Hypermotility, watery diarrhea syndromes with
hypokalemia and hypochloremia or hyperchloremia, dehydration. Lethargy,
muscular weakness, nausea, vomiting, and abdominal pain are frequent. Fluid
secretion may exceed 3 to 5 L, with a loss of 200 to 300 mEq of potassium
daily. Some cases of VIPoma have included hypercalcemia, flushing, and
glucose intolerance. Ectopic primary sites, such as the liver and jejunum,
occur in approximately 10% of patients. In children, the VIPoma syndrome
is caused by either a ganglioneuroma or ganglioneuroblastoma. In adults, it
is caused by bronchiogenic carcinoma, pheochromocytoma, medullar thyroid
carcinoma, and retroperitoneal histiocytoma. Multiple endocrine neoplasia
type 1 can be associated (in MEN, hypercalcemia is frequent).