A RETROSPECTIVE STUDY OF PANCREATIC TUMORS IN SLAUGHTER CATTLE

Sixteen primary pancreatic tumors were found in a retrospective study of bovine pancreatic lesions detected in slaughtered cattle. Eleven is let cell tumors and three pancreatic exocrine carcinomas were identifi ed based on light microscopy and immunohistochemistry. Nine of 11 isle t cell tumors were classified as malignant. Metastatic sites included iliac, mediastinal, hepatic, and mesenteric lymph nodes, peritoneum, m esentery, and liver. Six cows with multiple islet cell tumors also had pheochromocytomas. All 11 islet cell. tumors had positive immunoreact ivity to insulin and somatostatin. Three tumors also contained cells i mmunoreactive for glucagon and two tumors contained pancreatic polypep tide immunoreactive cells. Immunoreactivity of tumor cells in metastat ic sites was similar to their respective primary tumors. All exocrine pancreatic carcinomas metastasized widely and were immunonegative for insulin, somatostatin, glucagon, and pancreatic polypeptide. No mixed endocrine-exocrine tumors were identified. None of the endocrine or ex ocrine tumors contained amyloid. Additional primary tumors of the bovi ne pancreas included one neurofibroma and one neurofibrosarcoma. Addit ional cases with lesions of the bovine pancreas included nodular hyper plasia in 15 cows, exocrine acinar atrophy and fibrosis in four cows ( two of which also had pancreatic lithiasis), pancreatitis in one cow, peripancreatic fibrosis in two cows, pancreatic steatosis in one anima l, and pancreatic hemorrhages in one cow.