Thallium-pertechnetate subtraction scanning in the preoperative localization of an ectopic undescended parathyroid gland.

Although bilateral exploration is highly effective in the treatment of primary hyperparathyroidism, minimally invasive parathyroidectomy has evolved into the procedure of choice when a single parathyroid lesion can be localized preoperatively. In this article, we discuss the utilization of thallium-pertechnetate subtraction scanning (TPSS) after technetium Tc-99m sestamibi scintigraphy failed to localize an ectopic parathyroid adenoma. Subsequently, radioguided resection of an undescended parathyroid adenoma inferior to the left submandibular gland was performed with surgical cure after a single procedure. This case report illustrates the importance of TPSS as a second-line modality in preoperative adenoma localization, thereby using minimally invasive techniques to successfully treat this patient's primary hyperparathyroidism.