Persistance of endocrine cells in immuno-induced carcinoma of the exocrine pancreas: insulin, glucagon, and somatostatin cells]

In immuno-induced exocrine pancreatic carcinomas, which keep their exocrine secretory specificity through their different evolution stages (1), (2)], normal B, A and D endocrine cells are still found, demonstrated by immunochemical techniques. They are localized in the islets of Langerhans. B and A cells are scattered in adenomatous pancreatic remains, and in the anaplasic carcinoma; D cells are found in the ductular and adenomatous remains. The three types of endocrine secretion granules are analyzed by electron microscopy at the early and late stages of carcinogenesis. The origin of the persisting endocrine cells and the nature of undifferentiated cells proliferating from the ductular epithelium are discussed.