Primary hyperparathyroidism in neonates and childhood. The French experience (1984-2004).

Objectives: Primary hyperparathyroidism (HP1) in childhood is thought to be extremely rare. Its exact incidence remains unknown, as do the characteristics of HP1. A retrospective study collection was conducted on cases supplied by members of the Working Group on Calcium Metabolism throughout France over a 20-year period (1984-2004), since the availability of the intact parathormone (iPTH) radioimmunoassay.

Results: 55 cases were collected of which 11 were neonates. Among the 44 children and adolescents, there were 18 male and 26 female patients, ranging in age from 6 to 18 (mean 13) years. 83% were symptomatic and 43% had nephrolithiasis. Symptoms were associated with high serum calcium and inappropriate iPTH levels. Ultrasonography and technetium-labelled methoxyisobutylisonitrile scintigraphy are useful tools for the preoperative localization of adenomas, particularly in adolescents. Intraoperative iPTH assays are effective in minimizing invasive parathyroidectomy. All patients, except neonates, underwent surgery: 29 adenomas and 11 hyperplasias were found. Two multiple endocrine neoplasias (MENs) were subsequently discovered. Since the calcium-sensing receptor (CaSR) mutation was reported, the form of management in neonates has become more medical (intravenous diphosphonates) than surgical. On follow-up no recurrence was observed except for MEN.

Conclusion: These national results reflect HP1 epidemiology. HP1 is a rare entity and appears to be a severe disease in terms of symptoms with regard to management. The use of molecular biology tests could be useful not only in neonatal cases (CaSR mutation) but also prior to surgery in children (MEN mutation).