Primary hyperparathyroidism and multiple endocrine neoplasia (MEN).

In about 80% of the cases, primary hyperparathyroidism (pHPT) is caused by a single parathyroid adenoma. However, the disease may be complicated by involvement of more than one parathyroid gland or by the combination with other endocrine tumors (syndrome of multiple endocrine neoplasia = MEN). This presentation deals with our experience in such conditions. During 11 years, 98 cases of pHPT were seen (90 in Ulm from 1968 to 1979, 8 since then in Heidelberg). In 9 patients, 2 to 4 parathyroids were in hyperfunction. A recurrence of pHPT was diagnosed after symptomfree intervals of 2 - 13 years in 5 patients. Data are presented of 4 patients suffering from MEN type I (Wermer syndrome): 3 had Zollinger-Ellison syndrome and pHPT, and the 4th insulinoma and pHPT. Whereas pHPT is the most frequent endocrinopathy in MEN type I, it is rarely seen in MEN type II, the Sipple syndrome (combination of medullary thyroid carcinoma, MTC, and pheochromocytoma). Among 20 own cases with MTC and 10 others with pheochromocytoma, no pHPT was observed. The common basis for the development of MEN syndromes is Pearse's concept of the diffuse neuroendocrine system (DNES).