Long-Term Outcomes and Predictors of Recurrence in Primary Hyperparathyroidism

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.

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 (60).

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.

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.