Abstract: Cholangiocellular carcinoma is a malignant tumor derived from hepatic bile duct epithelial cells, which occurs in many species. In this study, two cases of canine liver tumors were diagnosed by histopathology and immunohistochemistry. Macroscopic of liver tumor is a spherical white mass, histopathological examination the tumor tissue consists of tumor cells arranged in a glandular tube, in the center of the gland have some necrotic and exfoliated cells,and some have mucus-like substances, the ducts are separated by thin fibrous connective tissue, and the tumor tissue has large area necrosis. The tumor cells are mostly oval, the nucleus is large, oval, and mitotic image is more common, CK19 was positively expressed in tumor cells, while CK18 and AFP were negatively expressed. According to the results of histopathology and immunohistochemistry, 2 cases of canine liver tumors were Cholangiocellular carcinoma, this study accumulated pathological data for the diagnosis of canine liver tumors.

Key words: canine, cholangiocellular carcinoma, CK19, CK18, AFP