Three patients with the watery diarrhea-hypokalemia-achlorhydria (WDHA) syndrome were studied. All had watery diarrhea, hypokalemia and hypercalcemia. Plasma vasoactive intestinal polypeptide (VIP) levels determined by radioimmunoassay were markedly elevated in these patients, indicating that they had VIP-producing tumors. Plasma VIP levels determined serially after the operation indicate that its determination is useful in estimating the effect of a treatment.
As for multiple endocrine neoplasia type 1 (MEN1), two out of the three cases belonged to this category. Patient 1 had a brother with insulinoma, and in case 2, even though there was no family history, the autopsy revealed not only multiple tumors of the pancreas but also pituitary adenomas, chief cell hyperplasia of the parathyroid glands, thyroid adenomas and adrenocortical adenomas.
VIP and other hormones in the tumors as well as in the plasma were examined extensively in these cases. In case 1, VIP, gastrin and calcitonin were produced in the tumor and only plasma VIP levels were elevated. In case 2, with multiple tumors, tumor 1 produced VIP, glucagon, pancreatic polypeptide, gastrin and calcitonin, and tumor 2, VIP, pancreatic polypeptide, gastrin and β-melanocyte stimulating hormone. In this case, plasma VIP, pancreatic polypeptide and glucagon levels were elevated. In case 3, VIP and calcitonin were produced in the tumor, and plasma VIP and calcitonin levels were elevated.
These results indicate that (1) VIP is a good tumor marker for the WDHA syndrome due to VIP-producing tumors ;(2) patients with the WDHA syndrome are sometimes associated with MEN1 ; and (3) VIP-producing tumors are multiple hormone-producing tumors, and VIP predominantly elevated in the plasma results inthe WDHA syndrome, although other hormones such as pancreatic polypeptide, glucagon and calcitonin are sometimes found to be elevated in plasma without contributing to the clinical features.