Urinary lithiasis, hypercalciuria and hyperparathyroidism are strictly related diseases, and the urologist diagnoses primary hyperparathyroidism (PHP) in the majority of cases. Herein we retrospectively analyze our experience of 20 cases of surgically proved PHP, operated on in the last 4 years. Hypercalcemia was the keystone for the diagnosis of all our cases PTH radioimmunoassay on selectivity sampled blood revealed a fundamental tool in the management of patients with suspicious or certain hyperparathyroidism. It confirmed the diagnosis in all the cases and gave the preoperative localization of parathyroid adenomas in 70\% of the cases. Besides, it made it possible to discriminate between parathyroid adenomas and diffuse hyperplasia preoperatively, so offering a considerable aid to the surgeon in deciding between the conservative and liberal approach to parathyroid surgery. At follow-up, 3 out of 14 cases revealed renal hypercalciuria, which could have been the cause of hyperparathyroidism, as proposed by Reiss and associates previously. The relationship between hypercalciuria and hyperparathyroidism and the problem of a new classification of parathyroid hyperfunction are discussed.
