Primary hyperparathyroidism in multiple endocrine neoplasia type 2A.

The rarity of primary hyperparathyroidism (PHPT) in multiple endocrine neoplasia type 2A (MEN 2A) led us to study clinical findings, surgical therapy and outcome in 67 patients in order to evaluate our therapeutic strategy. The retrospective study was based on cases registered by the EUROMEN study group (nine participating centres) from 1972 to 1993. Characteristics of PHPT in 67 patients (41 females, 26 males) with MEN 2A were reviewed. All patients underwent exploratory neck surgery; PHPT was confirmed histologically and/or biochemically. The median age at diagnosis of PHPT was 38 years. In 75% of the patients, PHPT and medullary thyroid carcinoma were diagnosed synchronously, while in 4%. PHT was diagnosed earlier. In 18% of the patients, PHPT was diagnosed after thyroidectomy, and in 3%, after discovery of pheochromocytoma. Primary hyperparathyroidism was asymptomatic in 84% of the patients; 15% suffered from renal stones. Serum calcium was slightly elevated in 69% (2.9 +/- 0.2 mmol-1) and normal in 16% of subjects. A single adenomectomy was performed in 42% of the patients, subtotal parathyroidectomy in 31% and total parathyroidectomy with autotransplantation in 16%. Independent from the extent of resection, cure was achieved in 94% of the patients, including 13% with hypoparathyroidism; hypercalcaemia persisted in 3% and no information was available in 3%. In an 8-year follow-up, hypercalcaemia recurred in 12% of the patients, although half had undergone parathyroidectomy totally or subtotally. CONCLUSION. MEN 2A-related PHPT is characterized by a mild hypercalcemia which is mostly asymptomatic and can be cured by simple resection of an enlarged parathyroid gland in most cases.