With a secure diagnosis of hyperparathyroidism, preoperative localization of abnormal glands is the initial step toward limited parathyroidectomy (LPX). We investigated whether ultrasonography in the hands of the surgeon (SUS) could improve the localization of abnormal parathyroids when sestamibi scans (MIBI) were negative or equivocal. One hundred eighty patients with sporadic primary hyperparathyroidism (SPHPT) underwent preoperative SUS and MIBI scans before LPX guided by intraoperative parathormone assay. When the sestamibi scans were negative, SUS was used to localize the parathyroid, distinguish parathyroid from thyroid tissue, and to guide the intraoperative jugular venous sampling for differential elevation of parathyroid hormone (PTH). Operative findings, intraoperative hormone dynamics, and postoperative calcium levels determined successful localization. MIBI was negative or equivocal in 36/180 (20%) patients: 1) showed no parathyroid gland in 22 patients, 2) suggested an incorrect location for the abnormal gland in 9, and 3) was insufficient in recognizing multiglandular disease in 5. In these 36 patients, the addition of SUS led to the successful identification of the abnormal tissue in 19/36 (53%). In the remaining 17 patients with negative/equivocal scans, the parathyroid could not be clearly visualized by SUS. In these patients, SUS facilitated LPX by aiding preoperative transcutaneous jugular venous sampling for differentially elevated PTH (n = 3) and identifying questionable thyroid nodule versus parathyroid tissue (n = 1). Overall, SUS was useful in 23/36 (67%) patients with nonlocalizing MIBI scans, thus improving the rate of localization from 80 per cent to 93 per cent ( P < 0.01). Surgeon-performed cervical ultrasonography improved the localization of abnormal parathyroids by MIBI scan, adding to the success of limited parathyroidectomy.
IMMUNOCHEMICAL IDENTIFICATION OF PARATHYROID HORMONE IN NON-PARATHYROID NEOPLASMS ASSOCIATED WITH HYPERCALCEMIA