Validation study of intraoperative fine-needle aspiration of parathyroid tissue with measurement of parathyroid hormone levels using the rapid intraoperative assay

Jeffrey P. Lamont, MD, Todd M. McCarty, MD, and Joseph A. Kuhn, MD

Background: Surgical treatment of hyperparathyroidism relies on the ability to accurately identify parathyroid tissue. The use of intraoperative fine-needle aspiration (FNA) with measurement of intact parathyroid hormone level (iPTH-FNA) has been suggested as a useful adjunct and is evaluated in this pilot study.

Methods: An institutional review board-approved retrospective review was performed on patients undergoing parathyroid exploration for primary hyperparathyroidism who also underwent selective FNA at the end of the procedure. FNA was performed on excised parathyroid tissue, ipsilateral thyroid tissue, and muscle.

Results: Ten patients underwent FNA. Mean iPTH-FNA values were 1559.6 pg/mL (range, 675-1775) for parathyroid, 51.4 pg/mL (range, 10-248) for thyroid, and 34.1 pg/mL (range, 14-128) for muscle. All iPTH-FNA assay results were significantly higher for parathyroid tissue than for either thyroid tissue (P < 0.05) or muscle (P < 0.05). There were no significant iPTH-FNA assay differences between thyroid and muscle (P = 0.09).

Conclusions: Intraoperative FNA of parathyroid tissue with the rapid iPTH assay can correctly identify parathyroid tissue. It may prove to be a useful surgical adjunct in the treatment of hyperparathyroidism.