Possible parathyroid origin of gastrin in a patient with multiple endocrine adenopathy type I.

After removal of two large pancreactic insulinomas, although the presenting spontaneous hypoglycaemia was eliminated, severe and persisting haematemesis and melaena supervened with a rise in serum gastrin. The patient had multiple endocrine adenopathy (pituitary, parathyroids and islet cells), but no evidence of a pancreatic gastrin-producing tumour. After emergency gastric operation for the bleeding, the serum gastrin remained high until the hypercalcaemia and hyperparathyroidism had been corrected by subtotal parathyroidectomy. Immunofluorescence studies showed gastrin in the parathyroid tissue.