ABSTRACT
Multiple endocrine neoplasia type I is characterized by multiple tumors, particularly in the parathyroid glands, the pituitary gland and the pancreatic islet. We observed multiple pancreatic islet cell tumors with diverse hormonal expression in a MEN-I patient. The patient suffered from protracted diarrhea and multiple gastrododuodenal ulcers for 10 years. In abdominal computed tomography, space occupying lesions were detected in the distal pancreas. Distal pancreatectomy was done. Three tumors that measured 2.0 X 1.0 cm (A), 1.0 X 1.0 cm (B), and 1.0 X 0.5 cm (C) were discovered. Microscopic examination revealed another tumor, 1.0 X 0.5 cm (D). Microadenomas, less than 0.5 cm, were also found throughout the pancreas. Immunohistochemical stainings for insulin, pancreatic polypeptide, gastrin, glucagon, somatostain, and chromogranin were performed. Tumor A was trabecular and acinar in form and showed weak cytoplasmic reactivity to insulin. Tumor B was a gyriform and a few cells showed cytoplasmic reactivity to pancreatic polypeptide. Tumor C was trabecular in form and showed cytoplasmic reactivity to chromogranin. Direct invasion and distant metastasis were not found.