Cholangiocarcinoma with carcinomatosis in a sugar glider

A 7-y-old, castrated male, leucistic sugar glider (Petaurus breviceps) was presented because of a progressive history of lethargy, ataxia, diarrhea, and anorexia. Abdominal ultrasound revealed fluid in the abdomen and an infiltrative mass in the liver. Due to a poor prognosis, euthanasia was performed. Postmortem examination revealed a focally extensive, infiltrative, off-white, firm mass in the liver with adhesion to the omentum, mesentery, gastric serosa, and diaphragm. The remaining hepatic parenchyma was diffusely yellow. Histologically, the hepatic mass was consistent with metastatic cholangiocarcinoma (cholangiocellular carcinoma) with proliferation of neoplastic epithelial cells surrounded by marked desmoplasia. Neoplastic cells expanded and infiltrated the adjacent omentum, mesentery, and the serosal surfaces of the stomach, kidney, and small and large intestines. To our knowledge, cholangiocarcinoma has not been reported previously in a sugar glider.