Repeat Fine Needle Aspiration Cytology (FNAC) in Thyroid Does Not Help in Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS)

Although the current recommendation in the category of “Atypia of undetermined significance/follicular lesion of undetermined significance” (AUS/FLUS) is a repetition of fine needle aspiration cytology (FNAC), it does not solve the problems. Our aim is to analyze the effectiveness of FNAC repeat in AUS/FLUS cases by comparing it with clinical and ultrasonographic criteria and to contribute to patient management. In our institution, 138 patients’ results, of those who were operated with AUS/FLUS FNAC between 2014 and 2019 and who had definite pathological diagnoses with clinical-pathological-radiological data, were examined. We divided the AUS/FLUS cases in our center into those with and without repeat FNAC (rFNAC), and we evaluated those with definite pathological results of these nodules with all clinical radiological data. We found that the incidence of malignancy increased significantly as the nodule size increased (2.6 cm) and in the presence of microcalcification in all nodules whose initial biopsy result was AUS/FLUS (p = 0.047, p = 0.019, respectively). The malignancy rate was 19.8