Multiple endocrine adenomatosis (Type I) and familial hyperparathyroidism.

Hyperparathyroidism is the commonest presenting feature in multiple endocrine adenomatosis Type I (MEA Type I), the other manifestations may be delayed for many years or appear only in relatives. A family now diagnosed as MEA Type I, who was previously thought, in 1965, to have familial hyperparathyroidism due to chief cell hyperplasia is now described. The importance is stressed of family surveillance and long-term follow-up in all cases of primary hyperparathyroidism. Those tests that are essential in the long-term surveillance of the patients and their first degree relatives are discussed.