Comparison of Preoperative Imaging and FNAB Results with Postoperative Pathology Results in Patients Undergoing AUS/FLUS

Objective: Thyroid nodules are observed in 3-7% of the general population, of which 4-8% are detected by palpation and 10-41% by thyroid ultrasonography (USG). In this study, we aimed to make early surgical or follow-up decisions in patients with thyroid atypia of undetermined significance (AUS)/follicular lesion of undetermined significance based on demographic and clinical characteristics, sonographic findings, and laboratory tests. Methods: Patients over the age of 18 years who were diagnosed with AUS and operated between August 2016 and August 2022 were included in the study. Patients under 18 years of age, those with missing data in the hospital automation system, and those with repeat fine-needle aspiration biopsy were excluded from the study. Results: Sonographic features of malignant and benign cases were compared. In malignant cases, the diameter of the dominant nodule was smaller, which was significant in terms of malignancy. Multicentricity, edge irregularity, and presence of cervical lymph nodes on USG and American Thyroid Association high-risk cases were found to be significant regarding malignancy. “Taller than wide (TTW)” appearance on sonographic images of nodules was observed more frequently in malignant cases. Conclusion: In regression analysis with age, gender, dominant nodule diameter, multicentricity, TTW shape, presence of calcification, presence of sonographic cervical lymph node, presence of lymphocytic thyroiditis in the parenchyma in the final pathology, and edge irregularity, the parameters TTW shape, presence of cervical lymph node, and presence of lymphocytic thyroiditis in the parenchyma were significant in favor of malignancy.