CHOLANGIOCARCINOMA IN A RED-TAILED HAWK (BUTEO-JAMAICENSIS)

A cholangiocarcinoma with multiple metastases was diagnosed in an adul t red-tailed hawk (Buteo jamaicensis) maintained in captivity for 14 y r. Antemortem radiography revealed an extensive periosteal reaction an d medullary opacification of the left femur and severe hepatomegaly. L aboratory sampling over a 5-wk period revealed a persistent mild leuko cytosis and elevations in aspartate aminotransferase, lactate dehydrog enase, alkaline phosphatase, and creatinine phosphokinase. On postmort em examination, unencapsulated masses consisting of epithelium-lined t ubulelike structures were observed in the liver, adrenal gland, lung, and left femur. The neoplastic epithelial cells contained eosinophilic cytoplasm and large round to ovoid nuclei with single large or multip le smaller nucleoli and exhibited extensive nuclear pleomorphism and v ariably abundant mitotic figures. This is the first report of bile duc t neoplasia in a bird of prey.