THE CONTRIBUTION OF CLINICAL AND RADIOLOGICAL FEATURES TO THE DIAGNOSIS IN AUS/FLUS AND FN/SFN THYROID NODULES

Aims: Atypical cytologies were categorized as Bethesda category III (atipia with unknown significance, follicular lesions with unknown significance, AUS/FLUS) and Bethesda category IV (follicular neoplasm or suspicious for follicular neoplasm, FN/SFN) in Bethesda system for reporting thyroid cytopathology (BSRTC). Tins study was planned to define the contribution of clinical and radiological features in the course of action for AUS/FLUS and FN/SFN thyroid nodules. Materials and methods: The age, gender, nodule size and definitive pathological results of 124 patients treated with total thyroidectomy after preoperative diagnosis of AUS/FLUS and FN/SFN lesions were recorded. Radiological features were grouped as increased vascularity, irregular borders, microcalcification, cystic component, presence of hypoechoic halo, hypoechogenicity and extraglandular involvement. Results: The malignancy rates in AUS/FLUS and FN/SFN lesions were 8% and 163%, respectively. Fine needle aspiration cytology (FNAC) was repeated only in 8 patients among 75 patients diagnosed as AUS/FLUS, but the diagnosis was not changed in direction to follow-up. The presence of irregular borders at ultrasonography, increased vascularity, microcalcification, presence of hypoechoic halo and hypoechoic nodules were found to be related to the malignancy in AUS/FLUS group. On the other hand, age less than 50, presence of irregular borders, increased vascularity and presence of microcalcifications were found to be related to the malignancy in FN/SFN group. Conclusions: The success of BSRTC in prevention of unnecessary thyroidectomies shows differences between clinics. Radiological criteria apart from patient's related factors play an important role in clinical judgement. Microcalcifications seem to be the most sensitive criteria both in AUS/FLUS and FN/SFN lesions. Irregular border was the criteria with the highest specificity in both categories.