Carlo Masserdotti, DVM, Dipl ECVCP, Spec Bioch Clin IAT, Consultant, Anatomic and Clinical Pathology, IDEXX Laboratories, Brescia, Italy.

About the Author ix Foreword xi Preface xiii Acknowledgments xv 1 Before the Analysis: Rules for Interpretation of Hepatic Cytology 1 1.1 The Rules for Cytological Diagnosis of Hepatic Diseases 2 1.1.1 Rule 1 2 1.1.2 Rule 2 2 1.1.3 Rule 3 2 1.1.4 Rule 4 3 1.1.5 Rule 5 3 1.1.6 Rule 6 3 1.1.7 Rule 7 4 1.1.8 Rule 8 4 1.2 Diagnostic Approach to Liver Disease 4 1.2.1 Clinical and Anamnestic Signs 5 1.2.2 Hematochemical Investigation 5 1.2.2.1 Pathological Bases of Liver Damage 5 1.2.2.2 Diagnosis of Liver Damage 8 1.2.2.3 Useful Enzymes for Recognition of Damage to Hepatocytes and Cholangiocytes 9 1.2.2.4 Liver Failure Diagnosis 11 1.2.2.5 Parameters of Liver Failure 12 1.2.3 Ultrasonographic Investigation 14 1.2.4 Cytological and Histopathological Investigation 15 1.2.4.1 Sample Collection 15 1.2.4.2 Cytological Approach to Hepatic Diseases 16 1.3 Key Points 16 References 17 2 Normal Histology and Cytology of the Liver 19 2.1 Normal Histology of the Liver 19 2.2 Normal Cytology of the Liver 27 2.2.1 Hepatocytes 28 2.2.2 Kupffer Cells 30 2.2.3 Stellate Cells (Ito Cells) 31 2.2.4 Cholangiocytes (Biliary Cells) 32 2.2.5 Hepatic Lymphocytes 33 2.2.6 Hepatic Mast Cells 34 2.2.7 Hematopoietic Cells 34 2.2.8 Mesothelial Cells 36 2.3 Key Points 38 References 39 3 Nonspecific and Reversible Hepatocellular Damage 41 3.1 Accumulation of Water 42 3.2 Accumulation of Glycogen 43 3.3 Accumulation of Lipids 46 3.4 Accumulation of Bilirubin and Bile Salts 57 3.5 Hyperplasia of Stellate Cells 57 3.6 Regenerative Changes 59 3.7 Key Points 64 References 64 4 Intracytoplasmic and Extracytoplasmic Pathological Accumulation 67 4.1 Pathological Intracytoplasmic Accumulation 67 4.1.1 Lipofuscin 67 4.1.2 Copper 73 4.1.3 Iron and Hemosiderin 76 4.1.4 Protein Droplets 82 4.1.5 Cytoplasmic Granular Eosinophilic Material 82 4.1.6 Hepatic Lysosomal Storage Disorders 85 4.2 Pathological Extracytoplasmic Accumulation 86 4.2.1 Bile 86 4.2.2 Amyloid 90 4.3 Key Points 96 References 96 5 Irreversible Hepatocellular Damage 101 5.1 Necrosis 101 5.2 Apoptosis 107 5.3 Key Points 110 References 110 6 Inflammation 113 6.1 Presence of Neutrophilic Granulocytes 115 6.2 Presence of Eosinophilic Granulocytes 123 6.3 Presence of Lymphocytes and Plasma Cells 125 6.4 Presence of Macrophages 130 6.5 Presence of Mast Cells 137 6.6 Key Points 139 References 139 7 Nuclear Inclusions 143 7.1 "Brick" Inclusions 143 7.2 Glycogen Pseudo-inclusions 144 7.3 Lead Inclusions 146 7.4 Viral Inclusions 146 7.5 Key Points 147 References 147 8 Cytological Features of Liver Fibrosis 149 8.1 Cytological Features of Liver Fibrosis 150 8.2 Key Points 159 References 160 9 Cytological Features of Biliary Diseases 163 9.1 General Features of Biliary Diseases 165 9.2 Cytological Features of Specific Biliary Diseases 167 9.2.1 Acute and Chronic Cholestasis 167 9.2.2 Acute Cholangitis 170 9.2.3 Chronic Cholangitis 170 9.2.4 Lymphocytic Cholangitis 170 9.3 Key Points 175 References 175 10 Bile and Gallbladder Diseases 177 10.1 Bactibilia and Septic Cholecystitis 179 10.2 Epithelial Hyperplasia 181 10.3 Gallbladder Mucocele 181 10.4 Limy Bile Syndrome 183 10.5 Biliary Sludge 183 10.6 Neoplastic Diseases of Gallbladder 183 10.7 Other Gallbladder Diseases 184 10.8 Key Points 184 References 184 11 Etiological Agents 187 11.1 Viruses 188 11.2 Bacteria 189 11.3 Protozoa 193 11.4 Fungi 194 11.5 Parasites 194 11.6 Key Points 197 References 197 12 Neoplastic Lesions of the Hepatic Parenchyma 199 12.1 Epithelial Neoplasia 200 12.1.1 Nodular Hyperplasia 200 12.1.2 Hepatocellular Adenoma 204 12.1.3 Hepatocellular Carcinoma 206 12.1.4 Cholangioma 215 12.1.5 Cholangiocellular Carcinoma 217 12.1.6 Other Nodular Lesions of Biliary Origin 222 12.1.7 Hepatic Carcinoid 223 12.1.8 Hepatoblastoma 227 12.2 Mesenchymal Neoplasia 227 12.2.1 Malignant Mesenchymal Neoplasms 227 12.3 Hematopoietic Neoplasia 229 12.3.1 Myelolipoma 231 12.3.2 Large Cell Hepatic Lymphoma 232 12.3.3 Small Cell Lymphoma 234 12.3.4 Large Granular Lymphocyte (LGL) Lymphoma 236 12.3.5 Epitheliotropic Lymphoma 239 12.3.6 Other Types of Hepatic Lymphoma 240 12.3.7 Malignant Histiocytic Neoplasms 242 12.3.8 Mast Cell Tumor 245 12.3.9 Hepatic Splenosis 247 12.4 Metastatic Neoplasia 247 12.5 Criteria for Selection of Sampling Methods for Liver Nodular Lesions 248 12.6 Key Points 250 References 250 Index 255

BOOK REVIEW
"The first edition of "Canine and Feline Liver Cytology" is a testament to Masserdotti's extensive research on liver disease and pathology, condensed into a concise and focused text. This book emphasizes the importance of diagnosing pathologic conditions through cytologic evaluation of hepatobiliary and bile samples. With over 30 years of experience in cytopathology and significant research on the cytologic features of spontaneous tumors and inflammatory diseases in companion animals, Masserdotti is exceptionally qualified to create this comprehensive resource. Aimed at clinical pathologists and researchers specializing in liver studies, the book not only enriches existing literature on liver cytology but also offers personal insights into misconceptions and inaccuracies in historically accepted terms such as "vacuolar liver disease."

The book is organized into 12 chapters, beginning with the groundwork for interpreting hepatic cytology and establishing rules for the cytologic diagnosis of hepatic diseases. This includes intrinsic aspects of the cytology process, limitations of analysis, stain differences, and the crucial need for collaboration with clinicians when diagnosing and managing hepatic diseases. The first chapter provides a framework for the diagnostic approach to liver disease, integrating clinicopathologic, anamnestic, ultrasonographic, and histopathologic findings. This introductory chapter also reviews normal liver histology and cytology, focusing on all possible cell types detected in healthy tissue, emphasizing that recognizing normal structures is essential for identifying pathological states.

The book then delves into various cytologic findings, categorized into nonspecific and reversible hepatocellular damage, pathological accumulations, irreversible hepatocellular damage, inflammatory patterns, nuclear inclusions, fibrosis, biliary diseases, bile and gallbladder diseases, etiological agents, and neoplastic lesions of the hepatic parenchyma. Each chapter provides ample context for the significance of cytologic findings, accompanied by high-quality images that effectively showcase cytologic features. Many images include different or special stains, such as PAS, oil red O, and rhodanine, highlighting specific cytologic findings. Additional graphical illustrations depict normal architectural features of the liver and the development of certain pathologic conditions. When relevant, cytologic images are contrasted with their histologic counterparts, highlighting areas where cytology excels, such as detecting etiologic agents in liver aspirates and diagnosing different types of hepatic neoplasia. The book provides detailed microscopic depictions of common conditions, such as reversible nonspecific changes and hepatocellular regeneration, as well as rare conditions like Ito (stellate) cell hyperplasia in cats. It includes side-by-side comparisons of amyloidosis and fibrosis, detailed descriptions of various inflammatory patterns affecting the liver, and tables with differential diagnoses for each condition. Regarding hepatic neoplasms, Masserdotti shares his candid perspective on the malignant potential of hepatocellular carcinomas in dogs and offers detailed descriptions of primary and metastatic hepatic neoplasms, providing histologic comparisons alongside cytology figures. Key points at the end of each chapter emphasize important aspects of the discussed topics.

Masserdotti makes a compelling case for why cytology should be integral to the diagnosis of pathologic conditions that affect the liver. While diagnosing liver disease typically requires a combination of clinical assessments, anamnestic data, blood and chemistry tests, ultrasound evaluations, and cytohistologic analyses, he acknowledges that clinical, laboratory, and ultrasound findings can sometimes be inconclusive. Similarly, cytologic findings are often nonspecific, as seen in cases of mixed inflammation or reversible changes. The role of cytology is frequently limited to ruling out other potential pathologies, and making a definitive diagnosis based solely on cytologic evaluation is often impossible without integrating clinical and anamnestic data, ancillary tests, and laboratory and imaging diagnostics. This underscores the necessity for a collaborative diagnostic approach. Advocating for better collaboration between clinicians and pathologists, he also calls for standardizing nomenclature in liver cytology, proposing the replacement of the term "vacuolar hepatopathy" with "nonspecific and reversible hepatocellular damage." To enhance communication and achieve consensus among clinicians, clinical pathologists, and anatomic pathologists, the book adheres to the WSAVA standard diagnostic terminology, eliminating confusion in nomenclature.

Masserdotti is honest about his personal experiences, often sharing his own perspective, especially on delicate topics where literature is scarce, authors disagree, or discussions bridge into other veterinary specialties, such as oncology. This book illustrates situations where hepatic cytopathology is sufficient for diagnosis and cases where cytology serves as a preliminary step for further evaluation, making it unsuitable for inexperienced cytologists. In Masserdotti's words, "the target audience of this book is the skilled and expert cytologist." I found this first edition to be a well-structured and informative contribution to the field of hepatobiliary pathology and a must-read for those whose diagnostic duties heavily involve liver cytology." -Francisco O. Conrado,...