A 41-year-old woman is known to have multiple endocrine neoplasia syndrome. She has multiple family members who have had adenoma tumors removed from the parathyroid, pancreas, and/or pituitary glands. She has severe diarrhea associated with low gastric acid secretion and a normal gastrin level. Which of the following serum assays would be best to evaluate the possible cause of the diarrhea?
High-Yield Explanation
VIP producing tumors (VIPomas) are usually malignant, although benign tumors and hyperplasia may also occur. Increase of VIP results in the WDHA syndrome. Diarrhea is severe and results in fluid and electrolyte disturbances. Treatment is directed to removal of the pancreatic tumor. Gastrinoma is more common but is associated with increased gastrin level in the blood.