Slaughterhouse report of intrahepatic cholangiocarcinoma in a Holstein cow

Cholangiocarcinoma (CCA) is a primary tumor of the bile duct epithelium. Cholangiocarcinoma is relatively uncommon in domestic animals and the previous reports are documented more in dogs and cats, and less in other species. The current study described intrahepatic CCA in a 6-year-old female Holstein cow. Grossly, multiple parenchyma were scattered throughout the liver parenchyma. Histopathologically, the tumoral masses were composed of gland-like, tubular, acinar structures or solitary islands that embedded in the abundant connective tissue stroma with a cuboidal to columnar epithelial cells. Polymorphism and mitotic figures were present. In considering to the histopathologic characteristics, a diagnosis of cholangiocarcinoma was made. Predisposing factors for this neoplasm have not been identified. More studies require for understanding the mechanisms and risk factors of CCA occurrence.