Fine needle aspiration of parathyroid gland with PTH analysis in washouts: is it worthy?
Miguel Melo, Cristina Ribeiro, Sandra Paiva, Alexandra Vieira, Francisco Carrilho & Manuela Carvalheiro
Introduction: Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcaemia in the outpatient setting. Surgical remove of an adenoma or hyperplastic glands results in cure, but an accurate localization, preoperative whenever possible, is essential for success. Taking into consideration that parathyroid carcinoma is a rare event, FNA of parathyroid glands, complemented by PTH measurement in washouts (FNA/PTH), may be a useful tool in the diagnostic workout.
Objectives: To determine if FNA/PTH may add valuable information to our standard localization workout for primary hyperparathyroidism (neck ultrasound+Sestamibi scan).
Material and methods: The study group consisted of seven consecutive patients with confirmed PHPT (mean PTH=275.4±166.4 ng/ml (140622); corrected calcium=11.3±0.9 mg/dl (10.213.2)). Neck ultrasound (US), Sestamibi scan and FNA/PTH were performed in all of them. The diagnosis of a parathyroid adenoma was confirmed after surgical treatment in every one.
Results: Neck US was able to identify images suspected of enlarged parathyroid glands in all the patients. In three patients US identified two suspected lesions; only one of the lesions in each patient was confirmed to correspond to a parathyroid by FNA/PTH and Sestamibi scan. The results of FNA/PTH and Sestamibi scan were concordant in these cases. Sestamibi scan revealed hyperfixation in six patients (85.7%). In two cases the FNA Cytology was non-diagnostic but the PTH washout analysis confirmed that the lesions corresponded to parathyroid tissue.
Conclusions: Neck ultrasound was the localization exam with the best performance in our patients. FNA/PTH added valuable information when more than one suspected lesion was detected by ultrasound. FNA/PTH was also important when the cytology was non-diagnostic and when the Sestamibi scan was negative.