VIPoma

Last reviewed 01/2018

This is the association of secretory diarrhoea with intestinal tumours secreting vasoactive intestinal peptide (VIP) - VIPoma.

The Verner-Morrison syndrome is characterised by a profuse, watery diarrhoea that results in massive intestinal loss of water, potassium, sodium and bicarbonate, leading to hypovolaemia, hypokalaemia and reduced total body potassium, and achlorhydria (metabolic acidosis).

VIPomas account for fewer than 10% of islet cell tumours

• mostly solitary tumours, arising from the VIP-secreting cells that are usually located in the region of the pancreatic tail and body
• more than 60% of these tumours are malignant and metastasize to lymph nodes, liver, kidneys and bone
• rarely, extrapancreatic tumours appearing as neuroblastomas, ganglioneuroblastomas or ganglioneuromas have been found
• VIPomas rarely occur in MEN-I patients (in approximately 1%).

Associated metabolic features include:

• impaired glucose tolerance; VIP causes mild insulin resistance
• hypercalcaemia

Management:

• directed by a specialist
• may require an intensive intravenous supplementation of fluid losses and a careful correction of electrolyte and acid–base abnormalities
• octapeptide somatostatin analogues lead to reduced tumoural VIP secretion by more than 50% and inhibit intestinal water and electrolyte secretion
• corticosteroids may also improve diarrhoea (1)
• surgical removal of the primary tumour may be curative in approximately 40% of patients with either benign VIPomas or non-metastatic malignant tumours

Reference:

1. de Herder WW and Lamberts SWJ. Best Practice & Research Clinical Endocrinology & Metabolism 2004; Volume 18(4): 477-495.