C-cell carcinoma (medullary thyroid carcinoma) associated with multiple endocrine neoplasms in a ferret (Mustela putorius).

A firm, infiltrative mass was found in the thyroid region of an adult castrated male ferret (Mustela putorius) presenting with vague signs of weight loss, minor inappetence, and decreased activity. Efforts to surgically excise the tissue were unsuccessful, and the animal was euthanatized. Gross and histopathologic evaluation revealed multiple endocrine neoplasms, including C-cell carcinoma, adrenocortical adenoma, pheochromocytoma, and endocrine tumor of the pancreas. This is the first descriptive account of a C-cell carcinoma, also known as medullary thyroid carcinoma, in a ferret, although other endocrine neoplasms in this species have been reported with some frequency. These findings mimic features observed in human multiple endocrine neoplasia syndromes.