Giant metastatic VIPoma in the liver

A case of giant metastatic liver VIPoma manifesting WDHA syndrome is described. The patient was a 33-year-old Japanese male who was admitted because of persisting watery diarrhea and weight loss. Laboratory examinations revealed marked hypokalemia, mild hypercalcemia and highly elevated plasma vasoactive intestinal peptide (VIP) and glucagon levels. Intensive imaging examinations disclosed two large tumors in the liver but not in other organs, including the pancreas. Laparoscopy disclosed a slightly elevated purplish-colored large tumor on the surface of the apparently normal liver. At operation, however, a small hard nodule was observed in the tail of the pancreas. Histologically, it was revealed to be a VIPoma resembling a carcinoid or an islet cell tumor, and was identical to the liver tumors. Thus, this neoplasm was considered to be a VIPoma of pancreatic origin, with metastatic lesions in the liver.