Consequences of parathyroidectomy in patients with "mild" sporadic primary hyperparathyroidism

The use of a targeted, less-invasive approach is changing the operative indications in sporadic primary hyperparathyroidism (SPHPT). Now, patients with "mild" HPT are offered parathyroidectomy. However, the operative findings and outcome of these patients are unknown. This study reports the differences between "mild" and "classic" biochemical SPHPT in incidence of multiglandular disease (MGD) and operative outcome.

All 343 patients underwent parathyroidectomy guided by intraoperative parathyroid hormone (PTH) monitoring (IPM). Among them, 301 patients (88%) had "classic" biochemical SPHPT (hypercalcemia and increased PTH) and 42 patients (12%) had "mild" HPT, which consisted of 28 patients with inappropriate secretion of PTH (ISP-hypercalcemia and normal PTH), and 14 patients with normocalcemic HPT (NCHPT-eucalcemia and increased PTH). Single or MGD was determined by IPM. Operative success is eucalcemia for greater than or equal to 6 months after operation and along with normal PTH levels in NCHPT.

Thirty nine of 301 patients (13%) with "classic" biochemical SPHPT had MGD with an operative failure rate of 1% (3/301). In the "mild" HPT group, 14 of 42 patients (33%) had MGD with a failure rate of 5% (2/42). The incidence of MGD was statistically significant (P < .001).

The incidence of MGD and operative failure are higher in patients with "mild" HPT when compared with classic SPHPT. Patients and surgeons should be aware of these consequences when parathyroidectomy is offered to patients with "mild" HPT.