CHOLANGIOCELLULAR CARCINOMA IN A DUCK – A CASE REPORT

Abstract

Cholangiocellular carcinomas are malignant tumors of biliary epithelium which usually arise from intrahepatic and extra hepatic bile ducts. These neoplasms occur frequently in ducks. Single or multiple nodules may be present within the liver, which are typically firm, raised, often with central depression (umbilicated), pale gray to tan colored. The tumors are composed of cells that resemble biliary epithelium. Characteristically well differentiated carcinomas are organized into tubular or acinar arrangement. In case of less differentiated neoplasms, some acinar arrangements can be detected among solid masses of neoplastic cells. Poorly differentiated carcinomas are composed of packets or cords of cells with areas of squamous differentiation. The epithelial components of neoplasms are usually separated by fibrous connective tissue. The amount of connective tissue varies among tumors but an abundant deposition of collagen termed as scirrhous response is relatively common and is responsible for the firm texture of these neoplasms. Multiple sites of local invasion by tumor cells to the surrounding hepatic parenchyma are usually seen. Multifocal hepatic necrosis are also common in the adjacent parenchyma. Metastasis to extra hepatic sites is common, particularly to the adjacent lymph nodes of the cranial abdomen, lungs, or by seeding into abdominal cavity. Peritoneal carcinomatosis can produce variably sized nodules within the mesentery and on the serosal surface of the viscera.