To assess the diagnostic value of the thyroid imaging reporting and data system (TIRADS) combined with BRAF^V600E testing in Bethesda system category Ⅲ thyroid nodules.

A total of 125 patients who underwent ultrasound-guided fine needle aspiration (FNA) at the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2019 were selected. Each nodule underwent TIRADS classification and BRAF^V600E testing and was confirmed by histopathology. The diagnostic efficacy of TIRADS, BRAF^V600E testing, and their combination were assessed according to histopathology findings.

A total of 125 nodules from 125 patients were enrolled. According to histopathology findings, 76 nodules were benign and 49 were malignant. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TIRADS 4c or 5 were 73.5%, 89.5%, 81.8%, 84.0%, and 83.2%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of BRAF^V600E mutation were 75.5%, 100.0%, 100.0%, 86.4%, and 90.4%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of the combination of TIRADS 4c or 5 and BRAF^V600E mutation were 93.9%, 89.5%, 85.2%, 95.8%, and 91.2%, respectively. The combination of TIRADS 4c or 5 and BRAF^V600E mutation significantly increased the sensitivity (P=0.002, P=0.004) and NPV (P=0.018, P=0.044) when compared with either TIRADS or BRAF^V600E mutation alone.

Our findings suggest that the combination method has improved sensitivity and NPV and may have great value in differentiating Bethesda system category Ⅲ nodules.