VIPoma

Infobox_Disease
Name = VIPoma


Caption =
DiseasesDB = 13877
ICD10 = ICD10|C|25|4|c|15 or ICD10|E|16|8|e|15
ICD9 =
ICDO = 8155/3
OMIM =
MedlinePlus = 000228
eMedicineSubj = med
eMedicineTopic = 2379
eMedicine_mult = eMedicine2|med|2399 eMedicine2|ped|2428
MeshID = D003969

A VIPoma (also known as Verner Morrison syndrome, after the physicians who first described it [Verner, J. V., and Morrison, A. B. Islet cell tumor and a syndrome of refractory watery diarrhea and hypokalemia. "Am J Med" 1958; 374: 1958.] ) is a rare (1 per 10,000,000 per year) endocrine tumor,cite web |url=http://www.mercksource.com/pp/us/cns/cns_hl_dorlands_split.jsp?pg=/ppdocs/us/common/dorlands/dorland/nine/000116307.htm |title=Dorlands Medical Dictionary:VIPoma |format= |work= |accessdate=] usually (about 90%) originating in the pancreas, which produces vasoactive intestinal peptide (VIP).

A syndrome caused by non-β islet-cell tumors.It may be associated with multiple endocrine neoplasia.

The massive amounts of VIP in turn cause profound and chronic watery diarrhea and resultant dehydration, hypokalemia, achlorhydria (hence WDHA-syndrome, or pancreatic cholera syndrome), acidosis, vasodilation (flushing and hypotension), hypercalcemia and hyperglycemia. [Mansour JC, Chen H. Pancreatic endocrine tumors. "J Surg Res" 2004; 120: 139-61. PMID 15172200]

ymptoms 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.
Hyperkalemia and impaired glucose tolerance occur in < 50% of patients.During attacks of diarrhea, flushing similar to the carcinoid syndrome occur rarely.

Diagnosis

Besides the clinical picture, fasting VIP plasma dosage may confirm the diagnosis, and CT scan and somatostatin receptor scintigraphy are used to localise the tumor, which is usually metastatic at presentation.

Treatment

Besides treating the water and electrolyte abnormalities, octreotide (a somatostatin analogue) can be used to temper symptoms. Surgery is the only curative option.

References

^The MERCK MANUAL Of Diagnosis And Therapy