Efficacy of localization studies and intraoperative parathormone monitoring in the surgical management of hyperfunctioning ectopic parathyroid glands

Background Hyperfunctioning ectopic glands remain an operative challenge in patients with sporadic primary hyperparathyroidism. This study examines the incidence of ectopic glands and the utility of sestamibi scans (MIBI), surgeon-performed ultrasonography, and intraoperative parathormone monitoring in such patients undergoing parathyroidectomy. Methods We conducted a retrospective analysis of prospectively collected data from patients who underwent parathyroidectomy from 1980 to 2011 for sporadic primary hyperparathyroidism at a single institution. Demographics, localizing imaging studies, intraoperative parathyroid monitoring dynamics, and surgical outcome for patients with hyperfunctioning ectopic parathyroid glands were studied. Results Among 1,195 patients who underwent parathyroidectomy for sporadic primary hyperparathyroidism, 120 patients (10%) had hyperfunctioning ectopic glands, which were localized to the neck ( n = 66) and mediastinum ( n = 54). MIBI had a sensitivity of 85%, specificity of 97%, and positive predictive value (PPV) of 91% for ectopic glands in the neck, whereas in the mediastinum there was a sensitivity of 88%, specificity of 95%, and PPV of 86%. Surgeon-performed ultrasonography had a sensitivity of 81%, specificity of 98%, and PPV of 95% for neck ectopic glands. The overall accuracy of surgeon-performed ultrasonography, MIBI, and intraoperative parathyroid monitoring in the neck or mediastinum was 93%. Overall, operative success was 93% with a multiglandular disease rate of 5%. Conclusion A high operative success rate for hyperfunctioning ectopic glands can be achieved using localization studies and intraoperative parathyroid monitoring. Nevertheless, surgeon judgment remains paramount in the operative direction of this patient population.