Background/Aims: Despite fine-needle aspiration (FNA) is frequently used to diagnose thyroid nodules, there is no universally accepted approach to follow-up of repeat FNA. This study aimed to investigate the value of immediately repeat FNA and the usefulness of ultrasonographic features in selection of thyroid nodule for immediately repeat fine needle aspiration. Methods: A chart review was performed including of 257 cases who underwent repeat FNA from January 2011 to September 2012 included. Repeat FNA was done within 7 days to 10 days after initial FNA. Results: Of 257 cases, 154 (59.8%) cases were initially nondiagnostic, and 39.6% of initial nodiagnostic were still nodiagnostic on repeat FNA. Of 59 operated cases, 24 (96%) cases of initial nondiagnostic were diagnosed papillary thyroid carcinoma (PTC). Of forty five (17.5%) initially benign cases, 31.1% (14/45) were suspicious PTC or PTC on repeat FNA. Of 59 operated cases, 11 cases were PTC who was diagnosed as benign on initial FNA. Of 59 operated cases, 90% (9/10) of initially atypical follicular lesion of undetermined significance (AUS) and 100% (2/2) of AUS on repeat FNA were diagnosed as PTC. Of 59 operated cases, the sensitivity and specificity based on the sonographic criteria were 83.6% and 75.0%. Statistically significant findings indicative of malignancy were hypoechogenecity (sensitivity, 83.6%; specificity, 75.0%) and spiculate margin (sensitivity, 52.7%; specificity, 100%). Conclusions: In this study, the author found that the diagnostic yield and accuracy of immediately repeat FNA was high and ultrasonographic features were valuable to decide immediately repeat FNA and operation.

Thyroid nodules represent a common disease, as they are palpated at an average rate of 3%-7% of normal adults, 1,2 and they are diagnosed at a rate of about 20%-76% during thyroid ultrasonography. 3,4 Most thyroid nodules are benign and fewer than 5% of these nodules are malignant. Conclusion:In this study, we found that US features were the most useful in preoperative differential diagnosis of thyroid nodules. BRAF V600E mutation co-testing in FNA cytology was also useful for diagnosis of thyroid tumors.