Cure of intractable watery diarrhoea by excision of a vipoma.

A 56-year-old man suffered unexplained watery diarrhoea for 5 years which ultimately produced quadraparesis due to serve potassium depletion. All investigations were negative until demonstration of elevated plasma vasoactive intestinal peptide (VIP) indicated the presence of a vipoma. Removal of the VIP-producing tumour tissue--an adrenal ganglioneuroma--resulted in complete cure. Plasma VIP measurement is thus a valuable diagnostic screen in such cases and can be used to predict prognosis and to guide further therapy.