[Primary hyperparathyroidism: clinical and laboratory spectrum].

The authors analyze clinical and laboratorial features of 13 patients with surgically confirmed primary hyperparathyroidism (HPT). Among them, 8 presented renal lithiasis, 7 had bone disease, and 2 had both. All patients were hypercalcemic and had elevated serum carboxyterminal levels of PTH. The aminoterminal portion of the PTH was above the normal range in 9 patients and inappropriately high for the level of serum calcium in other two. The c'AMP was elevated in 7/8 patients. Hypophosphatemia was detected in 8/11 patients. Among the lithiasic patients, hypercalciuria was found in only 3. Five patients were submitted to an oral calcium load test which detected no intestinal hyperabsorption of calcium (IH) secondary to HPT in any of them. The rate of elimination of stones/patient/year was 1.7 before the establishment of HPT diagnosis. Despite the presence of renal lithiasis, hypercalciuria and IH were not common findings in HPT patients. Serum calcium and urinary c'AMP were the best screening tests for the diagnosis of HPT in this series. The diagnosis should be further confirmed determining the PTH.