Besides the clinical picture, fasting VIP plasma level may confirm the diagnosis, and CT scan and somatostatin receptor scintigraphy are used to localise the tumor, which is usually metastatic at presentation. Tests include: * Blood chemistry tests (basic or comprehensive metabolic panel) * CT scan of the abdomen * MRI of the abdomen * Stool examination for the cause of diarrhea and electrolyte levels * Vasoactive intestinal peptide (VIP) level in the blood
VIPoma
Somatostatinoma
Gastrinoma
Glucagonoma
Goblet cell carcinoid
Insulinoma
Hibernoma
Glomus tumor