Localization of parathyroid tumors using endoscopic ultrasonography in primary hyperparathyroidism

Parathyroid adenomas responsible for primary hyperparathyroidism may be difficult to detect preoperatively. Furthermore parathyroid adenomas may arise behind the (nodular) thyroid gland, in a deep cervical location, and plans should be plane. The purpose of the present prospective study was to evaluate echoendoscopy, and to compare its accuracy to that of non invasive tests. Fourteen consecutive patients with primary hyperparathyroidism were prospectively studied. All patients underwent echoendoscopy, ultrasonography (US), CT scanning or magnetic resonance imaging (MRI) and Tc 99m sestamibi scanning before undergoing initial neck exploration. The parathyroid pathology was a solitary adenoma in 13 patients and a 4 glands hyperplasia in one. All tests were corroborating in 5 cases. Four adenomas were localized to the correc tside (33%), and no test accurately localized all hyperplastic glands. EUS, sestamibi and CT scanning or MRI correctly identified 10 parathyroid tumors in 14 cases (71%). US correctly localized only 5 adenomas (sensitivity 36%). The sensitivity of EUS to detect parathyroid adenomas is superior to US (p<0.05) and comparable to that of other non invasive tests. We conclude that EUS may be an useful tool to localize parathyroid lesions. This method may replace US prior to initial neck exploration with further miniaturization of probes, or find an intermediate place among invasive and noninvasive preoperative localization procedures in patients with persistent or recurrent PHPT.