VIPoma

A VIPoma or vipoma (

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.^[5]

Diagnosis

Besides the clinical picture,

• 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[6]

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]}

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]}

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.^{[citation needed]}

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.^{[citation needed]}

References