Causes :

•   VIPoma causes cells in the pancreas to produce high levels of a hormone called vasoactive intestinal peptide .
•   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.

 Symptoms :

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

   Signs :

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

Diagnostic  tests:

 Tests include:

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

Treatment :

•  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(Somatostatin analouge), 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.

 Complications :

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

 Prognosis:  

•   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.