Long-Term Outcomes and Predictors of Recurrence in Primary Hyperparathyroidism.

INTRODUCTION

Primary hyperparathyroidism is effectively treated with parathyroidectomy, but recurrence can occur after long intervals. Our study analyzed factors associated with long-term recurrence after initial parathyroidectomy.

METHODS

We conducted a retrospective cohort study of patients undergoing parathyroidectomy for sporadic primary hyperparathyroidism at a tertiary center (2000-2024). Patients with familial syndromes, prior parathyroid surgery, carcinoma, persistent disease, or missing 6-mo follow-up were excluded. Recurrence was defined as normocalcemia at 6 mo followed by hypercalcemia with inappropriately elevated parathyroid hormone (PTH) or reoperation and categorized as early (<60 mo) or late (≥60 mo). Clinical, biochemical, intraoperative, and postoperative data were compared between recurrent and nonrecurrent patients, stratified by follow-up duration (<and >60).

RESULTS

Among 2029 patients meeting the inclusion criteria, 1775 (87%) had a 6-59 mo follow-up and 254 (13%) had ≥60 mo. Early recurrence occurred in 23 patients (1%) at a median of 31 mo; late recurrence occurred in 13 patients (5%) at 90 mo. Early recurrence was associated with multigland disease (double adenoma/hyperplasia 48% vs 31%, P < 0.01), more frequent resection of ≥2 glands, higher 15-min intraoperative PTH (52 vs 30. pg/mL, P < 0.01), attenuated intraoperative PTH at 10 min (48% vs 70%, P < 0.01) and 15 min (55% vs 74%, P < 0.01), and higher but normal 6-mo calcium and PTH levels. In contrast, patients with late recurrence resembled long-term nonrecurrent patients, most had single adenomas, and differed mainly by higher 15-min intraoperative PTH (37 vs 28 pg/mL, P = 0.02). When compared directly, late-recurrence patients had higher preoperative PTH, more single-gland resections, and greater intraoperative PTH declines than early-recurrence patients.

CONCLUSIONS

Most patients remain cured after parathyroidectomy, but recurrence shows distinct patterns. Late recurrence is more common and typically represents de novo disease after successful single-gland resection. High-normal postoperative calcium or PTH and modest intraoperative PTH decline should prompt prolonged biochemical surveillance.