Bone Abstracts

Objective: Minimally invasive parathyroidectomy (MIP) has become a frequently used strategy but it requires a precise preoperative localization and the use of intraoperative PTH to fulfill its benefits. The current localization techniques (ultrasonography, MIBI scan) have shortcomings and intraoperative PTH is not available in our country.

Case presentation: We report the cases of two patients, females (63 and 55 years old), with clinical and biochemical features of primary hyperparathyroidism (total calcium: 10.1 and 12.4 mg/dl; PTH: 171 and 257.5 pg/ml). In the first case, neck ultrasonography (USG) revealed a mixed hypoechoic tumor along the posterior aspect of the left thyroid lobe of 15×8 mm, been difficult to say if it was intrathyroidal or not. There was only minimal residual uptake in the left thyroid lobe at 4 h on Tc^99m sestamibi imaging. She underwent USG-guided fine-needle aspiration (FNA) of the suspected tumor followed by PTH measurement from the needle washing (FNA-PTH). The cytology was non-diagnostic but the level of PTH in the aspirated fluid was 10.000 pg/ ml. In the second case, a CT scan performed elsewhere described two tumors with similar appearance, one (17×16 mm) in front of the other (20×15 mm), located posterior to the left thyroid lobe, suggesting one was a thyroid nodule and the other a parathyroid adenoma. USG-guided fine-needle aspiration of each tumor revealed PTH concentrations of 100.000 and 32.980 pg/ml respectively. MIP was performed in each case, and was curative. Histopathology revealed a left superior parathyroid adenoma included in the thyroid capsule in the first case, and a double left superior parathyroid adenoma in the second.

Conclusion: This case report highlights the importance of FNA-PTH in the localization of functionally parathyroid tissue in difficult cases, where a clear target exists, and facilitates MIP.