title: Classification of primary hepatic tumours in the cat.
abstract: Hepatic tumours in dogs have recently been re-classified to follow a revised human classification system that takes account of identified hepatic progenitor cells. This study investigated the presence and relative frequency of morphological types of feline primary hepatic neoplasms and aimed to determine whether a similar new classification scheme could be applied in cats. Feline primary liver tumours (n = 61) were examined histologically and with a series of immunohistochemical markers. Six cases of nodular hyperplasia and 21 tumours of hepatocellular origin were diagnosed. The latter were subdivided into hepatocellular tumours that were well differentiated and had no evidence of metastases (n = 18) and tumours that showed poorly differentiated areas with marked cellular and nuclear pleomorphism and had intrahepatic and, or, distant metastases (n = 3). These malignant feline hepatocellular tumours maintained their hepatocellular characteristics (HepPar-1, MRP2, pCEA positive) and were negative, or only <5% positive, for K19. Twenty-five cholangiocellular tumours were diagnosed and all had intrahepatic and, or, distant metastases. Eight NSE positive small cell carcinomas (carcinoids) were diagnosed and subdivided into small cell carcinomas with HPC characteristics (K19 positive) and neuroendocrine carcinomas (K19 negative). In addition, one squamous cell carcinoma originating from the distal part of the choledochal duct was recognised. Feline primary hepatic neoplasms can be sub-divided into benign and malignant hepatocellular tumours, cholangiocellular carcinomas, small cell carcinomas with HPC characteristics, neuroendocrine carcinomas and squamous cell carcinomas. The marked species difference justifies a specific classification for feline primary hepatic neoplasms.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: Renee G H M
authors.initials: RG
authors.lastname: van Sprundel
authors.affiliation: TCCI Consultancy BV, Utrecht, The Netherlands.
authors.forename: Ted S G A M
authors.initials: TS
authors.lastname: van den Ingh
authors.affiliation: Institute of Veterinary Pathology, University of Zürich, Zürich, Switzerland.
authors.forename: Franco
authors.initials: F
authors.lastname: Guscetti
authors.affiliation: Institute of Veterinary Pathology, Free University Berlin, Berlin, Germany.
authors.forename: Olivia
authors.initials: O
authors.lastname: Kershaw
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: Monique E
authors.initials: ME
authors.lastname: van Wolferen
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Rothuizen
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: B.Spee@uu.nl.
authors.forename: Bart
authors.initials: B
authors.lastname: Spee
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000453:epidemiology / Q000473:pathology*; D002415:Cats; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry / Q000662:veterinary; D008113:Liver Neoplasms / Q000145:classification / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D060787:Neoplasm Grading / Q000662:veterinary; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009367:Neoplasm Staging / Q000662:veterinary
chemical_list: D009363:Neoplasm Proteins
keywords: Classification; Feline; Immunohistochemistry; Liver tumours