View source for VIPoma

{{Short description|A tumor that often causes a syndrome of diarrhea and electrolyte imbalance}}
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A '''VIPoma''' or '''vipoma''' ({{IPAc-en|v|ɪ|ˈ|p|oʊ|m|ə}}) is a rare [[endocrine oncology|endocrine tumor]]<ref>{{DorlandsDict|nine/000116307|VIPoma}}</ref> that overproduces [[vasoactive intestinal peptide]] (thus ''VIP'' + ''[[wikt:-oma#Suffix|-oma]]''). The [[Incidence (epidemiology)|incidence]] is about 1 per 10,000,000 per year. VIPomas usually (about 90%) originate from the [[pancreatic islets|non-β islet cells]] of the [[pancreas]]. They are sometimes associated with [[multiple endocrine neoplasia type 1]]. Roughly 50–75% of VIPomas are [[cancer|malignant]], but even when they are [[benign tumor|benign]], they are problematic because they tend to cause a specific [[syndrome]]: the massive amounts of VIP cause a [[syndrome]] of profound and chronic watery [[diarrhea]] and resultant  [[dehydration]], [[hypokalemia]], [[achlorhydria]], acidosis, [[flushing (physiology)|flushing]] and [[hypotension]] (from [[vasodilation]]), [[hypercalcemia]], and [[hyperglycemia]].<ref>{{cite journal |vauthors=Mansour JC, Chen H |title=Pancreatic endocrine tumors |journal=J Surg Res |volume=120 |issue=1 |pages=139–61 |date=Jul 2004 |pmid=15172200 |doi=10.1016/j.jss.2003.12.007 }}</ref><ref>{{Cite web|url=https://rarediseases.info.nih.gov/diseases/5493/vipoma|title=VIPoma {{!}} Genetic and Rare Diseases Information Center (GARD) – an NCATS Program|website=rarediseases.info.nih.gov|language=en|access-date=2018-04-17}}</ref> This syndrome is called '''Verner–Morrison syndrome''' ('''VMS'''), '''WDHA syndrome''' (from watery diarrhea–hypokalemia–achlorhydria), or '''pancreatic cholera syndrome''' ('''PCS'''). The [[medical eponyms|eponym]] reflects the physicians who first described the syndrome.<ref>{{cite journal |vauthors=Verner JV, Morrison AB |title=Islet cell tumor and a syndrome of refractory watery diarrhea and hypokalemia |journal=Am J Med |volume=25 |issue=3 |pages=374–80 |date=Sep 1958 |pmid=13571250 |doi= 10.1016/0002-9343(58)90075-5}}</ref>

==Symptoms and signs==
The major clinical features are prolonged watery [[diarrhea]] (fasting stool volume > 750 to 1000 mL/day) and symptoms of [[hypokalemia]] and [[dehydration]].
Half of the patients have relatively constant [[diarrhea]] while the rest have alternating periods of severe and moderate [[diarrhea]].
One third have diarrhea < 1yr before diagnosis, but in 25%, diarrhea is present for 5 yr or more before diagnosis.
[[Lethargy]], muscle weakness, [[nausea]], vomiting and crampy abdominal pain are frequent symptoms.
[[Hypokalemia]] and impaired [[glucose]] tolerance occur in < 50% of patients. [[Achlorhydria]] is also a feature.
During attacks of diarrhea, flushing similar to the [[carcinoid syndrome]] occur rarely.<ref>{{cite web |url=https://www.lecturio.com/concepts/carcinoid-tumors-and-syndrome/ | title= Carcinoid Tumors and Syndrome | website= The Lecturio Medical Concept Library |access-date= 5 July 2021}}</ref>

==Diagnosis==
Besides the clinical picture, [[fasting]] VIP [[blood plasma|plasma]] level may confirm the diagnosis, and  [[CT scan]] and [[somatostatin]] receptor [[scintigraphy]] are used to localise the [[tumor]], which is usually [[metastasis|metastatic]] at presentation.<ref name="auto">{{cite journal | vauthors= Sandhu S, Jialal I | url=https://www.ncbi.nlm.nih.gov/books/NBK507698/ | title= ViPoma | website= National Center for Biotechnology Information, U.S. National Library of Medicine | date=2024 | pmid=29939520 |access-date= 5 July 2021}}</ref>

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<ref name="auto"/>

==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. [[Octreotide]], which is a human-made form of the natural hormone somatostatin, blocks the action of VIP.{{citation needed|date=August 2020}}

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 the condition.{{citation needed|date=August 2020}}

For metastatic disease, [[peptide receptor radionuclide therapy]] (PRRT) can be highly effective. This treatment involves attaching a radionuclide (Lutetium-177 or Yttrium-90) to a somatostatin analogue (octreotate or octreotide). This is a novel way to deliver high doses of beta radiation to kill tumours. Some people seem to respond to a combination chemo called capecitabine and temozolomide but there is no report that it totally cured people of VIPoma.{{cn|date=March 2019}}

==Prognosis==

Surgery can usually cure VIPomas. However, in one-third to one-half of patients, the tumor has spread by the time of diagnosis and cannot be cured.{{cn|date=March 2019}}

==References==
{{reflist}}
* Jensen RT, Norton JA. Endocrine tumors of the pancreas and gastrointestinal tract. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease . 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 32.
* [http://health.nytimes.com/health/guides/disease/vipoma/overview.html National Cancer Institute. Islet cell tumors (pancreatic) treatment PDQ. Updated October 31, 2008.]
== External links ==
{{Medical resources
| DiseasesDB      = 13877
| ICD10           = {{ICD10|C|25|4|c|15}} or {{ICD10|E|16|8|e|15}}
| ICD9            =
| ICDO            = {{ICDO|8155|3}}
| OMIM            =
| MedlinePlus     = 000228
| eMedicineSubj   = med
| eMedicineTopic  = 2379
| eMedicine_mult  = {{eMedicine2|med|2399}} {{eMedicine2|ped|2428}}
| MeshID          = D003969
| SNOMED CT       = 447643008
| Orphanet        = 97282
}}
{{Tumor morphology}}
{{Endocrine gland neoplasia}}

[[Category:Endocrine neoplasia]]
[[Category:Rare cancers]]
[[Category:Syndromes]]