DUCTULOENDOCRINE CELL-PROLIFERATION IN THE PANCREAS OF 2 YOUNG-DOGS WITH DIABETES-MELLITUS

Two cases of diabetes mellitus in juvenile does (a 3-4-month-old Golde n Retriever and a 2-month-old Labrador Retriever) are described here i n terms of their clinical, histologic, and immunohistologic findings. Only very few insulin-positive cells were demonstrated immunohistochem ically in one dog. In the second dog, the alterations of the pancreas consisted of hydropic vacuolar degeneration of B cells in the islets o f Langerhans. In both cases, hyperplasia of the vacuolated cells was p rominent. These cells formed tubular structures and were immunohistoch emically positive for cytokeratin and proliferating eel antigen (MIB-1 ). Furthermore, within these vacuolated areas, some cells were positiv e to varying degrees for insulin, glucagon, somatostatin, and pancreat ic polypeptide. Apoptotic cells could be seen in the exocrine pancreas , in vacuolated areas, and occasionally in the islets of both dogs. We interpret these alterations as ductuloendocrine cell proliferation, p robably as an idiopathic compensatory response.