Vasoactive intestinal peptide secreting tumour: An overview

Abstract

Vasoactive intestinal peptide (VIP) secreting tumour (VIPoma) is a rare functional neuroendocrine tumour that typically arises from pancreatic islet cells. These present as sporadic, solitary pancreatic neoplasias with an estimated incidence of one in ten million individuals per year. Only around 5% of VIPomas are associated with multiple endocrine neoplasia type I syndrome. Excessive VIP secretion produces a clinical syndrome characterized by refractory watery diarrhoea, hypokalemia and metabolic acidosis. These coupled with elevated plasma levels of VIP are diagnostic. The majority of VIPomas are malignant and have already metastasized at the time of diagnosis (60%). Metastases occur most frequently in the liver, or regional lymph nodes, lungs, kidneys and bones. Some reports of skin metastases have been documented. Complete surgical resection continues to be the only potentially curative treatment. However, when the neoplasia cannot be excised completely, surgical debulking may provide palliative benefit. Other palliative options have included recently the peptide receptor radionuclide therapy which has shown to be effective and well-tolerated. This article will review all aspects of pancreatic VIPomas highlighting aspects such as clinical presentation, diagnosis and management.

Keywords: VIPoma, Octreotide, Secretory diarrhoea, Multiple endocrine neoplasia, Vasoactive intestinal peptide, Vermer-Morrison syndrome

Core Tip: Vasoactive intestinal peptide (VIP) secreting tumour (VIPoma) is a rare functional neuroendocrine tumour that typically arises from pancreatic islet cells. It is usually sporadic but may present as part of the endocrine neoplasia type I syndrome in 5% of cases. Excessive VIP secretion produces a refractory secretory diarrhoea which left untreated will cause patient's death. The majority of VIPomas are malignant and have already metastasized at the time of diagnosis (60%), being the liver, or regional lymph nodes the most frequent site for metastases. Complete surgical resection is the only potentially curative treatment, however, surgical debulking may provide palliative benefit. Other palliative options include somatostatin analogues and recently the peptide receptor radionuclide therapy which has shown to be effective and well-tolerated.