Mucinous cholangiocarcinoma in captive sloth bear (Melursus ursinus) Karikalan M.3, Ilayaraja S.1,3, Sha Arun A.2,3, Mohan C.S.3, Sharma A.K.3,* 3Centre for Wildlife Conservation, Management and Disease Surveillance, ICAR-Indian Veterinary Research Institute, Izatnagar-243122, Uttar Pradesh, India 1Agra Bear Rescue Centre, Wildlife SOS, Keetham, Agra, Uttar Pradesh, India 2Bannerghatta Bear Rescue Centre, Wildlife SOS, Bangaluru, India *Corresponding author: e-mail: aksharmaivri@rediffmail.com
Abstract A 28 years old male sick sloth bear in captivity died with the history of poor appetite, distended abdomen with liver disorder at Agra Bear Rescue Centre. Post-mortem examination revealed pale mucous membranes, weak and debilitated body condition and presence of about two litres of serosanguinous fluid in the peritoneal cavity. Multiple mulberry sizedsemi-solid nodular growths were observed on the liver. The surface of the liver had adhesions with most of the abdominal organs. Serosal surfaces of most of the abdominal organs were also covered with thick mucus material. Histopathologically, the liver section showed variable sized areas where architecture of normal hepatic parenchyma was replaced by fibroadenomatous structures. The irregular variably dilated acinar structures resembled neoplastic bile ductules infiltrating the fibrous tissue stroma. The lining epithelial cells exhibited nuclear and cellular atypia with presence of many mitotic figures. The neoplastic cells, at times, exfoliated into the lumina. The lumina in majority of ductules contained mucin which stained pink with PAS stain. The neoplastic cells of proliferating bile ductules were intensely positive for cytokeratin immunostaining. Based on the characteristic histopathological features, the present case was diagnosed as mucinous chalangiocellular carcinoma, a rare variant of cholangiocellular carcinoma. Top Keywords Cholangiocarcinoma, Cytokeratin, Mucin, PAS, Sloth bear. Top |