Summary

• Rare neuroendocrine tumour typically of the pancreas and with high malignant potential.
• Tumour secretes vasoactive intestinal peptide (VIP).
• Clinical syndrome of watery diarrhoea, hypokalaemia, acidosis, hypochlorhydria, and hypercalcaemia.
• Usually with regional lymph node or liver involvement at diagnosis.
• Elevated VIP levels are diagnostic of VIPoma.
• Surgical resection is the treatment of choice. Symptoms may be controlled by hydration, electrolyte repletion, administration of octreotide, and/or surgical debulking if metastatic.