Multicentric intrahepatic cholangiocellular carcinoma in a budgerigar (Melopsittacus undulatus): a case report

Cholangiocarcinoma or intrahepatic bile duct carcinoma is a malignant neoplasm of biliary epithelium which occurs mainly in wild animals rather than domestic ones. An adult 4-year-old male budgerigar was referred with symptoms of lethargy, decreased activity, and vomiting with undigested food in feces. Supportive care was tried for 3 months, but the bird did not show any signs of recovery and was finally euthanized. Necropsy revealed hepatomegaly in one lobe of the liver while the other lobe was dwindled. The remaining large lobe had a multinodular appearance with white to gray, non-umbilicated foci ranging from 2 mm to 3 cm in diameter which was scattered throughout the parenchyma. The histopathological examination revealed multiple foci or masses of less differentiated cholangiocellular carcinoma. The large tumor masses had tubular, acinar, and solid arrangements with a center of necrosis. The masses were composed of neoplastic cells of biliary epithelium similar to the normal cuboidal ductal lining cells with moderate eosinophilic cytoplasm and round to oval vesicular nuclei. Multinuclear tumor giant cells were not seen; however, karyomegaly was rarely observed and infrequently in some foci. Based on histopathological characteristics, multicentric intrahepatic cholangiocellular carcinoma was confirmed. It seems that the probable cause of the tumor in this bird was chronic exposure to toxins such as aflatoxins.