Ampullary carcinoma in a group of aged rhesus macaques (Macaca mulatta).

Ampullary carcinoma was diagnosed in 6 rhesus macaques that ranged in age from 20 to 35 years. Signalment, premonitory signs of disease, and results of clinical biochemical and hematologic analyses varied among animals. Histologically, the neoplastic cells obliterated the ampulla, with regional spread to the duodenum in all 6 animals and to the pancreas in one animal. Two animals had metastases to the lung, and another two had metastases to the pancreoduodenal lymph nodes and liver. One animal had mesocolonic metastasis. Malignant tumors of the ampullary region are rare in domestic animals, and account for less than 5% of all cancers of the digestive tract in humans.