rarely, rupture of the tumor with hemoperitoneum may occur. Less common presentations include liver failure and Budd-Chiari syndrome. The tumor is an incidental finding in slightly less than half of the cases. The diagnosis can be established by imaging studies and liver biopsy. Grossly, EHE is usually white, and firm to hard, typically multifocal and involves both liver lobes with 0.2 to 14 cm nodules (3). Histologically, the tumor is composed of dendritic or epithelioid cells that often contain vacuoles representing intracellular lumina mimicking signet-ring cells. Blood cells may be found in the lumina. The stroma is fibrous in all cases, with myxohyaline areas, and occasional calcification. Sinusoidal growth of tumor cells and vascular occlusion by dense fibrous tissue containing tumor cells in both portal and hepatic vein branches are characteristic features (1). Growth within acini is associated with atrophy or replacement of liver cell plates, particularly toward the center of the tumor. The atrophied hepatocytes formed cords or even tubular structures. Intravenous growth in the form of polypoid or glomeruloid projections (tufts) comprised of epithelioid cells is common (Figure 29.2.6). Entrapped bile ductules and hepatocytes may be present at the periphery of the tumor (3). Immunohistochemically, tumor cells express Factor VIIIrelated antigen, CD34, and CD31 (3). All cases are positive for at least 1 endothelial marker. The routine use of multiple endothelial cell markers is recommended to confirm the diagnosis. In our experience, the most reliable sensitive and specific markers for this type of tumor are CD31 and CD34. The prognosis varies widely, some patients surviving for decades, whereas others die within months of diagnosis, but it is considered to be much more favorable than angiosarcoma or other hepatic malignancies. In the present case, the patient lived for 13 years before succumbing to the disease. High cellularity in these tumors appears to correlate with clinical outcome (3).
FIGURE 29. 2. 5 Tumor cells are strongly immunostained with anti-
body to CD31. D I SC U SSI ON
The principal differential diagnoses of epithelioid vascular tumor with spindle cell elements in the liver includes cholangiocarcinoma, angiosarcoma, hepatocellular carcinoma with extensive sclerosis, and metastatic carcinoma. Epithelioid hemangioendothelioma (EHE) is a rare neoplasm of vascular origin, which has been described in different sites, such as soft tissue, lung, liver, bone, and brain. It tends to behave like a low-grade malignancy, although the outcome can be unpredictable (1). The clinical-pathologic features have been detailed in 2 large series from the AFIP (2,3). The mean age at onset is about 50 years (range 2nd–8th decade) with slight predominance in females. Patients present with nonspecific symptoms, such as right upper quadrant pain,
F I G U R E 2 9 . 2 . 6 Polypoid growth of epithelioid cells in a portal vein
branch.
CASE
29.2:
EPITHELIOID
EHE of the liver has been misdiagnosed as cholangiocarcinoma, fibrolamellar hepatocellular carcinoma, or hepatocellular carcinoma. Sarcoma, or mixed tumors, and its histological differentiation from these lesions can be problematic on routine staining (2). Because of the abundant eosinophilic cytoplasm, prominent cytoplasmic vacuolization, growth in solid clusters, and the presence of intracellular vascular lumina, EHE may be misdiagnosed as metastatic carcinoma (eg, signet-ring cell carcinomas) (4). Newly formed vessels in EHE can mimic the tubules and glands of epithelial tumors. Hepatic EHE histologically may mimic other vascular tumors, such as angiosarcoma; however, preservation of the hepatic acinar structure, dense sclerosis, hyalinization, and calcification of tumor nodules typical of EHE are generally not observed in angiosarcoma (2). Features that are helpful in the diagnosis of EHE are infiltrative pattern of growth with preservation of the hepatic acinar landmarks such as portal areas, characteristic vascular invasion with tufting of portal vein branches and terminal hepatic venules, epithelioid and dendritic cells expressing endothelial cell markers (FVIII, CD34, and CD31), negative staining for mucin, bile, carcinoembryonic antigen (CEA), hepatocyte antigen (Hep Par 1) or alpha-fetoprotein. Care must be taken not to mistake focal keratin positivity in EHE for carcinoma; this may occur due to entrapped hepatocytes, ducts, or, possibly, reactivity in tumor cells (4). The extensive sclerosis can resemble cirrhosis or postnecrotic fibrosis (2).
HEMANGIOENDOTHELIOMA
461
Hepatic EHE also has been confused with venoocclusive disease because of its tendency to invade terminal hepatic venules (5,6) and to present clinically as Budd-Chiari syndrome (5). Identification of dendritic and/or epithelioid cells positive for endothelial cell markers and the invasive growth pattern will confirm the neoplastic nature of the occlusive venous lesions (6).
References 1. Ishak KG, Goodman ZD, Stocker JT: Tumors of the Liver and Intrahepatic Bile Ducts. Atlas of Tumor Pathology, Third Series, Fascicle 31. Washington, DC: Armed Forces Institute of Pathology; 2001:282–293. 2. Ishak K, Sesterhenn I, Goodman Z, Rabin L, Stromeyer F. Epithelioid hemangioendothelioma of the liver: a clinicopathologic and follow-up study of 32 cases. Hum Pathol. 1984;15:839–852. 3. Makhlouf HR, Ishak KG, Goodman ZD. Epithelioid hemangioendothelioma of the liver: a clinicopathologic study of 137 cases. Cancer. 1999;85:562–582. 4. Gary MH, Rosenberg AE, Dickersin GR, Bhan AK. Cytokeratin expression in epithelioid vascular neoplasms. Hum Pathol. 1990;21:212–217. 5. Fukayama M, Nihei Z, Takizawa T, Kawaguchi K, Harada H, Koike M. Malignant epithelioid hemangioendothelioma of the liver, spreading through the hepatic veins. Virchows Arch A Pathol Anat Histopathol. 1984;404:275–287. 6. Eckstein RP, Ravich RB. Epithelioid hemangioendothelioma of the liver: report of two cases histologically mimicking veno-occlusive disease. Pathology. 1986;18:459–462.
Case 29.3
Hepatic Angiosarcoma HALA R. MAKHLOUF AND ZACHARY D. GOODMAN
C L I N IC AL I N F OR M AT I ON
A 56-year-old diabetic man presented with symptoms and signs of decompensated end-stage liver disease. Endoscopy revealed esophageal varices and portal hypertensive gastropathy. Laboratory studies were remarkable for elevated total bilirubin at 9.3 mg/dL and mild liver-associated enzyme abnormalities, including AST 146, ALT 48, alkaline phosphatase 191. Alphafetoprotein was not elevated. Abdominal ultrasound and CT demonstrated hepatomegaly with multiple mass lesions. The liver was nodular and appeared cirrhotic, and there were innumerable, rounded enhancing foci of varying size (up to 6 cm) in both lobes with internal areas of low density suggesting necrosis in the larger lesions. The presumptive diagnosis was steatohepatitic cirrhosis with hepatocellular carcinoma. R E A S ON F OR R E F E R R AL
To establish the nature of liver tumor.
F I G U R E 2 9 . 3 . 2 Large, atypical, hyperchromatic endothelial cells
lining hepatic sinusoids. PAT H OL OG I C F E AT U R E S
The biopsy shows extensive fibrosis of liver parenchyma. Enlarged endothelial cells with large and hyperchromatic nuclei lining dilated hepatic sinusoids in many areas (Figures 29.3.1 and 29.3.2). In more severely involved areas, the abnormal cells filled the sinusoids. Atrophy of liver cells was seen in several foci, leaving collapsed cell plates lined by the malignant endothelial cells (Figures 29.3.3 and 29.3.4). Immunostains for CD31 and CD34 were positive in the tumor cells, confirming
F I G U R E 2 9 . 3 . 3 Proliferation of abnormal cells filling the sinusoids.
their endothelial nature (Figure 29.3.5). Most of the sinusoidal endothelial cells in areas not involved with tumor are also positive for CD31 and CD34, unlike normal hepatic sinusoidal cells which are typically negative.
DIAGNO SIS FIGURE 29. 3. 1 Endothelial cells with large and hyperchromatic nuclei lining vascular spaces.
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CASE
29.3:
H E PAT I C
FIGURE 29. 3. 4 Atrophy of liver cell plates with atypical endothelial cells lining sinusoids.
ANGIOSARCOMA
463
vinyl chloride monomer, iatrogenic exposure to the radiologic contrast material Thorotrast (colloidal thorium dioxide), anabolic steroid use, or chronic arsenic ingestion, either environmental or iatrogenic. Exposure to these carcinogens, with the possible exception of steroids, has been markedly reduced in the intervening years, and nearly all current cases of HAS are idiopathic. HAS is typically a disease of males (80%) with a peak incidence in the sixth decade (3). Rare cases have occurred in infants and children. Presentation is usually due to abdominal pain and evidence of hepatic decompensation. In approximately 20% of cases, there is rupture of the tumor with acute abdominal hemorrhage. The vascular nature of the tumor makes it especially prone to hemorrhage following needle biopsy. The clinical course is usually one of rapid deterioration with a median survival of 6 months. HAS is almost always multifocal and involves both lobes of the liver diffusely. Cut surface reveals multiple hemorrhagic nodules and blood-filled cavities of varying size. Histologically, there is growth of the malignant endothelial cells along hepatic sinusoids and venules. The tumor cells are usually spindle-shaped with enlarged, hyperchromatic nuclei. They involve sinusoids that become progressively dilated, but unlike EHE, the fibrous stroma is not prominent. The dilated sinusoids form irregular, cavernous, blood-filled spaces. At the same time, the hepatocytes plates surrounded by the malignant endothelial cells undergo atrophy and may have a trabecular appearance reminiscent of hepatocellular carcinoma. Continued proliferation of the tumor cells can fill the sinusoids with spindle or epithelioid cells that eventually form solid masses mimicking fibrosarcoma or poorly differentiated carcinoma (Figure 29.3.6). Parenchymal loss may result in scarring and occlusion of preexisting vessels leading to infarction and large areas of necrosis. Immunohistochemically, as with EHE, the tumor cells express Factor VIII-related antigen, CD34, and CD31 in
FIGURE 29. 3. 5 Tumor cells stain positively with immunostain for
CD31. D I S C U S S I ON
Angiosarcoma can occur in a variety of body sites, but those that are primary in the liver have special features related to the hepatic architecture and the nature of hepatic sinusoidal endothelium. The differential diagnosis includes epithelioid hemangioendothelioma (EHE), hepatocellular carcinoma, poorly differentiated metastatic carcinoma, fibrosarcoma, and nonneoplastic vascular and fibrosing diseases. Hepatic angiosarcoma (HAS) occurs about as often as EHE (1), and due to its association with known chemical carcinogens (2), its epidemiologic features were extensively studied in the 1970s. At that time it was estimated that approximately 20 cases occurred in the United States annually, with approximately 25% related to industrial exposure to
F I G U R E 2 9 . 3 . 6 Solid growth pattern of malignant endothelial cells
in angiosarcoma.
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almost all cases to some degree, allowing the endothelial origin to be recognized. Of these, CD31 is the most reliable marker. The most important factor in making a correct diagnosis of HAS is first to consider the possibility, as the histologic findings may be subtle or confusing. Sinusoidal dilatation may be confused with congestive hepatopathy of a variety of causes. In such cases, recognition of the atypical endothelial cells lining the sinusoids is critical. A trabecular arrangement of hepatocytes between the dilated sinusoids may suggest a welldifferentiated hepatocellular carcinoma, but recognition that the endothelial cell lining the trabeculae are atypical whereas the hepatocytes are atrophic rather than malignant should raise the possibility of HAS. Solid masses of spindled tumor cells can suggest fibrosarcoma. In such cases, vascular markers like CD34 and CD31 should be routinely applied. Cases with solid masses of epithelioid tumor cells can be confused with
TUMORS
carcinoma and use of vascular markers is imperative for diagnosis as cytokeratin expression can be seen in HAS. Finally, EHE is sometimes difficult to distinguish from HAS. That the fibrous and hyalinized stroma typical of EHE is lacking in HAS is the most important distinguishing point in the differential diagnosis.
References 1. Ishak KG, Goodman ZD, Stocker JT. Tumors of the Liver and Intrahepatic Bile Ducts. Atlas of Tumor Pathology, Third Series, Fascicle 31. Washington, DC: Armed Forces Institute of Pathology; 2001:293–307. 2. Falk H, Herbert J, Crowley S, Ishak KG, Thomas LB, Popper H, Caldwell GG. Epidemiology of hepatic angiosarcoma in the United States: 1964–1974. Environ Health Perspect. 1981;41:107–113. 3. Molina E, Hernandez A. Clinical manifestations of primary hepatic angiosarcoma. Dig Dis Sci. 2003;48:677–682.
Case 29.4
Infantile Hemangioma MICHAEL TORBENSON
C LI N I C AL H I S TORY
A 3-month-old female presented with weight loss, poor feeding, and oliguria. Imaging revealed heart failure and massive hepatomegaly. The liver contained multiple vascular lesions up to 4 cm in greatest dimension. Malrotation of the gut was also noted, with the appendix located in the left upper quadrant. Medical therapy including steroids and embolization failed, and a liver transplant was performed. PAT H OL OG I C F E AT U R E S
Gross examination showed multiple 1 to 4 cm red spongy nodules. Sections showed a vascular neoplasm composed of dilated and irregular capillary-like vessels in a dense collagenous background (Figure 29.4.1). Entrapped bile ducts were common, especially at the periphery. The centers of the larger lesions had cavernous hemangioma like appearances with areas of thromboses (Figure 29.4.2). In most sections, the neoplastic endothelial cells were plump to flat with no atypia. However, the largest lesion near the hilum showed (Figures 29.4.3 and 29.4.4) multiple atypical areas with endothelial cell tufting and a focal solid area (Figure 29.4.5).
F I G U R E 2 9 . 4 . 1 The lesions were composed of dilated and irregular small capillary-like structures in a dense collagenous background. Entrapped bile ducts can also be seen (H&E, 643).
D I AG N OS I S
Angiosarcoma arising in an infantile hemangioma (type 2 infantile hemangioma)
F I G U R E 2 9 . 4 . 3 In the largest tumor near the liver hilum, several
sections showed areas of endothelial cell tufting as shown here (H&E, 1003). DISCUSSIO N
FIGURE 29. 4. 2 In the centers of the larger lesions, the vascular
spaces were more dilated and resembled a cavernous hemangioma (H&E, 643).
Infantile hemangiomas (formerly known as infantile hemangioendothelioma) are the most common vascular tumor of the liver in infants and toddlers, with about 90% of tumors occurring before 6 months of age (1). Rare cases have been reported in teenagers and adults (1,2). There is a female predominance in most series (1,3,4).
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TA BL E 2 9 . 4 . 1 Reported associations with infantile hemangioma Developmental Abnormalities Congenital heart disease (1,6) Extranumerary digits (1) Unilateral or bilateral renal agenesis (6) Duplicate ureter (1) Hydrocephalus (1) Heterotopic liver in thorax (10) Absent common bile duct (6) Cornelia de Lange syndrome (11) Hemihypertrophy (12) Malrotation of gut Chromosomal Abnormalities Trisomy 2 (11) Deletion of 6q (13)
FIGURE 29. 4. 4 On higher power, endothelial atypia is evident
Tumors Wilm’s tumor (11) Hemangiomas (1) Mesenchymal hamartoma (14)
(H&E, 1603).
Gross Findings
A slight majority of infantile hemangiomas (~55%) are single lesions (1,3) and range in size from sub-cm incidental findings to 15 cm, with a mean of 4 cm. The tumors are usually well demarcated and nonencapsulated with a spongy appearance and vary from red to gray in color. The centers of large lesions can be fibrotic and even calcified. The neoplasm may be supplied by the hepatic artery and/or extrahepatic arteries as well as the portal vein. Arteriovenous shunting can at times be demonstrated by radiographic studies. Microscopic Findings
FIGURE 29. 4. 5 In the same tumor near the hilum, there was a small
foci of solid growth (H&E, 1003).
Most cases (60%) present with clinical symptoms, whereas the remainder are detected by parents or physicians as asymptomatic enlargement of the liver. Clinical symptoms are often nonspecific such as failure-to-thrive or gastrointestinal problems. Other cases can present with cardiac or respiratory failure resulting from hemodynamic compromise. A classic presentation is with a bleeding diathesis from platelet sequestration and consumption (Kasabach-Merritt syndrome). Infantile hemangiomas are associated with numerous congenital anomalies as illustrated in this case and listed in Table 29.4.1. The anomalies show no clear pattern, ranging from extranumerary digits to hydrocephalus. The frequency of extrahepatic hemangiomas is approximately 10% to 30%. Skin hemangiomas are the most common, but other reported sites include the lungs, gastrointestinal tract, adrenal gland, and thymus.
The tumor is composed of vascular channels, which can be small and capillary-like or dilated and irregular. The endothelial cells have flattened or plump nuclei with fine chromatin and a single nucleolus. Up to 12 mitoses per 10 HPF (high-power field) have been reported, but high mitoses do not appear to impact prognosis. In the case illustrated here, mitoses were nearly absent in most sections but were very high in sections near embolic material. Bile ducts are often entrapped within the lesion especially at the periphery. About one-third of cases have an infiltrative margin. In these cases, the hepatocytes at the interface can take on a ductular morphology. In some cases, the hepatocytes at the margins can produce large amounts of alpha-fetoprotein (3,5). The center of larger neoplasms often resembles cavernous hemangioma, though similar changes can be seen at the periphery of some tumors. In addition, the center of larger tumors frequently has fibrosis, thrombosis, myxoid change, and calcification. There can be sufficient histological overlap between infantile hemangioma and hepatic vascular malformations that some cases may be difficult to classify. One group has proposed that the features in Table 29.4.2 can be helpful in separating these two vascular lesions (4).
CASE
29.4
:
INFANTILE
HEMANGIOMA
Treatment
TABLE 29.4.2 Features that may be helpful in distinguishing infantile
hemangiomas from hepatic vascular malformations Infantile Hemangiomas Clinical Features Often asymptomatic hepatomegaly Present first few weeks to months of life Cardiomegaly and anemia less common Gross Typically multiple smaller nodules
Hepatic Vascular Malformations Often asymptomatic hepatomegaly Present first few weeks to months of life Cardiomegaly and anemia less common
Spontaneous regression is seen in 5% to 10% of infantile hemangiomas. Nevertheless, current management of symptomatic tumors often involves resection when possible and medical therapy when the tumor is unresectable (3). Steroids, embolization, or chemotherapy have all been employed with some success. In symptomatic cases that fail to respond to medical therapy, liver transplantation is an important option. Asymptomatic tumors are often watched carefully without medical intervention (3).
Typically single large mass
Histology Closely packed small capillary-sized vessels Often with involutional features
Malformed, irregular large vessels with infarction, hemorrhage, calcification Smaller capillary-sized reactive vessels at the periphery
Immunohistochemistry Glut1 positive
Glut1 negative
Clinical Course Spontaneous involution more common Good response to steroids and interferon therapy
Spontaneous involution unlikely Surgery often needed Unclear response to steroids and interferon therapy
Adapted from Ref (4).
Type 2 Change
In a comprehensive review of this tumor by Dehner and Ishak in 1971, the authors divided infantile hemangiomas into types 1 and 2 based on histological findings, with type 2 showing larger irregular endothelial nuclei, clumped chromatin, and irregular budding or branching of endothelial cell clusters (6). Type 2 change was referred to as more “aggressive in appearance” and significant histological overlap was noted between type 2 changes and frank angiosarcoma. In a 1994 study of 91 cases, the frequency of type 2 changes was found to be 19% but did not impact prognosis and the nuclear atypia was felt to possibly be degenerative in nature. Although rare, accumulated case reports and small series demonstrate a low but clear risk for aggressive behavior in some infantile hemangiomas (4,7–9). Type 2 changes appear to be the best available histological marker for aggressive potential. Although the clinical outcome in most cases is similar regardless of the presence or absence of type 2 changes, almost all tumors with malignant behavior show type 2 changes. Thus, although type 2 changes do not equal malignancy, they are an important marker for potential aggressive behavior. Some authors currently regard type 2 changes as equivalent to low-grade angiosarcoma. Regardless of the label placed on tumors with type 2 changes, it is important to adequately section the neoplasm and document type 2 changes in the pathology report. In many cases, including this case, type 2 changes can be patchy. In addition to atypia and endothelial tufting, other features indicating angiosarcoma are solid areas and spindly, kaposiform areas.
467
SUMMA RY
Infantile hemangiomas are vascular neoplasms mostly occurring in infants less than 6 months of age. Most are benign (type 1) though a minority have malignant potential (type 2). Clinical management includes resection, medical therapy, and transplantation for those who fail medical and surgical therapy. The 6-month survival rate is 60% to 70% with most deaths resulting from poor postoperative clinical courses secondary to cardiac failure and related complications.
References 1. Selby DM, Stocker JT, Waclawiw MA, Hitchcock CL, Ishak KG. Infantile hemangioma of the liver. Hepatology. 1994;20(1 pt 1):39–45. 2. Diment J, Yurim O, Pappo O. Infantile hemangioma of the liver in an adult. Arch Pathol Lab Med. 2001;125(7):931–932. 3. Moon SB, Kwon HJ, Park KW, Yun WJ, Jung SE. Clinical experience with infantile hepatic hemangioendothelioma. World J Surg. 2009;33(3):597–602. 4. Mo JQ, Dimashkieh HH, Bove KE. GLUT1 endothelial reactivity distinguishes hepatic infantile hemangioma from congenital hepatic vascular malformation with associated capillary proliferation. Hum Pathol. 2004;35(2):200–209. 5. Kim TJ, Lee YS, Song YS, et al. Infantile hemangioma with elevated serum alpha fetoprotein: report of 2 cases with immunohistochemical analysis. Hum Pathol. 2010;41(5):763–767. 6. Dehner LP, Ishak KG. Vascular tumors of the liver in infants and children. A study of 30 cases and review of the literature. Arch Pathol. 1971; 92(2):101–111. 7. Awan S, Davenport M, Portmann B, Howard ER. Angiosarcoma of the liver in children. J Pediatr Surg. 1996;31(12):1729–1732. 8. Noronha R, Gonzalez-Crussi F. Hepatic angiosarcoma in childhood. A case report and review of the literature. Am J Surg Pathol. 1984;8(11):863–871. 9. Strate SM, Rutledge JC, Weinberg AG. Delayed development of angiosarcoma in multinodular infantile hepatic hemangioendothelioma. Arch Pathol Lab Med. 1984;108(12):943–944. 10. Shah KD, Beck AR, Jhaveri MK, et al. Infantile hemangioma of heterotopic intrathoracic liver associated with diaphragmatic hernia. Hum Pathol. 1987;18(7):754–756. 11. Maruiwa M, Nakamura Y, Motomura K, et al. Cornelia de Lange syndrome associated with Wilms’ tumour and infantile haemangioendothelioma of the liver: report of two autopsy cases. Virchows Arch A Pathol Anat Histopathol. 1988;413(5):463–438. 12. Wood BP, Putnam TC, Chacko AK. Infantile hepatic hemangiomas associated with hemihypertrophy. Pediatr Radiol. 1977;5(4):242–245. 13. Ito H, Yamasaki T, Okamoto O, Tahara E. Infantile hemangioma of the liver in patient with interstitial deletion of chromosome 6q: report of an autopsy case. Am J Med Genet. 1989;34(3):325–329. 14. Carlotti CG Jr, Jay V, Rutka JT. Infantile hemangioma of the pericranium presenting as an occipital mass lesion. Case report. J Neurosurg. 2000;92(1):156–160.
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30 Hematopoietic Tumors of the Liver PATRICK A. TRESELER AND JOHN P. HIGGINS
I N T ROD U C T I ON
Hematopoietic tumors of the liver are seldom encountered by practicing pathologists, which is due in part to the rarity of such tumors as primary hepatic lesions and in part to the fact that many cases of secondary hepatic involvement by leukemias and lymphomas never come to biopsy. It addition to being uncommon, such lesions can often mimic hepatitis or other benign inflammatory conditions. They can thus pose distinct hazards for the diagnostic pathologist. Careful attention to cytologic, architectural, immunophenotypic, and—perhaps most importantly—clinical features are often necessary to reach a correct diagnosis. Most lymphoid tumors of the liver are non-Hodgkin or Hodgkin lymphomas, although some lymphoid leukemias can secondarily involve the liver, and at least one benign lymphoid tumor of the liver has been described. Myeloid tumors of the liver almost invariably represent hepatic involvement by myeloid leukemias, although rare cases of hepatic myeloid sarcomas have been reported. N O N - H OD G K I N LY M P H OM A
Primary hepatic non-Hodgkin lymphoma (NHL) is rare. It is estimated that less than 0.02% of all NHLs arise in the liver (1). Given that some hepatic lymphomas involving the porta hepatis may represent secondary spread from hilar lymph nodes, true primary hepatic lymphomas would be rarer still. Secondary involvement of the liver by NHL occurs in 15% to 74% of cases, depending on the tumor type and the time point in the disease course (ie, presentation vs autopsy) (2–6). Lymphoid neoplasms that present exclusively as leukemias (ie, those other than chronic lymphocytic leukemia/small lymphocytic lymphoma [CLL/SLL] and lymphoblastic leukemia/ lymphoma) do not generally involve the liver, although hairy cell leukemia may infiltrate hepatic portal tracts and sinusoids (7) and can on rare occasion form discrete parenchymal nodules (8).
to this cell size rule is mantle cell lymphoma, which has a poor prognosis despite having a small cell morphology in most cases (12). Prognosis is also affected by stage at presentation and other factors included in the International Prognostic Index (IPI) and its various revisions (13–16). Small B-cell lymphomas occur mainly in older adults, whereas most highgrade lymphomas can occur at any age, with some forms more frequent in children (11). DLBCL is the most common primary hepatic B-cell lymphoma (1,9–11). Many cases of primary hepatic DLBCL occur in patients with chronic hepatitis C (9–10,17–20). Most present as one or more discrete hepatic nodules (10), although diffuse hepatic involvement has also been rarely described, with some of the latter presenting as acute liver failure associated with a poor clinical outcome (10,21). Histologically, the neoplastic cells in hepatic DLBCL typically form diffuse sheets that efface the hepatic architecture, although more subtle infiltration can occur in the form of portal or periportal cellular aggregates or sinusoidal permeation by tumor cells (4,5). Two reports of the rare intravascular variant of DLBCL arising in liver have also been described (22,23). Burkitt lymphoma is a high-grade B-cell lymphoma that in Western countries occurs mainly in children and young adults, as well as in patients infected with human immunodeficiency virus (24–26). Abdominal presentations are common, and the liver is involved in the majority of cases by a characteristic population of intermediate size lymphoid cells with distinct nucleoli and scant cytoplasm (4). Two histologic patterns of hepatic infiltration have been reported. In most cases, there is diffuse capsular or subcapsular infiltration, which may reflect direct extension from the peritoneum, whereas a minority of patients have widespread portal infiltrates of varying size (4). Primary hepatic Burkitt lymphoma limited to the liver has also been described (27–30). Burkitt lymphoma typically displays an immunophenotype typical of germinal center B-cells, with expression of CD10 and BCL-6 in addition to common B-cell markers (11,31) (Table 30.2).
B-cell lymphomas
Most primary hepatic NHLs are of B-cell type (Table 30.1) (1,9,10). Most B-cell lymphomas correspond to specific stages of normal B-cell development and have consistent morphologic features that predict clinical behavior (11). Most small B-cell lymphomas (including CLL/SLL, low-grade follicular lymphoma, and marginal zone lymphoma) are low grade and indolent, whereas B-cell lymphomas composed of large or intermediate size cells (including diffuse large B-cell lymphoma [DLBCL], Burkitt lymphoma, and lymphoblastic leukemia/ lymphoma) are high grade and aggressive (12). The exception
TA BL E 3 0 . 1 B-cell lymphomas that may involve the liver Diffuse large B-cell lymphomaa Extranodal marginal zone lymphoma of MALT type (MALT lymphoma)a Follicular lymphoma, low gradea Burkitt lymphomaa Chronic lymphocytic leukemia/small lymphocytic lymphoma B-lymphoblastic leukemia/lymphoma Lymphoplasmacytic lymphoma a Can present as primary hepatic lymphoma. Abbreviation: MALT, mucosa-associated lymphoid tissue.
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OF
THE
LIVER
TA B LE 30. 2 B-cell lymphoma immunophenotypes CD20
CD5
CD43
CD10
CD23
BCL-1
BCL-6
TdT
CLL/SLL
Mantle cell lymphoma
Follicular lymphoma (low grade)
/
/
Marginal zone lymphoma (MALT)
/
/
/
/
Burkitt lymphoma
/
Diffuse large B-cell lymphoma
/
/
/
B-lymphoblastic
Percent cases positive: 90–100%, /50–90% cases positive, /10–50% cases positive, 0–10% cases positive. From Refs. 11 and 31.
B-lymphoblastic leukemia/lymphoma most commonly presents as leukemias (ie, involving the bone marrow and peripheral blood) in children or young adults, but extramedullary spread is frequent, with the central nervous system, lymph nodes, spleen, and liver being the most commonly involved sites (32). In the involved liver, blast cells with finely dispersed chromatin and scant cytoplasm can be seen to infiltrate the hepatic sinusoids (33), which represents a common pattern for hepatic involvement by leukemias. In certain cases, however, there may be massive fulminant hepatic failure due to diffuse and extensive parenchymal infiltration (34,35). Most cases of B-cell lymphoblastic leukemia/lymphoma that present as lymphomas (ie, purely extramedullary disease, sparing the marrow and peripheral blood) have not been reported to involve the liver (36–37). In most cases, the neoplastic cells express terminal deoxynucleotidyl transferase (TdT), which distinguishes this entity from the mature B-cell lymphomas (Table 30.2). CLL/SLL usually presents in leukemic phase, with involvement of the bone marrow and peripheral blood. Even the rare cases of CLL/SLL that present in extramedullary sites generally develop leukemia over time (38). Lymph nodes, spleen, and liver are typically secondarily infiltrated by the characteristic mature small lymphocytes, which have very round nuclear contours. Histologically, these appear as prominent monotonous portal infiltrates, although sinusoidal permeation can also be seen (4). Immunophenotyping will reveal a predominant B-cell population that expresses CD5, CD43, and CD23 in addition to typical pan B-cell markers, which confirms the diagnosis (11,31) (Table 30.2). Despite its welldeserved reputation as an indolent lymphoid neoplasm, CLL/ SLL may on occasion result in fulminant acute hepatic failure due to extensive parenchymal infiltration (39). Primary hepatic involvement by CLL/SLL has not been reported. Follicular lymphoma can also involve the liver, which it tends to do as discrete nodules, which may be solitary or multiple (40), a pattern similar to DLBCL. The tumor cells may show distinct follicle formation (4) or diffuse sheets (40). If the tumor architecture is diffuse, the diagnosis of follicular lymphoma rests on the identification of the characteristic centrocytic cytology (small cleaved cells) and expression of standard
B-cell markers along with BCL-6 and usually CD10 (11,31) (Table 30.2); this immunophenotype corresponds to the germinal center stage of B-cell differentiation and is not seen in other small B-cell lymphomas. As a primary hepatic tumor, follicular lymphoma is quite rare, with only 9 cases having been reported to date, most of these being grade 1 tumors (40). Extranodal marginal zone lymphoma of mucosaassociated lymphoid tissue (MALT), also referred to as MALT lymphoma, has been well described in the liver. Although considerably less frequent than DLBCL, and quite rare overall (only 38 primary hepatic cases having been reported in the literature (41)), MALT lymphoma nonetheless ranks as the second most common primary hepatic B-cell lymphoma in at least 2 published series (9–10). As a group, MALT lymphomas are quite indolent (12), and many arise in settings of chronic infections (eg, H. pylori gastritis) or autoimmune disorders (eg, salivary glands involved by Sjögren syndrome) (42,43). Similarly, a number of cases of hepatic MALT lymphoma have been reported in patients with chronic hepatitis C (10,44,45), along with several reports in patients with other chronic inflammatory liver disorders, including hepatitis B (46–48) and primary biliary cirrhosis (49), suggesting chronic inflammation may create an environment conducive to the evolution of MALT lymphoma in the liver as well. Hepatic MALT lymphoma tends to present as discrete and often solitary parenchymal nodules, which are often discovered incidentally (10,41,48,50). Although composed mainly of small lymphocytes including some resembling centrocytes (so-called centrocyte-like cells), MALT lymphomas contain diverse cell types more commonly than do other small B-cell lymphomas, including monocytoid and plasmacytoid small lymphocytes, plasma cells, and large lymphoid cells (51). Published reports of hepatic MALT lymphomas describe dense portal infiltrates composed primarily of small lymphocytes that show marked extension into periportal regions, occasionally infiltrating the epithelium of interlobular bile ducts to form lymphoepithelial lesions (41,44,46). Scattered reactive lymphoid follicles are often present, likely representing preexistent chronic inflammation, and may become infiltrated (or “colonized”) by the neoplastic cells (41,48).
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MALT lymphomas usually display what has been described as the “B-cell, NOS” phenotype, with no expression of antigens other than typical pan-B-cell markers, although a minority of cases will express CD43 and CD23 (41,46,48) (Table 30.2). The lack of expression of antigens typically seen in CLL/SLL (CD5, CD23), follicular lymphoma (CD10, BCL-6), and mantle cell lymphoma (CD5, BCL-1) can nonetheless be used to exclude these other entities and thus support the diagnosis of MALT lymphoma. Cases of MALT lymphoma showing extensive plasmacytoid differentiation can be difficult to distinguish from lymphoplasmacytic lymphoma (LPL), which can also involve the liver (52). Many patients with LPL have clinical features of Waldenström macrogloblinemia, including high levels of serum IgM paraprotein and consequent hyperviscosity, autoimmune phenomena, and cryoglobulinemia, which can be helpful in distinguishing LPL from MALT lymphoma. Plasmacytoid MALT lymphoma can also be mimicked morphologically and immunophenotypically by polymorphic post-transplant lymphoproliferative disorders (PTLDs), but the latter are distinguished by a clinical history of transplantation and frequent Epstein-Barr virus (EBV) positivity (see Chapter 30.4). T-cell lymphomas
T-cell lymphomas are much less common than B-cell lymphomas, and with the exception of anaplastic large cell lymphoma, most behave as aggressive, high-grade malignancies regardless of pathologic subtype. Cases of primary hepatic T-cell lymphoma (in which only the liver is involved at presentation) are quite rare, with a recent review finding only 14 such cases reported in the literature (53); nearly all such cases fall into the generic category of peripheral T-cell lymphoma, NOS (Table 30.3), and follow an aggressive clinical course (10,53). Most such patients are middle-aged men, who often present with systemic symptoms, and one to several discrete hepatic nodules, although, as with B-cell lymphomas, cases of diffuse hepatic involvement have been reported (10,53). Histologically, the malignant lymphoid infiltrates may be portal, periportal, or sinusoidal in location, with diffuse sheets of lymphoid cells completely obliterating the hepatic architecture in rare cases (53). As is typical of peripheral T-cell lymphoma, NOS, the cytological appearance of the infiltrate varies as well, from cases composed predominantly of small lymphoid cells,
TA B LE 30. 3 T-cell lymphomas that may involve the liver Peripheral T-cell lymphoma, NOSa Anaplastic large cell lymphomaa Hepatosplenic T-cell lymphoma Angioimmunoblastic T-cell lymphoma T-lymphoblastic leukemia/lymphoma Adult T-cell leukemia/lymphoma Systemic EBV-positive T-cell lymphoproliferative disease of childhood a
Can present as primary hepatic lymphoma
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OF
THE
LIVER
471
to others with a mixture of small to intermediate and occasional large cells, and finally to cases in which the neoplastic cells are virtually all cytologically malignant large cells (53). It is important to confirm the T-cell nature of the infiltrate by identification of T-cell markers, although the precise inmmunophenotype of the neoplastic cells can be quite variable, reflecting the heterogeneous nature of the peripheral T-cell lymphoma, NOS category. Cases where the T-cell infiltrate is cytologically bland may mimic hepatitis or other forms of chronic inflammation. In addition, granulomas can be present in T-cell lymphomas, leading to confusion with granulomatous hepatitis. In such cases, gene rearrangement studies documenting the presence of a clonal T-cell population can be helpful in confirming the diagnosis of lymphoma (53). Such molecular studies can yield false-negative and false-positive results however (54), and thus must be interpreted in the context of the clinical, pathologic, and immunophenotypic findings. Hepatosplenic T-cell lymphoma is another rare but distinctive form of peripheral T-cell lymphoma that involves the liver. It is characterized by small to medium-sized lymphoid cells that typically infiltrate the hepatic sinusoids as well as the sinuses of the splenic red pulp and bone marrow (55,56). Only about 100 cases have been reported in the literature (55). Most commonly, there is little to no infiltration of portal tracts, but in rare cases the infiltrate can be predominantly or exclusively portal (56,57). The disease usually strikes young patients, who present with hepatosplenomegaly, cytopenias, and systemic B symptoms (55,56,58). It has a poor prognosis, with a median survival of 11 to 16 months (55,56). A number of cases have been reported in patients treated with infliximab for Crohn disease (55). The initial reported cases all expressed the T-cell receptor, but more recently it has become evident that some cases with identical clinical, histologic, and cytogenetic features can display the more common T-cell receptor (56,59,60). The sinusoidal T-cells may be numerous, atypical, and cause sinusoidal dilation, but in some instances the infiltrate can be extremely sparse and the neoplastic cells cytologically bland (55,56,58,61). For this reason, a high index of suspicion for hepatosplenic T-cell lymphoma must be maintained, particularly in young patients who present with acute hepatic dysfunction but show no evidence of viral, toxic, autoimmune, or metabolic liver disease. Immunohistochemistry can be helpful in diagnosis because many cases show loss of CD5 expression and are double-negative for CD4 and CD8 (55–58). Detection of the and receptors is not generally possible by paraffin section immunohistochemistry, requiring either frozen tissue for staining or fresh tissue for flow cytometry (56). T-cell gene rearrangement studies to confirm clonality can also be helpful in diagnosis, although false-negative results can occur (54,55,57). Other lymphomas of T-cell or NK/T-cell origin can involve the liver on rare occasion, either primarily or—more commonly—as secondary hepatic involvement in systemic disease. These include NK/T-cell lymphoma (62), anaplastic large cell lymphoma (63–66), angioimmunoblastic T-cell lymphoma (67), T-lymphoblastic leukemia/lymphoma (68), adult T-cell leukemia/lymphoma (69), and systemic EBVpositive T-cell lymphoproliferative disease of childhood (70).
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These show morphologic and immunophenotypic features similar to those described in extrahepatic sites. Hodgkin Lymphoma
Classical Hodgkin lymphoma (CHL) typically presents in lymph nodes but can also involve the liver at presentation in 2% to 3% of cases (71). Hepatic involvement is uncommon unless the spleen is also involved (71–72), but very rare cases of CHL presenting as isolated liver lesions have been reported (73). Hepatic involvement usually takes the form of discrete nodules of varying size that—like CHL in other sites—are composed mainly of benign inflammatory cells such as small lymphocytes (mainly T-cells), eosinophils, and histiocytes (including occasional granulomas), but include variable numbers of atypical multinucleated Reed-Sternberg cells and mononuclear variants known as Hodgkin cells (3). These nodules often involve or surround portal tracts (3–5). The Hodgkin and Reed-Sternberg cells (collectively known as HRS cells) have a distinctive immunophenotype, showing membrane staining for CD30 in essentially all cases and CD15 in most cases, with both of these markers often positive in the perinuclear Golgi region as well (31) (Table 30.4). There is usually weak to absent expression of other B-cell or T-cell markers, although recent studies have shown at least weak nuclear expression of the B-cell markers Pax-5 and Oct-2 in be helpful in establishing the diagnosis (Table 30.4). Rare cases of extensive hepatic involvement by CHL presenting as acute liver failure have been described (78). Nodular lymphocyte predominant lymphoma (NLPHL) is the only nonclassical type of Hodgkin lymphoma. It typically presents at a lower stage than CHL, and extranodal spread is uncommon, but rare cases of secondary hepatic involvement have been reported, including 1 case presenting as fulminant hepatic failure due to extensive hepatic infiltration (79). More typically, hepatic involvement by NLPHL takes the form of focal microscopic portal or parenchymal infiltration by mature small B-cells containing variable numbers of the characteristic neoplastic LP cells, which, though multinucleated, are less atypical cytologically than HRS cells of CHL (80,81). Unlike the neoplastic cells of CHL, LP cells of NLPHL typically have a mature B-cell phenotype, strongly expressing CD20, and are negative for CD30 and CD15 in nearly all cases (82,83) (Table 30.4). In addition to the background small lymphocytes
TUMORS
OF
THE
LIVER
(which are predominantly B-cells, at least in nodular areas), histiocytes, and small nonnecrotizing granulomas are frequently present. In some patients with Hodgkin lymphoma, small foci of benign inflammatory cells or granulomas can be found in extranodal sites such as spleen and liver in the absence of HRS or LP cells. Such foci may represent reactions to systemic cytokines and should not be taken to indicate involvement by Hodgkin lymphoma in the absence of identifiable neoplastic cells (3,4). Identification of such foci should, however, trigger a diligent search for HRS or LP cells, including deeper level sections and immunohistochemistry. Post-transplant Lymphoproliferative Disorders
Transplant patients may develop pathologic proliferations of lymphoid cells known as post-tranplant lymphoproliferative disorders (PTLDs), which are well described in the liver (84). In liver transplant patients, PTLDs frequently involve the graft itself (85). PTLDs range from so-called early lesions that resemble reactive lymphoid hyperplasia to polymorphic and monomorphic forms that efface normal architecture and resemble malignant lymphomas (84,86). Many of these are EBV-driven B-cell proliferations that appear to arise when immunosuppressed patients become infected by EBV. Polymorphic PTLDs, as the name implies, consist of a mixed cell population including mature small lymphocytes, plasmacytoid small lymphocytes, plasma cells, and large lymphoid cells, most of which are of B-cell lineage (86,87). Polymorphic PTLDs can resemble plasmacytoid marginal zone lymphomas or LPLs morphologically and immunophenotypically. Despite their worrisome appearance, many of these are polyclonal, and they may regress either spontaneously or following reduction of immunosuppression (86,87). Monomorphic PTLDs consist of monomorphic sheets of lymphoid cells that resemble a high-grade NHL, most commonly DLBCL. Although most of these proliferations are monoclonal and behave as aggressive lymphomas, some may be polyclonal and/or regress with reduction of immunosuppression (86,87). Benign Lymphoid Tumors (Nodular Lymphoid Lesions)
Many lymphoid tumors formerly termed pseudolymphomas have been reclassified as MALT lymphomas in recent years, as it has become recognized that MALT lymphomas may
TA B LE 30. 4 Immunophenotype of neoplastic cells in Hodgkin lymphoma
Classical Hodgkin lymphoma Nodular LP Hodgkin lymphoma a
CD30
CD15
CD20
CD3
Pax-5
Oct-2
/
/a
b
/
c
c
c
Staining if present is focal and often weak. Focal weak staining present in many cases. c Staining diffuse and strong. Percent cases positive: 90%–100%, / 50%–90% cases positive, / 10%–50% cases positive, 0%–10% cases positive. From Refs. 31, 74–77, 82–83. b
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contain prominent benign follicles with reactive germinal centers (51). However, in some cases, lesions resembling MALT lymphomas morphologically have been found to consist entirely of nonneoplastic B-cells and T-cells, and thus represent true benign lymphoid tumors (or pseudotumors, depending on one’s nosologic preferences). In the liver, these lesions are termed nodular lymphoid lesions (NLLs) or, less often, reactive lymphoid hyperplasia of the liver (88). Like MALT lymphomas, NLLs present as discrete nodules in the liver, where they displace and even appear to infiltrate the surrounding hepatic parenchyma. Unlike MALT lymphomas, however, NLLs contain polyclonal B-cell and T-cell populations, and lack sheet-like growth of B-cells outside of benign reactive follicles. Many patients with hepatic NLLs have underlying chronic inflammatory conditions, such as hepatitis or autoimmune disorders, suggesting these represent foci of exuberant chronic inflammation (88). Myeloid Tumors Acute myeloid leukemia
In patients with acute myeloid leukemia, the neoplastic cells can infiltrate the hepatic sinusoids and portal tracts, and even among and between individual hepatocytes (5). Necrosis of parenchymal hepatocytes may be seen in extreme cases. If the infiltrate forms a discrete mass that effaces the hepatic architecture, it is designated a myeloid sarcoma (see below). Identification of cells with the morphology of myeloid blasts, combined with either cytochemical or immunohistochemical staining for myeloid markers, establishes the diagnosis (89). Chronic myeloproliferative disorders (myeloproliferative neoplasms)
Chronic myelogenous leukemia typically involves the liver in the form of distension of hepatic sinusoids by neoplastic cells, although in some cases there may be variably sized infiltrates in the portal tracts as well (5). Given that the majority of patients with chronic myelogenous leukemia have hepatomegaly at presentation, the prevalence of hepatic involvement is likely quite high, although few such cases come to liver biopsy. The incidence and histopathologic appearance of hepatic involvement by other chronic myeloproliferative disorders (which are termed “myeloproliferative neoplasms” in the 2008 WHO Classification), such as polycythemia vera, primary myelofibrosis, and essential thrombocythemia, have not been well described. Myeloid sarcoma (extramedullary myeloid tumor)
As defined in the 2008 WHO Classification, myeloid sarcoma is a tumor composed of myeloid blasts, with or without more mature myeloid elements, that occurs in an anatomic site other than the bone marrow (89). If a myeloid sarcoma arises in a patient with no prior history of leukemia, it is considered equivalent to a diagnosis of acute myeloid leukemia, even
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if the marrow and peripheral blood are not involved (89). If the patient has known myeloid leukemia, the tumor must efface the tissue architecture of the extramedullary site to warrant designation as myeloid sarcoma (89). Cases of myeloid sarcoma involving the liver, though uncommon, are well described and occasionally form obstructive masses resulting in clinical jaundice (90–92). This presentation is often related to a mass lesion in the region of the biliary tree (93,94). As in cases of AML, the neoplastic cells need to be confirmed as myeloid blasts by morphology and phenotyping to establish the diagnosis.
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17. Kaneko F, Yokomori H, Sato A, et al. A case of primary hepatic nonHodgkin’s lymphoma with chronic hepatitis C. Med Mol Morphol. 2008;41:171–174. 18. Kim JH, Kim HY, Kang I, et al. A case of primary hepatic lymphoma with hepatitis C liver cirrhosis. Am J Gastroenterol. 2000;95:2377–2380. 19. Kitabayashi K, Hasegawa T, Ueno K, et al. Primary hepatic nonHodgkin’s lymphoma in a patient with chronic hepatitis C: report of a case. Surg Today. 2004;34:366–369. 20. Mohler M, Gutzler F, Kallinowski B, Goeser T, Stremmel W. Primary hepatic high-grade non-Hodgkin’s lymphoma and chronic hepatitis C infection. Dig Dis Sci. 1997;42:2241–2245. 21. Emile JF, Azoulay D, Gornet JM, et al. Primary non-Hodgkin’s lymphomas of the liver with nodular and diffuse infiltration patterns have different prognoses. Ann Oncol. 2001;12:1005–1010. 22. Roshal M, Till BG, Fromm JR, Cherian S. Intravascular large B cell lymphoma presenting in a liver explant. J Clin Pathol. 2008;61:877–878. 23. Shiraki K, Sugimoto K, Deguchi M, Ito N, Masuda C, Takei Y. Hepatic intravascular large B cell lymphoma. Intern Med. 2007;46:1761–1762. 24. Aldoss IT, Weisenburger DD, Fu K, et al. Adult Burkitt lymphoma: advances in diagnosis and treatment. Oncology (Williston Park). 2008;22:1508–1517. 25. Perkins AS, Friedberg JW. Burkitt lymphoma in adults. Hematology Am Soc Hematol Educ Program. 2008:341–348. 26. Yustein JT, Dang CV. Biology and treatment of Burkitt’s lymphoma. Curr Opin Hematol. 2007;14:375–381. 27. Lee SH, Kim HJ, Mun JS, et al. A case of primary hepatic Burkitt’s lymphoma. Korean J Gastroenterol. 2008;51:259–264. 28. Mantadakis E, Raissaki M, Tzardi M, et al. Primary hepatic Burkitt lymphoma. Pediatr Hematol Oncol. 2008;25:331–338. 29. Jacobs SL, Rozenblit A. HIV-associated hypervascular primary Burkitt’s lymphoma of the liver. Clin Radiol. 2006;61:453–455. 30. Huang CB, Eng HL, Chuang JH, Cheng YF, Chen WJ. Primary Burkitt’s lymphoma of the liver: report of a case with long-term survival after surgical resection and combination chemotherapy. J Pediatr Hematol Oncol. 1997;19:135–138. 31. Higgins RA, Blankenship JE, Kinney MC. Application of immunohistochemistry in the diagnosis of non-Hodgkin and Hodgkin lymphoma. Arch Pathol Lab Med. 2008;132:441–461. 32. Borowitz MJ, Chan JKC. B lymphoblastic leukaemia/lymphoma, not otherwise specified. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:168–170. 33. Takamatsu T. Preferential infiltration of liver sinusoids in acute lymphoblastic leukemia. Rinsho Ketsueki. 2001;42:1181–1186. 34. Litten JB, Rodriguez MM, Maniaci V. Acute lymphoblastic leukemia presenting in fulminant hepatic failure. Pediatr Blood Cancer. 2006;47: 842–845. 35. Devictor D, Tahiri C, Fabre M, Mielot F, Dussaix E. Early pre-B acute lymphoblastic leukemia presenting as fulminant liver failure. J Pediatr Gastroenterol Nutr. 1996;22:103–106. 36. Lin P, Jones D, Dorfman DM, Medeiros LJ. Precursor B-cell lymphoblastic lymphoma: a predominantly extranodal tumor with low propensity for leukemic involvement. Am J Surg Pathol. 2000;24:1480–1490. 37. Maitra A, McKenna RW, Weinberg AG, Schneider NR, Kroft SH. Precursor B-cell lymphoblastic lymphoma. A study of nine cases lacking blood and bone marrow involvement and review of the literature. Am J Clin Pathol. 2001;115:868–875. 38. Muller-Hermelink HK, Montserrat E, Catovsky D, et al. Chronic lymphocytic leukemia/small lymphocytic lymphoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008: 180–182. 39. Hasuike S, Hayashi K, Abe H, et al. Acute hepatic failure due to hepatic involvement by chronic lymphocytic leukemic cells in a patient with chronic hepatitis B. J Gastroenterol. 2004;39:499–500.
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40. Gomyo H, Kagami Y, Kato H, et al. Primary hepatic follicular lymphoma: a case report and discussion of chemotherapy and favorable outcomes. J Clin Exp Hematop. 2007;47:73–77. 41. Koubaa Mahjoub W, Chaumette-Planckaert MT, Murga Penas EM, et al. Primary hepatic lymphoma of mucosa-associated lymphoid tissue type: a case report with cytogenetic study. Int J Surg Pathol. 2008;16: 301–307. 42. Du MQ. MALT lymphoma: recent advances in aetiology and molecular genetics. J Clin Exp Hematop. 2007;47:31–42. 43. Isaacson PG. Mucosa-associated lymphoid tissue lymphoma. Semin Hematol. 1999;36:139–147. 44. Mizuno S, Isaji S, Tabata M, et al. Hepatic mucosa-associated lymphoid tissue (MALT) lymphoma associated with hepatitis C. J Hepatol. 2002;37:872–873. 45. Orrego M, Guo L, Reeder C, et al. Hepatic B-cell non-Hodgkin’s lymphoma of MALT type in the liver explant of a patient with chronic hepatitis C infection. Liver Transpl. 2005;11:796–799. 46. Nart D, Ertan Y, Yilmaz F, Yüce G, Zeytunlu M, Kilic M. Primary hepatic marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type in a liver transplant patient with hepatitis B cirrhosis. Transplant Proc. 2005;37:4408–4412. 47. Takeshima F, Kunisaki M, Aritomi T, et al. Hepatic mucosa-associated lymphoid tissue lymphoma and hepatocellular carcinoma in a patient with hepatitis B virus infection. J Clin Gastroenterol. 2004;38:823–826. 48. Gockel HR, Heidemann J, Lugering A, et al. Stable remission after administration of rituximab in a patient with primary hepatic marginal zone B-cell lymphoma. Eur J Haematol. 2005;74:445–447. 49. Ye MQ, Suriawinata A, Black C, Min AD, Strauchen J, Thung SN. Primary hepatic marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type in a patient with primary biliary cirrhosis. Arch Pathol Lab Med. 2000;124:604–608. 50. Doi H, Horiike N, Hiraoka A, et al. Primary hepatic marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type: case report and review of the literature. Int J Hematol. 2008;88:418–423. 51. Isaacson PG, Norton AJ. Extranodal Lymphomas. St. Louis, MO: Churchill Livingstone;1994. 52. Swerdlow SH, Berger F, Pileri SA, et al. Lymphoplasmacytic lymphoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:194–195. 53. Stancu M, Jones D, Vega F, Medeiros LJ. Peripheral T-cell lymphoma arising in the liver. Am J Clin Pathol. 2002;118:574–581. 54. Hodges E, Williams AP, Harris S, Smith JL. T-cell receptor molecular diagnosis of T-cell lymphoma. Methods Mol Med. 2005;115:197–215. 55. Falchook GS, Vega F, Dang NH, et al. Hepatosplenic gamma-delta T-cell lymphoma: clinicopathological features and treatment. Ann Oncol. 2009;20:1080–1085. 56. Belhadj K, Reyes F, Farcet JP, et al. Hepatosplenic gammadelta T-cell lymphoma is a rare clinicopathologic entity with poor outcome: report on a series of 21 patients. Blood. 2003;102:4261–4269. 57. Wei SZ, Liu TH, Wang DT, et al. Hepatosplenic gammadelta T-cell lymphoma. World J Gastroenterol. 2005;11:3729–3734. 58. Vega F, Medeiros LJ, Bueso-Ramos C, et al. Hepatosplenic gamma/delta T-cell lymphoma in bone marrow. A sinusoidal neoplasm with blastic cytologic features. Am J Clin Pathol. 2001;116:410–419. 59. Macon WR, Levy NB, Kurtin PJ, et al. Hepatosplenic alphabeta T-cell lymphomas: a report of 14 cases and comparison with hepatosplenic gammadelta T-cell lymphomas. Am J Surg Pathol. 2001;25:285–296. 60. Suarez F, Wlodarska I, Rigal-Huguet F, et al. Hepatosplenic alphabeta T-cell lymphoma: an unusual case with clinical, histologic, and cytogenetic features of gammadelta hepatosplenic T-cell lymphoma. Am J Surg Pathol. 2000;24:1027–1032. 61. Veldt BJ, Meijers C, Zondervan PE, de Man RA. Hepatosplenic gammadelta T cell lymphoma: a diagnostic pitfall. J Hepatol. 2003;39: 455–457.
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62. Chang SE, Lee SY, Choi JH, Sung KJ, Moon KC, Koh JK. Cutaneous dissemination of nasal NK/T-cell lymphoma with bone marrow, liver and lung involvement. Clin Exp Dermatol. 2002;27:120–122. 63. Cai G, Inghirami G, Moreira A, Sen F. Primary hepatic anaplastic large-cell lymphoma diagnosed by fine-needle aspiration biopsy. Diagn Cytopathol. 2005;33:106–109. 64. Harada Y, Yamada S, Murakami S, et al. Ki-1 lymphoma with nodular involvement in liver and spleen: possible role of cytokines in systemic manifestation of fever and leukocytosis. Dig Dis Sci. 2000;45:2240–2246. 65. Andres E, Perrin AE, Maloisel F, Marcellin L, Goichot B. Primary hepatic anaplastic large cell Ki-1 non-Hodgkin’s lymphoma and hereditary hemochromatosis: a fortuitous association? Clin Lab Haematol. 2003;25:185–186. 66. Baschinsky DY, Weidner N, Baker PB, Frankel WL. Primary hepatic anaplastic large-cell lymphoma of T-cell phenotype in acquired immunodeficiency syndrome: a report of an autopsy case and review of the literature. Am J Gastroenterol. 2001;96:227–232. 67. Dogan A, Attygalle AD, Kyriakou C. Angioimmunoblastic T-cell lymphoma. Br J Haematol. 2003;121:681–691. 68. Felice MS, Hammermuller E, De Davila MT, et al. Acute lymphoblastic leukemia presenting as acute hepatic failure in childhood. Leuk Lymphoma. 2000;38:633–637. 69. Bunn PA Jr, Schechter GP, Jaffe E, et al. Clinical course of retrovirusassociated adult T-cell lymphoma in the United States. N Engl J Med. 1983;309:257–264. 70. Quintanilla-Martinez L, Kumar S, Fend F, et al. Fulminant EBV() T-cell lymphoproliferative disorder following acute/chronic EBV infection: a distinct clinicopathologic syndrome. Blood. 2000;96:443–451. 71. Colby TV, Hoppe RT, Warnke RA. Hodgkin’s disease: a clinicopathologic study of 659 cases. Cancer. 1982;49:1848–1858. 72. Gordon CD, Sidawy MK, Talarico L, Kondi E. Hodgkin’s disease in the liver without splenic involvement. Arch Intern Med. 1984;144: 2277–2278. 73. Yokomori H, Kaneko F, Sato A, et al. Primary hepatic presentation of Hodgkin’s lymphoma: a case report. Hepatol Res. 2008;38:1054–1057. 74. Browne P, Petrosyan K, Hernandez A, Chan JA. The B-cell transcription factors BSAP, Oct-2, and BOB.1 and the pan-B-cell markers CD20, CD22, and CD79a are useful in the differential diagnosis of classic Hodgkin lymphoma. Am J Clin Pathol. 2003;120:767–777. 75. Garcia-Cosio M, Santon A, Martin P, et al. Analysis of transcription factor OCT.1, OCT.2 and BOB.1 expression using tissue arrays in classical Hodgkin’s lymphoma. Mod Pathol. 2004;17:1531–1538. 76. Rudiger T, Ott G, Ott MM, Müller-Deubert SM, Müller-Hermelink HK. Differential diagnosis between classic Hodgkin’s lymphoma, T-cell-rich B-cell lymphoma, and paragranuloma by paraffin immunohistochemistry. Am J Surg Pathol. 1998;22:1184–1191. 77. Zukerberg LR, Collins AB, Ferry JA, et al. Coexpression of CD15 and CD20 by Reed-Sternberg cells in Hodgkin’s disease. Am J Pathol. 1991;139:475–483. 78. Vardareli E, Dundar E, Aslan V, Gülba Z. Acute liver failure due to Hodgkin’s lymphoma. Med Princ Pract. 2004;13:372–374. 79. Woolf KM, Wei MC, Link MP, Arber DA, Warnke RA. Nodular lymphocyte-predominant Hodgkin lymphoma presenting as fulminant
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hepatic failure in a pediatric patient: a case report with pathologic, immunophenotypic, and molecular findings. Appl Immunohistochem Mol Morphol. 2008;16:196–201. Chang KL, Kamel OW, Arber DA, et al. Pathologic features of nodular lymphocyte predominance Hodgkin’s disease in extranodal sites. Am J Surg Pathol. 1995;19:1313–1324. Siebert JD, Stuckey JH, Kurtin PJ, et al. Extranodal lymphocyte predominance Hodgkin’s disease. Clinical and pathologic features. Am J Clin Pathol. 1995;103:485–491. Anagnostopoulos I, Hansmann ML, Franssila K, et al. European Task Force on Lymphoma project on lymphocyte predominance Hodgkin disease: histologic and immunohistologic analysis of submitted cases reveals 2 types of Hodgkin disease with a nodular growth pattern and abundant lymphocytes. Blood. 2000;96:1889–1899. Poppema S, Delsol G, Pileri SA, et al. Nodular lymphocyte predominant Hodgkin lymphoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:323–325. Jain A, Nalesnik M, Reyes J, et al. Posttransplant lymphoproliferative disorders in liver transplantation: a 20-year experience. Ann Surg. 2002;236:429–436 (discussion 36–37). Aseni P, Vertemati M, De Carlis L, et al. De novo cancers and posttransplant lymphoproliferative disorder in adult liver transplantation. Pathol Int. 2006;56:712–715. Harris NL, Ferry JA, Swerdlow SH. Posttransplant lymphoproliferative disorders: summary of Society for Hematopathology Workshop. Semin Diagn Pathol. 1997;14:8–14. Swerdlow SH, Webber SA, Chadburn A, et al. Post-transplant lymphoproliferative disorders. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:343–348. Willenbrock K, Kriener S, Oeschger S, Hansmann ML. Nodular lymphoid lesion of the liver with simultaneous focal nodular hyperplasia and hemangioma: discrimination from primary hepatic MALT-type nonHodgkin’s lymphoma. Virchows Arch. 2006;448:223–227. Pileri SA, Orazi A, Falini B. Myeloid sarcoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer: Lyon. 2008:140–141. Lee JY, Lee WS, Jung MK, et al. Acute myeloid leukemia presenting as obstructive jaundice caused by granulocytic sarcoma. Gut Liver. 2007;1:182–185. Mano Y, Yokoyama K, Chen CK, Tsukada Y, Ikeda Y, Okamoto S. [Acute myeloid leukemia presenting with obstructive jaundice and granulocytic sarcoma of the common bile duct]. Rinsho Ketsueki. 2004;45:1039–1043. Matsueda K, Yamamoto H, Doi I. An autopsy case of granulocytic sarcoma of the porta hepatis causing obstructive jaundice. J Gastroenterol. 1998;33:428–433. Ascani S, Piccaluga PP, Pileri SA. Granulocytic sarcoma of main biliary ducts. Br J Haematol. 2003;121:534. Piccaluga PP, Ascani S, Agostinelli C, et al. Myeloid sarcoma of liver: an unusual cause of jaundice. Report of three cases and review of literature. Histopathology. 2007;50:802–805.
Case 30.1
Dense Small B-Cell Infiltrate With Reactive Follicles PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N I C AL I N F OR M AT I ON
A 68-year-old woman with chronic hepatitis B had been undergoing hepatic ultrasound for surveillance. The most recent scan revealed multiple nodules in the left lobe of the liver, up to 6 cm, which were confirmed by computed tomography (CT) scan and thought to represent hepatocellular carcinoma. Serum alpha-fetoprotein (AFP) level was normal. A left partial hepatectomy was performed.
(Figure 30.1.5). There are rare scattered histiocytes and large lymphoid cells, but the large cells do not form significant clusters or sheets. The mitotic rate is very low, with only rare mitotic figures outside of germinal centers. Immunoperoxidase stains reveal the vast majority of the lymphoid cells to be positive for the B-cell marker CD20 (Figure 30.1.6); this is true not only in the follicles with reactive germinal centers but also in the expanded interfollicular
R E A S ON F OR R E F E R R A L
Dense small B-cell infiltrate with reactive follicles, rule out small B-cell lymphoma. PAT H OL OG I C F E AT U R E S
The gross specimen contained 3 discrete tan-pink fleshy nodules ranging from 0.8 to 5.2 cm. Microscopically, all 3 masses consist of dense infiltrates of lymphoid tissue (Figure 30.1.1). At both low power (Figure 30.1.1) and intermediate power (Figure 30.1.2), reactive germinal centers are easily identified, but there is also a dense and extensive lymphoid infiltrate in the interfollicular areas. At high power magnification, the cells in the interfollicular areas are mainly mature small lymphocytes with a few having irregular nuclear contours consistent with centrocytes (Figure 30.1.3). In some areas, the small cells have a distinct monocytoid appearance (Figure 30.1.4). Focally, these cells infiltrate bile duct epithelium, forming lymphoepithelial lesions
FIGURE 30. 1. 1 Dense lymphoid infiltrate in liver, with reactive ger-
minal center (center right) (H&E, 100).
F I G U R E 3 0 . 1 . 2 A reactive germinal center is present (left), but
there is also a dense diffuse small lymphoid infiltrate outside of the follicle (right) (H&E, 200).
F I G U R E 3 0 . 1 . 3 The extrafollicular lymphoid infiltrate consists mainly of small round lymphocytes, but some small cleaved cells (centrocytes) are also present (H&E, 1000).
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FIGURE 30. 1. 4 Focally, the small lymphocytes have a monocytoid
appearance, with abundant pale cytoplasm surrounding the small nuclei with mature chromatin (H&E, 1000).
FIGURE 30. 1. 5 Monocytoid small lymphocytes infiltrate the epithelium of interlobular bile ducts, forming lymphoepithelial lesions (H&E, 1000).
areas (Figures 30.1.6 and 30.1.7). Stains for the T-cell markers CD3, CD5, and CD43 highlight an admixed minority population of mature small lymphocytes consistent with reactive T-cells, with no apparent co-expression of CD5 or CD43 by the interfollicular B-cell population (Figure 30.1.8). Similarly, the interfollicular B-cells are negative for CD10, CD23, BCL-1 (cyclin D1), and BCL-6, although, as expected, the cells in the reactive germinal center express CD10 and BCL-6.
D I AG N OS I S
Extranodal marginal zone lymphoma of mucosaassociated lymphoid tissue (MALT lymphoma).
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F I G U R E 3 0 . 1 . 6 A stain for CD20 highlights not only reactive germinal centers, but also the dense interfollicular lymphoid infiltrate (CD20, 200).
F I G U R E 3 0 . 1 . 7 Strong staining for CD20 in the dense interfollicular infiltrate of small lymphocytes (CD20, 100).
DISCUSSIO N
Although the presence of lymphoid follicles with reactive germinal centers raises the possibility of reactive follicular hyperplasia, it must be kept in mind that reactive follicles are often seen in MALT lymphoma, which, as discussed above, may arise in settings of chronic inflammation including viral hepatitis. The key feature that distinguishes this case from chronic inflammation is the presence of extensive diffuse sheets of small B-cells in the interfollicular areas, where small T-cells would predominate in a reactive process. In true reactive lymphoid hyperplasia of the liver, densely aggregated B-cells are largely restricted to relative widely scattered follicles, and though interfollicular B-cells can be variable in number, they will not form diffuse sheets, and are greatly outnumbered by T-cells. This reactive pattern of B-cell hyperplasia is demonstrated in Figure 30.1.9, which shows a CD20 stain from a case of benign
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FIGURE 30. 1. 8 A stain for CD5 highlights only admixed reactive
T-cells and is negative in the B-cells (CD5, 1000).
FIGURE 30. 1. 9 Benign nodular lymphoid lesion of the liver;
there are scattered B-cells between follicles, but not the diffuse sheets of interfollicular small seen in MALT lymphoma (CD20, 100).
nodular lymphoid lesion of the liver. Hepatic nodular lymphoid lesions are a distinct form of hepatic reactive lymphoid hyperplasia that produces a discrete mass, which can closely mimic MALT lymphoma histologically (Figure 30.1.10), making CD20 staining imperative (1). Nodular lymphoid lesions of the liver are at their essence inflammatory pseudotumors; in addition to lacking diffuse sheets of extrafollicular B-cells, they will also lack evidence of B-cell clonality by flow cytometry and gene rearrangement studies. Reactive B-cell follicles with germinal centers can also be seen in portal areas in chronic hepatitis, particularly in cases due to hepatitis C (2), but as single scattered follicles with reactive germinal centers, they are rarely confused with malignant lymphoma.
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F I G U R E 3 0 . 1 . 1 0 Benign nodular lymphoid lesion, low power; the mass of reactive lymphoid tissue forms a discrete mass (H&E, 20).
Although highly characteristic, and seen in many cases, neither lymphoepithelial lesions nor persistent reactive follicles are specific for MALT lymphoma; in addition, neither of these morphologic features is seen in all cases. Thus, even though MALT lymphoma typically shows no expression of antigens other than usual pan-B-cell markers (with the exception of CD43 in a minority of cases; see Table 30.2), it is important to perform immunophenotyping beyond CD20 staining to confirm the characteristic “B-cell, NOS” phenotype and thus exclude other less common small B-cell lymphomas that can involve the liver. MALT lymphoma showing extensive plasmacytoid differentiation (i.e., numerous admixed plasmacytoid lymphocytes and plasma cells) can be very difficult to distinguish from LPL (3), which can also involve the liver (4,5), sometimes in association with hepatitis C (5). Many patients with LPL have systemic disease and clinical features of Waldenström macrogloblinemia, including high levels of serum IgM paraprotein and consequent hyperviscosity, autoimmune phenomena, and cryoglobulinemia, which can be helpful in distinguishing LPL from MALT lymphoma (5). Plasmacytoid MALT lymphoma can also be mimicked morphologically and immunophenotypically by a polymorphic post-transplant PTLD, but the latter is distinguished by a clinical history of transplantation and frequent EBV positivity (6).
References 1. Willenbrock K, Kriener S, Oeschger S, Hansmann ML. Nodular lymphoid lesion of the liver with simultaneous focal nodular hyperplasia and hemangioma: discrimination from primary hepatic MALT-type nonHodgkin’s lymphoma. Virchows Arch. 2006;448:223–227. 2. Lamps LW, Washington K. Acute and chronic hepatitis. In: Odze RD, Goldblum JR, Crawford JM, eds. Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas. Philadelphia, PA: Saunders; 2004:783–810.
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3. Swerdlow SH, Berger F, Pileri SA, et al. Lymphoplasmacytic lymphoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer;2008: 194–195. 4. Doi H, Horiike N, Hiraoka A, et al. Primary hepatic marginal zone B cell lymphoma of mucosa-associated lymphoid tissue type: case report and review of the literature. Int J Hematol. 2008;88:418–423.
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5. Vitolo U, Ferreri AJ, Montoto S. Lymphoplasmacytic lymphomaWaldenstrom’s macroglobulinemia. Crit Rev Oncol Hematol. 2008;67:172–185. 6. Harris NL, Ferry JA, Swerdlow SH. Posttransplant lymphoproliferative disorders: summary of Society for Hematopathology Workshop. Semin Diagn Pathol. 1997;14:8–14.
Case 30.2
Diffuse Large B-Cell Infiltrate PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N I C AL I N F OR M AT I ON
A 55-year-old woman presented with fever, hyperbilirubinemia, and elevated alkaline phosphatase. She was also noted to have an enlarged spleen. A clinical workup for hepatitis was negative. A liver needle biopsy was performed. R E A S ON F OR R E F E R R A L
Large cell lymphoid infiltrate, rule out large cell lymphoma. PAT H OL OG I C F E AT U R E S
The hepatic parenchyma is infiltrated by diffuse sheets of cells that lack evidence of organization into discrete follicles (Figure 30.2.1). High power microscopic examination reveals large cells with round to irregular nuclei, coarse chromatin, distinct and often multiple nucleoli, and moderately abundant eosinophilic cytoplasm, consistent with large lymphoid cells (Figure 30.2.2). There are frequent scattered mitotic figures. This large cell infiltrate is seen to randomly involve portal tracts, central veins, and intervening lobular parenchyma, with no specific pattern of localization. There is no evidence of hepatitis in the residual hepatic parenchyma. Immunoperoxidase stains reveal the large cells to be diffusely and strongly positive for the B-cell marker CD20 (Figure 30.2.3) but negative in stains for CD3, CD5, and BCL-1 (cyclin D1). In situ hybridization for Epstein-Barr virus-encoded RNA (EBER) is negative in the large cells.
F I G U R E 3 0 . 2 . 2 The large lymphoid cells resemble centroblasts, with
multiple distinct nucleoli; there are also frequent mitotic figures, some atypical (H&E, 1000).
F I G U R E 3 0 . 2 . 3 A CD20 stain shows diffuse strong positive staining of the neoplastic large lymphoid cells (CD20, 1000).
DIAGNO SIS
Diffuse large B-cell lymphoma.
DISCUSSIO N FIGURE 30. 2. 1 Large lymphoid cells in diffuse sheets infiltrate
hepatic parenchyma (H&E, 200).
The destructive infiltration of the hepatic parenchyma in this case by a diffuse infiltrate of CD20-positive large lymphoid
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cells supports the diagnosis of diffuse large B-cell lymphoma, and can be mimicked by few other entities. The pleomorphic (or blastoid) variant of mantle cell lymphoma can be rich in large cells that can resemble diffuse large B-cell lymphoma morphologically (1), but the negative staining of the neoplastic large cells in this case for CD5 and BCL-1 (cyclin D1) excludes that diagnosis. Grade 3B follicular lymphoma also contains a relatively pure population of large B-cells but would be required to display entirely follicular (rather than diffuse) architecture (2). Diffuse large B-cell lymphomas that occur in patients over 50 years of age and show evidence of Epstein-Barr virus infection by LMP1 staining or EBER studies have a poor prognosis and are placed by the 2008 WHO Classification into a separate category termed EBV-positive diffuse large B-cell lymphoma of the elderly (3), but the EBV studies in this case were negative. Of note, absence of CD20 expression would not entirely exclude the diagnosis of diffuse large B-cell lymphoma. Plasmablastic lymphoma, which is generally considered to be a form of diffuse, large B-cell lymphoma, displays a plasma cell phenotype, and has weak to absent CD20 expression by definition (4). The B-cell marker Oct-2 can be utilized to confirm the B-cell identity of CD20-negative plasmablastic lymphomas, given that it is expressed in both standard diffuse large B-cell lymphomas and plasma cell tumors (5), and many plasmablastic lymphomas express CD79a as well (4). The pattern of involvement seen in this case is typical of hepatic involvement by diffuse large B-cell lymphoma, but in other cases one may encounter more subtle portal or sinusoidal infiltration (6,7). The presence of monotonous populations of
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large B-cells in prominent clusters or sheets, lacking evidence of follicular architecture, will lead to the proper diagnosis in subtle cases. Finally, a monomorphic PTLD can perfectly mimic diffuse large B-cell lymphoma. Monomorphic PTLDs are essentially high-grade lymphomas, mainly of B-cell type, that occur in the post-transplant setting (Chapter 30.4).
References 1. Tiemann M, Schrader C, Klapper W, et al. Histopathology, cell proliferation indices and clinical outcome in 304 patients with mantle cell lymphoma (MCL): a clinicopathological study from the European MCL Network. Br J Haematol. 2005;131:29–38. 2. Harris NL, Swerdlow SH, Jaffe ES, et al. Follicular lymphoma. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:220–226. 3. Nakamura S, Jaffe ES, and Swerdlow SH. EBV positive diffuse large B-cell lymphoma of the elderly. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:243–244. 4. Colomo L, Loong F, Rives S, et al. Diffuse large B-cell lymphomas with plasmablastic differentiation represent a heterogeneous group of disease entities. Am J Surg Pathol. 2004;28:736–747. 5. Saez AI, Artiga MJ, Sanchez-Beato M, et al. Analysis of octamer-binding transcription factors Oct2 and Oct1 and their coactivator BOB.1/OBF.1 in lymphomas. Mod Pathol. 2002;15:211–220. 6. Jaffe ES. Malignant lymphomas: pathology of hepatic involvement. Semin Liver Dis. 1987;7:257–268. 7. Scheimberg IB, Pollock DJ, Collins PW, Doran HM, Newland AC, van der Walt JD. Pathology of the liver in leukaemia and lymphoma. A study of 110 autopsies. Histopathology. 1995;26:311–321.
Case 30.3
Portal Infiltrate With Reed-Sternberg Cells PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N I C AL I N F OR M AT I ON
A previously well 25-year-old woman developed progressive fatigue, weight loss, and abdominal distention over 1 month. Imaging studies revealed bulky mediastinal and retroperitoneal lymphadenopathy, as well as massive splenomegaly and thrombus in the splenic and portal veins. The liver appeared to be of normal size and lacked focal lesions. The patient’s total bilirubin was elevated at 2.5 mg/dL, but serum aspartate transaminase (AST), alanine aminotransferase (ALT) levels, and alkaline phosphatase levels were within normal limits. A CT-guided needle biopsy of a retroperitoneal lymph node was nondiagnostic. The patient subsequently underwent splenectomy and liver wedge biopsy.
are multinucleated tumor giant cells. The former are compatible with mononuclear Reed-Sternberg cell variants (Hodgkin cells), whereas the latter are characteristic of classical ReedSternberg cells of classical Hodgkin lymphoma. Immunoperoxidase stains reveal the HRS cells to be positive for CD30, with staining seen in both the cell membrane and cytoplasm, the latter sometimes accentuated in the perinuclear region corresponding to the Golgi apparatus (Figure 30.3.3). A similar pattern of staining is seen for CD15.
R E A S ON F OR R E F E R R A L
Portal infiltrate with Reed-Sternberg cells, rule out Hodgkin lymphoma. PAT H OL OG I C F E AT U R E S
The portal areas are expanded by a cellular infiltrate, which even at low power appears to consist of a polymorphous mixture of cell types that includes small lymphocytes, histiocytes, and eosinophils, along with scattered atypical large cells (Figure 30.3.1). At higher magnification, the large cells can be seen to be highly atypical, with coarse, hyperchromatic nuclear chromatin, prominent acidophilic nucleoli, and abundant eosinophilic cytoplasm (Figure 30.3.2). Some of these atypical large cells are mononuclear, whereas others
F I G U R E 3 0 . 3 . 2 The portal infiltrate includes small lymphocytes,
histiocytes, eosinophils, and tumor giant cells consistent with ReedSternberg cells (H&E, 1000).
F I G U R E 3 0 . 3 . 3 CD30 expression by Hodgkin and Reed-Sternberg FIGURE 30. 3. 1 The portal areas contain a mixed cellular infiltrate
that includes atypical large cells (H&E, 200).
cells, with staining on membrane and in Golgi region (CD30, 1000).
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FIGURE 30. 3. 4 The B-cell marker Pax-5 is almost always expressed
at least focally in the nuclei of HRS cells of classical Hodgkin lymphoma (Pax-5, 1000).
FIGUR E 30. 3. 5 CD20 stain is entirely negative in the HRS cells
(CD20, 1000).
The HRS cells also show variable but often strong staining for the B-cell marker Pax-5 (Figure 30.3.4) but are entirely negative in stains for the B-cell markers CD20 (Figure 30.3.5), Oct-2, and BOB.1.
D I AG N OS I S
Classical Hodgkin lymphoma.
D I S C U S S I ON
The morphologic appearance, with HRS cells, in a background of mixed inflammatory cells is highly characteristic of
WITH
REED-STERNBERG
CELLS
483
classical Hodgkin lymphoma, which in the liver typically involves portal areas (1–3); however, it is not entirely specific for that entity. It is now recognized that several large B-cell non-Hodgkin lymphomas (T-cell/histiocyte-rich large B-cell lymphoma (4), EBV-positive diffuse large B-cell lymphoma of the elderly (5,6), and the anaplastic variant of diffuse large B-cell lymphoma (7)) and at least one T-cell lymphoma (anaplastic large cell lymphoma (8)) can be histologically indistinguishable from classical Hodgkin lymphoma, including cells morphologically identical to classical Reed-Sternberg cells. In addition, all of these lymphomas can express CD30, and on rare occasion, CD15 (9–10). In current practice, then, immunophenotyping studies are essential to exclude histopathologic imitators (10). Classical Hodgkin lymphoma has been proven to be of B-cell origin in essentially all cases, but the only B-cell antigen consistently expressed by the neoplastic HRS cells is Pax-5, although this expression can be weak and focal (11); the expression of most other B-cell markers, such as CD20, is generally either entirely absent or focal and usually weak (11,12), with the exception of BOB.1, which is strongly expressed in a minority of cases (11) (Table 30.4). In contrast, the large B-cell non-Hodgkin lymphomas that can mimic classical Hodgkin lymphoma typically show strong and uniform expression of most or all pan-B-cell markers (12,13). Anaplastic large cell lymphoma, being of T-cell type, does not generally express Pax-5 (14,15) and typically displays a number of T-cell antigens that are absent from HRS cells (16), although it should be noted that its expression of CD3 is often weak to absent (16–17). Nodular lymphocytepredominant Hodgkin lymphoma can occasionally contain cells resembling classical Reed-Sternberg cells, but such cases are rare, and the neoplastic cells (termed L&H LP cells) almost always lack CD30 and CD15 and show strong expression of multiple pan-B-cell markers (18). Hepatic involvement by classical Hodgkin lymphoma is rarely seen unless there is also extensive involvement of lymph nodes and spleen (19,20). Although the morphology in this liver biopsy is most suggestive of the mixed cellularity subtype of classical Hodgkin lymphoma, histologic sections of the spleen (not shown) revealed cellular nodules separated by bands of sclerotic collagen diagnostic of the nodular sclerosis subtype.
References 1. Biemer JJ. Hepatic manifestations of lymphomas. Ann Clin Lab Sci. 1984;14:252–260. 2. Jaffe ES. Malignant lymphomas: pathology of hepatic involvement. Semin Liver Dis. 1987;7:257–268. 3. Scheimberg IB, Pollock DJ, Collins PW, Doran HM, Newland AC, van der Walt JD. Pathology of the liver in leukaemia and lymphoma. A study of 110 autopsies. Histopathology. 1995;26:311–321. 4. Abramson JS. T-cell/histiocyte-rich B-cell lymphoma: biology, diagnosis, and management. Oncologist. 2006;11:384–392. 5. Nakamura S, Jaffe ES, Swerdlow SH. EBV positive diffuse large B-cell lymphoma of the elderly. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:243–244. 6. Asano N, Yamamoto K, Tamaru J, et al. Age-related Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders: comparison
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8.
9.
10. 11.
12.
13.
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with EBV-positive classic Hodgkin lymphoma in elderly patients. Blood. 2009;113:2629–2636. Haralambieva E, Pulford KA, Lamant L, et al. Anaplastic large-cell lymphomas of B-cell phenotype are anaplastic lymphoma kinase (ALK) negative and belong to the spectrum of diffuse large B-cell lymphomas. Br J Haematol. 2000;109:584–591. Vassallo J, Lamant L, Brugieres L, et al. ALK-positive anaplastic large cell lymphoma mimicking nodular sclerosis Hodgkin’s lymphoma: report of 10 cases. Am J Surg Pathol. 2006;30:223–229. Barry TS, Jaffe ES, Sorbara L, Raffeld M, Pittaluga S. Peripheral T-cell lymphomas expressing CD30 and CD15. Am J Surg Pathol. 2003;27: 1513–1522. Mani H, Jaffe ES. Hodgkin lymphoma: an update on its biology with new insights into classification. Clin Lymphoma Myeloma. 2009;9:206–216. Garcia-Cosio M, Santon A, Martin P, et al. Analysis of transcription factor OCT.1, OCT.2 and BOB.1 expression using tissue arrays in classical Hodgkin’s lymphoma. Mod Pathol. 2004;17:1531–1538. Higgins RA, Blankenship JE, Kinney MC. Application of immunohistochemistry in the diagnosis of non-Hodgkin and Hodgkin lymphoma. Arch Pathol Lab Med. 2008;132:441–461. Browne P, Petrosyan K, Hernandez A, Chan JA. The B-cell transcription factors BSAP, Oct-2, and BOB.1 and the pan-B-cell markers CD20, CD22, and CD79a are useful in the differential diagnosis of classic Hodgkin lymphoma. Am J Clin Pathol. 2003;120:767–777.
TUMORS
OF
THE
LIVER
14. Feldman AL, Dogan A. Diagnostic uses of Pax5 immunohistochemistry. Adv Anat Pathol. 2007;14:323–334. 15. Feldman AL, Law ME, Inwards DJ, Dogan A, McClure RF, Macon WR. PAX5-positive T-cell anaplastic large cell lymphomas associated with extra copies of the PAX5 gene locus. Mod Pathol. 2010;23:593–602. 16. Benharroch D, Meguerian-Bedoyan Z, Lamant L, et al. ALK-positive lymphoma: a single disease with a broad spectrum of morphology. Blood. 1998;91:2076–2084. 17. Bonzheim I, Geissinger E, Roth S, et al. Anaplastic large cell lymphomas lack the expression of T-cell receptor molecules or molecules of proximal T-cell receptor signaling. Blood. 2004;104:3358–3360. 18. Anagnostopoulos I, Hansmann ML, Franssila K, et al. European Task Force on Lymphoma project on lymphocyte predominance Hodgkin disease: histologic and immunohistologic analysis of submitted cases reveals 2 types of Hodgkin disease with a nodular growth pattern and abundant lymphocytes. Blood. 2000;96:1889–1899. 19. Colby TV, Hoppe RT, Warnke RA. Hodgkin’s disease: a clinicopathologic study of 659 cases. Cancer. 1982. 49: 1848–1858. 20. Gordon CD, Sidawy MK, Talarico L, Kondi E. Hodgkin’s disease in the liver without splenic involvement. Arch Intern Med. 1984;144: 2277–2278.
Case 30.4
Polymorphic Lymphoid Infiltrate in a Transplant Patient PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N IC AL I N F OR M AT I ON
A 6-year-old girl who had undergone orthotopic liver transplantation 2 years prior for cryptogenic cirrhosis developed fever and unspecified liver function test abnormalities. She had negative serum antibodies to EBV antigens (anti-early antigen [EA] and anti-virus capsid antigen immunoglobulin G [VCA IgG]) at the time of her transplant but had been recently found to have seroconverted. A liver needle biopsy was performed. R E A SON F OR R E F E R R AL
Dense lymphoid infiltrate suspicious for malignant lymphoma. PAT H OL OG I C F E AT U R E S
The needle biopsy shows extensive destructive infiltration of hepatic parenchyma by a diffuse polymorphic population of mature small lymphocytes, large lymphoid cells, histiocytes, and plasma cells (Figures 30.4.1 and 30.4.2). The large cells, although relatively numerous in some areas, are present mainly as scattered cells and do not form large clusters or diffuse sheets. Immunoperoxidase stains reveal the vast majority of the lymphoid cells to be positive for the B-cell marker CD20 (Figure 30.4.3). There is no positive staining of this dominant B-cell population for CD5, CD10, CD23, BCL-1, or BCL-6. In situ hybridization for EBER showed nuclear positivity in scattered small and large lymphoid cells (Figure 30.4.4).
F I G U R E 3 0 . 4 . 2 The polymorphic infiltrate includes mature small
lymphocytes, histiocytes, large lymphoid cells, and plasma cells (H&E, 1000).
F I G U R E 3 0 . 4 . 3 CD20 stain is diffusely positive in the small and large lymphoid cells (CD20, 1000).
DIAGNO SIS
Polymorphic post-transplant lymphoproliferative disorder.
DISCUSSIO N FIGURE 30. 4. 1 Destructive infiltration of hepatic parenchyma by a
mixed lymphoid cell population (H&E, 200).
Although the morphologic and immunophenotypic features show much in common with a malignant lymphoma, in the
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FIGURE 30. 4. 4 An in-situ hybridization study for Epstein-Barr
virus-encoded RNA (EBER) is positive in the nuclei of numerous small and large lymphoid cells (EBER, 1000).
post-transplant setting, such a lymphoid cell population is more properly termed a PTLD. Used in its broadest sense, the term PTLD refers to any abnormal lymphoid proliferation occurring in the post-transplant setting, from follicular B-cell hyperplasia to Hodgkin lymphoma but most are EBV-driven B-cell proliferations thought to be etiologically related to suppression of T-cell immunity in the post-transplant state (1,2). To a first approximation, the B-cell PTLDs can be segregated into 3 categories: (1) so-called early lesion PTLDs, which resemble chronic inflammation (eg, infectious mononucleosis) and do not efface tissue architecture; (2) polymorphic PTLDs,
TUMORS
OF
THE
LIVER
which efface architecture and consist of a polymorphic mixture of small and large cells that typically includes many plasma cells; and (3) monomorphic PTLDs, which resemble high-grade B-cell lymphomas, most commonly diffuse large B-cell lymphoma (1,2). Many polymorphic and essentially all monomorphic PTLDs contain clonal B-cell populations, yet they may still regress at least partially in response to reduction of immunosuppression, which is typically the initial therapeutic measure taken (1,2). A minority of B-cell PTLDs are EBVnegative, and rare PTLDs are of T-cell phenotype, although in such instances it is difficult to be certain that the lymphoid proliferation is related to the transplant. The effacement of hepatic architecture in this case excludes a so-called early lesion PTLD, whereas the predominantly small cell morphology excludes a monomorphic PTLD. Given that polymorphic B-cell PTLDs usually display the “B-cell, NOS” phenotype seen in this case, with no expression of antigens not typically found on benign B-cells, they can be easily confused with plasmacytoid B-cell marginal zone lymphomas if one is not aware of the clinical history. In this instance, however, the young age of the patient would steer one away from a diagnosis of marginal zone lymphoma, which, like other small B-cell lymphomas, is uncommon in the pediatric age group.
References 1. Harris NL, Ferry JA, Swerdlow SH. Posttransplant lymphoproliferative disorders: summary of Society for Hematopathology Workshop. Semin Diagn Pathol. 1997;14:8–14. 2. Swerdlow SH, Webber SA, Chadburn A, et al. Post-transplant lymphoproliferative disorders. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:343–348.
Case 30.5
Sinusoidal T-Cell Infiltrate PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N IC AL I N F OR M AT I ON
A 65-year-old man presented with abdominal fullness and bloating. Abdominal CT scan revealed splenomegaly and mild ascites. The complete blood cell count was normal except for a low white blood cell count of 3.1. The bilirubin was elevated to 3.5; liver transaminases were normal and viral hepatitis serologies were negative.
Flow cytometry performed on a subsequent bone marrow biopsy revealed an aberrant population of lymphocytes that expressed cytoplasmic CD3, CD7, and CD56 with only partial expression of surface CD3 and weak surface expression of the T-cell receptor (TCR ). These aberrant T-cells lacked expression of CD4, CD5, CD8, TdT, and the T-cell receptor (TCR ). The patient received chemotherapy with cyclophosphamide, etoposide, and prednisone but developed
R E A SON F OR R E F E R R AL
Hepatic sinusoidal lymphoid infiltrate of uncertain significance. PAT H OL OG I C F E AT U R E S
The liver biopsy shows a dense sinusoidal infiltrate of atypical lymphoid cells, with sparing of the portal areas (Figure 30.5.1). These cells have small to medium-sized nuclei with slightly irregular nuclear contours (Figure 30.5.2). The cells are irregularly distributed within the sinusoids such that, in some areas, the sinuses are expanded by clusters of cells, whereas in other areas single cells are present that do not significantly expand the sinuses (Figure 30.5.3). Immunohistochemistry reveals the sinusoidal lymphoid infiltrate to have an atypical T-cell phenotype, with expression of CD3 (Figure 30.5.4) but no expression of either CD4 or CD8. The proliferation marker Ki-67 highlights 30% to 40% of the population. This pattern of infiltration and the immunophenotypic profile are characteristic of a hepatosplenic T-cell lymphoma (HSTCL).
FIGURE 30. 5. 1 Typical sinusoidal lymphoid infiltrate of HSTCL,
with sparing of the portal areas (H&E, 200).
F I G U R E 3 0 . 5 . 2 Small to medium-sized sinusoidal lymphocytes in
HSTCL showing slightly irregular nuclear contours; cytologic atypia can vary from case to case (H&E, 400).
F I G U R E 3 0 . 5 . 3 The T-cell infiltrate in HSTCL typically expands the
sinusoids by three or more lymphocytes, at least focally (H&E, 200).
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FIGURE 30. 5. 4 Positive staining of T-cells for CD3 is typical of
HSTCL, but other T-cell markers are often negative (CD3, 400).
TUMORS
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F I G U R E 3 0 . 5 . 5 Sinusoidal T-cell infiltrate in Epstein-Barr virus in-
fection, which can mimic HSTCL (H&E, 400).
peritonitis in the setting of profound neutropenia and died. At autopsy, he was found to have residual lymphoma involving the spleen, liver, and bone marrow.
D I AG N OS I S
Hepatosplenic T-cell lymphoma.
D I SC U SSI ON
The hallmark of liver involvement by HSTCL is sinusoidal infiltration by monotonous lymphocytes of medium size (1). These cells show a T-cell phenotype but characteristically do not express either CD4 or CD8 (1). They also frequently lack CD5 (2). Most cases are of type, but a subset is of type (3). The latter are more common in females but otherwise have similar clinical features (3). Molecular studies reveal clonal rearrangement of the TCR -chain genes. Thus, the diagnosis is often relatively straightforward once immunohistochemistry and molecular studies are employed. Unfortunately, several reactive processes may show a similar pattern of sinusoidal T-cell infiltration. For this reason, it is helpful to be able to recognize morphologic features that distinguish HSTCL from these benign entities. Herpesviral infections, particularly cytomegalovirus (CMV) and EBV, are the most problematic forms of hepatitis in the differential diagnosis of HSTCL. Both of these viruses can produce a mononucleosis-like syndrome and cause a lymphocytic infiltrate in the hepatic sinusoids (4) (Figure 30.5.5). This infiltrate is predominantly of T-cell lineage (Figure 30.5.6). When CMV hepatitis occurs in immunocompetent hosts, characteristic viral inclusions may not be seen, and immunohistochemistry usually does not highlight
F I G U R E 3 0 . 5 . 6 CD3 expression by sinusoidal lymphocytes in EBV
infection, which can mimic HSTCL (CD3, 400).
lymphoid cells in the biopsy tissue since the infiltrate is reactive (5–6). In EBV hepatitis, EBV is detected in most but not all cases by in situ hybridization (7) (Figure 30.5.7). However, even in positive cases, the infiltrate is predominantly composed of reactive T-cells, and EBV-harboring B-cells are rare (7–8). Furthermore, the reactive T-cell infiltrate may be cytologically atypical in cases of EBV infection. Both HSTCL and viral hepatitides due to EBV and CMV hepatitis may be exacerbated by immunosuppression (2). Although the cytologic features of the lymphoid infiltrate may be very similar in HSTCL and herpesviral hepatitis, morphologic features can usually permit a distinction of the two processes. The volume of the infiltrate is typically greater in lymphoma. It may show the “string of beads” pattern of EBV hepatitis in some areas but usually there is an
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:
SINUSOIDAL
T- C E L L
I N F I LT R AT E
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The sinusoidal pattern of lymphocytic infiltration seen in HSTCL can also be caused by drugs. Phenytoin is the classic example (9), but similar changes have been associated with para-amino salicylate, dapsone, and sulfonamides (10). Phenytoin hepatitis characteristically shows extensive hepatocellular injury, which helps to distinguish it from HSTCL (9).
References
FIGURE 30. 5. 7 Rare scattered lymphoid cells show evidence of EBV-encoded RNA (EBER) by in-situ hybridization in case of EBV infection (EBER, 400).
expansion of the sinusoids with three or more lymphocytes spanning the sinusoid in HSTCL. The lymphoid population is largely restricted to the sinusoids in HSTCL, whereas in herpesviral hepatitis there is usually portal inflammation as well. Moreover, hepatocellular injury is less commonly present in HSTCL, and this is reflected by only minimally increased serum transaminase levels as well as a lack of hepatocyte necrosis histologically (2). Herpesviral hepatitis, in contrast, often shows hepatocyte ballooning and lobular disarray (7). Finally, granulomas may be seen in CMV hepatitis (5), but these are not a feature of HSTCL.
1. Cooke CB, Krenacs L, Stetler-Stevenson M, et al. Hepatosplenic T-cell lymphoma: a distinct clinicopathologic entity of cytotoxic gamma delta T-cell origin. Blood. 1996;88:4265–4274. 2. Belhadj K, Reyes F, Farcet JP, et al. Hepatosplenic gammadelta T-cell lymphoma is a rare clinicopathologic entity with poor outcome: report on a series of 21 patients. Blood. 2003;102:4261–4269. 3. Macon WR, Levy NB, Kurtin PJ, et al. Hepatosplenic alphabeta T-cell lymphomas: a report of 14 cases and comparison with hepatosplenic gammadelta T-cell lymphomas. Am J Surg Pathol. 2001;25:285–296. 4. Purtilo DT, Strobach RS, Okano M, et al. Epstein-Barr virus-associated lymphoproliferative disorders. Lab Invest. 1992;67:5–23. 5. Clarke J, Craig RM, Saffro R, et al. Cytomegalovirus granulomatous hepatitis. Am J Med. 1979;66:264–269. 6. Snover DC, Horwitz CA. Liver disease in cytomegalovirus mononucleosis: a light microscopical and immunoperoxidase study of six cases. Hepatology. 1984;4:408–412. 7. Suh N, Liapis H, Misdraji J, Brunt EM, Wang HL. Epstein-Barr virus hepatitis: diagnostic value of in situ hybridization, polymerase chain reaction, and immunohistochemistry on liver biopsy from immunocompetent patients. Am J Surg Pathol. 2007;31:1403–1409. 8. Pagidipati N, Obstein KL, Rucker-Schmidt R, et al. Acute hepatitis due to Epstein-Barr virus in an immunocompetent patient. Dig Dis Sci. 2010;55:1182–1185. 9. Mullick FG, Ishak KG. Hepatic injury associated with diphenylhydantoin therapy. A clinicopathologic study of 20 cases. Am J Clin Pathol. 1980;74:442–452. 10. Goodman ZD. Drug hepatotoxicity. Clin Liver Dis. 2002;6:381–397.
Case 30.6
Portal and Lobular Infiltration by Blasts PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N I C AL I N F OR M AT I ON
The patient was a 41-year-old woman who presented with pancytopenia, and was found to have blasts in the peripheral blood. A bone marrow aspiration was performed, and flow cytometry revealed lymphoid blasts expressing CD34, TdT, CD19, and cytoplasmic CD79a. She underwent induction chemotherapy and achieved a complete remission. However, prior to undergoing intensification chemotherapy, she developed serum liver enzyme elevation. Serum AST was 150 and ALT 386. Total bilirubin and alkaline phosphatase levels were normal, and a complete blood count (CBC) was also normal. Clinical evaluation for viral and autoimmune hepatitis was negative. An ultrasound revealed increased hepatic echogenicity, suggesting possible fatty liver, but no evidence of chronic liver disease or portal hypertension.
fatty change in the hepatocytes but no significant hepatocyte ballooning degeneration or necrosis. By immunohistochemistry, the cells are seen to show strong nuclear staining for TdT (Figure 30.6.3) and membrane staining for CD34.
DIAGNO SIS
Involvement by B-lymphoblastic leukemia/lymphoma.
R E A S ON F OR R E F E R R A L
Hepatic infiltration by blasts.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows extensive hepatic infiltration by a dense lymphoid infiltrate that appears to involve both portal areas and lobules (Figure 30.6.1). In the lobules, the pattern of infiltration is predominantly sinusoidal. At higher power, the lymphoid cells are seen to be medium-sized cells with finely dispersed chromatin and scant cytoplasm, consistent with blasts (Figure 30.6.2). There is moderate macrovesicular
FIGURE 30. 6. 1 Dense portal and lobular infiltration by lymphoid
cells, with a sinusoidal pattern in the hepatic lobules (H&E, 100).
FIGURE 30.6.2 Infiltrating cells are of medium size with finely dispersed chromatin and scant cytoplasm, consistent with blasts (H&E, 200).
F I G U R E 3 0 . 6 . 3 Strong TdT expression by infiltrating blasts, TdT,
100.
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:
P O RTA L
AND
LOBULAR
D I S C U S S I ON
The morphologic and immunophenotypic features in this case indicate hepatic involvement by B-lymphoblastic leukemia/ lymphoma, which can present as acute lymphoblastic leukemia (ALL), with involvement of bone marrow and peripheral blood, or as lymphoblastic lymphoma, in which only extramedullary disease is present. Hepatic involvement in ALL patients is common. Transaminase elevations are noted in about onethird of ALL patients at presentation and are assumed to be related to leukemic infiltration of the liver (1). Such patients seldom undergo liver biopsy unless there is a specific reason to suspect a superimposed hepatic process. However, in rare cases, hepatic infiltration by ALL may be so massive as to result in liver failure (2,3) and this may be the presenting sign of leukemia (2). Lymphoblastic lymphoma, with no involvement of the blood or marrow, presenting in the liver appears to be very rare (4–6). When ALL involves the liver, a sinusoidal pattern of infiltration is common (7), and, generally, the degree of hepatocellular injury is less than would be expected based on the degree of infiltration, suggesting that it is the mass of the infiltrate that results in the liver injury. Acute myeloid leukemia (AML) can involve the liver in a pattern identical to that seen in ALL (8), and is the principal alternative to be considered in the differential diagnosis, particularly given that AML is not infrequently TdT-positive (9), and can on occasion express antigens commonly associated with B-cell lineage, including CD19, CD79a, Pax-5, Oct-2, and BOB.1 (10). Generally, AML expresses multiple myeloid markers not typically found in ALL, and lacks expression of most lymphoid antigens, but extensive analysis utilizing flow cytometry and cytogenetic studies may be required in equivocal cases (9).
I N F I LT R AT I O N
BY
BLASTS
491
References 1. Segal I, Rassekh SR, Bond MC, Senger C, Schreiber RA. Abnormal liver transaminases and conjugated hyperbilirubinemia at presentation of acute lymphoblastic leukemia. Pediatr Blood Cancer. 2010;55:434–439. 2. Litten JB, Rodriguez MM, Maniaci V. Acute lymphoblastic leukemia presenting in fulminant hepatic failure. Pediatr Blood Cancer. 2006;47: 842–845. 3. Zafrani ES, Leclercq B, Vernant JP, Pinaudeau Y, Chomette G, Dhumeaux D. Massive blastic infiltration of the liver: a cause of fulminant hepatic failure. Hepatology. 1983;3:428–432. 4. Lin P, Jones D, Dorfman DM, Medeiros LJ. Precursor B-cell lymphoblastic lymphoma: a predominantly extranodal tumor with low propensity for leukemic involvement. Am J Surg Pathol. 2000;24:1480–1490. 5. Maitra A, McKenna RW, Weinberg AG, Schneider NR, Kroft SH. Precursor B-cell lymphoblastic lymphoma. A study of nine cases lacking blood and bone marrow involvement and review of the literature. Am J Clin Pathol. 2001;115:868–875. 6. Lei KI, Chow JH, Johnson PJ. Aggressive primary hepatic lymphoma in Chinese patients. Presentation, pathologic features, and outcome. Cancer. 1995;76:1336–1343. 7. Takamatsu T. Preferential infiltration of liver sinusoids in acute lymphoblastic leukemia. Rinsho Ketsueki. 2001;42:1181–1186. 8. Walz-Mattmuller R, Horny HP, Ruck P, Kaiserling E. Incidence and pattern of liver involvement in haematological malignancies. Pathol Res Pract. 1998;194:781–789. 9. Arber DA, Brunning RD, Orazi A, et al. Acute myeloid leukaemia, not otherwise specified. In: Swerdlow SH, et al, eds. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: International Agency for Research on Cancer; 2008:130–139. 10. Gibson SE, Dong HY, Advani AS, Hsi ED. Expression of the B cell-associated transcription factors PAX5, OCT-2, and BOB.1 in acute myeloid leukemia: associations with B-cell antigen expression and myelomonocytic maturation. Am J Clin Pathol. 2006;126:916–924.
Case 30.7
Portal and Lobular Infiltration by Mature Granulocytes PATRICK A. TRESELER AND JOHN P. HIGGINS
C L I N I C AL I N F OR M AT I ON
The patient was a 57-year-old woman with a history of chronic hepatitis C. More recently, she was found to have chronic myelogenous leukemia (CML) and underwent liver biopsy as part of the evaluation for a bone marrow transplant.
R E A S ON F OR R E F E R R A L
Sinusoidal granulocytic infiltrate without hepatocellular injury.
PAT H OL OG I C F E AT U R E S
The biopsy shows preserved architecture with a mild predominantly portal-based infiltrate (Figure 30.7.1). This infiltrate includes numerous eosinophils, many of which have bilobed nuclei, but some of which have a more immature mononuclear appearance, suggestive of eosinophilic myelocytes. Many of the hepatic sinusoids appear unremarkable, but many others contain populations of granulocytes, which include both mature neutrophils and more immature forms, although blasts are not identified (Figures 30.7.2 and 30.7.3). Rare precursors of nongranulocytic lineage are also seen, such as the abnormal small megakaryocyte shown in Figure 30.7.4. The hepatocytes show only mild macrovesicular fatty change. Clear evidence of hepatic involvement by hepatitis C is not identified. There is no significant lymphocytic infiltration in either portal areas or lobules and no significant hepatic fibrosis.
F I G U R E 3 0 . 7 . 2 Some hepatic sinusoids appear normal, but others
contain maturing granulocytes (H&E, 200).
F I G U R E 3 0 . 7 . 3 The sinusoids contain both immature and mature granulocytes, along with a single small megakaryocyte (H&E, 400).
DIAGNO SIS
Involvement by chronic myelogenous leukemia.
DISCUSSIO N FIGURE 30. 7. 1 Portal areas are involved by eosinophilic granulo-
cytes, including immature forms (H&E, 400).
Hepatomegaly is present in over 50% of patients with CML at presentation (1), and at least the subtle hepatic involvement
492
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:
P O RTA L
AND
FIGURE 30.7.4 The neutrophilic infiltrate in “surgical hepatitis” is also sinusoidal but consists entirely of mature neutrophils (H&E, 400).
of the type seen in this case is probably universal in this disease. Of note, the neutrophilic infiltrate is not associated with any significant hepatocellular injury. If such a sinusoidal myeloid infiltrate is encountered in a routine biopsy, review of the patient’s clinical history should identify most patients in whom the infiltrate represents CML. If the patient does not have a known history of CML, then the possibility should be suggested to the clinicians, who could undertake definitive evaluation of the peripheral blood and/or bone marrow. The differential diagnosis of hepatic involvement by CML includes other chronic myeloproliferative disorders, a leukemoid reaction, so-called surgical hepatitis, and blast crisis of CML. The chronic myeloproliferative disorders (which are termed “myeloproliferative neoplasms” in the 2008 WHO Classification) include, in addition to CML, chronic neutrophilic leukemia, polycythemia vera, primary myelofibrosis, and essential
LOBULAR
I N F I LT R AT I O N
493
thrombocythemia, all of which can have significant clinical and morphologic overlap with CML, although the histopathologic appearance of hepatic involvement by many of these disorders remains poorly described. A leukemoid reaction, which is essentially a reactive hyperplasia of the marrow, is also a well-known mimic of CML. Distinguishing such entities from CML requires correlation with a variety of clinical features and laboratory and genetic tests and is beyond the scope of his chapter. So-called surgical hepatitis represents a margination reaction of neutrophils in the liver sinusoids related to prolonged surgery. This infiltrate resembles CML in that it prominently features mature granulocytes that are largely restricted to the hepatic sinusoids and are not associated with liver cell injury (Figure 30.1.4). In contrast to CML, however, the infiltrate is composed exclusively of mature neutrophils. The clinical history of a liver biopsy taken at the end of a long surgery, combined with the absence of any clinical history of CML, should clinch the diagnosis in most cases. CML in blast crisis may also involve the liver and can be associated with hepatic failure due to massive infiltration of the hepatic parenchyma by blasts (2) or to obstructive jaundice related to a granulocytic sarcoma in the biliary tree (3). Blast crisis of CML involving the liver can on occasion contain numerous mature neutrophils but is distinguished by the presence of a significant population of blast forms, which can be of either myeloid or lymphoid phenotype.
References 1. Walz-Mattmuller R, Horny HP, Ruck P, Kaiserling E. Incidence and pattern of liver involvement in haematological malignancies. Pathol Res Pract. 1998;194:781–789. 2. Ondreyco SM, Kjeldsberg CR, Fineman RM, Vaninetti S, Kushner JP. Monoblastic transformation in chronic myelogenous leukemia: presentation with massive hepatic involvement. Cancer. 1981;48:957–963. 3. Fleming DR, Slone SP. CML blast crisis resulting in biliary obstruction following BMT. Bone Marrow Transplant. 1997;19:853–854.
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31 Other Infiltrative Neoplasms of Liver LAWRENCE BURGART
There are 3 major patterns of hepatic involvement by hematolymphoid neoplasms and other infiltrative disorders: sinusoidal infiltrates, portal infiltrates, and large tumor formation (Table 31.1). Each of these patterns occurs infrequently, making them susceptible to misdiagnosis as inflammatory conditions. Consideration of these disorders in the differential diagnosis and awareness of the key morphologic features are critical to identifying these neoplasms (1). In most instances, infiltrative neoplasms are of lymphoid histogenesis, although other infiltrative disorders like mast cell disease and Langerhans cells can also present with portal infiltrates. The portal involvement can mimic inflammatory processes and the lymphohistiocytic background can be an excellent mimic of primary biliary cirrhosis, including damage to the bile duct epithelium.
TA BL E 3 1 . 1 Pattern of hepatic involvement and prototypical
diagnoses Pattern
Benign
Malignant
Sinusoidal lymphocytosis
Infectious mononucleosis
Hepatosplenic T-cell lymphoma
Portal infiltrates
Chronic biliary disease
Hodgkin lymphoma Mast cell disease Langerhans cell Histiocytosis
Tumor
Inflammatory pseudotumor
Large B-cell lymphoma
Reference 1. Baumhoer D, Tzankov A, Dirnhofer S, Tornillo L, Terracciano LM. Patterns of liver infiltration in lymphoproliferative disease. Histopathology. 2008;53:81–90.
495
Case 31.1
Portal-Based Infiltrative Neoplasm Versus Biliary Disease LAWRENCE BURGART
C L I N I C AL I N F OR M AT I ON
A 39-year-old man presented with fatigue, pruritis, and weight loss. He had no significant past history. Physical exam and imaging revealed low-grade ascites and mild hepatosplenomegaly. There was no evidence of large duct obstruction. Liver enzyme tests revealed alkaline phosphatase 2.5 times normal and transaminases just above upper limits of normal. Bilirubin and proteins were within normal limits. Autoimmune and viral serologies were negative. Peripheral blood counts and morphology were within normal limits. A liver biopsy was obtained. R E A S ON F OR R E F E R R A L
The biopsy showed portal infiltrates suspicious for biliary disease, but of uncertain classification. F I G U R E 3 1 . 1 . 2 Bile ducts are intact with no ductular reaction. The bile duct appears reactive and contains focal lymphocytes.
PAT H OL OG I C F E AT U R E S
The liver biopsy shows mononuclear infiltration of the portal tracts (Figure 31.1.1). Bile ducts are intact with mild perturbation, including occasional intraepithelial lymphocytes (Figure 31.1.2). There is no ductular reaction. The infiltrates are associated with mild to moderate portal expansion with extension of the infiltrate into the immediate periportal sinusoids. There is no portal fibrosis. The hepatic parenchyma is quiescent despite the zone 1 sinusoidal involvement and mild patchy sinusoidal infiltrates in zones 2 and 3 (Figures 31.1.2 and 31.1.3). No granulomatous or significant eosinophilic inflammation is noted.
F I G U R E 3 1 . 1 . 3 The zone 3 parenchyma is quiescent with only focal
sinusoidal mononuclear cells.
FIGURE 31. 1. 1 Mononuclear infiltration of the portal tracts.
The mononuclear infiltrate consists of small cells with lymphoid features. However, the cells are relatively uniform with mildly elongate nuclei (Figure 31.1.4). Cell borders are inconspicuous. Based on the overall histologic and cytologic findings, immunoperoxidase stains were performed to specifically identify the infiltrative cell type. The cells were negative for CD3 and CD20 but stained positively for tryptase and CD117, diagnostic of mast cell disease (Figure 31.1.5).
496
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:
P O RTA L - B A S E D
FIGURE 31. 1. 4 The portal infiltrate consists of small cells with mildly elongate nuclei and no significant atypia.
FIGURE 31. 1. 5 Tryptase immunoperoxidase stain decorates the por-
tal infiltrate, indicative of mast cell disease.
D I AG N OS I S
Mast cell disease mimicking inflammatory biliary disease.
D I S C U S S I ON
The pathologic features are highly suggestive of a biliary inflammatory process based on the portal infiltrates and quiescent hepatic parenchyma. This correlates well with the serum alkaline phosphatase elevation with mild transaminase elevations. Chronic biliary conditions typically feature ductopenia, ductular reaction, and/or fibrosis.
I N F I LT R AT I V E
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497
Based on this inconsistent group of findings, other less typical causes of expansive biliary infiltrates need to be carefully considered. Such an evaluation may lead to nonspecific result, leading to careful scrutiny of drug or toxin exposure. However, occult neoplasm should be excluded by histologic and immunophenotypic evaluation. Uniform CD20 expression would suggest a low-grade B-cell neoplasm, such as small lymphocytic lymphoma/CLL, extranodal MALT-type lymphoma (1–3). Other conditions requiring consideration include Hodgkin lymphoma, Langerhans cell histiocytosis, and mast cell disease (4,5). The latter three can have eosinophils present as a clue, but this is inconsistent and can be absent as in this case. Overtly atypical portal infiltrates can occasionally occur with peripheral T-cell lymphoma, requiring immunophenotyping for a correct diagnosis. Mast cell disease is an excellent mimic of primary sclerosing cholangitis and primary biliary cirrhosis (6). The typical neoplastic mast cell is a medium-sized ovoid cell with moderate nuclear to cytoplasmic ratio. The neoplastic mast cells are typically admixed with edema, eosinophils, and scattered lymphocytes. Ductopenia is uncommon although lymphocytic cholangitis may be focally present. Overt granulomatous cholangitis (florid duct lesions) is not identified. However, the lack of prominent hypercellularity, the admixture of inflammatory cells (including apparent histiocytes), and the portal/ periportal expansion without accompanying hepatitis are all suggestive of chronic biliary disease, hence requiring a high degree of suspicion for the correct diagnosis. The neoplastic mast cells are not granular and do not stain reliably with Giemsa. Tryptase or c-kit (CD117) immunohistochemical stains are most reliable in confirming the diagnosis. Mast cells are very few in number in inflammatory liver diseases. Mast cell disease is typically divided into 2 categories, purely cutaneous and systemic. Systemic cases commonly include gastrointestinal involvement (but rarely liver involvement) as well as marrow involvement and are typically progressive (7,8). Liver involvement in Langerhans cell histiocytosis (LCH) typically occurs in the disseminated form of the disease and may have an adverse prognosis (9,10). The cholestatic biochemical picture can clinically mimic biliary disease. Biliary tree involvement can lead to sclerosing cholangitis (9). The distinctive morphology of Langerhans cells with nuclear groves and the frequent admixture of eosinophils in the infiltrate can raise the suspicion for the disease. The diagnosis can be easily confirmed by CD1a and S-100 expression by Langerhans cells. Treatment with steroids and chemotherapeutic agents has been tried in LCH with multiorgan involvement; liver transplant may be required in some cases.
References 1. Baumhoer D, Tzankov A, Dirnhofer S, Tornillo L, Terracciano LM. Patterns of liver infiltration in lymphoproliferative disease. Histopathology. 2008;53:81–90.
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OTHER
I N F I LT R AT I V E
2. Isaacson PG, Banks PM, Best PV, McLure SP, Muller-Hermelink HK, Wyatt JI. Primary low-grade hepatic B-cell lymphoma of mucosaassociated lymphoid tissue (MALT)-type. Am J Surg Pathol. 1995;19: 571–575. 3. Prabhu RM, Medeiros LJ, Kumar D, et al. Primary hepatic low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) associated with primary biliary cirrhosis. Mod Pathol. 1998;11:404–410. 4. Gupta A, Roebuck DJ, Michalski AJ. Biliary involvement in Hodgkin’s disease. Pediatr Radiol. 2002;32:202–204. 5. Liangpunsakul S, Kwo P, Koukoulis GK. Hodgkin’s disease presenting as cholestatic hepatitis with prominent ductal injury. Eur J Gastroenterol Hepatol. 2002;14:323–327.
NEOPLASMS
OF
LIVER
6. Kyriakou D, Kouroumalis E, Konsolas J, et al. Systemic mastocytosis: a rare cause of noncirrhotic portal hypertension simulating autoimmune cholangitis—report of four cases. Am J Gastroenterol. 1998;93:106–108. 7. Jensen RT. Gastrointestinal abnormalities and involvement in systemic mastocytosis. Hematol Oncol Clin North Am. 2000;14:579–623. 8. Sokol H, Georgin-Lavialle S, Grandpeix-Guyodo C, et al. Gastrointestinal involvement and manifestations in systemic mastocytosis. Inflamm Bowel Dis. 2010;16:1247–1253. 9. Pagnoux C, Hayem G, Roux F, Palazzo E, Meyer O. Sclerosing cholangitis as a complication of Langerhans’ cell histiocytosis. Rev Med Interne. 2003;24:324–327. 10. Savva-Bordalo J, Freitas-Silva M. Langerhans cell histiocytosis involving the liver of a male smoker: a case report. J Med Case Reports. 2008;2:376.
32 Mesenchymal Tumors of the Liver
Case 32.1
Mesenchymal Hamartomaa WENDY L. FRANKEL AND XIAOPING ZHOU
C L I N IC AL I N F OR M AT I ON
A 14-month-old boy presented with abdominal pain and a large palpable liver mass. Abdominal ultrasonography, computed tomography (CT) scan, magnetic resonance imaging (MRI), and angiogram revealed a greater than 10 cm hypovascular and multicystic right lobe liver mass. R E A SON F OR R E F E R R AL
This tumor was a large liver mass in a young child, and so was referred for further evaluation (as to exact tumor type). PAT H OL OG I C F E AT U R E S
The right hepatic lobectomy specimen shows a sharply demarcated and partially encapsulated lesion measuring larger than 10 cm in greatest dimension with solid and multicystic areas (Figure 32.1.1). The solid component includes tan white fibrotic areas mixed with congested liver parenchyma. The cysts vary from 0.5 cm to 7.0 cm with smooth to trabeculated lining and are filled with clear to slightly cloudy serous nonviscous fluid. The adjacent liver parenchyma is unremarkable.
F I G U R E 3 2 . 1 . 2 Epithelial and stromal components arranged in a
haphazard growth pattern.
Microscopic examination of the mass shows both epithelial and stromal components arranged in a haphazard growth pattern (Figure 32.1.2). The epithelial component consists of hepatocytes and bile ducts which are overgrown by a prominent myxoid to fibrous stroma. The clusters or islands of hepatocytes retain normal cell plate thicknesses without cytologic atypia (Figure 32.1.3). The bile ducts show a branched appearance with variable inflammatory infiltrates
FIGURE 32. 1. 1 Mesenchymal hamartoma. A sharply demarcated and partially encapsulated lesion with solid and multicystic areas on cut sections, gross appearance.
a The authors wish to acknowledge and thank Dr. Robert Newbury from Rady Children’s Hospital in San Diego, California for contributing this case.
F I G U R E 3 2 . 1 . 3 Entrapped hepatocytes retain normal cell plates.
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TUMORS
OF
THE
LIVER
TA BL E 3 2 . 1 . 1 Differential diagnosis of mesenchymal hamartoma
of the liver Diagnosis
Histologic Features
IHC Profile
Mesenchymal hamartoma
2 years, male female
Entrapped hepatocytes, branching bile ducts, myxoid to fibrous stroma
Mixed epithelialmesenchymal hepatoblastoma
5 years, male and female
Epithelial componentembryonal and fetal hepatocytes; mesenchymal components-spindle cells, osteoid, cartilage
Infantile hemangioma
3 years (most in 6 months), female male
Vascular channels CD31, CD34, of variable size; Factor VIII infiltrative edges entrapped hepatocytes and bile ducts
Embryonal sarcoma
6-10 years, male and female
Spindle, stellate, anaplastic, and pleomorphic tumor cells; eosinophilic PAS-D globules, numerous mitosis, necrosis common
FIGURE 32. 1. 4 Bile ducts show branching appearance surrounded by myxoid fibrous stroma.
and are compressed by the surrounding fibrous stroma (Figure 32.1.4). The stroma consists of spindled fibroblasts and small vessels in a myxoid background. No well-formed portal structures are present in the lesion. The cyst walls are composed of loose fibrous tissue and are focally lined by flattened epithelial cells.
Age and Gender
Hepatocyte
Vimentin, Bcl-2
Abbreviations: IHC, immunohistochemical; PASd, periodic acid-Schiff diastase.
D I AG N OS I S
Mesenchymal hamartoma.
D I SC U SSI ON
The principal differential diagnoses of a large liver mass composed of mesenchymal and epithelial (either part of the lesion or entrapped) elements in a young child includes mesenchymal hamartoma, mixed epithelial-mesenchymal hepatoblastoma, infantile hemangioma (IH), and embryonal sarcoma (Table 32.1.1). These lesions typically occur in noncirrhotic livers. Mesenchymal hamartoma is an uncommon benign tumor occurring almost exclusively in children, with the majority of cases presenting in children less than 2 years of age. It is the third most common tumor of the liver in this age group, following hepatoblastoma and IH (1,2). The patients often present with a palpable liver mass, abdominal distention and/or respiratory distress due to compression by the tumor. The pathogenesis of mesenchymal hamartoma remains unclear. The recurrent cytogenetic abnormalities at chromosome 19q13.4 documented in a number of mesenchymal hamartomas support a neoplastic process rather than a postischemia and/or injury reparative phenomenon (3–10). Moreover, accumulating evidence of malignant transformation of occasional mesenchymal hamartoma to embryonal sarcoma and the shared cytogenetic abnormalities at 19q13.4 (8,11–14) suggest these 2 entities are pathogenetically related.
Mesenchymal hamartoma can be solid or cystic with the solid portion typically tan white to gray in color. The cysts usually contain a translucent fluid or a gelatinous material (1). The cysts may develop due to degeneration of the loose mesenchymal tissue in the tumor, and the tumor may enlarge by continued accumulation of fluid into the cysts. The tumors have both epithelial and stromal components. The epithelial component consists of hepatocytes and bile ducts, both of which are surrounded by varying amounts of myxoid to fibrous stroma. The hepatocytes are cytologically normal-appearing and are arranged, for the most part, either in small clusters or in large islands with retention of the normal cell plate architecture. No portal structures are present in the lesion. The bile ducts are typically elongated and many contain compressed lumina with a haphazard, branched appearance. They are often associated with inflammatory infiltrates in or adjacent to ducts. The cyst walls are composed of loose myxoid or dense fibrous tissue that may be devoid of any lining cells or lined by flattened to cuboidal epithelial cells. The stroma typically consists of spindled fibroblasts, inflammatory cells, and variable numbers of small vessels. Extramedullary hematopoiesis is often present. The clinical information and pathological features in the present case strongly support the diagnosis of mesenchymal hamartoma. Hepatoblastoma is the most common liver tumor in children, with about 68% occurring under the age of 2 years and 90% under the age of 5 (2) (see Chapter 28). Tumors are typically large single masses. Clinical presentation may overlap
CASE
32.1:
MESENCHYMAL
with that of mesenchymal hamartoma, but an elevated serum alpha-fetoprotein (AFP) is almost always present in patients with hepatoblastoma (15) and not usually in those with mesenchymal hamartoma. The gross appearance can be variable, but the tumor is often multinodular with foci of hemorrhage and necrosis. The morphology of hepatoblastoma with mixed epithelial and mesenchymal components may cause confusion with mesenchymal hamartoma. Differentiation is based on characteristic histologic features of each. Hepatoblastoma contains embryonal and/or fetal patterns of the epithelial component (hepatocytes), whereas mesenchymal hamartoma shows fairly normal cytologic features in the hepatocytes but arrangement in islands due to the overgrowth of the stroma. The stromal component also helps differentiate the lesions. Mixed epithelial and mesenchymal hepatoblastoma contains spindle cells, osteoid, and cartilage rather than the overgrowth of fibromyxoid stroma in mesenchymal hamartoma. Infantile hemangioma (IH) is the second most common tumor of the liver in children and the age range is similar to that seen in mesenchymal hamartoma (2) (see Case 29.4). Clinically, IH may be associated with heart failure, can be single or multifocal, and most commonly occurs in the right lobe. IHs are usually poorly circumscribed, with sizes varying from a few millimeters to more than 20 cm. This benign tumor consists of proliferating small vessels with plump endothelial cells. Multiple nodules can impart a spongiform appearance. Scattered calcifications and foci of extramedullary hematopoiesis are commonly present. The proliferation of small vessels of variable size and few entrapped bile duct elements are characteristic features. The entrapped bile ducts can lead to the incorrect assumption that the tumor is epithelial or mixed epithelial and mesenchymal. The bile ducts are not elongated with branched appearance as in mesenchymal hamartoma. IHs always express the endothelial markers CD31, CD34, and factor VIII. Embryonal sarcoma is a rare highly aggressive malignant tumor typically occurring in slightly older children than the previously described tumors and in teenagers (see Case 32.2). Grossly embryonal sarcomas are usually large, soft tumors with variegated surface. Areas of hemorrhage, necrosis, and cyst formation are often present. These tumors consist of a mixture of spindled, oval, or stellate-shaped cells with a myxoid stroma. Differentiation of mesenchymal hamartoma from embryonal sarcoma can be difficult in occasional cases, since both lesions may display loose, edematous, myxoid stroma. Although this tumor does not contain an epithelial component, infiltration into adjacent benign liver and entrapment of hepatocytes and portal structures can cause diagnostic concern for an epithelial component. Cytoplasmic and stromal eosinophilic, periodic
HAMARTOMAA
501
acid-Schiff (PAS)-positive and diastase-resistant globules are commonly noted in embryonal sarcoma. In most, the hypercellularity and highly malignant cytologic features, including marked pleomorphism, nuclear atypia, and numerous mitotic figures, are readily evident in contrast to the bland stromal component in mesenchymal hamartoma.
References 1. Stocker JT, Ishak KG. Mesenchymal hamartoma of the liver: report of 30 cases and review of the literature. Pediatr Pathol. 1983;1:245–267. 2. Ishak KG, Goodman ZD, Stocker JT. Tumors of the liver and intrahepatic bile ducts. Atlas of tumor pathology, 3rd Series, Fascicle 31. Washington, DC: Arm Forces Institute of Pathology; 2001. 3. Speleman F, De Telder V, De Potter KR, et al. Cytogenetic analysis of a mesenchymal hamartoma of the liver. Cancer Genet Cytogenet. 1989;1:29–32. 4. Mascarello JT, Krous HF. Second report of a translocation involving 19q13.4 in a mesenchymal hamartoma of the liver. Cancer Genet Cytogenet. 1992;58:141–142. 5. Bove KE, Blough RI, Soukup S. Third report of t(19q)(13.4) in mesenchymal hamartoma of liver with comments on link to embryonal sarcoma. Pediatr Dev Pathol. 1998;1:438–442. 6. Rakheja D, Margraf LR, Tomlinson GE, Schneider NR. Hepatic mesenchymal hamartoma with translocation involving chromosome band 19q13.4: a recurrent abnormality. Cancer Genet Cytogenet. 2004;153:60–63. 7. Talmon GA, Cohen SM. Mesenchymal hamartoma of the liver with an interstitial deletion involving chromosome band 19q13.4: a theory as to pathogenesis? Arch Pathol Lab Med. 2006;130:1216–1218. 8. Rajaram V, Knezevich S, Bove KE, Perry A, Pfeifer JD. DNA sequence of the translocation breakpoints in undifferentiated embryonal sarcoma arising in mesenchymal hamartoma of the liver harboring the t(11;19) (q11;q13.4) translocation. Genes Chromosomes Cancer. 2007;46:508–513. 9. Baboiu OE, Saal H, Collins M. Hepatic mesenchymal hamartoma: cytogenetic analysis of a case and review of the literature. Pediatr Dev Pathol. 2008;11:295–299. 10. Sugito K, Kawashima H, Uekusa S, et al. Mesenchymal hamartoma of the liver originating in the caudate lobe with t(11;19)(q13;q13.4): report of a case. Surg Today. 2010;40:83–87. 11. de Chadarévian JP, Pawel BR, Faerber EN, Weintraub WH. Undifferentiated (embryonal) sarcoma arising in conjunction with mesenchymal hamartoma of the liver. Mod Pathol. 1994;7:490–493. 12. Lauwers GY, Grant LD, Donnelly WH, et al. Hepatic undifferentiated (embryonal) sarcoma arising in a mesenchymal hamartoma. Am J Surg Pathol. 1997;21:1248–1254. 13. Begueret H, Trouette H, Vielh P, et al. Hepatic undifferentiated embryonal sarcoma: malignant evolution of mesenchymal hamartoma? Study of one case with immunohistochemical and flow cytometric emphasis. J Hepatol. 2001;34:178–179. 14. O’Sullivan MJ, Swanson PE, Knoll J, Taboada EM, Dehner LP. Undifferentiated embryonal sarcoma with unusual features arising within mesenchymal hamartoma of the liver: report of a case and review of the literature. Pediatr Dev Pathol. 2001;4:482–489. 15. Schmidt D, Harms D, Lang W. Primary malignant hepatic tumours in childhood. Virchows Arch A Pathol Anat Histopathol. 1985;407:387–405.
Case 32.2
Embryonal Sarcoma WENDY L. FRANKEL AND XIAOPING ZHOU
C L I N I C AL I N F OR M AT I ON
A 23-year-old woman presented with 40 pound weight loss, abdominal fullness, and nonspecific abdominal pain. She has no significant past medical history and denied using medications, or drug abuse. Abdominal CT scan revealed a liver mass with no evidence of cirrhosis or other background liver disease. R E A S ON F OR R E F E R R A L
This tumor had both spindle cell and epithelioid components with focal cytokeratin and diffuse vimentin staining, and so the case was referred for consultation as to whether this represented a sarcoma or carcinoma. PAT H OL OG I C F E AT U R E S
The hepatic lobectomy specimen contained a soft noncapsulated mass measuring greater than 10 cm in greatest dimension. Cut sections show variably tan yellow to white solid mass with areas of hemorrhage, necrosis, and cystic change (Figure 32.2.1). Liver parenchyma away from the mass was unremarkable. Microscopic examination revealed a mixture of spindle and stellate to epithelioid cells (Figures 32.2.2 and 32.2.3). The tumor cells show a granular to bubbly, light eosinophilic cytoplasm and hyperchromatic nuclei. Occasional dense eosinophilic cytoplasmic and stromal globules of various sizes are present that are PAS-positive and resistant to diastase digestion (Figure 32.2.4). Frequent mitotic figures and rare multinucleated giant cells are present. IHC stains show the tumor cells are focally positive for cytokeratin and diffusely positive for vimentin, and negative for Hepatocyte, c-Kit (CD117), S100, CD34, and smooth muscle actin.
F I G U R E 3 2 . 2 . 2 Mixture of spindle and stellate tumor cells with
myxoid stroma.
F I G U R E 3 2 . 2 . 3 Epithelioid tumor cells.
DIAGNO SIS
Embryonal sarcoma of the liver. DISCUSSIO N
FIGURE 32. 2. 1 Embryonal sarcoma. A noncapsulated mass with variably tan yellow to white solid areas and hemorrhage, necrosis, and cystic change on cut sections, gross appearance.
The principal differential diagnosis of a high-grade spindle cell tumor in the liver includes embryonal sarcoma, scirrhous-type hepatocellular carcinoma (HCC) or HCC with sarcomatoid differentiation, gastrointestinal stromal tumor (GIST), highgrade sarcomas including leiomyosarcoma, angiosarcoma, and embryonal rhabdomyosarcoma, epithelioid hemangioendothelioma (EHE), and malignant melanoma (Table 32.2.1).
502
CASE
32.2:
EMBRYONAL
FIGURE 32. 2. 4 Cytoplasmic and stromal periodic acid-Schiff dia-
503
SARCOMA
F I G U R E 3 2 . 2 . 5 Tumor with abundant coagulative necrosis ( 200).
stase positive globules.
Embryonal sarcoma of the liver is a rare, highly aggressive malignant tumor that typically occurs in children between 6 and 10 years of age, with some occurring in young adults (Case 32.1, 2); (1). It is the most common hepatic malignant mesenchymal tumor in children. The pathogenesis is largely unknown. The evidence suggests that at least a subset of embryonal sarcomas arise from mesenchymal hamartomas (Case 32.1, 8, 11–14). The clinical presenting features are often that of a mass or of abdominal pain. Embryonal sarcomas are usually large, well-demarcated soft tumors with a white, shiny, or gelatinous or mucoid cut surface. They are usually solid with multiple areas of
hemorrhage, necrosis, and cystic degeneration. Microscopically, the tumors are composed of a spectrum of spindle, oval, or stellate to epithelioid cells with poorly defined cell borders and nuclear pleomorphism. Scattered pleomorphic giant multinucleated tumor cells are commonly seen (Figure 32.2.5). Intraand extracellular eosinophilic hyaline globules of variable size are often present which are PAS-positive and diastaseresistant. The background stroma is usually myxoid, but some dense collagen may be present. Mitotic activity is usually brisk and extramedullary hematopoiesis is often present. Entrapped hepatocytes and scattered hyperplastic or degenerating bile duct-like structures may be present at the periphery. The tumor cells have been shown to be positive at least focally for
TA B LE 32. 2. 1 Differential diagnosis of embryonal sarcoma of the liver Diagnosis
Age and Gender
Histologic Features
IHC Profile
Embryonal sarcoma
6-10 years, male and female
Spindle, stellate, anaplastic, and pleomorphic tumor cells; eosinophilic PAS-D globules, numerous mitosis, necrosis common
Vimentin, Bcl-2
HCC, scirrhous variant; HCC, with sarcomatoid differentiation
Elderly, rarely children, male and female
Cirrhosis/liver disease in many; polygonal, epithelioid or spindle tumor cells, tumor nests separated by prominent fibrous tissue (scirrhous type)
Hepatocyte, alpha-fetoprotein, p-CEA, glypican-3
Gastrointestinal stromal tumor
Adults, rarely children, male and female
Spindle or epithelioid cells, eosinophilic fibrillary cytoplasm, cytoplasmic vacuoles indenting the nuclear poles
CD117 (c-Kit), DOG1, CD34
Leiomyosarcoma
Adults, male and female
Fascicular bundles of spindle cells intersecting at wide angles, cytoplasmic vacuoles indenting the nuclear poles, elongated nuclei with blunted ends, mitoses, and necrosis
Smooth muscle myosin, actin, desmin, H-caldesmon
Angiosarcoma
Adults, rarely children, male female
Sinusoidal, solid, papillary, and cavernous growth pattern, spindle tumor cells with high-grade atypia, frequent mitoses
CD31, CD34, Factor VIII
Embryonal rhabdomyosarcoma of the biliary tree
Mean 3 years, female male
Botryoid growth pattern, a cambium layer of small blue tumor cells beneath the bile duct epithelium, abundant mitoses
Myogenin, myoD1
Epithelioid hemangioendothelioma
Adults, female male
Epithelioid or spindle (dendritic) cells with myxoid or fibrous stroma, intracellular “capillary” luminal spaces, predilection for invading large vascular structures
CD31, CD34, Factor VIII
Malignant melanoma
Adults, male and female
Epithelioid, polygonal, or spindle cells, melanin pigment may be present
HMB-45, Melan-A, S-100
Abbreviations: HCC, hepatocellular carcinoma; HMB human melanoma black; IHC, immunohistochemical; PAS-D, periodic acid-Schiff diastase; p-CEA, polyclonal carcinoembryonic antigen.
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vimentin, Bcl-2, cytokeratin, desmin, alpha-1 antitrypsin and alpha-1 antichymotrypsin. Hepatocyte, S100, myogenin, and CD34 are usually not expressed (2, 3). The giant cells of this tumor can also stain for glypican-3 (unpublished observation). The pathological features of this tumor support the diagnosis of embryonal sarcoma. Some special types of HCC may enter into the differential diagnosis of embryonal sarcoma. The scirrhous type and HCC with sarcomatoid features can be difficult to distinguish from embryonal sarcoma particularly on small biopsy specimens. The presence of intracellular bile, Mallory-Denk -bodies and nests and trabeculae containing epithelioid/polygonal tumor cells on hematoxylin and eosin (HE) sections strongly support the diagnosis of HCC. In some cases, immunohistochemical stains for one or more hepatocellular markers such as Hepatocyte, AFP, canalicular polyclonal carcinoembryonic antigen (p-CEA), and glypican-3 may be helpful; however, giant cells of embryonal sarcoma can be glypican-3 positive (unpublished observation). The absence of immunoreactivity to hepatocellular markers and presence of vimentin in embryonal sarcoma help in the differential. GISTs of the liver can present as single or multiple nodules that are usually well circumscribed with areas of hemorrhage, necrosis, and cystic degeneration. GISTs are usually composed of spindle cells or epithelioid cells with eosinophilic fibrillary cytoplasm. Cytoplasmic vacuoles indenting the nuclear poles are characteristically present in the spindle cells. Some high-grade tumors contain mitoses and necrosis. Distinguishing GISTs from other tumors composed of spindle and epithelioid cells is particularly important, since treatment using tyrosine kinase inhibitors is effective in some of these tumors. In most cases, the diagnosis of GIST can be reliably established using IHC stains. The majority of GISTs express CD34 and CD117 (c-Kit), and a more recently described marker DOG1 (4). GISTs also would be very unusual tumors at the young age so typical for embryonal sarcoma. Other sarcomas of a wide variety of cell origins occurring in the liver can exhibit spindle and epithelioid cellular morphology. These include but are not limited to leiomyosarcoma, angiosarcoma, and embryonal rhabdomyosarcoma of the biliary tree. Leiomyosarcomas, either primary or metastatic, are typically large well-circumscribed nodules composed of spindled or epithelioid cells. Hemorrhage, necrosis, and cystic degeneration may be present. The spindled cell leiomyosarcoma is composed of fascicular bundles of spindle cells intersecting at wide angles with eosinophilic cytoplasm and elongated nuclei. Cytoplasmic vacuoles indenting the nuclear poles and/or blunted nuclear ends are often present. A panel of immunohistochemical stains is necessary to establish the diagnosis of leiomyosarcoma. Useful markers, such as smooth muscle myosin, actin, desmin, and H-caldesmon, are typically expressed in leiomyosarcomas. Embryonal sarcomas, in contrast, are usually negative for these markers, whereas most are consistently positive for vimentin and Bcl-2 (3). Primary angiosarcoma of the liver is the most common malignant mesenchymal neoplasm of middle-aged adults and rarely occurs in children. Angiosarcomas are often large, dark red to brown, hemorrhagic tumors with indistinct borders and variably solid and cystic areas usually containing blood. A
TUMORS
OF
THE
LIVER
mixed histologic pattern showing sinusoidal, solid, papillary, and cavernous growth types is typically present. The tumor consists of predominantly spindle cells often with high-grade cellular atypia and mitotic activity. The diagnosis of angiosarcoma usually requires positive IHC stains for endothelial markers, such as CD31, CD34, and factor VIII in tumor cells. Embryonal rhabdomyosarcoma of the biliary tree is a rare malignant tumor that typically occurs in young children with a mean age of 3 years (Case 32.1, 2). Tumors characteristically show a botryoid growth pattern. Microscopically, the poorly differentiated small blue tumor cells cluster beneath the bile duct epithelium forming a cambium layer. Abundant mitoses are usually present. On routine HE section, these small tumor cells display little evidence of myogenic differentiation; hence, cross-striations are rarely seen. IHC stains for skeletal muscle differentiation markers, such as myogenin, MyoD1, myosin, muscle-specific actin, and desmin, are usually required to establish the diagnosis. Myogenin and MyoD1 are the most sensitive and specific markers for this type of tumor (5). EHE is a rare, lower-grade malignancy occurring in adults of any age with a female predominance (see Case 29.2). Presenting symptoms and signs are nonspecific and may include abdominal discomfort or a mass lesion. EHEs are firm, white to yellow tumors that are usually multifocal and involve both liver lobes. Tumors are comprised of either epithelioid or dendritic cells with myxoid or fibrous stroma. Cytoplasmic vacuoles representing intracellular “capillary” luminal space may be present. Entrapped hepatocytes and bile ducts may be present at the periphery of the tumor. EHE also shows a predilection for invading large vascular structures, such as portal and central veins. Differentiation of this tumor from embryonal sarcoma may be difficult at times on HE stain. However, a panel of IHC stains including endothelial markers such as CD31, CD34, and factor VIII helps confirm the diagnosis. Malignant melanomas are composed of epithelioid or polygonal cells and, less commonly, may contain spindle cells. The finding of melanin pigments within the cells is helpful but not always present. The IHC stains can help separate melanomas from sarcomas such as embryonal sarcoma. The majority of malignant melanomas express one or more melanocytic markers such as human melanoma black (HMB)-45 and Melan-A, and S100.
References 1. Stocker JT, Ishak KG. Undifferentiated (embryonal) sarcoma of the liver: report of 31 cases. Cancer. 1978;42:336–348. 2. Lack EE, Schloo BL, Azumi N, Travis WD, Grier HE, Kozakewich HP. Undifferentiated (embryonal) sarcoma of the liver. Clinical and pathologic study of 16 cases with emphasis on immunohistochemical features. Am J Surg Pathol. 1991;15:1–16. 3. Kiani B, Ferrell LD, Qualman S, Frankel WL. Immunohistochemical analysis of embryonal sarcoma of the liver. Appl Immunohistochem Mol Morphol. 2006;14:193–197. 4. West RB, Corless CL, Chen X, et al. The novel marker, DOG1, is expressed ubiquitously in gastrointestinal stromal tumors irrespective of KIT or PDGFRA mutation status. Am J Pathol. 2004;165:107–113. 5. Morotti RA, Nicol KK, Parham DM, et al. An immunohistochemical algorithm to facilitate diagnosis and subtyping of rhabdomyosarcoma: the children’s oncology group experience. Am J Surg Pathol. 2006;30:962–968.
Case 32.3
Angiomyolipoma CHERISE MARIE CORTESE AND RAOUF E. NAKHLEH
C L I N IC AL I N F OR M AT I ON
This 60-year-old Caucasian male suffered from end-stage liver disease secondary to alcohol use and refractory ascites requiring transjugular intrahepatic portosystemic shunt procedure prior to treatment. He underwent a liver transplant. Examination of the native liver revealed a prominent 1.2 cm tan nodule near the hilum. R E A SON F OR R E F E R R AL
In the setting of cirrhosis, the diagnosis was unclear as to whether this lesion was hepatocellular carcinoma (HCC), an unusual stromal tumor, or perhaps a metastatic lesion. PAT H OL OG I C F E AT U R E S
The diffusely nodular native liver weighed 1210 grams. Serial sectioning revealed a prominent 1.2 cm tan nodule near the hilum. Microscopically, in a background of cirrhosis, the nodule was well demarcated, but not encapsulated, and entrapped a portal tract. The nodule was very cellular with a solid growth pattern. There was variable morphology. Some of the cells were epithelioid with slightly pleomorphic nuclei and occasional nucleoli, without mitoses. There was eosinophilic cytoplasm with peripheral clearing. Other areas were more cellular with a hepatoid look, crowded nuclei, and less cytoplasm (Figure 32.3.1). Focally, the cells were spindled with cytoplasmic clearing. Occasional thick-walled vessels were seen. There was a small amount of fat within the tumor. Immunostains revealed the tumor cells to be diffusely positive for HMB-45 (Figure 32.3.2), actin positive in spindled
FIGURE 32. 3. 1 Tumor myoepithelial cells, some with crowded
nuclei and less cytoplasm.
F I G U R E 3 2 . 3 . 2 Diffuse positive staining of tumor cells with HMB 45 immunohistochemistry.
areas and vessels, and S-100 positive in fat. Keratin (AE1/ AE3) and Cam 5.2 were negative.
DIAGNO SIS
Angiomyolipoma of the liver.
DISCUSSIO N
Angiomyolipoma (AML) is most commonly found in the kidney, especially in the setting of tuberous sclerosis. However, angiomyolipoma can arise in the liver. Hepatic AML occurs primarily in adults in the third decade to an age of about 70 and predominantly in women. They are often found incidentally. In the liver, AML are typically single lesions, although multiple lesions have been identified (1). They may vary in size from less than 1 cm to as large as 36 cm (2). The larger lesions often cause abdominal pain or a feeling of fullness, related to space-occupying effects. There is a risk of rupture of the larger tumors (3). Radiographically, AML of the liver is often a difficult diagnosis to make, especially if the fat content is low (4). Other fat-containing hepatocellular neoplasms such as hepatocellular carcinoma can be difficult to distinguish from AML. Fine needle aspiration biopsy is often performed at the time of imaging to assist in the diagnosis. Grossly, AMLs are usually soft, yellow, tan, or grey and may contain areas of hemorrhage. They are often well circumscribed but not encapsulated. Microscopically, they are composed of 3 main cell types, vessels (angio), smooth muscles
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cells (myo), and adipose tissue (lipoma). The vessels show hallmark changes of tortuous thick walls and loss of elastic lamina (Figure 32.3.3). They may be rimmed by epithelioid smooth muscle cells. The smooth muscle cells may be of 4 types: spindle-shaped, intermediate, epithelioid, and pleomorphic (5). The epithelioid variant contains large polygonal cells which may be arranged in sheets, with central cytoplasmic granular eosinophilic material and peripheral clearing, lending to a spider web appearance (Figure 32.3.4). Spindled smooth muscle cells have pale or clear cytoplasm and may be arranged in fascicles. Their nuclei are round to oval with moderate pleomorphism. A distinct nucleolus can be seen. Unusual smooth muscle cell types include clear cell change, oncocytic change, and pleomorphic type (6). The adipose tissue is comprised of benign appearing adipose cells with small nuclei and clear cytoplasm. The fat is usually mature; however, occasional lipoblast-like cells may be seen (Figure 32.3.5).
TUMORS
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THE
LIVER
Hematopoietic cells may also be seen in hepatic AMLs. The tumor cells may be arranged in different patterns, including trabecular, pelioid, pleomorphic, or inflammatory (6), the trabecular pattern often causing confusion with hepatocellular carcinoma. The 3 components of cells can be distributed in different manners, with a lipomatous variant (>70% fat), myomatous or epithelioid variants (<10% fat or even without fat), an angiomatous variant, and a mixed variant, which is most common (7). Immunohistochemistry may be helpful in the diagnosis of AML. The smooth muscle cells are variably positive for actin and desmin (Figure 32.3.6). They are usually strongly positive for Melan A and HMB 45 as well as other melanin markers, including HBSA5, MART-1, HMB-50, and CD63 (NKIC-3)(6), confirmed by the ultrastructural findings of premelanosome-like electron dense granules on electron microscopy (8). The adipose cells are positive for S100. Most AMLs are positive for CD117 (9).
FIGURE 32. 3. 3 Thick-walled vessels that are characteristic of
angiomyolipoma.
F I G U R E 3 2 . 3 . 5 Mature fat within the tumor.
FIGURE 32. 3. 4 Myoepithelial cells with cytoplasmic clearing and
small clusters of lymphocytes.
F I G U R E 3 2 . 3 . 6 Variable positivity with actin in tumor cells.
CASE
32.3:
ANGIOMYOLIPOMA
Molecular analysis of sporadic AMLs has shown most of the tumors to be monoclonal with no evidence of loss of heterozygosity or microsatellite instability (10). There have been documented cases of malignant transformation and metastatic spread in hepatic AML (11,12,13). Most of these cases had distinguishing features of malignant AML (11); they were large (.10 cm), had extreme cellular and nuclear pleomorphism with increased mitotic figures (2–5/ HPF), and had areas of coagulative necrosis. Vascular invasion was identified and IHC revealed weak or absent CD117 staining (see Chapter 32.5). Recently, case reports of hepatic AML with coincidental HCC have been published (14). A case of synchronous hepatic AML and lung AML (15), AML of liver with trace amounts of fat (5), multiple hepatic AMLs with omental AML (1), a pedunculated hepatic AML (16), AML causing Budd-Chiari syndrome (17), hepatic AML with inflammatory pseudotumor features (18) (see Chapter 32.3), and hepatic AML with giant cell component (19) have also been described. Treatment of AML is resection, if the lesion is large and worrisome for rupture or if there is a suggestion of malignant features. Conservative treatment may be used, with imaging and close follow-up. The histogenesis of AML is unknown. It has been considered a mesenchymal hamartoma, and, more recently, a neoplastic lesion of perivascular epithelioid cells (PECs) (8,20), labeling it a perivascular epithelioid cell tumor (PEComa). This classification is based on the HMB-45 positivity and the cytokeratin negativity, along with histology. A recent article showed that hepatic AML had a similar gene expression profile of hepatic stellate cells and may differentiate toward this cell line; however, only 1 tumor was examined (21). Recently, it has been suggested that AML is a neoplasm of stem cells, based on the expression of NG2 and L1 cell markers, which are also expressed by stem cells (22). The differential diagnosis of hepatic AML includes several liver tumors such as hepatocellular carcinoma, adenoma, and hepatoblastoma as well as leiomyoma, melanoma, and gastrointestinal stromal tumor. Clinical and radiologic parameters may help in the diagnosis. Histology is not always helpful in differentiation; however, IHC can aid in making the proper diagnosis. AML is positive for melanoma markers and, in contrast, the other tumors are negative with the exception of melanoma. AML is negative for CAM 5.2 and HepPar-1, which are generally positive in hepatocellular carcinoma (HCCA). Hepatoblastoma, which is usually seen in the pediatric population, is positive for keratin; AML is not. Leiomyoma is melanoma marker negative. In melanoma, the tumor cells are S100 positive, whereas in AML the smooth muscle cells are S100 negative. Gastrointestinal stromal tumor (GIST) is melanoma marker negative.
507
References 1. Takamura K, Miyake H, Fujii M, Nishi M, Tashiro S, Shimada M. Multiple hepatic angiomyolipomas with a solitary omental angiomyolipoma. J Med Invest. 2005;52:218–222. 2. Petrolla A, Xin W. Hepatic angiomyolipoma. Arch Pathol Lab Med. 2008;132:1679–1682. 3. Guidi G, Catalano O, Rotondo A. Spontaneous rupture of a hepatic angiomyolipoma: CT findings and literature review. Eur Radiol. 1997;7:335–337. 4. Zheng R, Kudo M. Hepatic angiomyolipoma: identification of an efferent vessel to be hepatic vein by contrast-enhanced harmonic ultrasound. Brit J Radiol. 2005;78(934):956–960. 5. Wang S, Tsai K, Lee K. Hepatic angiomyolipoma with trace amounts of fat: a case report and literature review. J Clin Pathol. 2006;59:1196–1199. 6. Tsui W, Colombari R, Portmann B, et al. Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants. Am J Surg Pathol. 1999;23:34–48. 7. Takahara M, Miyake Y, Matsumoto K, et al. A case of hepatic angiomyolipoma difficult to distinguish from hepatocellular carcinoma. World J Gastroenterol. 2009;15(23):2930–2932. 8. Hornick J, Fletcher C. PEComa: what do we know so far? Histopathology. 2006;48:75–82. 9. Makhlouf H, Remotti H, Ishak K. Expression of KIT (CD117) in angiomyolipoma. Am J Surg Pathol. 2002;26(4):493–497. 10. Xu A, Zhang S, Zheng J, Zheng WQ, Wu MC. Pathological and molecular analysis of sporadic hepatic angiomyolipoma. Hum Pathol. 2006;37:735–741. 11. Nguyen T, Gorman B, Shields D, et al. Malignant hepatic angiomyolipoma: report of a case and review of literature. Am J Surg Pathol. 2008;32(5):793–798. 12. Dalle I, Sciot R, De Vos, R, et al. Malignant angiomyolipoma of the liver: a hitherto unreported variant. Histopathology. 2000;36:443–450. 13. Deng Y, Lin Q, Zhang S, Ling Y, He J, Chen X. Malignant angiomyolipoma in the liver: a case report with pathological and molecular findings. Pathol Res Pract. 2008;204:911–918. 14. Yang B, Chen W, Shi P, Xiang JJ, Xu RJ, Liu JH. Coincidence of hepatocellular carcinoma and hepatic angiomyolipomas in tuberous sclerosis complex: a case report. World J Gastroenterol. 2008;14(5):812–814. 15. Garcia T, Mestre de Juan M. Angiomyolipoma of the liver and lung: a case explained by the presence of perivascular epithelioid cells. Pathol Res Pract. 2002;198:363–367. 16. Akatsu T, Sakamoto M, Shimazu M, Kitajima M. Pedunculated angiomyolipoma of the liver with a predominant pelioid pattern. Virchows Arch. 2004;444:467–469. 17. Sebastian S, Tuite D, Torreggiani W, Crotty P, Buckley M. Angiomyolipoma of the liver causing Budd-Chiari syndrome. J Gastroenterol Hepatol. 2004;19(6):722–723. 18. Kojima M, Nakamura S, Ohno Y, Sugihara S, Sakata N, Masawa N. Hepatic anigomyolipoma resembling an inflammatory pseudotumor of the liver. A case report. Pathol Res and Pract. 2004;200:713–716. 19. Alatassi H, Sahoo S. Epithelioid angiomyolipoma of the liver with striking giant cell component: fine-needle aspiration biopsy findings of a rare neoplasm. Diag Cytopathol. 2009;37(3):192–194. 20. Folpe A, Kwiatkowski D. Perivascular epithelioid cell neoplasms: pathology and pathogenesis. Human Path. 2010;41:1–15. 21. Kannangai R, Diehl A, Sicklick J, Rojkind M, Thomas D, Torbenson M. Hepatic angiomyolipoma and hepatic stellate cells share a similar gene expression profile. Hum Pathol. 2005;36:341–347. 22. Lim S, Stallcup W, Lefkove B, et al. Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells? Mol Med. 2007;13(3–4):160–165.
Case 32.4
Angiomyolipoma, Inflammatory Variant LINDA D. FERRELL
C L I N I C AL I N F OR M AT I ON
A 40-year-old man presented with weight loss, chills, and fever. CT scan demonstrated a highly vascular lesion in the right lobe. The preoperative diagnosis based on needle biopsy was inflammatory pseudotumor. After several months of treatment with antibiotics, there was no change in the mass on CT scan. Surgical resection revealed a 3.5 3 3.0 3 3.2 encapsulated, friable, tan tumor with intraoperative impression being hemangioma. R E A S ON F OR R E F E R R A L
The referring pathologist favored a benign process but was not able to put a specific name to the lesion. Considerations included ectopic splenic tissue and juvenile hemangioma due to the prominence of the lymphoid infiltrate and rich vascularity. PAT H OL OG I C F E AT U R E S
F I G U R E 3 2 . 4 . 2 High magnification of the trabecular regions demonstrates the mix of mononuclear cells with the spindled and somewhat epithelioid cells, and the trabeculae are lined by endothelial cells. The endothelial-lined spaces contain rare red blood cells.
The resected tumor showed 2 major components: mononuclear inflammation and spindle cell/vascular network (Figure 32.4.1). The prominent inflammatory component consisted predominantly of small lymphocytes (Figures 32.4.2 and 32.4.3), which were CD31 and CD8+ on immunohistochemical staining. Occasional plasma cells and mast cells, the latter identified on CD117 immunostain were also present. The
F I G U R E 3 2 . 4 . 3 A region of tumor that is essentially overrun by mononuclear cells, mostly lymphocytes.
FIGURE 32. 4. 1 The tumor in this region has a focally prominent
inflammatory cell infiltrate that is composed mostly of lymphocytes. The background shows spindly to vaguely epithelioid tumor cells with trabecular-like framework. Inflammatory cells are also admixed with tumor cells in these regions as well.
inflammatory component alternated and was admixed with zones of somewhat spindled cells with small oval to spindleshaped nuclei and slightly vacuolated to bubbly cytoplasm. These cells were arranged in trabeculae lined by a single layer of endothelial cells, the latter CD341 positive on immunostain. The endothelial cells lined vascular spaces without blood components and were wrapped around the spindled cells (Figure 32.4.2). Focal areas of fibrosis in regions of the spindled cells were scattered throughout the tumor. The tumor
508
CASE
32.4:
ANGIOMYOLIPOMA,
FIGURE 32. 4. 4 HMB-45 immunohistochemistry highlights numer-
ous epithelioid cells within the tumor.
was encapsulated by fibrous tissue, which was interrupted by tumor extending into capsule. Lymphoid aggregates were present outside of the capsule. Desmin immunostain was negative for any muscle component in the lesion, and CD117 (C-kit) stain was negative except for isolated mast cells. HMB-45 immunostain demonstrated scattered cytoplasmic staining in the spindle-cell component (Figure 32.4.4) but was negative in the solid areas of small lymphocytes or fibrotic zones. Smooth muscle actin (SMA) was positive in small to medium-sized artery-like vesselsand focally positive in periendothelial zones and spindled tumor cells (Figure 32.4.5).
D I AG N OS I S
Angiomyolipoma, inflammatory (pseudotumor-like) variant.
I N F L A M M AT O RY
VA R I A N T
509
F I G U R E 3 2 . 4 . 5 Smooth muscle actin immunohistochemistry highlights an abnormal vessel and scattered cells in the tumor.
DISCUSSIO N
This case demonstrates an unusual variant of AML that can occur in the liver as described well by Tsui, et al (1). Other variants and differential diagnosis of AML are discussed in Case 32.3 and 32.5. The diagnosis by needle biopsy may be very difficult due to the unusual morphological features of this variant, particularly if the sample primarily contains the edge of the lesion with the fibrous capsule and pericapsular lymphoid infiltrates. Recognition can be challenging even on resection as it mimics inflammatory pseudotumor, although the vascular nature of the lesion both grossly and microscopically provides clues for the diagnosis. The key in the diagnosis of this AML variant is to recognize the tumor cells with bland cytology and foamy to bubbly cytoplasm, in combination with the vascular network.
Reference 1. Tsui WMS, Colombari R, Bonetti F, et al. Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphological variants. Am J Surg Pathol. 1999;23:34–48.
Case 32.5
Malignant Angiomyolipoma—Malignant Perivascular Epithelioid Cell Tumor WILLIAM A. AHRENS
C L I N I C AL I N F OR M AT I ON
A 53-year-old woman presented with weakness, weight loss, and abdominal pain for several months. Imaging studies revealed a large mass in the right lobe of the liver without evidence of cirrhosis. CT scans of the chest/abdomen/pelvis did not identify any other sites of disease. A needle biopsy performed of the lesion was diagnosed as “consistent with high-grade malignant neoplasm.” The patient subsequently underwent hepatic trisegmentectomy. R E A S ON F OR R E F E R R A L
This case was sent for consultation for further possible classification of an anaplastic malignant neoplasm in the absence of chronic liver disease. The differential diagnosis included poorly differentiated hepatocellular carcinoma, metastatic “hepatoid” carcinoma, epithelioid form of sarcoma, poorly differentiated cholangiocarcinoma, and metastatic melanoma.
F I G U R E 3 2 . 5 . 2 Undifferentiated/pleomorphic tumor with giant
cells ( 3200).
PAT H OL OG I C F E AT U R E S
The trisegmentectomy specimen contained a large (17.5 cm) multilobulated mass (Figure 32.5.1). The tumor was undifferentiated with highly pleomorphic epithelioid cells with clear cytoplasm, including tumor giant cells, arranged in a nested/organoid pattern (Figure 32.5.2). There was a prominent sinusoidal-type vascular pattern, and abundant tumor coagulative necrosis was also present (Figure 32.5.3). The mitotic rate was high and many atypical mitoses were present (Figure 32.5.4). Immunostains revealed tumor cell positivity for HMB-45 (Figure 32.5.5), melan A, tyrosinase, and vimentin. Focal SMA staining was present (Figure 32.5.6). Stains for
F I G U R E 3 2 . 5 . 3 Tumor with abundant coagulative necrosis ( 200).
FIGURE 32. 5. 1 Gross image of tumor.
hepar-1, AFP, Cam 5.2, thyroid transcription factor 1 (TTF-1), MOC-31, wide spectrum keratin, S-100, CD117, carcinoembryonic antigen (CEA), Oscar-keratin, myosin, and desmin were all negative. In situ hybridization for albumin was also negative. The patient developed widespread peritoneal metastasis, as well as distant organ metastasis and died 9 months after the initial tumor resection (Figure 32.5.7). 510
CASE
32.5:
MALIGNANT
FIGURE 32. 5. 4 Tumor with atypical mitosis ( 200).
ANGIOMYOLIPOMA
511
F I G U R E 3 2 . 5 . 7 Pulmonary metastasis at autopsy ( 200).
DIAGNO SIS
Malignant angiomyolipoma—malignant perivascular epithelioid cell tumor (PEComa).
DISCUSSIO N
FIGURE 32. 5. 5 HMB45 Immunostain ( 200).
FIGURE 32. 5. 6 Smooth muscle actin immunostain ( 200).
The morphologic features demonstrated by the tumor, in conjunction with the immunohistochemical profile and negative albumin in situ hybridization study, is consistent with a malignant angiomyolipoma (malignant PEComa). Perivascular epithelioid cell neoplasms (PEComas) are tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells. The PEComa family includes angiomyolipoma, clear cell sugar tumor, lymphangioleiomyomatosis, and a variety of visceral/soft tissue tumors. PEComas exhibit both muscle and melanocytic (“myomelanocytic”) differentiation with co-expression of SMA/Myosin/Calponin and HMB-45/Melan-A/Tyrosinase/ microphthalmia transcription factor (MITF). After their initial recognition in the kidney, AML was described to occur primarily in the liver (1). It is frequently an incidental finding. They can be multiple and in the vast majority of cases behave in a benign fashion (2). The typical histology includes a heterogeneous mixture of blood vessels, smooth muscle, and adipose tissue in varying proportion and distribution. Although this pattern is distinctive, “monotypic” AML, specifically epithelioid AML, is not uncommon, and in those cases the lack of vascular and myoid/spindled components may make diagnosis challenging (2–3). The differential diagnosis when considering AML, including malignant AML, covers both primary hepatic lesions and a variety of tumors that may metastasize to the liver. The typical immunohistochemical findings of lesions that would more commonly enter the differential diagnosis are summarized in Table 32.5.1.
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TA B LE 32. 5. 1 Lesions commonly in the differential diagnosis of
AML and malignant AML Diagnosis
Typical Immunohistochemical Profile
Hepatocellular carcinoma
Positive: Hep Par 1, p-CEA, GPC-3, AFP Negative: HMB45, Melan A, SMA
Renal cell carcinoma
Positive: PAX-2, RCCa, CK, EMA, Negative: HMB45, Melan A, SMA
Melanoma
Positive: S-100, HMB-45, Melan A, GPC-3 Negative: SMA, Myosin, Calponin
Clear cell neuroendocrine tumors
Positive: CG, Syn, CD56 Negative: HMB-45, Melan A, SMA
Adrenal cortical carcinoma
Positive: Inhibin, Melan A, Calretinin Negative: SMA, Myosin, Calponin
Gastrointestinal stromal tumor
Positive: CD117, CD34 Negative: HMB45, Melan A
Abbreviations: AFP, alpha-fetoprotein; AML, angiomyolipoma; CEA, carcinoembryonic antigen; CG, chromogranin; CK, cytokeratin; EMA, epithelial membrane antigen; GPC, glypican-3; Hep Par 1, hepatocyte antigen; HMB-45, human melanoma black 45; PAX-2, paired homeobox-2p; p-CEA, polyclonal carcinoembryonic antigen; RCCa, renal cell carcinoma antigen; SMA, smooth muscle actin; Syn, synaptophysin.
HCC is the primary entity that must be excluded to secure a diagnosis of malignant AML. The morphologic overlap may be significant and, in fact, it is likely that examples of malignant AML have been called HCC in the past. A background chronic injury pattern would point toward HCC; however, HCC may rarely arise in the absence of chronic liver injury. Where the nonneoplastic liver has been commented on in examples of malignant AML, as in the presented case, chronic hepatitis/fibrosis/etc. has not been present. It is conceivable that AML could arise in a background of chronic liver injury, so again this is not absolute. Immunohistochemistry can be utilized given that HCC will not demonstrate the “myomelanocytic” phenotype of AML. HMB-45/Melan-A/Tyrosinase/ MITF and SMA/Myosin/Calponin should be helpful. Hep Par 1 is a specific marker in this clinical context and should be positive in HCC (4). AFP, cytokeratins, and p-CEA, though not as specific, may be used as well for cases of HCC. Glypican-3 can be especially helpful in poorly differentiated HCC (5). Hepatocellular adenoma is a more likely consideration when a benign AML is encountered, specifically oncocytic or epithelioid variants without significant atypia. Clinical clues such as a history of oral contraceptive use, in conjunction with immunohistochemistry (Hep Par 1, HMB45, SMA, cytokeratin) should be sufficient to distinguish adenoma from AML. The liver is a very common site of metastatic disease, and a variety of nonhepatic primaries must be excluded when considering AML. Clear cell (Conventional) renal cell carcinoma, melanoma, adrenal cortical carcinoma, neuroendocrine carcinoma with clear cell features, and GIST may show both morphologic and immunohistochemical overlap. Sarcomas including epithelioid sarcoma and alveolar soft parts sarcoma could rarely be considered. Correlation with imaging studies is very helpful as a first step in identifying a potential primary
TUMORS
OF
THE
LIVER
lesion. In the presented case, initial imaging studies did not reveal other sites of disease. Autopsy did show widespread peritoneal metastasis as well as pulmonary lesions and a single adrenal (1 cm) metastasis. Involvement of perirenal adipose tissue was present. However, no parenchymal renal lesions were present. Clear cell renal cell carcinoma (RCC) frequently exhibits the clear cytoplasm and vascular pattern typical of AML. RCC with sarcomatoid differentiation can also mimic malignant AML. The expression of cytokeratin and epithelial membrane antigen would be helpful to identify RCC. Pax-2, important in renal development, will successfully identify 85% of metastatic RCC (6). RCC antigen will stain approximately 80% of RCC as well (7). This panel should successfully distinguish RCC and malignant AML. Melanoma may assume a variety of histologic appearances, many of which (balloon cell, spindle cell, etc.) may resemble both benign and malignant AML. Immunohistochemical markers expressed by melanoma such as S-100, HMB-45, and Melan A may further complicate distinction from AML. CD117 expression can also be present in both melanoma and benign hepatic AML as well (8). Melanoma should not show muscle marker positivity in any significant fashion. Therefore, a panel of markers to include SMA, muscle-specific actin, calponin, etc. should be utilized to exclude melanoma. Adrenal cortical carcinomas (ACC) frequently have clear cells that can mimic AML. Although a significant proportion (89%) of ACC express Melan A, as would be seen in AML, the addition of inhibin and calretinin should be sufficient to exclude ACC from the differential diagnosis (9). In addition, synaptophysin expression, lacking in AML, can be used. Neuroendocrine carcinomas frequently metastasize to the liver and may rarely demonstrate cytoplasmic clearing thus entering the differential diagnosis. The majority of those will express one or more neuroendocrine markers (chromogranin, synaptophysin). Similar to melanoma, GIST can assume a wide variety of histologic appearances (10). CD117 expression, present in the vast majority of GIST from all anatomic locations, as previously mentioned, may also be seen in benign hepatic AML. In the small number of malignant hepatic AML, which have been studied, CD117 expression has not been seen (11). However, this lack of expression should be interpreted with caution as the number of cases evaluated is small and CD117 expression may ultimately be demonstrated as awareness of malignant hepatic AML increases and additional cases emerge. Muscle marker positivity (SMA/HHF-35) may be seen in GIST. However, expression of melanocytic markers is not seen. Finally, metastatic lesions derived from carcinomas, and even sarcomas, from a wide variety of anatomic locations may demonstrate morphologic features that can overlap with AML. In each case, the clinical context (imaging, prior history) should be considered with a specific immunohistochemical evaluation to confirm the diagnosis. The diagnosis of malignant AML should be approached with caution as nuclear and cytologic atypia is frequently
CASE
32.5:
MALIGNANT
seen in otherwise benign AML. Bizarre giant cells can be common and are generally considered a degenerative phenomenon. In addition, an infiltrative pattern of growth can be seen and by itself does not portend malignant or aggressive behavior (12). Definitive criteria for malignancy for hepatic AML have not been established. In PEComa of soft tissue or gynecologic origin, the presence of two or more of the following features is strongly associated with recurrence or metastasis: size more than 5 cm, infiltrative growth pattern, high nuclear grade/cellularity, mitotic rate more than 1/50 HPF, necrosis and vascular invasion (13). In their review of 4 cases of malignant AML, Nguyen et al noted coagulative necrosis, lesion size more than 10 cm, evidence of metastasis, or death directly attributable to tumor and lack of CD117 expression to be features associated with all malignant hepatic AML recorded in the literature (11). The presented case displayed all of the features associated with aggressive/malignant behavior. As seen with the previous cases, the current patient’s death was directly attributable to her tumor.
References 1. Ishak KG. Mesenchymal tumors of the liver. In: Okuda K, Peters RL, eds. Hepatocellular Carcinoma. New York, NY: John Wiley & Sons; 1976:247–304. 2. Tsui WM, Colombari R, Portmann BC, et al. Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants. Am J Surg Pathol. 1999;23:34–48. 3. Yamasaki S, Tanaka S, Fujii H, et al. Monotypic epithelioid angiomyolipoma of the liver. Histopathology. 2000;36:451–456.
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4. Kakar S, Muir T, Murphy LM, Lloyd RV, Burgart LJ. Immunoreactivity of Hep Par 1 in hepatic and extrahepatic tumors and its correlation with albumin in situ hybridization in hepatocellular carcinoma. Am J Clin Pathol. 2003;119(3):361–366. 5. Shafizadeh N, Ferrell LD, Kakar S. Utility and limitations of glypican-3 expression for the diagnosis of hepatocellular carcinoma at both ends of the differentiation spectrum Mod Pathol. 2008;21:1011–1018. 6. Gokden N, Gokden M, Phan DC, McKenney JK. The utility of PAX-2 in distinguishing metastatic clear cell renal cell carcinoma from its morphologic mimics: an immunohistochemical study with comparison to renal cell carcinoma marker. Am J Surg Pathol. 2008;32:1462–1467. 7. McGregor DK, Khurana KK, Cao C et al. Diagnosing primary and metastatic renal cell carcinoma: the use of the monoclonal antibody “Renal Cell Carcinoma Marker.” Am J Surg Pathol. 2001;25(12):1485–1492. 8. Makhlouf HR, Remotti HE, Ishak KG. Expression of KIT (CD117) in angiomyolipoma. Am J Surg Pathol. 2002; 26:493–497. 9. Zhang PJ, Genega EM, Tomaszewski JE, Pasha TL, LiVolsi VA. The role of calretinin, inhibin, Melan-A, BCL-2 and C-KIT in differentiating adrenal cortical and medullary tumors: an immunohistochemical study. Mod Pathol. 2003;16(6):591–597. 10. Miettinen M, Sobin LH, Lasota J. Gastrointestinal stromal tumors of the stomach: a clinicopathologic, immunohistochemical, and molecular genetic study of 1765 cases with long-term follow-up. Am J Surg Pathol. 2005;29(1):52–68. 11. Nguyen TT, Gorman B, Shields D, Goodman Z. Malignant hepatic angiomyolipoma: report of a case and review of literature. Am J Surg Pathol. 2008;32(5):793–798. 12. Nonomura A, Mizukami Y, Kadoya M, et al. Angiomyolipoma of the liver: its clinical and pathological diversity. J Hepato-Biliary Pancreatic Surg. 1996;3:122–132. 13. Folpe AL, Mentzel T, Lehr HA, Fisher C, Balzer BL, Weiss SW. Perivascular epithelioid cell neoplasms of soft tissue and gynecologic origin: a clinicopathologic study of 26 cases and review of the literature. Am J Surg Pathol. 2005;29:1558–1575.
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Appendix A Adequacy of Needle Biopsy
There are 2 types of liver biopsies, depending on the needles used (1): a. Thin needle biopsies. These typically yield cores with a diameter of less than 1 mm. This width is adequate for evaluation of mass lesions but is not recommended for evaluation of diffuse liver diseases (2). b. Large needle biopsies. These can be performed using suction needles (Menghini, Klatskin, Jamshidi) or cutting needles (Vim-Silverman, Tru-cut). Cutting needles have increased risk of bleeding compared with suction needles but are less prone to fragmentation when significant fibrosis is present (3). The use of spring-loaded mechanism with cutting needles decreases the risk of bleeding. Most liver biopsies are performed using the percutaneous approach with or without ultrasonic guidance. The transjugular approach can be used in patients in whom the percutaneous approach is contraindicated due to risk of bleeding. Transjugular biopsies tend to be thin and are prone to fragmentation (3). However, multiple passes can be performed without increasing the risk of bleeding (4). Adequacy of liver biopsy directly influences the histologic evaluation, especially in assessment of bile duct loss, and grading and staging of chronic liver disease. It has been
shown that inadequate biopsies lead to erroneous assignments of lower grade and stage (2). Biopsies that are less than 1.5 cm in length and less than 1 mm in width have a significant risk of under-grading and under-staging. It has been recommended that more than 11 complete portal tracts are necessary for accurate grading and staging of the disease (2,4). However, it is difficult to define adequacy by the number of portal tracts alone and this judgment should be made by the pathologist while evaluating the liver biopsy (1). It is prudent to include a statement about adequacy of the liver biopsy in the pathology report by commenting on the number of complete portal tracts and fragmentation.
References
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1. Demetris AJ, Ruppert K. Pathologist’s perspective on liver needle biopsy size? J Hepatol. 2003;39:275–277. 2. Colloredo G, Guido M, Sonzogni A, Leandro G. Impact of liver biopsy size on histological evaluation of chronic viral hepatitis: the smaller the sample, the milder the disease. J Hepatol. 2003;39:239–244. 3. Bravo AA, Sheth SG, Chopra S. Liver biopsy. N Engl J Med. 2001; 344:495–500. 4. Cholongitas E, Quaglia A, Dhillon AP, Patch D, Burroughs AK. Length versus width in liver biopsies. J Hepatol. 2006;44:822–823; author’s reply 823–824.
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Appendix B Grading and Staging
C H RON I C H E PAT I T I S
TA BL E 3 Scheuer grading system
It is standard practice to provide grading and staging for chronic hepatitides like viral hepatitis and autoimmune hepatitis. Several systems are currently in use, each with its advantages and disadvantages, and yield reasonably good inter- and intra-observer reproducibility. The most commonly used systems include Batts-Ludwig (1), Scheuer (2,3), Metavir (4,5), and Ishak (6) systems (Tables 1–8). Irrespective of which system is used, it is important to mention the name of the system in the pathology report to avoid misinterpretation. For example, cirrhosis is assigned stage 4 in Batts-Ludwig system but signifies bridging fibrosis without regenerative nodules in the Ishak system.
Grade
Portal/Periportal Activity
Lobular Activity
Grade 0
None
None
Grade 1
Portal inflammation
Inflammation but no necrosis
Grade 2
Mild piecemeal necrosis
Focal necrosis or acidophil bodies
Grade 3
Moderate piecemeal necrosis
Severe focal cell damage
Grade 4
Severe piecemeal necrosis
Bridging necrosis
TA B LE 1 Batts-Ludwig grading system Grading Terminology
Criteria
TA BL E 4 Scheuer staging system
Lymphocytic piecemeal necrosis
Lobular inflammation and necrosis
Stage
Histologic Feature
Stage 0
None
None
Stage 1
Enlarged fibrotic portal tracts
Stage 2
Periportal or porto-portal septa but intact architecture
Grade
Description
0
Portal inflammation only
None
1
Minimal
Minimal, patchy
Minimal, occasional spotty necrosis
Stage 3
Fibrosis with architectural distortion but no obvious cirrhosis
2
Mild
Mild, some or all portal tracts
Mild, little hepatocellular damage
Stage 4
Probable or definite cirrhosis
3
Moderate
Moderate, involving all portal tracts
Moderate, with noticeable hepatocellular damage
Severe, may have bridging fibrosis
Severe, with prominent diffuse hepatocellular damage
4
Severe
TA BL E 5 Metavir grading system
TA B LE 2 Batts-Ludwig staging system Stage
Description
Criteria
Stage 0
No fibrosis
Normal connective tissue
Stage 1
Portal fibrosis
Fibrous portal expansion
Stage 2
Periportal fibrosis
Periportal or rare porto-portal septa
Stage 3
Septal fibrosis
Fibrous septa with architectural distortion; no obvious cirrhosis
Stage 4
Cirrhosis
Cirrhosis
Histologic Feature Score
Grading
Piecemeal necrosis (PMN) 0none 1mild 2moderate 3severe
A0-no histologic activity A1-mild activity A2-moderate activity A3-severe activity
Lobular necrosis (LN) 0no or mild 1moderate 2severe
Grading guidelines (1) If PMN0 A0, if LN0 A1, if LN1 A2, if LN2 (2) If PMN1 A1, if LN0 or LN1 A2, if LN2 (3) If PMN2 A2, if LN0 or LN1 A3, if LN2 (4) If PMN3 A3, if LN0, LN1, or LN2
Portal inflammation 0-none 1mild 2moderate 3severe Bridging necrosis Yes No
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TA B LE 6 Metavir staging system Histologic Description
AND
S TA G I N G
TA BL E 8 Ishak staging system for chronic hepatitis Fibrosis Score
Ishak Stage
Description
No scarring
0
Stage 0
No fibrosis
Minimal scarring
1
Stage 1
Scarring extends outside areas that contain blood vessels
2
Fibrous expansion of some portal tracts with or without short fibrous septa
Stage 2
Bridging fibrosis is spreading and connects to other areas with fibrosis
3
Fibrous expansion of most portal tracts with or without short fibrous septa
Stage 3
Cirrhosis or advanced scarring
4
Fibrous expansion of most portal tracts with occasional porto-portal bridging
Stage 4
Fibrous expansion of portal tracts with marked porto-portal or porto-central bridging
Stage 5
Marked bridging with occasional nodules
Stage 6
Cirrhosis, probable or definite
TA B LE 7 Ishak modification of hepatic activity index Histologic Feature (A) Periportal or periseptal interface hepatitis Absent Mild (focal, few portal areas) Mild/moderate (focal, most portal areas) Moderate (continuous around 50% of portal tracts or septa) Severe (continuous around 50% of portal tracts or septa)
Points
0 1 2 3 4
4. 5.
(B) Confluent necrosis Absent Focal Zone 3 necrosis in some areas Zone 3 necrosis in most areas Zone 3 necrosis with occasional porto-central bridging Zone 3 necrosis with multiple porto-central bridging Panacinar or multiacinar necrosis
0 1 2 3 4 5 6
(C) Focal necrosis, apoptosis, and focal inflammation Absent One focus or less per 10 field 2–4 foci per 10 field 5–10 foci per 10 field Less than 10 foci per 10 field
0 1 2 3 4
(D) Portal inflammation Absent Mild, some or all portal tracts Moderate, some or all portal tracts Moderate/marked, all portal tracts Marked, all portal tracts
0 1 2 3 4
6. 7. 8.
Guidelines for Staging for Chronic Hepatitis (Batts-Ludwig System)
1. Under-staging is likely in limited or fragmented biopsies (see criteria for adequacy above). 2. Tangentially cut or branching portal tracts: If the fibrous tissue “expansion” or “septa” contains an artery and/or duct, it is likely an extension of the portal tract rather than true fibrosis. 3. Large portal tracts can be mistaken for portal fibrosis. More connective tissue is normal in this setting and the larger size of duct and artery are helpful. Nerves within fibrous zones also indicate a large portal tract. If ductular
9.
reaction is present at the edge of a large fibrous zone, it is more likely to be true fibrosis. Subcapsular biopsy can lead to over-staging as nodularity can be normally seen in this region, and the portal tracts in this region have more connective tissue. Periportal ductular reaction or hepatocytes entrapped at the edge of the portal zone or surrounded by strands of fibrous tissue helps in identification of stage 1 fibrosis. Portal tracts that are much larger than expected for the size of the interlobular bile duct and interlobular artery indicate stage 1 fibrosis. If periportal fibrous septa are thin, it qualifies for stage 2 even if there is focal porto-portal bridging as long as there are no nodular regenerative changes. Several thin bridges would qualify for architectural distortion and should be labeled as stage 3. If bridging fibrosis in some areas is accompanied by portal tracts lacking significant fibrosis in other areas, stage 3 (and not stage 4) is appropriate. ST EATO H EPAT IT IS Grading
The two grading schemes used for steatohepatitis are the Brunt system and nonalcoholic fatty liver disease (NAFLD) activity score (NAS)(7,8). Unlike staging, the clinical utility of grading in steatohepatitis is not clearly established. Since clinical decisions are not dictated by the histologic grade, it is not considered a necessary component of the pathology report. (1) Brunt grading scheme
This is based on combined evaluation of steatosis, hepatocellular ballooning, and inflammation (Table 9). This scheme can create problems, since the severity of these three features do not always occur in conjunction. It is not uncommon for nonalcoholic steatohepatitis (NASH) biopsies to show marked (>66%) steatosis but minimal hepatocellular ballooning and inflammation. These problems can be resolved if each of these three features are graded separately (mild, moderate, severe).
APPENDIX
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GRADING
TA B LE 9 Brunt scheme for grading steatohepatitis
AND
S TA G I N G
519
TA BL E 1 1 Modified Brunt-Kleiner method
for staging of steatohepatitis Grade 1 (mild)
Steatosis: Up to 66%, predominantly macrovesicular Ballooning: Occasional, zone 3 Lobular inflammation: Scattered, mixed Portal inflammation: None or mild
Grade 2 (moderate)
Steatosis: Any degree, macrovesicular or mixed Ballooning: Present, zone 3 Lobular inflammation: Neutrophils often present, / chronic inflammation Portal inflammation: None, mild, or moderate
Grade 3 (severe)
Steatosis: Usually 66%, often mixed Ballooning: Marked, predominantly in zone 3 Lobular inflammation: Scattered, mixed inflammation; neutrophils are often prominent in zone 3 Portal inflammation: Mild or moderate, not predominant or marked
Stage
Histologic Description
Stage 0
No fibrosis
Stage 1
Zone 3 perivenular or pericellular fibrosis, focal or extensive 1a. Delicate (usually discernible only on trichrome stain) 1b. Dense (usually discernible on hematoxylin and eosin (HE stain) 1c. Periportal fibrosis only
Stage 2
As in stage 1 plus portal fibrosis, focal or extensive
Stage 3
Bridging fibrosis, focal or extensive
Stage 4
Cirrhosis (/ residual pericellular fibrosis)
monitor disease progression, staging should always be included in the pathology report (8). TA B LE 10 NAFLD activity score (NAS) for histologic
grading of fatty liver disease Guidelines for Staging in Steatohepatitis Histological Feature
Definition
Score
Steatosis
5% 5–33% 33–66% 66%
0 1 2 3
Lobular inflammationa
None 2 foci 2–4 foci 4 foci
0 1 2 3
Ballooningb
None Few cells Prominent
0 1 2
The number of foci were counted per 200 field for lobular inflammation. Few ballooned cells indicate rare but definite ballooned hepatocytes as well as cases that are diagnostically borderline.
a
b
(2) NAFLD activity score
This grading scheme has been proposed by the NASH Clinical Research Network (Table 10). The score is defined as the sum of the scores for steatosis (0–3), lobular inflammation (0–3), and hepatocellular ballooning (0–2). NAFLD activity score (NAS) can hence range from 0 to 8. The primary purpose of NAS is to assess overall histological changes. It is not intended to replace the pathologist’s diagnostic determination of steatohepatitis. Presently, NAS is being used for research studies, but can also be used in pathology reports for grading steatohepatitis. Staging
The modified Brunt-Kleiner scheme is widely used for the staging of steatohepatitis (Table 11). Since the degree of fibrosis can influence therapeutic approach and can be used to
1. Quality of trichrome staining is very important for staging of steatohepatitis. Overstaining can lead to thin trichrome-positive strands lining the sinusoids that can be mistakenly interpreted as stage 1 fibrosis. 2. Dense nodular deposits of fibrous tissue are common around central veins and should not be interpreted as abnormal. Unlike true fibrosis, these nodular collagen deposits are well demarcated and do not show percellular extension along the sinusoids. 3. Subclassification of stage 1 into 1a, 1b, and 1c is not necessary for routine clinical cases. 4. Periportal fibrosis without perivenular fibrosis is uncommon in steatohepatitis, but can occur in children and some adult patients with diabetes. 5. In the original Brunt scheme, porto-portal bridging was considered stage 2, whereas centro-central or centro-portal bridging was considered stage 3. In the modified BruntKleiner methodology that is now in use, porto-portal bridging fibrosis is also considered stage 3 and architectural distortion (multiple bridges) are not necessary. 6. Collagen deposition around macrophage collections or in lipogranulomas can mimic pericellular fibrosis. Correlation of trichrome staining with the hematoxylin and eosin (HE) sections is thus important to avoid overstaging due to these findings. Focal areas of fibrosis in nodular configuration especially around central veins may be due to lipogranulomas and should not be considered for staging. 7. In addition to steatohepatitis, pericellular fibrosis can be seen in chronic venous outflow obstruction, diabetic hepatosclerosis, nodular regenerative hyperplasia, and with use of chemotherapeutic agents like oxaliplatin. 8. Pericellular fibrosis may not be evident in steatohepatitic cirrhosis.
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References 1. Bedossa P, Bioulac-Sage P, Callard P, et al. Intraobserver and interobserver variations in liver biopsy interpretation in patients with chronic hepatitis C. Hepatology. 1994;20:15–20. 2. Regev A, Berho M, Jeffers LJ, et al. Sampling error and intraobserver variation in liver biopsy in patients with chronic HCV infection. Am J Gastroenterol. 2002;97:2614–2618. 3. Robert M, Sofair AN, Thomas A, et al. A comparison of hepatopathologists’ and community pathologists’ review of liver biopsy specimens from patients with hepatitis C. Clin Gastroenterol Hepatol. 2009;7:335–338. 4. Batts KP, Ludwig J. Chronic hepatitis. an update on terminology and reporting. Am J Surg Pathol. 1995;19:1409–1417. 5. Scheuer PJ. Classification of viral hepatitis: a need for reassessment. J Hepatol. 1991;13:372–374.
AND
S TA G I N G
6. Scheuer PJ. Standish RA, Dhillon AP. Scoring of chronic hepatitis. Clin Liver Dis. 2002;6:335–347. 7. Bedossa P, Poynard T. An algorithm for the grading of activity in chronic hepatitis C. Hepatology. 1996;24:289–293. 8. Theise ND. Liver biopsy assessment in chronic viral hepatitis: a personal, practical approach. Mod Pathol. 2007;20(suppl 1):S3–14. 9. Ishak K, Baptista A, Bianchi L, et al. Histological grading and staging of chronic hepatitis. J Hepatol. 1995;22:696–699. 10. Brunt EM, Janney CG, Di Bisceglie AM, Neuschwander-Tetri BA, Bacon BR. Nonalcoholic steatohepatitis: a proposal for grading and staging the histological lesions. Am J Gastroenterol. 1999;94:2467–2474. 11. Kleiner D, Brunt E, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology. 2005;41:1313–1321.
Appendix C Special Stains in Liver Biopsy Pathology
T R I C H ROM E STAI N
R ET ICULIN STA IN
Utility
Utility
1. Assess degree of fibrosis. HE stain is not reliable for demonstration of fibrosis especially in early stages. Pericellular fibrosis in steatohepatitis can be difficult to discern on the HE stain. 2. Distinguish fibrosis from necrosis. Areas of necrosis show pale staining compared with dense staining of fibrous septa (see Chapter 1.2). 3. Identification of amyloidosis. Amyloid deposits show pale homogenous staining compared with dark staining of collagen (see Chapter 11.4). In the absence of clinical suspicion, subtle amyloid deposits can be overlooked on the HE stain, but can more easily be identified on the trichrome stain. Definite identification can then be performed with Conge red.
1. Highlights the architecture of liver cell plates. Helpful in demonstrating collapse of reticulin network in parenchymal necrosis. 2. Highlights the nodular architecture in nodular regenerative hyperplasia and demonstrates compression of cell plates at the periphery of the nodules. 3. Demonstrates loss or fragmentation of reticulin network in hepatocellular carcinoma. Pitfall
Reticulin network can be disrupted in areas of steatosis and can be confused with reticulin loss seen in hepatocellular carcinoma. Routine Use
Pitfalls
1. Overstaining. Normal sinusoids should not stain with trichrome stain. If high background staining is present, it can lead to erroneous interpretation of pericellular fibrosis in steatohepatitis. It is also not possible to distinguish necrosis from fibrosis in overstained sections. 2. Understaining. This can lead to under-staging and does not enable distinction of necrosis from fibrosis.
Often obtained routinely with liver biopsies. However, it is unlikely to yield useful information in most liver biopsies and can be restricted to situations outlined above where it is likely to be useful. IRO N STA IN Utility
Distinguishes hemosiderin from other pigments in the liver (bile, lipofuchsin, copper).
Routine Use
Trichrome stain should be routinely used for assessment of fibrosis in all liver biopsies done for nonneoplastic diseases (1–3). E L A S T I C STAI N
Pitfall
Faint blush of ferritin seen in cytoplasm of hepatocytes should not be confused with granular deposits of hemosiderin. Since ferritin is an acute phase reactant, any chronic inflammatory disorder can be associated with the ferritin blush.
Utility
Distinguish confluent or bridging necrosis from fibrosis. Elastic fibers are not seen in areas of necrosis, whereas fibrous septa of long duration are richly endowed with elastic fibers. The connective tissue in normal portal tracts also contains elastic fibers. Pitfall
The adequacy of staining must be checked by ensuring that elastic fibers are present in portal tracts and vessel walls.
Routine Use
The amount of iron is often underestimated on HE stained slides, and hence the routine use of iron has been advocated. The presence of hepatic siderosis has been associated with disease progression in chronic liver diseases like hepatitis C. However, the significance of mild hepatic siderosis is unclear and use of iron stains in specific situations rather than on a routine basis is acceptable practice. CO P P ER STA IN
Routine Use
Not necessary.
Rhodanine, rubeanic acid, and orcein stains can be used to demonstrate copper. Orcein stain highlights copper binding
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SPECIAL
S TA I N S
proteins and hence is an indirect stain for copper. Orcein stain also stains elastic fibers and ground-glass hepatocytes in chronic hepatitis B. Utility
1. Distinguishes copper from other pigments in the liver (bile, lipofuchsin, iron). 2. Since copper is excreted in the bile, it accumulates in periportal hepatocytes in cholestatic conditions. Demonstration of copper in periportal hepatocytes helps in distinction of biliary from hepatitic diseases. 3. Wilson disease is associated with elevated hepatic copper, which may be demonstrated on copper stain. Pitfalls
1. Copper accumulation can be seen in any liver disease with advanced fibrosis and cirrhosis. In this setting, it is not useful in the distinction of biliary and hepatitic diseases. 2. Periportal hepatic copper in cholestatic diseases can be focal and careful evaluation is necessary. 3. Absence of periportal copper does not exclude biliary disease. 4. Copper stain is unreliable for the diagnosis of Wilson disease. The copper stain can be patchy and even negative in Wilson disease. Quantitative copper analysis from the block is a more reliable assay for hepatic copper.
IN
LIVER
BIOPSY
PAT H O L O G Y
2. Presence of PASd positive cytoplasmic globules does not establish the diagnosis of alpha-1-antitrypsin deficiency. Heterozygous disease can also show cytoplasmic globules, but these tend to be smaller and less numerous compared with homozygous disease. Protease inhibitor phenotype testing by isoelectric focusing is necessary to establish the diagnosis (see Chapter 16.) Globules can be seen in acute hepatitic conditions due to transient defects in secretion. Cytoplasmic globules with similar appearance can be seen in other settings like fibrinogen storage diseases (see Chapter 16.) 3. Use of PAS stain without diastase digestion has limited use. It can highlight excessive glycogen in storage disorders and can show depletion of glycogen in centrizonal region in recent ischemic injury (1). Routine Use
The cytoplasmic globules of alpha-1-antitrypsin deficiency can be easily missed on HE stain. Hence, routine use of PASd has been advocated. It offers an added advantage of evaluation of bile ducts by highlighting the basement membrane. However, its routine use is not a standard practice. BILE STA IN ( FO UCH ET O R H A LL STA IN) Utility
Demonstrate bile and distinguish it from other liver pigments
Routine Use
Not necessary.
Pitfalls
Has limited used in diagnostic pathology. PA S W I T H D I A S TA S E (PA S D ) Utility
1. Demonstrates cytoplasmic globules of alpha-1-antitrypsin deficiency. 2. Stains basement membrane of bile ducts and can be helpful to evaluate bile duct damage and ductopenia. 3. Highlights ceroid-laden macrophages in acute and resolving hepatitis (see Chapter 1.3). 4. May highlight fine copper granules in periportal hepatocytes (1).
Routine Use
Not necessary. OT H ER STA INS
Victoria blue stain can highlight ground-glass hepatocytes in hepatitis B, copper, and elastic fibers (3). Chromotrope aniline blue and picrosirius red are connective tissue stains that have been used to assess fibrosis (1).
References Pitfalls
1. Inadequate digestion can lead to staining of residual glycogen in the hepatocytes. This can be misinterpreted as cytoplasmic globules of alpha-1-antitrypsin deficiency. Unlike the large globules seen in alpha-1-antitrypsin deficiency, glycogen particles are smaller and have a granular rather than globular appearance.
1. Lefkowitch JH. Special stains in diagnostic liver pathology. Semin Diagn Pathol. 2006;23:190–198. 2. Tretheway D, Jain A, LaPoint R, et al. Should trichrome stain be used on all post-liver transplant biopsies with hepatitis C virus infection to estimate the fibrosis score? Liver Transpl. 2008;14:695–700. 3. Bateman AC. Patterns of histological change in liver disease: my approach to “medical” liver biopsy reporting. Histopathology. 2007;51: 585–596.
In dex
Note: Page numbers followed by “f ” indicate figures, and those followed by “t” indicate tables. A A1AT deficiency, 243 ABCB11 gene, 157, 162 ABCB4 gene, 103, 157, 162, 203 ABCC2 gene, 155 Ablated hepatocellular carcinoma, 428–429, 428f, 429f Abscesses amebic liver, 139, 141f pyogenic, 139, 141 Acetaminophen, 15, 15t, 16, 18, 19, 211, 214 Acetaminophen-induced fulminant liver failure, 217–219, 217f, 218f. See also Acute liver failure (ALF) causality analysis, 218t Acid-fast bacilli (AFB) stains, 71, 72, 77 Acrocephalopolydactylous dysplasia, 134t Acute Budd-Chiari syndrome, 16. See also Budd-Chiari syndrome (BCS) Acute cellular rejection (ACR), 309–310, 309f, 310f, 331f versus recurrent hepatitis C, 313–314 Acute cholestasis, histologic patterns in classical ductular reaction (DR) type (pattern 1), 90–91, 91–92f with hepatitis (pattern 4), 92–93, 93f with intrahepatic bile duct disease (pattern 3), 92, 93f pure (bland) cholestasis (pattern 2), 92, 92t Acute cholestatic hepatitis, and statins, 221 Acute fatty liver of pregnancy (AFLP), 16, 203, 204, 207–209, 207f, 208f, 209f microvesicular steatosis causes, 207f, 208t Acute hepatitis definition of, 1 injury pattern features, 1 by lobular hepatocellular injury, 1 nonspecific reactive hepatitis, 5, 13–14, 13f pathologist role, 1 pathology report, 6 subpatterns of with bridging necrosis, 4, 9–10, 9–10f with centrizonal necrosis, 4, 4f cholestatic hepatitis, 3 giant cell hepatitis, 5–6 inflammation-dominant pattern, 1–3, 1–2f, 7–8, 7–8f mild hepatitis pattern, 5, 5f resolving hepatitis, 4–5, 11–12, 11f “toxic” pattern, 3, 4f Acute hepatitis C, 8 Acute hepatic sickle cell crisis, 181
Acute large bile duct obstruction, cholestasis in, 90–91, 91–92f Acute liver failure (ALF). See also Drug-induced liver injury (DILI) causes of, 15t clinical features, 15, 15t definition and terminology, 15 histological patterns of injury in microvesicular steatosis, 15t, 16 necrosis with little/no inflammation, 16 necrosis with prominent inflammatory activity, 16, 16f with necrosis-dominant injury pattern, 18–19, 18f, 19f pathologic features and differential diagnosis, 15–16, 15t, 16f Acute lymphoblastic leukemia (ALL), 491 Acute myeloid leukemia (AML), 473, 491 Acute viral hepatitis, 2 Acyl-CoA racemase (AMACR), 162t Adams-Oliver syndrome, 191 Adenocarcinoma of bile duct, 361 Adenoma with atypical features, 359–360 Adenomatous hyperplasia, 116 Adenomatous polyposis coli (APC) gene, 445 Adenoviral hepatitis, 16, 19 Adrenocortical carcinomas (ACC), 414, 415, 415t, 434, 512, 512t Adrenocorticotropic hormone (ACTH), 448 Adrenohepatic fusion, 427 Adult giant cell hepatitis, 36 Adult polycystic liver disease versus Caroli disease, 147–148, 147f Adverse drug reaction, 2–3 Agranulocytosis, 228 Aka kala azar, 267 Alagille syndrome, 117, 160, 161 paucity of bile ducts with, 170–171, 170f, 171f Alanine aminotransferase (ALT), 1, 3, 18, 249, 275 Albumin, 244 Alcohol foamy degeneration, 16 Alcoholic lipopeliosis, 188, 188f Alcoholic liver disease (ALD), 28, 46, 208 Alcoholic steatohepatitis, 54–55, 54f. See also Steatohepatitis diagnosis, 54 Alkaline phosphatase (ALP), 1, 3 Alpha fetoprotein (AFP), 407, 432, 504, 512 Alpha-1-antichymotrypsin (ACT) deficiency, 243, 249–250 characteristics, 246t Alpha-1-antitrypsin (AAT), 450 abnormal accumulation of, 245f deficiency, 161–162, 243, 245–248, 255, 276 characteristics, 246t eosinophilic cytoplasmic globules, 245f globules, 246, 248 neonatal hepatitis due to, 172–174, 172f, 173f, 174f Alpha-fetoprotein (AFP), 359, 391, 501 Alpha-glucosidase inhibitors, 258 Amebic liver abscesses, 139, 141f
523
524
INDEX
Amineptine, 16 Amino acid metabolism, disorders of, 266 Aminoglycoside antibiotics, 238 Amiodarone, 56, 265 Amiodarone-induced phospholipidosis, 237–239, 237–238f causality analysis, 239t Amyloidosis, 184–186, 184f, 185f, 186f Anabolic steroids, 187 “Anchovy-sauce pus,” 139, 141f Angiomyolipoma (AML), 414, 415t, 505–507, 505f, 506f epithelioid variant of, 434 inflammatory variant, 508–509, 508f, 509f Angiosarcoma, 503t. See also Hepatic angiosarcoma (HAS) Angiotension converting enzyme (ACE) inhibitors, 97 Anticonvulsants, 16 Anticopper drug treatment, 299 Anti-LKM (anti–liver-kidney microsomal antibody), 23, 23t, 24, 35 Antimitochondrial antibodies (AMA), 50, 50f, 75, 117 primary biliary cirrhosis with nonspecific changes and, 120–122, 120f, 121t Antimitochondrial antibody-negative PBC, 123–124, 123–124f Antinuclear antibody (ANA), 23t, 50 Anti–smooth muscle antibody (ASMA), 50 Apocrine-like snouts, 381 Argininosuccinate lyase deficiency, 251, 251f Arias syndrome, 154 Arteriohepatic dyplasia. See Alagille syndrome Artifactual sinusoidal dilatation, 175, 176f Asian Pacific Association for the Study of the Liver (APASL), 200, 201 Aspartate aminotransferase (AST), 1, 3, 18, 249, 275 Aspergillus flavus, 387 Aspergillus parasiticus, 387 Aspergillus sp., 86 Asphyxiating thoracic dystrophy, 134t Asplenia, with cystic liver, kidney and pancreas, 134t Associated liver nodules, 354–355 Atorvastatin, 63 ATP8B1 mutations, 97, 97f, 157, 162 ATP-binding cassette (ABC) transport system, 155 Atypical focal nodular hyperplasias, on imaging, 347–348 Autoimmune cholangitis. See Antimitochondrial antibody-negative PBC Autoimmune diseases, 245, 249 Autoimmune hepatitis (AIH), 3, 5, 15, 16, 275, 276 autoantibodies in, 23t with bile duct injury versus primary biliary cirrhosis, 26–28, 26–28f with cholestasis, 92–93, 93f versus chronic hepatitis C with autoantibodies, 34–35, 34f, 35f clinical features of, 23, 23t definition of, 21 diagnosis and scoring criteria, 21–22, 22–23f histologic differential diagnosis of, 21t histologic features of PBC and, 121t immunologic features of, 23–24, 23t, 24t natural history and treatment of, 24, 24f primary biliary cirrhosis overlap syndrome, 30–31, 30f, 31t primary sclerosing cholangitis overlap syndrome, 32–33, 32f revised scoring system for, 21–22t serologic classification of, 24t simplified diagnostic criteria for, 22t syncytial giant cell hepatitis, 36–37, 36f
Autoimmune pancreatitis (AIP), 111 Autoimmune sclerosing cholangitis, 33 Autosomal dominant polycystic kidney disease (ADPKD), 133t, 135, 137f, 138, 148 Autosomal dominant polycystic liver disease (ADPLD), 148 Autosomal recessive polycystic kidney disease (ARPKD), 133–135, 133t, 135f, 143, 145 Azathioprine, 183, 187 Azithromycin, 231, 231t B B72.3 (tumor-associated glycoprotein-72), 383, 433 Balloon cell melanoma, 414, 415t Bardet-Beidl syndrome, 134t Bartonella henselae, 69, 83 Batts-Ludwig grading and staging system, 517t, 518 β-catenin gene, 360f, 443t, 445, 448f, 449f, 450 β-catenin–mutated HCA, 344 B-cell lymphomas, 469–471, 469t immunophenotypes, 470t “B-cell, NOS” phenotype, 470–471, 478, 486 BCL-1, 477 BCL-2, 504 BCL-6, 477 Beckwith-Wiedemann syndrome, 441t Benign hepatocellular lesions, 343 atypical focal nodular hyperplasias on imaging, 347–348 biopsy diagnosis, challenges in, 345 focal nodular hyperplasia (FNH), 343 histological patterns, 343 versus inflammatory/telangiectatic hepatocellular adenoma, 349–350 hepatocellular adenomas, 343 immunophenotypical features of, 344 multiple adenomas and liver adenomatosis, 344–345 pathological findings, 343–344 pathomolecular classification of, 344 hepatocellular adenoma subtyping adenoma with atypical features, 359–360 associated liver nodules, 354–355 inflammatory/telangiectatic adenoma, 356–358 inflammatory/telangiectatic versus steatotic adenoma, 351–352 immunophenotypical characteristics of, 345t Benign recurrent intrahepatic cholestasis (BRIC), 97 Ber-Ep4, 433 Beta-2-microglobulin, 185 Beta-oxidation, 241 Bile acid synthesis defects, 162 histologic patterns, 162t Bile duct adenoma (BDA), 368, 369, 381 versus biliary hamartoma, 365–369 Bile duct injury versus primary biliary cirrhosis autoimmune hepatitis (AIH) with, 26–28, 26–28f Bile ducts biopsies, 376 injury, absence of, 1 cystadenoma, 378–380 damage and ductopenia, 117 paucity of, 161, 161t
INDEX
Bile ductular cholestasis, 90 associated with sepsis, 99–101, 99–101f Bile salt export pump (BSEP), 157, 162 Bile stain (Fouchet/Hall stain), 522 Bilharz, Theodore, 79 Bilharziasis. See Schistosomiasis Biliary adenofibroma, 381–382 Biliary atresia (BA), 159, 164–165, 164f, 165f histology, 160, 160f and neonatal hepatitis, 160t Biliary cysts, 139 Biliary diseases, 276 Budd-Chiari syndrome (BCS) versus, 177–179, 177–178f, 178t mast cell disease, 276 primary biliary cirrhosis, 276 vanishing bile duct syndrome and idiopathic adult ductopenia, 276 Biliary intraepithelial neoplasia (BilIN), 108, 109f, 383 Biliary microhamartomas. See von Meyenberg complexes (VMCs) Biliary neoplasms, 361 bile duct adenoma versus biliary hamartoma, 365–369 bile duct cystadenoma/carcinoma versus foregut cyst, 378–380 biliary adenofibroma, 381–382 biliary papillomatosis/intraductal cholangiocarcinoma, 383–386 cholangiocarcinoma in association with Von Meyenburg complexes, 373–374 differential diagnosis and practical issues, 364 epidemiology, 362 hilar/extrahepatic cholangiocarcinoma, diagnosis of, 375–377 intrahepatic cholangiocarcinoma versus hepatocellular carcinoma, 370–372 pathology, 363–364 risk factors and etiology, 362–363 treatment and prognosis, 364 Biliary papillomatosis, 383–386 Bilirubin, 236 Biopsy diagnosis, challenges in, 345 B-lymphoblastic leukemia/lymphoma, 469, 470t involvement by, 491 Bridging necrosis, acute hepatitis with case study, 9–10, 9–10f differential diagnosis, 4 pathologic features, 4 Bromosulphthalein (BSP), 154 Brucellosis, 68 Brunt grading scheme, for steatohepatitis, 518, 519t B-thalassemia, 153 Budd-Chiari syndrome (BCS), 3, 195–198, 195f, 196f, 197f, 461 versus biliary disease, 177–179, 177–178f etiology of, 178t Bupropion, 222 Burkitt lymphoma, 469, 470t Byler disease, 157 C C reactive protein (CRP), 344 C-27 peroxisomal side-chain oxidation, 162t C282Y HFE gene mutation, 53, 286 C3 protein, 244 C4 protein, 244 CAM 5.2, 507 Canalicular polyclonal carcinoembryonic antigen (p-CEA), 504
525
Carbamazepine, 126 Carbamoyl phosphate synthetase deficiency, 251 Carbon tetrachloride, 16, 218 Carcinoembryonic antigen (CEA), 364 Carcinoma versus foregut cyst, 378–380 Carnitine deficiency, 16 Caroli disease, 133t, 134–135, 135f versus adult polycystic liver disease, 147–148, 147f and congenital hepatic fibrosis (CHF), overlapping features, 135 versus other cystic disease, 145–146, 145f Castleman disease, 175, 176f Cat scratch disease (CSD), 69, 82–84, 82f, 83f, 84f Caudal drosophila homeobox analogue (CDX-2), 409, 413f, 433 Cavernous hemangioma variants, 457–458, 457–458f CD3, 472, 472t, 477, 487, 488 CD5, 470, 471, 477, 478f CD8+, 508 CD10, 91, 92f, 410, 422, 432, 434, 470, 477 CD15, 472, 472t, 482 CD20, 472, 472t, 477, 478f, 480, 481, 483, 483f, 497 CD23, 470, 477 CD30, 472, 472t, 482 CD31, 459, 460, 460f, 462, 463f, 463–464, 504, 508 CD34, 133, 193, 410, 410f, 432, 443t, 460, 462, 463–464, 502, 504 CD43, 470, 477 CD56, 415, 434 CD68, 189, 189f CD117 (C-kit) stain, 438, 439f, 497, 502, 504, 506, 508, 509, 512 CD163, 269f CDC50A, 97 Celiac disease, 3, 275–276 Centrilobular hepatocyte pigments, 89, 89f Centrizonal necrosis, acute hepatitis with differential diagnosis, 4 pathologic features, 4, 4f Ceramidase deficiency, 267 Cerebrotendinous xanthomatosis, 162t Ceruloplasmin, 3 Chemotherapy-associated steatohepatitis, due to irinotecan, 61–63 Children’s Oncology Group (COG) staging system, 441, 444t Chlamydia, 72 Chlorpheniramine, 238 Chlorpromazine, 126 Cholangiocarcinoma (CC), 33, 361, 363, 364, 370 immunophenotype of, 364 mass-forming, 361f and metastatic adenocarcinoma pseudoglandular hepatocellular carcinoma versus, 409–410, 409f, 410f, 410t needle biopsy of, 368f primary sclerosing cholangitis and, 107–109, 107f, 108f, 109f transformation of VMC to, 374 variants of, 364t and von Meyenburg complexes, 373–374 Cholate stasis, 44, 45 Choledochal cysts, 139, 139t, 149–150, 149f Choledocholithiasis, 91 Cholestasis, 320f acute cholestasis, histologic patterns in classical ductular reaction (DR) type (pattern 1), 90–91, 91–92f with hepatitis (pattern 4), 92–93, 93f with intrahepatic bile duct disease (pattern 3), 92, 93f pure (bland) cholestasis (pattern 2), 92, 92t
526
INDEX
Cholestasis, (cont.) in acute large bile duct obstruction, 90–91, 91–92f bile ductular cholestasis, associated with sepsis, 99–101, 99–101f chronic cholestasis, histologic changes in, 93–94, 93f, 94f, 95f in chronic large bile duct obstruction, 93f, 95f, 101f, 104–106, 104–105f Crohn’s disease with primary sclerosing cholangitis, 102–103, 102f, 103f drug-induced pure cholestasis, 96–97, 96–97f etiopathogenesis of, 90t hepatolithiasis (HL), 113–116, 113–114f, 114t, 115t immunoglobin G4-associated cholangitis (IAC) versus primary sclerosing cholangitis (PSC), 110–112, 110–111f, 111t, 112f primary sclerosing cholangitis and cholangiocarcinoma, 107–109, 107f, 108f, 109f Cholestatic hepatitis, 227 differential diagnosis, 3 pathologic features, 3 Cholestatic injury, 215 Chondroectodermal dysplasia, 134t Chromogranin, 412, 412f Chronic biliary disease chronic hepatitis distinction from, 27–28, 27–28f Chronic cholestasis histologic changes in, 93–94, 93f, 94f, 95f of sarcoidosis, 74, 74f Chronic ductopenic liver disease, with cholestasis, 102 Chronic graft versus host disease, 340f, 341f Chronic granulomatous disease (CGD), 85–87, 85f, 86f Chronic hepatitis, 5 grading and staging Batts-Ludwig systems, 517t Ishak systems, 518t Metavir systems, 517t, 518t Scheuer systems, 517t guidelines for staging in, 518 Chronic hepatitis C, 5 with autoantibodies versus autoimmune hepatitis, 34–35, 34f, 35f lymphocytic infiltration of bile duct in, 5f setting, iron in, 294–295 Chronic hepatitis distinction from chronic biliary disease, 27–28, 27–28f Chronic large bile duct obstruction, cholestasis in, 93f, 95f, 101f, 104–106, 104–105f Chronic liver disease, methotrexate and, 232–234, 232f, 233f, 234t Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 340, 469, 470t, 470 Chronic myelogenous leukemia (CML), 492–493 Chronic myeloproliferative disorders, 473 Chronic nonsuppurative destructive cholangitis, 118 Chronic rejection, 329f versus recurrent primary sclerosing cholangitis versus non-PSC stricture, 326–329 Chronic viral hepatitis, 21t, 24, 35 histologic features of PBC, AIH, and, 121t Cilliated foregut cyst, 139 Cirrhosis, 39, 245, 246, 299 chronic hepatitis consistent with Wilson disease, 305–306 congenital hepatic fibrosis (CHF) versus, 143–144, 143f primary biliary cirrhosis (PBC) with, 128, 128f, 129f, 129t
Cirrhosis-like hepatocellular carcinoma (CL-HCC), 421–422, 421f, 422f Cirrhotic liver, hepatocellular carcinoma diagnosis in, 389–391 CK7 immunostains, 90, 91–92f, 121t, 131, 139, 157, 161, 165, 169f, 170, 171f, 172, 210, 211f, 231, 276, 327, 328f, 364, 371f, 404f, 409, 410, 412, 412f, 426, 433, 443t, 455 CK8, 208, 208f, 239 CK 8/18 immunostains, 409 CK19 immunostains, 90, 91–92f, 121t, 131, 131f, 132f, 133, 139, 161, 231, 276, 364, 371f, 409, 410, 433, 443t, 434 CK20 immunostains, 409, 426, 433 CK AE1/3 stain, 443t Classic hepatocellular carcinoma (HCC), 387, 389 Classical Hodgkin lymphoma (CHL), 472, 483 Clear cell neuroendocrine tumors, 415t, 512t Clear cell renal cell carcinoma (RCC), 512 Clear cell variant, hepatocellular carcinoma, 414–416, 414f, 415f differential diagnosis, 415t Clinical Diagnostic Scale (CDS), 213 Clonorchis sinensis, 116, 362 cMOAT (canalicular multispecific organic anion transporter), 155 c-myc gene, 445 COACH syndrome, 134t Cocaine, 16 Collagen vascular diseases, 275 Combined hepatocellular-cholangiocarcinoma (cHCC-CC), 419–420, 419f, 420t Congenital deficiency, in urea-cycle enzymes, 16 Congenital disorder, 134t Congenital hepatic fibrosis (CHF), 133t, 134, 136f and Caroli disease, overlapping features, 135 versus cirrhosis, 143–144, 143f Congo red stain, 184, 185, 186f Copper staining, 3, 5, 300, 521–522 Coproporphyrin isomer I, 155 Coralgil, 238 Cotrimoxazole, 16 Coxiella burnetii, 77, 83 CP (Ceruloplasmin) gene, 287t Crigler-Najjar syndrome (CJS), 154t CJS type I, 153–154, 153f, 154f CJS type II, 154 Crohn’s disease, 471 with primary sclerosing cholangitis, 102–103, 102f, 103f Crowded fetal hepatoblastoma, 442, 443f Cryptococcus infection, 267 Cryptococcus neoformans, 267 Cryptogenic cirrhosis with nonalcoholic steatohepatitis (NASH), 45–46, 45–46f Cyanamide, 261, 262t Cyclin D1 gene, 443t, 445 Cyclosporine, 183 CYP2D6, 35 “Cystadenocarcinomas,” 379 Cystic liver disease cystic neoplasms of liver, 141 and ductal plate malformation (DPM), 132–133, 133f fibrocystic liver diseases, 133t hereditary DPM-related. See Hereditary DPM-related cystic liver disease infectious hepatic cysts, 139, 140f, 141, 141f non-DPM-related. See Non-DPM-related cystic liver disease syndromes associated with, 134t
527
INDEX
Cystic neoplasms, of liver, 141 Cystinosis, 266 Cytochrome P450 (CYP) system, 217 Cytochrome P450 2D6 (CYP2D6), 35 Cytologic atypia, 403f Cytomegalovirus (CMV) hepatitis, 19, 171, 337–339, 337f, 338f, 488 Cytoplasm, 43 Cytoplasmic contents, in hepatocellular carcinomas (HCCs), 407, 423–424, 423f, 424f Cytoplasmic globules, 243, 249 alpha-1-antitrypsin (AAT) deficiency, 245–248 alpha-1-antichymotrypsin (ACT) deficiency, 249–250 Cytoplasmic pigment (lipofuscin), 275 D Dechallenge/rechallenge, principle of, 215 Dense small B-cell infiltration, with reactive follicles, 476–478, 476–477f, 478f Desmin immunostain, 504, 506, 509 Diastase-digested periodic acid Schiff (DPAS) stain, 89, 95f Diastase-resistant globules, 501 Didanosine, 242 Diethylaminoethoxyhexestrol, 238 Diethylstilboestrol contraceptive steroids, 187 Diffuse cirrhosis-like hepatocellular carcinoma (CL-HCC), 421–422, 421f, 422f Diffuse large B-cell infiltration, 480–481, 480f Diffuse large B-cell lymphoma (DLBCL), 469, 470t, 472 Dimetal transporter-1 (DMT-1), 281 Down syndrome, 297 Doxorubicin, 429 Drug-induced autoimmune hepatitis (DIAIH), 223–225, 223f, 224f causality analysis (minocycline), 225t drugs associated with, 224t Drug-induced cholestatic hepatitis, 226–228, 226f, 227f, 228t Drug-induced ductopenia, 229–231, 229–230f, 231t causality analysis (azithromycin), 231t drugs associated with, 230t Drug-induced hepatitis, 21t Drug-induced liver injury (DILI). See also Acute liver failure (ALF) acetaminophen-induced fulminant liver failure, 217–219, 217f, 218f amiodarone-induced phospholipidosis, 237–239, 237–238f, 239t drug-induced autoimmune hepatitis (DIAIH), 223–225, 223f, 224f, 224–225t drug-induced cholestatic hepatitis, 226–228, 226f, 227f, 228t drug-induced ductopenia, 229–231, 229–230f, 230t, 231t drug-induced microvesicular steatosis, 240–242, 240–241f, 241t, 242t evaluation of, 213–216, 215t liver biopsy and, 213, 214t liver injury due to total parenteral nutrition, 235–236, 235f, 236t methotrexate-induced chronic liver disease, 232–234, 232f, 233f, 234t statin-acute hepatotoxicity, 220–222, 220f, 221f, 222t Drug-Induced Liver Injury Network (DILIN), 213 Drug-induced microvesicular steatosis, 240–242, 240–241f causality analysis, 242t drugs and toxins with, 241t Drug-induced pure cholestasis, 96–97, 96–97f cholestatic rosettes in, 96, 97f
Drugs and NAFLD, 56 Dubin-Johnson pigment, 89, 89f Dubin-Johnson syndrome (DJS), 154t, 155, 155f case illustration, 157 Duct epithelial senescence, 325f Ductal plate, 131, 131–132f Ductal plate malformation (DPM), 132–133, 133f. See also Cystic liver disease Ductopenia, 102f, 103, 230, 231 bile duct damage and, 117 differential diagnosis of, 117t primary biliary cirrhosis with, 125–127, 125f, 126f Ductular reaction (DR) of acute cholestasis, 90–91, 91–92f in chronic biliary obstruction, 104, 104f obstructive-type pattern of, 159, 160t, 164 Dysplastic foci, 387, 388 Dysplastic nodules, 387, 388–389 characteristic areas from, 390f evidence of atypia in, 391f E Early versus classic hepatocellular carcinoma, 389 Echinococcus granulosus, 139 Elastic stain, 4, 10, 10f, 521 Electrophoresis, serum, 245 Ellis–van Creveld syndrome, 134t Embryonal hepatoblastoma, 442, 444f Embryonal rhabdomyosarcoma, 448, 503t, 504 Embryonal sarcoma, 500t, 501, 502–504, 502f, 503f, 503t Emperipolesis, in autoimmune hepatitis, 22, 22f Entamoeba histolytica, 139 Enterocytes, 281 Epithelial cell adhesion molecule (EPCAM). See MOC31 Epithelial hepatoblastoma, 442, 444 Epithelial membrane antigen (EMA) stain, 121t Epithelioid granulomas, with/without necrosis, 67–68 necrotizing epithelioid granulomas, 70–72, 70f, 71f, 72f Epithelioid hemangioendothelioma (EHE), 459–461, 459f, 460f, 503t, 504 Epithelioid tumor cells, 502f Epithelioid variant of angiomyolipoma, 434 Epstein-Barr virus (EBV), 19, 488 Epstein-Barr virus-encoded RNA (EBER), 480 Escitalopram, 222 Estrogen receptor (ER), 378, 433, 436f Ewing’s sarcoma/ primitive neuroectodermal tumor (EWS/PNET), 453, 453f Exclusion of Competing Causes, in DILI evaluation, 214–215 Extramedullary hematopoiesis (EMH), 160, 160t, 165, 168, 455 Extramedullary myeloid tumor, 473 Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), 477 F Factor VIII-related antigen, 189, 460, 463, 501, 504 Familial adenomatous polyposis coli syndrome (APC), 441t Familial intrahepatic cholestasis 1 (FIC1), 162 Farber disease, 267 “Fatal infectious mononucleosis,” 268f
528
INDEX
Fatty liver disease (FLD), 304 alcoholic steatohepatitis, 54–55, 54f chemotherapy-associated steatohepatitis, due to irinotecan, 61–63 drugs and NAFLD, 56 introduction to, 39 microvesicular steatosis, 57, 57f nonalcoholic steatohepatitis with moderate portal inflammation, 47–51, 47f, 48f, 49–50f pediatric fatty liver disease, 58–60, 58f, 59f steatohepatitis with elevated serum iron indices and siderosis, 52–53, 52f steatohepatitis with minimal ballooning, 43–44, 43–44f steatohepatitis without activity, 45–46, 45–46f steatosis with inflammation versus steatohepatitis, 41, 41f, 42f subacute steatohepatitis, 64–65, 64–65f in type I diabetes, 255–256 Feathery degeneration, of hepatocytes in cholestasis, 89, 89f Ferritin, 53, 281, 282, 289 Ferroportin, 281, 288 Fialuridine, 242, 242t Fibrin ring granulomas, 68, 77, 77–78f Fibrinogen, 244, 261, 262t Fibrinogen storage disease, 244, 246t Fibrocystic liver diseases, 132, 133t Fibrocystin, 134 Fibrolamellar carcinoma (FLC), 418t Fibro-obliterative sclerosing cholangitis, 108, 108f Fibrosing cholestatic hepatitis C versus biliary obstruction versus adverse reaction to medication, 319–322 marked ductular reaction in, 92f Fibrosing cholestatic viral hepatitis (FCVH), 320 Fibrosis, 134, 200, 201 absence of, 1 in Budd-Chiari syndrome (BCS), 179 bridging necrosis and, 4 pericellular, 2, 2f Fine needle aspiration cytology (FNAC), 386 Florid duct lesion, in primary biliary cirrhosis, 118 5-fluorouracil (5-FU), 62 Focal mononuclear inflammation, 351f Focal nodular hyperplasia (FNH), 196–197, 197f, 343, 348, 349, 397 histological patterns, 343 versus inflammatory/telangiectatic hepatocellular adenoma, 349–350 FOLFIRI (5-FU/leucovorin with irinotecan), 62 FOLFOX (5-FU/ leucovorin with oxaliplatin), 62 Follicular lymphoma, 470t Foregut cyst, 139 Fouchet/Hall stain, 522 Francisella tularensis, 68, 84 Fructosemia, 297
G Galactosemia, 297 Gamma-glutamyl transferase (GGT), 157, 162 Gastrointestinal stromal tumor (GIST), 503t, 504, 512t Gaucher disease, 267, 271f GCDFP-15, 437
Genetic hemochromatosis, 284–288 Germander, 16, 224 Giant cavernous hemangiomas, 457 Giant cell change, neonatal hepatitis with, 160, 161f Giant cell hepatitis differential diagnosis, 6 pathologic features, 5–6 Gilbert syndrome (GS), 153, 154t Glucose-6-phosphate dehydrogenase (G6PD) deficiency, 153 Glue thistle, 16 Glutamine synthetase immunostain, 197, 348f, 350f, 357f, 443t, 448, 450, 455 Glycogen, 262t in liver, 251, 257 Glycogen-laden hepatocytes, 253 Glycogen phosphorylase (PGYL), 253 Glycogen pseudo–ground-glass, 261–262, 261f Glycogen-rich hepatocytes, in glycogenic hepatopathy, 43, 44f Glycogen storage diseases, 251, 251f, 262t types I-IV, 441t Glycogenic abnormalities, on liver biopsy, 251 clinical course, 253 clinical findings, 252–253 glycogen in liver, 257 glycogen pseudo–ground-glass, 261–262, 261f glycogen storage diseases, 251, 251f, 252t glycogenic hepatopathy, 252, 252f, 255–256, 258 type II diabetes, 260 histological findings, 253 mechanisms, 253 smooth endoplasmic reticulum proliferation, 262 urea cycle defects, 251 Glycogenic hepatopathy, 252, 252f, 255–256, 258 type II diabetes, 260 Glycoprotein metabolism, disorders of, 266 Glycoprotein P, 186 Glycosyl ceramide lipidosis, 267 Glycosylation, 134t Glypican-3 (GPC-3), 198, 400f, 409, 410, 415, 431–432, 432f, 434, 443t, 448f, 449f, 450, 450f, 453f, 455, 504, 512 Gömöri methenamine silver (GMS) stains, 71 Goodpasture syndrome, 300 Gp210, 121 gp91phox, 86 Grading iron, 289–290 Graft versus host disease (GVHD), 183, 340–342 Granulomatous inflammation. See Hepatic granulomas and granulomatous hepatitis
H H63D mutations, 286 “Halo effect,” in biliary cirrhosis, 94 Halothane, 16, 218 HAMP (hepcidin) gene, 287t H-caldesmon, 504 HELLP syndrome/toxemia, 203, 204, 210–212, 210–211f periportal hepatocellular damage, causes of, 211t Hemangioendothelioma. See Infantile hemangioma Hemangioma-like vessels (HLVs), 458 Hematoidin pigment, in hepatic schistosomiasis, 80f Hematopoietic cells, 506
INDEX
Hematopoietic tumors, of liver benign lymphoid tumors, 472–473 dense small B-cell infiltration, with reactive follicles, 476–478, 476–477f, 478f diffuse large B-cell infiltration, 480–481, 480f Hodgkin lymphoma, 472 by maturing granulocytes, 492–493 myeloid tumors acute myeloid leukemia, 473 chronic myeloproliferative disorders, 473 myeloid sarcoma, 473 non-Hodgkin lymphoma (NHL) B-cell lymphomas, 469–471, 469t T-cell lymphomas, 471, 471t polymorphic lymphoid infiltration, in transplant patient, 485–486, 485f, 486f portal and lobular infiltration by blasts, 490–491, 490f portal infiltration with Reed-Sternberg cells, 482–483, 482–483f post-transplant lymphoproliferative disorders (PTLDs), 472 sinusoidal T-cell infiltration, 487–489, 487–488f, 489f Hematoxylin and eosin (HE) stains, 54, 80, 102, 251, 322f, 465f, 466f, 504 Heme-iron, 281 Hemihypertrophy, 441t Hemochromatosis, neonatal, 296–297 Hemojuvelin, 281 Hemophagocytic lymphohistiocytosis (HLH), 268 Hemophagocytosis, liver with, 268f Hemosiderin, 281, 282, 289 Hep Par 1 (hepatocyte antigen), 409, 410, 415, 431, 431f, 512. See also Hepatocellular carcinomas (HCCs) Hepatic angiosarcoma (HAS), 462–464, 462f, 463f “Hepatic arterial buffer response,” 196 Hepatic artery thrombosis (HAT), 334 Hepatic cyst, simple, 138–139. See also Infectious hepatic cysts Hepatic foregut cysts, 379, 380f Hepatic granulomas and granulomatous hepatitis with/without admixed suppurative inflammation, 68 cat scratch disease (CSD), 82–84, 82f, 83f, 84f chronic granulomatous disease (CGD), 85–87, 85f, 86f classification of, 67t epithelioid granulomas, with/without necrosis, 67–68 fibrin ring granulomas, 68, 77, 77–78f foamy macrophage aggregates, 68 lipogranulomas, 68 microgranulomas, 68 necrotizing epithelioid granulomas, 70–72, 70f, 71f, 72f noninfectious causes of, 75t sarcoidosis, 73–76, 73f, 74f, 75f, 76f schistosomiasis, 79–80, 79f, 80f, 81t stellate abscesses with, 69 Hepatic iron index, 291–292 Hepatic iron, marked, 293 Hepatic megamitochondria, 247 Hepatic parenchyma, 480 Hepatic stellate cells (Ito cells), 276 Hepatic vascular malformations, infantile hemangiomas from, 466, 467t Hepatic vein (HV), 196f thrombosis, 195f
529
Hepatitic diseases, 275 celiac disease, 275–276 collagen vascular diseases, 275 nonspecific reactive hepatitis, 275 resolving hepatitis, 275 viral hepatitis, 275 Hepatitis, acute. See Acute hepatitis Hepatitis A virus, 15 Hepatitis B surface antigen (HbsAg), 247, 262f Hepatitis B virus (HBV), 15, 387 Hepatitis C virus (HCV), 23t, 249, 363, 387 with steatosis, 49–50, 49–50f Hepatitis E virus (HEV), 15, 203, 211 Hepatobiliary cystadenomas (HCA), 378 epithelial denudation of, 380f Hepatobiliary disorders, 90 Hepatoblastomas (HBs), 441–445, 441t, 442t, 443t, 443f, 444f, 444t, 500, 501, 507 biopsy diagnosis of, 447–448, 447f, 448f Children’s Oncology Group Staging System for, 444t clinical features, 441, 441t epidemiology, 441 gross, 441–442 histology, 442, 442t crowded fetal HB, 442, 443f embryonal HB, 442, 444f macrotrabecular HB, 444 mixed HB, 444 molecular genetics of, 445 prognostic factors, 445 pure fetal HB, 442, 443f small cell HB, 442–443 teratoid HB, 444 treatment and outcome, 444–445 immunohistochemical profi le of, 443t macrotrabecular hepatoblastoma versus hepatocellular carcinoma, 449–451, 449f, 450f pathology, 441 small cell hepatoblastoma versus other small round cell tumors, 452–454, 452f, 453f, 554f teratoid hepatoblastoma versus malignant teratoma/ yolk sac tumor, 455, 455–456f Hepatocanalicular drug toxicity, 96 Hepatocellular adenoma subtyping adenoma with atypical features, 359–360 associated liver nodules, 354–355 inflammatory/telangiectatic adenoma, 356–358 inflammatory/telangiectatic versus steatotic adenoma, 351–352 Hepatocellular adenomas (HCAs), 343, 360, 512 immunophenotypical features of, 344 multiple adenomas and liver adenomatosis, 344–345 pathological findings, 343–344 pathomolecular classification of, 344 Hepatocellular arcinoma, 512t Hepatocellular atypia, of cholestasis, 104, 105f Hepatocellular carcinomas (HCCs), 24, 343, 355, 360, 361, 387, 391, 399, 431, 441, 503t, 504, 505, 507, 512 ablation therapies, 428–429, 428f, 429f altered appearances due to grade, vascular permeation, pedunculation, and therapeutic ablation, 407–408 clear cell variant, 414–416, 414f, 415f, 415t combination with primary intrahepatic cholangiocarcinoma, 407
530
Hepatocellular carcinomas (HCCs), (cont.) combined hepatocellular-cholangiocarcinoma (cHCC-CC), 419–420, 419f, 420t diagnosis, in cirrhotic liver, 389–391 diagnosis, immunohistochemical algorithms for, 433t Hep Par 1 diffuse positive, MOC31 negative, 433 Hep Par 1 negative, MOC31 diffuse positive, 433 Hep Par 1 negative, MOC31 negative, 433–434 Hep Par 1 positive, MOC31 positive, 433 diffuse cirrhosis-like hepatocellular carcinoma (CL-HCC), 421–422, 421f, 422f diffuse multifocality with cirrhosis-like nodularity, 407 early, 402–405 versus classic hepatocellular carcinoma, 389 epidemiology and risk factors, 387 histologic features of precancerous lesions, 388 dysplastic foci, 388 dysplastic nodules, 388–389 intrahepatic cholangiocarcinoma versus, 370–372 macrotrabecular hepatoblastoma versus, 449–451, 449f, 450f versus metastasis adrenocortical carcinoma, 434 angiomyolipoma, epithelioid variant of, 434 melanoma, 434 neuroendocrine tumor, 434 renal cell carcinoma, 434 scirrhous and poorly differentiated HCC, 434 versus metastatic adenocarcinoma, 436–437, 436f, 437f versus metastatic polygonal cell tumor, 438–439, 438f, 439f mimicry to metastatic and other primary tumors, 407 versus neuroendocrine carcinoma, 412–413, 412–413f, 413t pedunculated variant of, 427, 427f poor differentiation, 397–402 and vascular invasion in, 425–426, 425f, 426f pseudoglandular hepatocellular carcinoma versus cholangiocarcinoma and metastatic adenocarcinoma, 409–410, 409f, 410f, 410t risk factors for, 387t scirrhous hepatocellular carcinoma, 417–418, 417f, 418t spectrum of cytoplasmic contents in, 423–424, 423f, 424f terminology of hepatocellular nodules and precancerous lesions, 387–388 well-differentiated, 394–397, 396t with variety of prominent cytoplasmic contents, 407 Hepatocellular injury, 2 with/without necrosis, 1 Hepatocellular neoplasms, 187, 197, 394 Hepatocellular nodules terminology of, 387–388 Hepatocyte necrosis, 195, 196f Hepatocyte nuclear factor 1α (HNF1α) transcription factor, 344 Hepatocyte nuclear factor 6 (HNF6), 131, 132 Hepatocyte rosette formation, 22, 23f Hepatocytes, 281, 282, 296f, 504 in cholestasis, 106 large cell change of, 389f small cell change of, 388, 388f Hepatocytic ballooning, 43, 43f Hepatocytic lesion, 349f Hepatolithiasis (HL), 113–116, 113–114f conditions in stones formation in intrahepatic bile ducts, 114t and primary sclerosing cholangitis, comparison between, 115t
INDEX
Hepatoportal sclerosis (HPS), 191–192, 191f, 192f, 200, 201 Hepatopulmonary syndrome, 165 Hepatosclerosis, 256 Hepatosplenic T-cell lymphoma (HSTCL), 487–489 Hepatotropic viruses, 15t Hepcidin, 283, 283f HepPar-1 stain, 443t, 507 Herbal agents, 16 Hereditary DPM-related cystic liver disease autosomal dominant polycystic kidney disease (ADPKD), 133t, 135, 137f, 138 autosomal recessive polycystic kidney disease (ARPKD), 133–135, 133t, 135f Caroli disease, 133t, 134–135, 135f versus adult polycystic liver disease, 147–148, 147f versus other cystic disease, 145–146, 145f congenital hepatic fibrosis (CHF), 133t, 134, 136f versus cirrhosis, 143–144, 143f overlap of diseases, 135 polycystic liver disease (PLD), 133t, 138 von Meyenberg complexes (VMCs), 135, 138, 138f, 147–148 Hereditary hyperbilirubinemias conjugated hyperbilirubinemias Rotor syndrome (RS), 154–155 Crigler-Najjar syndrome (CJS) CJS type I, 153–154, 153f, 154f CJS type II, 154 Dubin-Johnson syndrome (DJS), 155, 155f case illustration, 157 salient laboratory features, 154t unconjugated hyperbilirubinemia Gilbert syndrome (GS), 153 Hereditary spherocytosis, 153 Hermansky-Pudlak syndrome, 267 Herpes simplex virus (HSV), 18, 19, 19f, 203 HSV-1/HSV-2, 19 HFE mutations, 53, 286, 287t, 294 Hilar/extrahepatic cholangiocarcinoma, diagnosis of, 375–377 Histiocytic sarcoma, 268 Histiocytosis X, 231 Histoplasma capsulatum, 267 Histoplasmosis, 267 HIV/hepatitis C virus (HCV) coinfection, 263 HJV (hemojuvelin) gene, 287t HMB-45 immunostain, 415, 434, 505, 509, 509f, 511f, 512 Hodgkin and Reed-Sternberg (HRS) cells, 472, 482, 483 Hodgkin lymphoma, 175, 206, 231, 472 immunophenotype of neoplastic cells in, 472t Human herpes viruses (HHV) HHV-1/HHV-2, 19 HHV-6/HHV-8, 19 Human immunodeficiency virus (HIV) infection, 8, 191 Human melanoma black (HMB)-45, 504 Hydatid cyst, 139, 140f solitary hepatic cyst versus, 151, 151f Hydroxymethylglutaryl coenzyme A reductase, 221 Hyperbilirubinemia, 159 in sickle cell anemia, 181 Hypercellular cyst lining with focally papillary configuration, 379f Hypercellular spindle cell stroma, 379f Hyperemesis gravidarum, 203
531
INDEX
Hyperplastic polyp of intrahepatic bile ducts, 385 Hypopituitarism, neonatal hepatitis with, 167–169, 167–168f, 169f Hypoxic-ischemic injury, 218 I Ibuprofen, 126 Idiopathic adulthood ductopenia, 103, 127, 276 Idiosyncratic drug reaction, 16 IL6ST gene, 344 Immunoallergic DILI (IA-DILI), 224 Immunoglobulin G (IgG), 16, 22t, 50 Immunoglobulin G4 (IgG4) immunostain, 108 Immunoglobin G4-associated cholangitis (IAC), 108 versus primary sclerosing cholangitis (PSC), 110–112, 110–111f, 112f Immunoglobin G4-bearing plasma cells, in AIH, 28 “Immunologic disorders,” 268 Incomplete septal cirrhosis (ISC), 200 Indocyanine green (ICG), 154 Infantile hemangioma (IH), 465–467, 465f, 466f, 500, 500t, 501 associations with, 466t gross findings, 466 microscopic findings, 466, 467t treatment, 467 type 2 change, 467 Infectious hepatic cysts amebic liver abscesses, 139, 141f hydatid cyst, 139, 140f pyogenic abscesses, in liver, 139, 141 Infiltrative neoplasms of liver, 495 Inflammation-dominant acute hepatitis pattern case study, 7–8, 7–8f differential diagnosis, 2f acute viral hepatitis, 2 adverse drug reaction, 2–3 autoimmune hepatitis (AIH), 3 Celiac disease, 3 Wilson disease, 3 defining features, 1–2, 1–2f Inflammatory/telangiectatic adenoma, 356–358 versus steatotic adenoma, 351–352 Infliximab, 471 INI1/BAF47 gene, 453 INI1 stain, 443t, 452f, 453, 454f Insulin resistance (IR), 49–50 Integrase interactor 1 (INI1), 443 Interface hepatitis for autoimmune hepatitis (AIH), 22, 22f, 26f, 32, 32f, 34f, 36f International Autoimmune Hepatitis Working Group, 21, 21–22t International Consensus Group for Hepatocellular Neoplasia (ICGHN), 387 International Prognostic Index (IPI), 469 International Working Party (IWP), 387 Intracellular hyaline bodies (IHB), 246, 247, 423 characteristics, 246t Intracytoplasmic globules/inclusions, characteristics of, 246t Intraductal cholangiocarcinoma, 383–386 Intraductal papillary mucinous neoplasm (IPMN), 383 Intraductal papillary neoplasm (IPN) of bile ducts, 383, 384 gastric-type, 384f
intestinal-type, 384f oncocytic-type, 384f pancreatobiliary-type, 383f Intrahepatic bile duct (IHBD) system, 131, 133, 139t with cholestasis, 92, 93f, 95f Intrahepatic cholangiocarcinoma (ICC), 418t versus hepatocellular carcinoma, 370–372 Intrahepatic pigmented stone disease, 116 Irey, NS, 214, 215t Irinotecan and steatohepatitis, 62, 62f Iron absorption, 282f Iron deposition, in NAFLD, 52–53, 52f Iron interpretation, in liver specimens, 281 chronic hepatitis C setting, iron in, 294–295 genetic hemochromatosis, 284–288 grading iron, 289–290 hepatic iron index, 291–292 hepcidin, 283, 283f major proteins and cells involved in iron metabolism, 281 marked hepatic iron, 293 metabolism of iron, 281 getting iron from the blood to cells throughout the body, 281–282 iron absorption, 281 iron storage, 282–283 neonatal hemochromatosis, 296–297 Iron metabolism, disorders of, 267 Iron stain, 296f, 297f, 521 Iron, grading, 289–290 Ischemia, 15, 15t Ischemic hepatitis, 16 Ishak systems, for chronic hepatitis, 518t Isoniazid, 16, 215 Ito cell lipidosis (ICL), 279 mild hepatic steatosis versus, 278–280 Ivermark syndrome, 134t J JAG 1, 161 Jamaican vomiting sickness, 16 Jeune syndrome, 134t Joubert syndrome, 134t K Kasabach-Merritt syndrome, 466 Kasai procedure, 164, 165 Kayser-Fleischer (KF) rings, 299 Keratin 8/18, 44 Keratins, 433, 507 Ketoconazole, 16 Ki67 stain, 443t Klatskin trichrome stain, 143f Known Potential for Injury, principle of, 215 Kupffer cells, 41, 43, 52f, 68, 89, 101, 118, 227f, 265, 266, 267, 268, 274f, 285, 288, 334f with crinkled fibrillated appearance in Gaucher disease, 271f hypertrophied, 266f prominent, 1, 2f, 7 and storage disorders, 266t
532
INDEX
L L-asparaginase, 16 Lafora disease, 248, 261, 262t Langerhans cell histiocytosis (LCH), 497 Laser ablation (LA), 429 Late cellular rejection versus autoimmune hepatitis versus recurrent hepatitis C, 315–318 Leiomyoma, 507 Leiomyosarcomas, 503t, 504 Leishmania sp., 267 Leukemoid reaction, 493 Leukocytosis, 268 Li-Fraumeni syndrome, 441t Lipofuscin pigment, 89, 89f Lipogranulomas, 68 Lipopeliosis, 335 in transplanted donor livers, 189, 189f, 190f Lipopolysaccharide (LPS), 100 Lipoprotein and lipid metabolism, disorders of, 266–267 Lisinopril, 11, 96, 97 Liver, hematopoietic tumors of. See Hematopoietic tumors, of liver Liver, mesenchymal tumors of. See Mesenchymal tumors, of liver Liver biopsy, approach to, 275 adequacy of, 515 biliary diseases, 276 mast cell disease, 276 primary biliary cirrhosis, 276 vanishing bile duct syndrome and idiopathic adult ductopenia, 276 differential diagnosis, 275t hepatitic diseases, 275 celiac disease, 275–276 collagen vascular diseases, 275 nonspecific reactive hepatitis, 275 resolving hepatitis, 275 viral hepatitis, 275 metabolic diseases, 276 mild hepatic steatosis versus Ito cell lipidosis, 278–280 portal hypertension, 276 quantitative copper assay on, 299 Liver biopsy pathology, special stains in, 521–522 bile stain (Fouchet/Hall stain), 522 copper stain, 521–522 elastic stain, 521 iron stain, 521 PAS with diastase (PASd), 522 reticulin stain, 521 trichrome stain, 521 Victoria blue stain, 522 “Liver cell dysplasia,” 388 Liver diseases, in pregnancy acute fatty liver of pregnancy (AFLP), 203, 204, 207–209, 207f, 208f, 208t, 209f clinical and morphological spectrum of, 203–204 hyperemesis gravidarum, 203 recurrent intrahepatic cholestasis of pregnancy, 203, 205–206, 205f, 206f, 206t toxemia/HELLP syndrome, 203, 204, 210–212, 210–211f, 211t Liver fatty acid binding protein (LFABP), 344, 355f Liver injury due to total parenteral nutrition (TPN), 235–236, 235f, 236t
Liver-kidney microsomal antibody (LKM), 23t Liver transplant pathology, 307 acute cellular rejection (ACR), 309–310, 309f, 310f, 331f versus recurrent hepatitis C, 313–314 chronic rejection versus recurrent primary sclerosing cholangitis versus non-PSC stricture, 326–329 cytomegalovirus (CMV) hepatitis, 337–339, 337f, 338f factors affecting outcome in, 307t fibrosing cholestatic hepatitis C versus biliary obstruction versus adverse reaction to medication, 319–322 graft versus host disease, 340–342 late cellular rejection versus autoimmune hepatitis versus recurrent hepatitis C, 315–318 mechanical biliary obstruction versus chronic rejection, 323–325 recurrent hepatitis C, 311–312 zone 3 (centrilobular) necrosis, 330–335, 330f, 332f, 333f, 334f Lobular hepatocellular injury, 1 Lobular inflammation and hepatocellular swelling, in acute alcoholic hepatitis, 2f Long chain 3 hydroxyl co-enzyme A dehydrogenase deficiency (LCHAD), 204 Lymphoblastic lymphoma, 491 Lymphocytes, 41, 43 Lymphogranuloma venereum (LGV), 84 Lymphoid neoplasm, 469 Lymphoid tumors, 472–473 Lymphoplasmacytic lymphoma (LPL), 471 M Macrophage infiltrate, 265 after hepatocyte injury, 265f classification, by cytoplasmic contents, 266t Gaucher disease, 271–272 immunologic, 268 infectious, 267 neoplastic and mimics, 268–269 Niemann-Pick disease, 273–274 PASd-resistant ceroid material in macrophages, 265f storage disorders, 266 amino acid metabolism, disorders of, 266 glycoprotein metabolism, disorders of, 266 iron metabolism, disorders of, 267 lipoprotein and lipid metabolism, disorders of, 266–267 unclassified, 267 Macrophages, 281 Macrotrabecular hepatoblastoma, 444 versus hepatocellular carcinoma, 449–451, 449f, 450f Macrovesicular steatosis, in hepatocellular carcinoma cells, 424, 424f Malignant angiomyolipoma, 510–513, 510f, 511f, 512t Malignant melanomas, 503t, 504 Malignant rhabdoid tumor (MRT), 453 Malignant teratoma/yolk sac tumor, teratoid hepatoblastoma versus, 455, 455–456f Mallory-Denk bodies (MB), 28, 37, 28, 37, 44, 237f, 238, 243, 246, 247, 247f, 306f, 423, 434 characteristics, 246t hepatocellular ballooning with, 2, 2f periseptal pseudoxanthomatous change and, 107f Mammaglobin, 437 Mantle cell lymphoma, 470t
533
INDEX
Marginal zone lymphoma (MALT), 470t Massive hepatic necrosis (MHN), 211 Masson’s Trichrome stain, 39f, 41, 43, 47, 220, 221f, 223, 399f, 459, 460f Mast cell disease, 276 mimicking inflammatory biliary disease, 497 Maturity-onset diabetes of the young type 3 (MODY3), 344 Mauriac syndrome, 252 Mechanical biliary obstruction versus chronic rejection, 323–325 Meckel syndrome, 134t Medullary cystic kidney disease 1, 134t Medullary cystic kidney disease 2, 134t Megamitochondria, 240, 243, 246, 247f, 255f characteristics, 246t Melan A, 415, 438, 504, 512 Melanoma, 434, 512, 512t 6-Mercaptopurine, 6 Mesenchymal component, in hepatoblastoma, 456f Mesenchymal hamartoma, 499–501, 499f, 500f, 500t Mesenchymal hepatoblastoma, 442, 444 Mesenchymal tumors, of liver angiomyolipoma, 505–507, 505f, 506f inflammatory variant, 508–509, 508f, 509f embryonal sarcoma, 502–504, 502f, 503f, 503t malignant angiomyolipoma, 510–513, 510f, 511f, 512t mesenchymal hamartoma, 499–501, 499f, 500f, 500t Metabolic disease, 15, 15t, 39, 276 Metastatic adenocarcinoma, hepatocellular carcinoma (HCC) versus, 436–437, 436f, 437f Metastatic carcinoma, 16 Metastatic gastrointestinal stromal tumor (GIST), 438–439 Metastatic polygonal cell tumor, hepatocellular carcinoma (HCC) versus, 438–439, 438f, 439f Metastatic renal cell carcinoma, 414 Metastatic tumors commonly used markers glypican-3 (GPC-3), 431–432, 432f Hep Par 1 (hepatocyte antigen), 431, 431f MOC31 (epithelial cell adhesion molecule/EPCAM), 432–433, 432f polyclonal carcinoembryonic antigen (pCEA), 432, 432f hepatocellular carcinoma (HCC). See Hepatocellular carcinomas (HCCs) Metavir grading and staging system, 517t, 518t Metformin, 222 Methimazole, 228, 228t hepatitis, 93f Methotrexate, 6, 56 Methotrexate-induced chronic liver disease, 232–234, 232f, 233f causality analysis, 234t Roenigk classification, 234t 3,4-Methylenedioxymethylamphetamine (MDMA), 16 Microgranulomas, 68 Microvesicular steatosis, 15t, 16, 57, 57f, 207f, 208, 208t, 209f, 211, 240–242, 240–241f causality analysis, 242t drugs and toxins with, 241t hepatocytes in, 43, 44f Microwave coagulation therapy (MCT), 429 Mild hepatic steatosis versus Ito cell lipidosis, 278–280 Mild hepatitis pattern differential diagnosis, 5 pathologic features, 5, 5f
Minocycline, 224, 225t Minocycline-induced autoimmune hepatitis, 224 Mitochondrial DNA replication, 241 Mitochondrial sterol 27-hydroxylase, 162t Mixed epithelial-mesenchymal hepatoblastoma, 500t, 501 MOC31, 364, 414, 415, 432–433, 432f, 434, 436. See also Hepatocellular carcinomas (HCCs) Modified Brunt-Kleiner method, for steatohepatitis staging, 519 519t Monoamine oxidase inhibitors, 16 Monoclonal CEA (mCEA), 432 Monoclonal protein (M-protein), 186 MRP2 (multidrug resistant protein 2), 155 Mucin core (MUC) proteins, 364 Mucolipidoses, 266 Mucosa-associated lymphoid tissue (MALT lymphoma), 470 extranodal marginal zone lymphoma of, 477 Multidrug-resistance-3 (MDR3) pathway, 103, 162, 203 Multilocular cyst with adjacent hepatocytes, 378f Multiple adenomas and liver adenomatosis, 344–345 Mycobacterium avium-intracellulare (MAI) infection, 68, 72, 77 Mycobacterium tuberculosis, 67, 70, 71, 84 Myeloid sarcoma, 473 Myeloid tumors acute myeloid leukemia, 473 chronic myeloproliferative disorders, 473 myeloid sarcoma, 473 Myeloproliferative neoplasms. See Chronic myeloproliferative disorders Myeloproliferative syndromes, 191 MyoD1, 504 Myogenin, 504 Myosin, 504
N N-acetylp-benzoquinone (NAPQI), 217 Necrosis epithelioid granulomas with/without, 67–68 hepatocellular injury with/without, 1 with little/no inflammation, 15t, 16 with prominent inflammatory activity, 16, 16f venocentric pattern of, 196f Necrosis-dominant injury pattern, acute liver failure (ALF) with, 18–19, 18f, 19 Necrosis-dominant pattern of liver injury, 4f Necrotizing epithelioid granulomas, 70–72, 70f, 71f, 72f Needle biopsy, adequacy of, 515 Neonatal cholestatic liver disease, 159t alpha-1-antitrypsin deficiency (AATD), 161–162 neonatal hepatitis due to, 172–174, 172f, 173f, 174f bile acid synthesis defects, 162 histologic patterns, 162t bile ducts, paucity of, 161, 170–171, 170f, 171f in neonatal period, 161t biliary atresia, 159, 164–165, 164f, 165f histology, 160, 160f and neonatal hepatitis, histologic features of, 160t neonatal hepatitis, 159t, 160 and biliary atresia, histologic features of, 160t due to alpha-1-antitrypsin deficiency (AATD), 172–174, 172f, 173f, 174f
534
INDEX
Neonatal cholestatic liver disease, (cont.) histology, 160–161 with hypopituitarism, 167–169, 167–168f, 169f progressive familial intrahepatic cholestasis (PFIC), 162 Neonatal giant cell hepatitis. See also Neonatal hepatitis (NH) with cholestasis and bile duct paucity, 92f Neonatal hemochromatosis (NH), 159, 297 Neonatal hepatitis (NH), 159, 159t, 160 due to alpha-1-antitrypsin (AAT) deficiency, 172–174, 172f, 173f, 174f etiologies, 159t histology, 160–161, 161f and biliary atresia, 160t with hypopituitarism, 167–169, 167–168f, 169f Neonatal liver disease, 243 Nephronophthisis, 134t Neuroblastoma (NB), 453 Neuroendocrine carcinomas, 415, 433 hepatocellular carcinoma versus, 412–413, 412–413f, 413t Neuroendocrine tumor, 434 Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, 86 Niemann-Pick disease, 238, 238f, 273–274, 273f Nitrofurantoin, 214, 224 Nodular lymphocyte predominant lymphoma (NLPHL), 472, 472t Nodular lymphoid lesions (NLLs), 473 Nodular regenerative hyperplasia (NRH), 87, 201 Nonalcoholic fatty liver disease (NAFLD) drugs and, 56 NAFLD activity score (NAS), for steatohepatitis, 519, 519t Nonalcoholic steatohepatitis (NASH). See also Steatohepatitis features of, 39f overview of, 39 with moderate/marked portal inflammation, 47–51, 47f, 48f, 49–50f Noncirrhotic portal hypertension, 191, 192 Non-DPM-related cystic liver disease biliary cysts, 139 choledochal cysts, 139, 139t, 149–150, 149f cilliated foregut cyst, 139 simple hepatic cyst, 138–139 solitary hepatic cyst versus hydatid cyst, 151, 151f Nonhepatotropic viruses, 3, 15t, 16 Non-Hodgkin lymphoma (NHL) B-cell lymphomas, 469–471, 469t T-cell lymphomas, 471, 471t Non-neoplastic injury patterns in drug-induced liver injury (DILI), 213, 214t Nonspecific reactive hepatitis, 5, 12, 13–14, 13f, 275 “Nontriadal” arteries, 389
O “Obliterative portovenopathy,” 191 Oct-2, 472, 472t, 481 3β-OH steroid dehydrogenase, 162t Oil red O, 57, 155, 242 Opisthorchis viverrini, 362 Oral contraception (OC), 343 Orcein/aldehyde fuchsin stains, 10, 10f, 27, 114, 114f, 121, 521–522 Oriental cholangiohepatitis, 116 Ornithine transcarbamylase deficiency, 251
Orthotopic liver transplantation (OLT), 286 Osteoblasts, 444 “Oval-like” periportal progenitor/stem cells and ductular reaction, 104, 105f Overlap syndromes. See Autoimmune hepatitis (AIH) Oxaliplatin, 62, 63f, 183, 183t Oxidative phosphorylation, 241 Oxysterol 7α-hydroxylase, 162t
P p22phox, 86 p47phox, 86 p67phox, 86 Paired homeobox 2 (PAX-2), 414, 416, 434, 512 Paired homeobox 5 (PAX-5), 472, 472t, 483, 483f Pale bodies, 247 characteristics of, 246t p-ANCA testing, 35 Pancytokeratin stain, 438 Parenchymal canalicular cholestasis, with “cholestatic rosettes”, 205f Parenchymal injury, 195 Parvovirus B19, 19 Pathologist, role of, 1 Paucity of bile ducts, 161 Paucity of intrahepatic bile ducts, 170–171, 170f, 171f Pediatric Acute Liver Failure Study Group, data from, 15 Pediatric fatty liver disease, 58f, 59f in children and adolescents, 58 differential diagnosis, 60 histologic changes in, 59–60 liver biopsy role, 60 prognosis, 59 risk factors for, 59 Pedunculated hepatocellular carcinoma, 427, 427f Peliosis hepatic, 187, 187f alcoholic lipopeliosis, 188, 188f causes of, 187t lipopeliosis, in transplanted donor livers, 189, 189f, 190f Penicillamine, 300 Penicillin, 215 Pennyroyal, 16 Percutaneous transhepatic cholangiography (PTC), 385, 386 Perhexiline maleate, 238 Peri-canalicular polyclonal carcinoembryonic antigen (p-CEA), 409, 410, 415, 415f, 512, 416, 426 Pericellular fibrosis, 2, 2f Pericholangitis, 1 Periodic acid–Schiff (PAS) stains, 121t, 245, 249, 251, 253, 256f, 257, 257f, 385f, 501, 503f Periodic acid–Schiff diastase (PASd) stain, 4, 7, 8f, 45, 172, 173f, 191, 275, 522 Peripheral pulmonic stenosis, 171 Periportal ductular reaction, 104, 105f Perivascular epithelioid cell tumor (PEComa), 507. See also Malignant angiomyolipoma Perls’ iron stain, 52, 52f, 284f, 285f, 288f, 289f, 291f, 293f, 294f Perls’ Prussian Blue, 289 Phenytoin hepatitis, 16, 489 Phospholipidosis, 238
535
INDEX
Phosphomannose isomerase deficiency, 134t Phosphotungstic acid-haematoxylin (PTAH) stain, 255, 256f PiM gene, 243 Pipestem, 79 PiS allele, 243 PiZ allele, 243 PiZZ allele, 162, 243, 245, 246 PKD1 gene, 135 PKD2 gene, 135 PKHD1 gene, 134, 143 Plasma alpha-1-antitrypsin (AAT), 246 Plasma cells, of AIH, 3 Polyclonal antibody for carcinoembryonic antigen (pCEA), 398 Polyclonal carcinoembryonic antigen (pCEA), 432, 432f Polyclonal hypergammaglobulinemia, 268 Polycystic liver disease (PLD), 133t, 138 versus Caroli disease, 147–148, 147f Polycystin1, 135 Polycystin2, 135 Polymerase chain reaction (PCR), 2, 5, 8, 68, 83–84, 275 Polymorphic lymphoid infiltration, in transplant patient, 485–486, 485f, 486f Polysorbate 80, 239 Poorly differentiated hepatocellular carcinoma, 425–426, 425f, 426f Portal and lobular infiltration by blasts, 490–491, 490f by maturing granulocytes, 492–493 Portal-based infiltrative neoplasm versus biliary disease, 496–497, 496f, 497f Portal cavernoma, 194 Portal hypertension without cirrhosis Budd-Chiari syndrome (BCS), 195–198, 195f, 196f, 197f hepatoportal sclerosis, 191–192, 191f, 192f portal vein thrombosis (PVT), 193–194, 193f regressed cirrhosis case, 199–201, 199f, 200f Portal hypertension, 276 Portal infiltrates, 495t Portal infiltration with Reed-Sternberg cells, 482–483, 482–483f Portal inflammation, in nonalcoholic steatohepatitis (NASH), 47 hepatitis C virus with steatosis, 49–50, 49–50f non–organ-specific autoantibody positive cases, 50–51, 50f and other concurrent disease(s), 48–49 diagnostic criteria, 49 significance of, 48, 49f Portal vein thrombosis (PVT), 193–194, 193f Post-transplant lymphoproliferative disorders (PTLDs), 314, 471, 472, 481, 486 Pott’s disease, 99 Precancerous lesions histologic features of, 388 dysplastic foci, 388 dysplastic nodules, 388–389 terminology of, 387–388 Precedent for pathologic pattern, principle of, 215 Pregnancy, liver diseases in. See Liver diseases, in pregnancy Preservation and reperfusion injury (PRI), 335 PRETEXT (Pretreatment assessment of extent of disease) staging, 441, 444
Primary biliary cirrhosis (PBC), 3, 5, 5f, 21t, 23t, 27, 28, 276 AMA-negative PBC, 123–124, 123–124f autoimmune hepatitis (AIH) with bile duct injury versus, 26–28, 26–28f with cirrhosis, 128, 128f, 129f histologic staging of PBC, 129t definition of, 117 diagnostic criteria for, 117 with ductopenia, 125–127, 125f, 126f histologic features, 118 overlap syndrome, AIH and, 30–31, 30f, 31t with nonspecific changes and positive AMA, 120–122, 120f, 121t clinical and immunologic features, 121 histopathology of early-stage PBC, 121–122 treatment and natural history of, 118 Primary intrahepatic cholangiocarcinoma, and hepatocellular carcinomas, 407 Primary sclerosing cholangitis (PSC), 21t, 23t, 89, 326, 327f, 328f, 362, 375 and cholangiocarcinoma, 107–109, 107f, 108f, 109f Crohn’s disease with, 102–103, 102f, 103f and hepatolithiasis, comparison between, 115t overlap syndrome/AIH, 32–33, 32f versus immunoglobin G4-associated cholangitis (IAC), 110–112, 110–111f, 111t, 112f PRKSCH gene, 138, 148 Pro to Ala substitution, 243 Progesterone receptor (PR), 378, 433 Progressive familial intrahepatic cholestasis (PFIC), 162 PFIC1, 97, 162 PFIC2, 157, 162 PFIC3, 162 Prominent cytoplasmic contents, hepatocellular carcinomas with, 407 Prostate specific antigen (PSA), 409, 433 Protoplasmic antineutrophil cytoplasmic antibodies (p-ANCA), 23–24, 35, 50 Pseudoglandular hepatocellular carcinoma versus cholangiocarcinoma and metastatic adenocarcinoma, 409–410, 409f, 410f, 410t Pseudolymphomas. See Lymphoid tumors Pure (bland) cholestasis (pattern 2), 92, 92t Pure fetal hepatoblastoma, 442, 450f Pyogenic abscesses, in liver, 139, 141 Q Q-fever, 77 Quantitative copper assay, on liver biopsy, 299 R Radiofrequency ablation (RFA) therapy, 429, 429f Recurrent cholestasis of pregnancy, 205–206, 205f, 206f histologically “pure” parenchymal cholestasis, 206t Recurrent hepatitis C, 311–312 Recurrent intrahepatic cholestasis of pregnancy (RCP), 203 Recurrent pyogenic cholangitis (RPC), 116 5β-Reductase, 162t Reed-Sternberg cells, 472 portal infiltration with, 482–483, 482–483f
536
INDEX
Regressed cirrhosis, 192, 199–201, 199f, 200f Renal cell carcinoma (RCC), 175, 433, 434, 512, 512t clear cell type, 415t Resolving hepatitis case study, 11–12, 11f differential diagnosis, 5 pathologic features, 4 Reticulin stain, 10, 278f, 303f, 360f, 521 Reverse nodularity, 195 Reyes syndrome, 56, 16 Rhodanine, 121t Rickettsia conori, 72i Rickettsial organisms, 187 Rituximab, 112 Rochalimaea henselae, 83 Roenigk classification, of liver injury from methotrexate, 234t Rosai-Dorfman disease, 268 Rotor syndrome (RS), 154–155, 154t Roussel Uclaf Causality Assessment Method (RUCAM), 213 Rubeanic acid copper stain, 3, 121t, 302, 305, 306f Rubella, 171 S S-100, 415, 434, 438, 502, 504, 506, 512 Sarcoid granulomas, 74 74f Sarcoidosis, 73–76, 73f, 74f, 75f, 76f Scheuer grading and staging system, 517t Scheuer’s system, 290t Schistosoma haematobium, 81t Schistosoma intercalatum, 81t Schistosoma japonicum, 79, 81t, 362 Schistosoma malayi, 81t Schistosoma mansoni, 79, 81t Schistosoma mekongi, 79, 81t Schistosomiasis, 79–80, 79f, 80f, 81t Scirrhous and poorly differentiated HCC, 434 Scirrhous hepatocellular carcinoma, 417–418, 417f, 418t SCL11A2 (DMT-1) gene, 287t SEC63 gene, 138, 148 Secondary sclerosing cholangitis, 106 Selective serotonin reuptake inhibitors (SSRIs), 238 Sepsis, bile ductular cholestasis associated with, 99–101, 99–101f Septo-optic dysplasia, 160 Sequential syndromes, of AIH-PSC, 33 SERPINA1 gene, 243, 245f SERPINA3 gene, 243 Serum amyloid A (SAA), 344, 350f, 351f, 357f Serum autoantibodies (SMA), 16 Serum ceruloplasmin, 299 Severe combined immune deficiency (SCID), 268 Shikata stain, 121t Short rib-polydactyly syndromes, 134t Sickle cell anemia, 181 Simple hepatic cyst, 138–139 Simpson-Golabi-Behmel syndrome, 441t Simvastatin, 221, 222t Single nucleotide polymorphism (SNP) markers, 103 Sinusoidal dilatation and congestion (SDC) amyloidosis, 184–186, 184f, 185f, 186f Budd-Chiari syndrome (BCS) versus biliary disease, 177–179, 177–178f, 178t
cirrhosis and nonneoplastic liver adjacent to tumors, 176 differential diagnosis, 175t extrahepatic neoplasms without liver involvement, 175 intraoperative biopsies, 176 mechanical artifact, 175, 176f sinusoidal obstruction, 180–181, 180f, 181f systemic inflammatory diseases, 175, 176f transplant biopsies, 176 veno-occlusive disease, 182–183, 182f, 183t venous outflow obstruction, 175 Sinusoidal lymphocytosis, 495t Sinusoidal obstruction syndrome (SOS), 180–181, 180f, 181f. See also Veno-occlusive disease Sinusoidal T-cell infiltration, 487–489, 487–488f, 489f SLC40A1 (ferroportin) gene, 287t Slit-lamp examination for KF rings, 299 “Small cell dysplasia,” 388 Small cell hepatoblastoma, 442–443 versus other small round cell tumors, 452–454, 452f, 453f, 554f Small hepatic veins, 175 Smooth endoplasmic reticulum proliferation, 262 Smooth muscle actin (SMA), 23t, 133, 434, 438, 509, 509f, 511f Solitary hepatic cyst versus hydatid cyst, 151, 151f Soluble liver antigen/liver pancreas antigen (SLA/LP), 23t Space of Disse, 175, 177, 177f, 189, 190f, 196f, 276, 279, 279f Staphylococcus aureus, 86 Statin-acute hepatotoxicity, 220–222, 220f, 221f, 222t Stauffer syndrome, 175 Steatohepatitis, 2. See also Nonalcoholic steatohepatitis (NASH) without activity, 45–46, 45–46f alcoholic steatohepatitis, 54–55, 54f chemotherapy-associated, due to irinotecan, 61–63 with elevated serum iron indices and siderosis, 52–53, 52f grading brunt grading scheme, 518, 519t NAFLD activity score (NAS), 519, 519t guidelines for staging in, 519 with minimal ballooning, 43–44, 43–44f staging, 519 steatosis with inflammation versus, 41, 41f, 42f subacute steatohepatitis, 64–65, 64–65f Steatosis, 236 hepatitis C virus with, 49–50, 49–50f with inflammation versus steatohepatitis, 41, 41f, 42f Stevens-Johnson syndrome, 231 Stricturing/obstruction, 321 Subacute steatohepatitis, 64–65, 64–65f Sulfonamides, 16 Sulphatide lipidosis, 267 Symmers’ fibrosis, 79 Synaptophysin, 409, 412, 414 Syncytial giant cell hepatitis, 36–37, 36f Syphilis, tertiary, 72 SZ and MZ phenotypes, 162, 174 T T-cell lymphomas, 471, 471t αβ T-cell receptor, 471 γδ T-cell receptor, 471 Tamoxifen, 187, 238 Tangier disease, 266
537
INDEX
Tannic acid, 218 Tel/Infl HCAs, 358 Tel/Infl with steatotic HNF1α-mutated tumors, 357 “Telangiectatic form of FNH,” 344 Telangiectatic/inflammatory (Tel/Infl) HCA, 344 Temporal Eligibility, principle of, 214 Teratoid hepatoblastoma, 444 versus malignant teratoma/yolk sac tumor, 455, 455–456f Teratomas, 455 Terminal deoxynucleotidyl transferase (TdT), 470 Tertiary syphilis, 72 Tetracycline, 16, 126 Tetrathiomolybdate, 300 Tf (Transferrin) gene, 287t TfR2 gene, 287t Thioridazine, 238 Thorotrast (thorium dioxide), 187, 363 Thyroid transcription factor 1 (TTF-1), 409, 432, 433 Total parenteral nutrition (TPN), liver injury due to, 235–236, 235f causality analysis, 236t Toxemia/HELLP syndrome, 203, 204, 210–212, 210–211f periportal hepatocellular damage, causes of, 211t “Toxic” pattern, of acute hepatitis differential diagnosis, 3, 3f pathologic features, 3 Toxicology, in DILI evaluation, 215–216 Transarterial chemoembolization (TACE), 429 Transferrin receptor 1, 281 Transferrin receptor 2, 281 Trichrome stain, 4, 4f, 10, 10f, 45, 48f, 50f, 101f, 102, 121t, 296f, 301f, 302f, 521 Trientine, 300 Trimethoprim-sulfamethoxazole, 126 Trisomy 18, 441t Tuberous sclerosis, 134t Tubular-dilatation, of ductal plate, 131 Tumoral hepatocytes, 359f Twenty-four–hour urine copper, 299 Type 1 autoimmune hepatitis (AIH), 24, 24t Type 2 autoimmune hepatitis (AIH), 24, 24t Type 2 diabetes, steatohepatitis with, 43 Type 3 autoimmune hepatitis (AIH), 24, 24t Type IV collagen immunoperoxidase stains, 189, 190f U UDCA. See Ursodeoxycholic acid (UDCA) UDP-glucuronosyltransferase (UGT1A1) gene, 153 “Unpaired” arteries, 389 Urea cycle defects, 251 Uremia, 261, 262t Urinary coproporphyrin, in DJS, 155 Ursodeoxycholic acid (UDCA), 28, 31, 33, 118 V Vaginal atresia syndrome, 134t Valproate, 16
Valproic acid, 16, 57 Vanishing bile duct syndrome (VBDS), 230, 276 Varicella-zoster virus (VZV), 19 Vascular tumors cavernous hemangioma variants, 457–458, 457–458f epithelioid hemangioendothelioma (EHE), 459–461, 459f, 460f hepatic angiosarcoma (HAS), 462–464, 462f, 463f infantile hemangioma, 465–467, 465f, 466f, 466t, 467t Veno-occlusive disease, 182–183, 182f etiology of, 183t Venoportal necrosis, 196f Venous outflow obstruction (VOO), 211 Victoria blue stain, 522 Vimentin, 410, 438, 439f, 443t, 504 Viral hepatitis, 15, 16, 275 Viral hepatitis A, 3 Visceral leishmaniasis, 267, 267f Vitamin A, 187, 276, 279, 279t, 280 von Meyenberg complexes (VMCs), 135, 138, 138f, 147–148, 147f, 368, 369 cholangiocarcinoma, 373–374 transformation, to cholangiocarcinoma (CC), 374 W Waldenström macrogloblinemia, 471, 478 Warthin-Starry silver impregnation stain, 82, 82f, 83 Whipple’s disease, 72 Wilms tumor (WT), 448, 453 Wilson disease, 3, 15, 16, 21t, 45, 48, 60, 246, 276, 299 anticopper drug treatment, 299 assessment of copper deposits by light microscopy, 299 chronic hepatitis due to, 304 cirrhosis of, 305f chronic hepatitis consistent with, 305–306 clinical presentations, 299 differential diagnosis, 299 fulminant form of, 301–303 giant (multinucleate) hepatocytes, 305f and glycogenated nuclei, 305f Wnt signaling pathway, 445 Wolman disease, 267 Y Yolk sac tumor (YST), teratoid hepatoblastoma versus, 455, 455–456f Z Zellweger syndrome, 161, 162, 162t, 297 Zidovudine, 16 Ziehl-Neelsen stain, 71f Zimmerman, Hyman, 227 Zinc, 300 Zone 3 (centrilobular) necrosis, 330–335, 330f, 332f, 333f, 334f ZZ phenotype, 174, 243
