VIPoma is a very rare type of cancer that usually grows from certain cells in the pancreas.

VIPoma causes cells in the pancreas to produce high levels of a hormone called vasoactive intestinal peptide (VIP). This hormone increases secretions from the intestines and relaxes some of the smooth muscles in the GI system.

The cause is not known.

VIPomas are usually diagnosed in adults, most commonly at age 50. Women are more likely to be affected than men. This cancer is rare, affecting an estimated 1 in 10 million people per year.

• Abdominal pain and cramping
• Flushing or redness of the face
• Nausea
• Watery diarrhea (often massive amounts)
• Weight loss

Signs may include:

• Dehydration
• High volume of diarrhea (even without eating)
• Low stomach acid (achlorhydria)
• Low blood potassium (hypokalemia), which can cause leg cramps

Tests include:

• CT scan
• MRI
• Stool examination for cause of diarrhea and electrolyte levels
• Vasoactive intestinal peptide (VIP) in the blood

The first goal of treatment is to correct dehydration. Fluids are often given through a vein (intravenous fluids) to replace fluids lost in diarrhea.

The next goal is to slow the diarrhea. Some medications can help control diarrhea. Ocreotide, which is a man-made form of a natural hormone, blocks the action of VIP.

The best chance for a cure is surgery to remove the tumor. If the tumor has not spread to other organs, surgery can often cure it.

Surgery can usually cure VIPomas. However, in one-third to one-half of patients, the tumors have spread by the time of diagnosis and are not curable.

• Cancer spread (metastasis)
• Cardiac arrest from electrolyte imbalances
• Dehydration

If you have watery diarrhea for more than 2-3 days, call your doctor.

Jensen RT, Norton JA. Endocrine tumors of the pancreas and gastrointestinal tract. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 31.