Symptomatic pancreatic polypeptide-secreting tumor of the distal pancreas (PPoma).

Our report describes a 46-yr-old woman who presented with watery diarrhea in the presence of multiple endocrine neoplasia type I (MEN I) syndrome. Of various potential pancreatic endocrine hormones, only serum levels of pancreatic polypeptide were elevated. Radiologic imaging failed to identify a pancreatic tumor; her diarrhea was therefore managed with subcutaneous administration of somatostatin. Three years later she developed gallstone pancreatitis with the subsequent development of a pancreatic pseudocyst. At exploration for drainage of the pseudocyst, intraoperative ultrasound identified a 6-mm tumor in the distal pancreas that was resected. Final pathology documented a pancreatic endocrine tumor with immunohistochemical staining demonstrating the presence of pancreatic polypeptide. The present case illustrates the symptomatology that may be associated with pancreatic polypeptide-secreting endocrine tumors of the pancreas.