During a 15-year period (1977–1992) 2,000 consecutive patients with renal stones were studied. Fasting serum and 24-hour urinary samples were analyzed for calcium and phosphate. In 32 cases (1.6%) primary hyperparathyroidism was diagnosed on the finding of hypercalcemia associated with hypophosphatemia, hypercalciuria and hyperphosphaturia. At surgery 14 adenomas and 2 multiglandular hyperplasias were found. For the preoperative localization of diseased glands double-tracer scintigraphy and ultrasonography were used. Double-tracer scintigraphy and ultrasound showed a sensitivity rate of 62% and 75%. When performed in association ultrasound and scintigraphy allowed a sensitivity rate of 87%.
