[Endocrine pancreas tumor as a cause of exocrine pancreas insufficiency: problems of immunologic tumor diagnosis and classification].

The case of a 32-year old man with exocrine pancreatic insufficiency and progressive weight loss is reported. Ultrasound examination of the abdomen revealed a huge tumor of the pancreatic head. Smears obtained by a percutaneous fine-needle biopsy showed characteristics of a neuroendocrine tumor. Serum hormone levels and immunocytochemistry presented no evidence for a hormonal activity of the tumor. The exocrine pancreatic insufficiency was explained by an obstruction of the pancreatic duct system. In the present case report the problems of diagnostic approaches to endocrine pancreatic tumors are discussed.