Vasoactive Intestinal Polypeptide Secreting Tumor - VIPoma

Last Literature Review: September 2017 Last Update:

Medical Experts


Vasoactive intestinal polypeptide secreting tumors (VIPomas) are very rare pancreatic neuroendocrine tumors (PNETs) associated with profuse diarrhea. They are usually single tumors and metastatic at diagnosis. Generally, laboratory testing includes an electrolyte panel and vasoactive intestinal peptide test.


Indications for Testing

Chronic, profuse, secretory diarrhea

Criteria for Diagnosis

  • Documented elevated (>200 pg/mL) vasoactive intestinal polypeptide (VIP) concentration (National Cancer Institute [NCI], 2018) in patient with large-volume secretory diarrhea (Vinik, North American Neuroendocrine Tumor Society [NANETS], 2010)
    • VIP level >75 pg/mL highly suggestive
  • Large-volume diarrhea (Kulke, NANETS, 2010)
    • 70-80% of patients with VIPoma have more than 3L/day
    • Virtually all patients with VIPoma have >700mL/day
  • Hypokalemia
  • Achlorhydria

Laboratory Testing

  • Electrolytes
    • Hypokalemia in 100% of patients
  • VIP level


  • Definitive diagnosis requires biopsy and pathologist examination
    • Useful immunohistochemical stains may include chromogranin A, synaptophysin, and cytokeratin​
    • For detailed descriptions, including recommended tests, refer to ARUP’s Immunohistochemistry Stain Offerings

Imaging Studies

  • Computed tomography (CT)/magnetic resonance imaging (MRI) or endoscopic ultrasound
  • Somatostatin-receptor scintigraphy

 Differential Diagnosis


Plasma chromogranin – often used to monitor functional and nonfunctional PNETs after resection (Vinik, NANETS, 2010)



Risk Factors

Genetic – ~5% associated with MEN1 (Jensen, 2012)


  • Most tumors occur in the body and tail of the pancreas and are unifocal (other locations include adrenal, paraganglia)
  • Symptoms result from the secretion of the peptide hormone VIP, an amino acid polypeptide that is a potent stimulator of intestinal secretion and inhibitor of gastric acid secretion
  • Other tumors can produce VIP – ganglioneuroblastoma, bronchogenic carcinoma, pheochromocytoma, and medullary thyroid carcinoma

Clinical Presentation

  • Verner-Morrison syndrome (pancreatic cholera)
    • Chronic watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome)
    • Profuse diarrhea (may exceed 6-8L/day) causes dehydration, metabolic acidosis, and renal failure

ARUP Laboratory Tests

Related Tests


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