Epithelial tumors of the rat pancreas.

During routine necropsy of 1,252 rats of the Chester Beatty stock albino strain between January 1962 and October 1965, we saw 10 epithelial pancreatic tumors. Eight were in males and 2 were in females. Five were single or multiple exocrine adenomas, 3 were exocrine adenocarcinomas, and 2 were islet-cell tumors. A search through the literature revealed 3 reports of exocrine adenomas, 11 of exocrine adenocarcinomas, and 19 of islet-cell tumors. Histological criteria for distinguishing between adenomas of exocrine and islet origin and between benign and malignant variants of each are discussed. An association between islet-cell adenomas and adenomas of other endocrine glands in rats has been recorded by several authors; its significance is unknown.--J Nat Cancer Inst 39: 18-32, 1967.