Pathological and immunohistochemical aspects of primary hepatobiliary neoplasms in cats

Abstract

Primary hepatobiliary neoplasms (PHN) are uncommon in cats, and originate in hepatocytes, intra- and extrahepatic bile ducts, mesenchymal cells, and cells of neuroendocrine origin. The aim of this study was to determine the frequency of PHN in cats diagnosed in the metropolitan region of Porto Alegre (RS), Brazil, for a period of 17 years, determining their epidemiological, anatomopathological and immunohistochemical aspects. Necropsy reports of 2.090 cats were analyzed, 125 were diagnosed with primary hepatobiliary diseases, of which 15 were cases of PHN, representing 12% of the specific hepatobiliary conditions and 0.7% of the necropsies. All PHN were malignant, of which 93.3% had epithelial origin and 6.7% presented mesenchymal origin. Cholangiocarcinoma was the most commonly diagnosed neoplasm, followed by hepatocellular carcinoma and hemangiosarcoma. In general, cats with no defined breed were the most affected. Concerning sex, 60% were females and 40% males. Age ranged from five to 18 years, with a mean age of 10.5 years (median of ten years). Grossly, cholangiocarcinoma and hemangiosarcoma were multinodular and hepatocellular carcinoma was massive. Microscopically, cholangiocarcinomas were arranged in acini and ducts, whereas hepatocellular carcinomas were arranged in solid sheets or trabeculae. On immunohistochemistry, cholangiocarcinomas, hepatocellular carcinomas, and hemangiosarcomas were positive for the antibodies CK 7, Hep Par-1, and vimentin and von Willebrand factor, respectively.

Neoplasias hepatobiliares primárias (NHP) são incomuns em gatos e se originam de hepatócitos, células dos ductos biliares intra e extra-hepáticos, células mesenquimais e ainda células de origem neuroendócrina. O objetivo do trabalho foi determinar a frequência das NHP em gatos diagnosticados na Região Metropolitana de Porto Alegre, no período de 17 anos, abordando seus aspectos epidemiológicos, anatomopatológicos e imuno-histoquímicos (IHQ). Foram analisados os laudos de necropsia de 2.090 gatos sendo que 125 foram diagnosticados com doenças hepatobiliares primárias, destes 15 foram casos de NHP, representando 12% das condições hepatobiliares específicas e 0,7% do total de necropsias. Todos os diagnósticos de NHP eram malignos, destes 93,3% apresentaram origem epitelial e 6,7% mesenquimal. Colangiocarcinoma foi a neoplasia mais diagnosticada, seguido do carcinoma hepatocelular e hemangiossarcoma. De uma maneira geral, os gatos sem raça definida foram os mais acometidos. Em relação ao sexo 60% eram fêmeas e 40% machos. A idade variou de cinco a 18 anos, com a idade média de 10,5 anos (mediana de 10 anos). Macroscopicamente o colangiocarcinoma e hemangiossarcoma eram multinodulares, e o carcinoma hepatocelular, maciço. À histologia, houve predomínio do arranjo acinar e ductal nos colangiocarcinomas e sólido, no carcinoma hepatocelular. Na IHQ os colangiocarcinomas foram reativos para CK 7, carcinoma hepatocelular para Hep Par-1 e hemangiossarcoma para vimentina e fator de von Willebrand.