ABSTRACT
Vasoactive intestinal peptide(VIP) is a 28-amino acid peptide, which may cause secretory diarrhea by stimulating the production of adenylate cyclase. Neuroendocrine tumors, secreting vasoactive intestinal peptide (VIP), are almost always of a pancreatic in origin. However, a pheochromocytoma may produce several neuropeptides, containing VIP, as they are considered to be neuroendocrine tumors. A 57-year-old woman, who presented with chronic watery diarrhea, hypokalemia, weight loss and a left adrenal mass, is described. Histologically, the tumor was diagnosed as a pheoch-romocytoma, with ganglioneuronal differentiation, and was histochemically confirmed to produce a vasoactive intestinal polypeptide. A left adrenal VIP-producing pheochromocytoma was successfully resected. After surgery, her diarrhea subsided and the electrolytes, affected neuroendocrine hormone levels, blood pressure and blood sugar level were normalized.