[Nonulcerogenic gastrinoma of the pancreas]

Non-beta-cell adenoma of the islet apparatus in the pancreas was described. The tumor measured 8 X 4 X 4 cm. Histological examination revealed its mixed structure. The tumor was composed of trabecular and solid structures, adenoma-like rosettes, and pericytial muffs. APUD-amyloid was found in its stroma. Application of a specific immunoperoxidase technique and electron microscopy provided good evidence for the fact that the tumor consisted of gastrin-producing cells. In view of clinical features, the tumor was regarded as gastrinoma.