Mixed pancreatic apudoma with symptoms of excess vasoactive intestinal polypeptide and insulin: improvement of diarrhoea with metoclopramide.

A female patient is described with a single pancreatic tumour producing vasoactive intestinal polypeptide (VIP), insulin, and pancreatic polypeptide. The initial presentation was with diarrhoea and hypokalaemia and a raised plasma VIP was demonstrated. Her symptoms improved with metoclopramide administration and absolute concentrations of 28 aminoacid (peak IV) VIP were found to have fallen. She then developed hypoglycaemia with hyperinsulinism. All symptoms resolved after surgical excision. This case emphasises the potential of these tumours to contain more than one endocrine cell type synthesising different biologically active peptides.