Correlation of the Thyroid Nodules' Sonographic Features With Fine Needle Aspiration (FNA) Cytology Results

Background: Thyroid nodules are a common finding in clinical practice. Although ultrasonography is an accepted method for evaluating and following these nodules, Fine Needle Aspiration (FNA) is the procedure of choice for assessing the risk of malignancy. This study aims to determine the correlation between sonographic features of thyroid nodules based on Thyroid Imaging Reporting and Data System (TIRADS) classification and the cytology results obtained by FNA of thyroid nodules.Methods: In this prospective cohort study, 147 patients with thyroid nodules underwent FNA under the guide of ultrasonography based on TIRADS classification, and their sonographic features were recorded. The pathologic findings were also obtained according to the Bethesda system. Finally, the association between sonographic features and cytology results were analyzed.Results: 147 patients with a mean ± SD age of 49.8 ± 13.7 years were assessed. 16 (10.9%) nodules were malignant, and 131 nodules (89.1%) were benign. The association of TIRADS categories with the risk of malignancy is as follows: TIRADS 1 (0%), TIRADS 2 (16.9%), TIRADS 3 (10.5%), TIRADS 4 (16.7%), and TIRADS 5 (0%). The location of thyroid nodules and their bloody lamellae were significantly correlated with the risk of malignancy (P value< 0.05). However, the association between the risk of and gender, calcification, hardness, halo sign and nodules’ echogenicity were not statistically significant. Conclusions: Although there are trusted classifications for categorizing the thyroid nodules, there is still uncertainty in utilizing them as an accepted method of choice for managing the thyroid nodules, as various sonographic features are shared between benign and malignant ones.