Fine needle aspiration cytology in the preoperative diagnosis of ultrasonically enlarged parathyroid glands

The value of fine needle aspiration (FNA) cytology in the diagnosis of ultrasonically suspected parathyroid gland enlargements was reviewed for a six-year series of cases. In 146 patients, 277 FNA biopsies under ultrasound guidance were performed on suspected enlarged parathyroid glands. Smears were routinely stained by the Pappenheim (May-Grünwald-Giemsa) method, and the Grimelius silver stain was used to demonstrate argyrophilic granules in the cytoplasm of parathyroid cells. Diagnostic material was obtained by FNA from 121 (83%) patients, whereas the aspirates were considered inadequate for cytologic diagnosis in 25 (17%) patients. For the 121 cases with adequate FNA samples, cytology diagnosed a parathyroid origin in 80 (55%) of the 146 total patients) and a thyroid origin in 41 (28%). The cytologic-histologic correlation available for 36 patients showed a cytologic sensitivity of 86%. Parathyroid lesions are frequently treated preoperatively as a disease of the thyroid; the results of this study suggest that cytomorphologic analysis of FNA samples can demonstrate the parathyroid origin of such samples, especially when a silver stain is used in addition to the routine stain.