Objective: Intrathyroidal and subcapsular (IT/SC) parathyroid adenomas are reported in ~1% of patients with primary hyperparathyroidism (pHPT). The aim of this study is to examine the experience of IT/SC parathyroidectomy at a high-volume center.
Methods: A prospectively-collected parathyroid database was queried for pHPT patients between 11/99– 6/16 who had a hyperfunctioning IT/SC parathyroid resected. All patients underwent preoperative imaging and were considered to lateralize if imaging suggested the correct side of abnormal parathyroid(s). Cure was defined as normocalcemia at ≥6 months postoperatively.
Results: Of 1914 patients, 44 (2%) had abnormal IT/SC parathyroid glands, including 37 (84%) with single gland disease (SGD). Eleven (25%) patients had preoperative suspicion for an IT/SC parathyroid; 8 underwent unilateral exploration (UE) and thyroid lobectomy (TL). Nineteen (43%) patients lateralized by imaging, without preoperative suspicion for IT/SC disease. BE was performed in 15 patients, including 6 who had planned concurrent total thyroidectomy (TT). Of the 14 (32%) patients who did not lateralize preoperatively, 13 underwent BE, including 4 who had planned concurrent TT.
Of the IT/SC glands, 27 (61%) were right-sided and 29 (66%) were inferior. There were no differences in the incidence of SGD, laterality, or location of the abnormal gland(s) on preoperative imaging. Patients with preoperative suspicion more often had UE (p=.001). All patients had biochemical cure.
Conclusions: The incidence of IT/SC parathyroid glands might be higher than previously reported. Preoperatively, surgeons should be aware of the possibility of IT/SC glands and possible need for planned UE and TL to avoid failed parathyroidectomy.
