This was retrospective descriptive and analytic research carried out at three medical institutions from November 2014 to October 2015. 795 thyroid nodules were categorized by TIRADS according to number of suspicious US features (marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, taller-than-wide shape, high stiffness with elastography, metastatic lymph nodes). Simply hypoechoic nodules without any signs of malignancy were classified as TIRADS 3. TIRADS 2 group corresponded to benign nodule: simple cyst, spongiform nodule, homogeneous hyperechoic nodules (“white knight”), typical subacute thyroiditis and nodules with macrocalcification.

FNA cytology were reported according to the Bethesda system. In this time period we also surveyed patients who had thyroidectomy. 125 nodules from 119 patients had confirmed histopathological diagnoses.