Localization of ectopic parathyroid adenomas by the technetium-thallium subtraction scan.

Among numerous methods utilized for preoperative localization of hyperfunctioning ectopic parathyroid tissue, the technetium-thallium scan appears to be a major advance. Eight patients are presented where this method located ectopic parathyroid tissue in the neck, in the mediastinum, within the pericardium, and within the thyroid gland. To date, these findings have been confirmed operatively in five of the eight patients. On the basis of our limited experience, the authors believe that this is a valuable method in the preoperative localization of ectopic parathyroid tissue, especially in patients with persistent or recurrent hyperparathyroidism following a thorough neck exploration.