title: Normocalcemic hyperparathyroidism revisited.
abstract: From 1957 through 1981, 550 cervical explorations for presumed primary hyperparathyroidism were performed in 536 patients at the North Carolina Baptist Hospital. Fifty-one of those patients who did not have persistent hypercalcemia are the basis of this report. Twenty-six patients with hypercalciuria and normal renal function had recurrent passage of calcium-containing renal stones, but never had documented hypercalcemia. Only five patients (19%) had positive findings at exploration: small, hyperplastic glands (n = 3); small adenomas (n = 2). Seventeen of the 23 patients for whom follow-up data were available continued to form and pass renal stones postoperatively, including three of the five patients with "pathologic" glands (follow-up range: 4 months to 21.3 years; mean--7 years, 9 months). Twenty-five patients (also with normal renal function) had chronic calcium nephrolithiasis, hypercalciuria, and isolated or occasional elevations of serum calcium ranging from 10.6 to 10.9 mg/dl. Thirteen of these patients had abnormal parathyroid glands: adenomas (n = 12); hyperplasia (n = 1). All but two of the 13 were cured of their nephrolithiasis, but all ten of the patients with no abnormal glands for whom follow-up data were available continued to pass renal stones (follow-up range--8 months to 18 years; mean--5 years, 7 months). Thus, our experience with treating "normocalcemic" hyperparathyroidism has been disappointing. Although a substantial number of patients with occasional mild hypercalcemia may benefit from cervical exploration, those patients are not, by definition, truly normocalcemic. Metabolic evaluation can separate hypercalciuric recurrent stone formers with autonomous secondary hyperparathyroidism from patients with suppressible secondary hyperparathyroidism, and can thus more accurately identify patients who may benefit from parathyroid exploration.
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood / Q000652:urine*; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D007669:Kidney Calculi / Q000150:complications / Q000175:diagnosis; D008297:Male; D008875:Middle Aged
chemical_list: D002118:Calcium