Pancreatic endocrine tumor

Alternative names
Vasoactive intestinal peptide-producing tumor; VIPoma

VIPomas are exceedingly rare cancerous tumors that arise from a type of hormone-secreting cell in the pancreas. VIPomas cause diarrhea, hypokalemia (low blood potassium), and a decrease in the amount of acid in the stomach.

Causes, incidence, and risk factors

VIPomas affect cells in the pancreas that produce vasoactive intestinal peptide (VIP). The cancer causes symptoms by producing high levels of this hormone. The cause is not known.

VIPomas are usually diagnosed in adulthood, most commonly at age 50 or so. Women are more likely to be affected than men.


  • Watery diarrhea (often massive amounts)  
  • Hypokalemia (low blood potassium), which can cause leg cramps  
  • Low acid in the stomach (achlorhydria)  
  • Nausea  
  • Dehydration  
  • Abdominal pain and cramping  
  • Weight loss  
  • Facial flushing or redness

Signs and tests

  • High level of VIP (vasoactive intestinal peptide) in the blood  
  • High volume of diarrhea (continues despite fasting)

Fasting is one way to test for VIPoma.

The physician may also request that the stool be collected and analyzed to determine electrolyte content.

A CT scan or MRI may be ordered to determine the location of the tumor.


The first goal of treatment is to correct dehydration. Intravenous (IV) fluids are often required to replace fluids lost in diarrhea.

The next goal is to slow the diarrhea. Some medications can help control the diarrhea, such as octreotide, which is a hormone.

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

Expectations (prognosis)
Surgery can usually cure VIPomas, but about one-third to one-half of patients will have tumors that have spread by the time of diagnosis and are thus incurable.


  • Metastasis  
  • Dehydration  
  • Cardiac arrest from electrolyte imbalances

Calling your health care provider
If you have watery diarrhea for more than 2-3 days, you should call your doctor.

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, M.D.

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