Is parathyroidectomy safe and effective in patients with normocalcemic primary hyperparathyroidism?

Indications and advantages of parathyroidectomy in patients with normocalcemic primary hyperparathyroidism (NHPT) are still matter of debate. We aimed to compare clinical presentation and surgical outcome between normocalcemic and hypercalcemic forms in a consecutive series of patients who underwent parathyroidectomy for primary hyperparathyroidism.

Data of 731 consecutive patients were reviewed and retrospectively compared according to normocalcemic (group A) and hypercalcemic (group B) phenotypes.

No significant differences were found between the two groups concerning demographics and symptomatic onset. Mean preoperative PTH levels were significantly higher in group B (252.0 ± 320.7 pg/ml vs 151.7 ± 112.0; p < 0.001). Mean PTH levels in first postoperative day were significantly lower in group B (30.9 ± 26.2 vs 22.7 ± 20.7; p < 0.001). No significant difference in overall accuracy of preoperative imaging studies was found. Significantly more patients in group A underwent bilateral explorations (83 vs 255; p < 0.05). The rate of multigland disease was significantly higher in group A (13.0 vs 6.8%; p < 0.05). At a mean follow-up period of 72.9 ± 46.8 months, all but three patients, among the 96 of group A who completed follow-up evaluation, were biochemically cured. The remaining patients had persistent high PTH values. Among NHPT patients who had target organ disease before parathyroidectomy, improvement in bone density and in kidney stones was observed in 41.7 and 40.0%, and stability in 50.0 and 60.0% respectively.

In normocalcemic patients, parathyroidectomy is as safe and effective as in hypercalcemic patients. In the presence of symptoms and/or target organ disease, parathyroidectomy may have a positive effect on the outcome of NHPT patients.