Evaluation of repeat fine-needle aspiration biopsy according to ACR-EU-K TIRADS scores in the management of nodules with Bethesda III (AUS) cytology

Authors : Yusuf Öztürk, Muhammet Kocabaş

Pages : 329-338

Doi:10.29058/mjwbs.1638847

View : 30 | Download : 55

Publication Date : 2025-12-31

Article Type : Research Paper

Abstract :Aim: There is no consensus on the management of nodules with Bethesda III (atypia of undetermined significance [AUS]) cytology. This study aimed to evaluate the diagnostic contribution of repeat fine-needle aspiration biopsy (FNAB) in nodules with AUS and to investigate whether it provides additional value when interpreted together with ultrasound- based risk stratification systems. Material and Methods: Patients whose initial FNAB results were AUS and who underwent thyroidectomy were included. The nodules were classified into two distinct categories, benign and malignant, based on their histopathological features. Single and repeat FNAB groups were compared, and their distributions according to ACR, EU, and K-TIRADS scores were analyzed. In addition, malignancy rates of repeat FNAB cytology were assessed based on Bethesda categories and TIRADS 4–5 (intermediate-to-high risk) classifications. Results: While 87 (28.2%) of the nodules that underwent thyroidectomy had undergone a single FNAB before surgery, 222 (71.8%) had undergone repeat FNAB. 35 (40.2%) of the nodules that underwent single FNAB and 106 (47.7%) of the nodules that underwent repeat FNAB were reported as malignant on final histopathology results (p = 0.233). The distributions of ACR, EU, and K-TIRADS scores were generally similar between the groups. The most frequent repeat FNAB result was AUS (50.9%) with a malignancy rate of 40.7%. High malignancy rates were also observed in benign (30.0%) and nondiagnostic (31.2%) repeat FNAB results. A substantial proportion of these subgroups were classified as TIRADS 4–5, where malignancy rates reached 60–70% across the ACR, EU, and K-TIRADS systems. Conclusion: Repeat FNAB in AUS nodules showed limited diagnostic utility, as malignancy rates remained high regardless of cytological results, particularly in nodules classified as TIRADS 4–5. Our findings suggest that ultrasound-based risk stratification may be more reliable than repeat FNAB alone in guiding clinical decision-making. However, further prospective multicenter studies are needed to validate these results.
Keywords : Önemi belirsiz atipi (ÖBA), İİAB tekrarı, ACR-TIRADS, EU-TIRADS, K-TIRADS

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