Management of normocalcemic primary hyperparathyroidism.

Traditional hypercalcemic primary hyperparathyroidism is a common endocrine disease. Patients with a history of nephrolithiasis or a suspected metabolic bone disease are increasingly being identified with elevated PTH concentrations in the setting of consistently normal serum and ionized calcium concentrations. In the absence of secondary causes of hyperparathyroidism, a diagnosis of normocalcemic primary hyperparathyroidism is reasonable. As most cohorts described in the literature are from referral populations, involvement of the skeleton and the kidneys is common, two traditional target organs of primary hyperparathyroidism. Data from small cohorts show patients with normocalcemic disease respond similarly to hypercalcemic primary hyperparathyroidism with regard to medical and surgical approaches. In normocalcemic patients, multiglandular disease may be more common. In this article, we review the available literature on the epidemiology, diagnosis, clinical features, medical and surgical management of this newer phenotype of primary hyperparathyroidism.