Somatostatinoma of the pancreas

A case of a pancreatic somatostatinoma in a 74-year-old male is presented. It was very difficult to establish the clinical diagnosis because of absence of typical symptoms. However, it was very easy to establish the histological diagnosis because typical cytoplasmic neurosecretory granules (D-cell granules) and immunoreactivity for somatostatin were demonstrated. Moreover, immunoassay of tumor tissues enables one to not only establish a definitive diagnosis but also to demonstrate multiple hormone production.