Diagnostic accuracy of surgeon-performed ultrasound-guided fine-needle aspiration of thyroid nodules

Background: There is scant data concerning surgeon-performed thyroid fine-needle aspiration (FNA), and controversy regarding its accuracy in larger nodules. This study aimed to specifically assess accuracy of surgeon-performed ultrasound (US)-guided FNA on a per-nodule basis, with a subanalysis of nodule size. Methods: Data of 1,000 surgeon-performed US-guided thyroid FNAs at a single institution from 2000 to 2010 were prospectively collected. Standard clinical information, FNA results using the Bethesda criteria, and final histology were recorded. Results: Fine-needle aspiration results were reported as: cancer (7%), suspicious for cancer (2%), suspicious for follicular neoplasm (17%), atypia of unknown significance (AUS) (1%), benign (67%), and insufficient (6%). Of nodules with FNA results of cancer, suspicious for cancer, suspicious for follicular neoplasm, and atypia of unknown significance, 94% were operated on, with malignancy rates of 97%, 58%, 21%, and 12%, respectively. Of nodules with benign FNA, 26% underwent surgery for associated symptoms, concerning features, or other remote pathology. A total of 56% were followed, and 18% were lost to follow-up. Of nodules with insufficient FNA, 46% had repeat FNA (yielding a diagnosis in 81%), 23% underwent surgery, 21% with hypocellular features were followed, and 9% were lost to follow-up. In size subanalysis, there was no statistically significant difference in risk of malignancy or increased rate of falsely negative FNA with increasing nodule size. Conclusions: The Bethesda system appropriately stratified lesions for risk of malignancy, and repeat FNA had high diagnostic yield in lesions with inadequate FNA. The results suggest no trend toward larger lesions harboring thyroid malignancy nor an increased likelihood of false-negative benign FNA.