ABSTRACT
A case of 39-year-old diabetic patient with a calcitonin and somatostatin secreting pancreatic islet tumor is presented. He had suffered from chronic diarrhea and dyspepsia for 10 years and was diagnosed with diabetes 2 years ago. Abdominal CT revealed a huge abdominal mass which was considered as a neuroendocrine tumor after US-guided needle biopsy. A distal pancreatectomy and splenectomy were performed. Histologically, tumor cells, amanged in solid sheets, showed small nuclei without significant atypia and granular eosinophilic cytoplasm. Tumor cells showed strong immunoreacitivity for calcitonin and somatostatin. The serum clacitonin was markedly elevated (268.7 pmol/L, normal range; 0.9-7.6 pmol/L). After resection of the tumor, diarrhea and dyspepsia diappeared, and oral glucose tolerance test showed normal glucose tolerance with normalization of calcitonin.
