[Hyperparathyroidism associated with Zollinger-Ellison syndrome. 4 cases (author's transl)]

In approximately 20% of the cases the Zollinger-Ellison syndrome (ZES) is associated with primary hyperparathyroidism (HPT). In view of this frequent association, serum calcium and phosphorus levels should be measured in all patients with ZES. Conversely, all patients with HPT I accompanied or preceded by peptic ulcer and/or diarrhoea should have their gastric acid secretion and serum gastrin level measured. Since the association may reflect a type I multiple endocrine neoplasia (MENI), involvement of other endocrine systems, notably the pituitary gland, should be investigated in the patients and their family. A rise in basal plasma pancreatic polypeptide has been observed in about 50% of cases of familial MEN I (Wermer's syndrome) and appears to be a good index of pancreatic endocrine tumour. When ZES is associated with HPT I, the latter should be treated first for three reasons: (7) lethal acute hypercalcaemia may occur after abdominal surgery; (2) HPT I itself may increase the gastric acid secretion and hypergastrinaemia of the ZES, and (3) parathyroidectomy and medical treatment with gastric antisecretory drugs may postpone the need for total gastrectomy.