Diagnostic value of BRAF^V600E mutation analysis of thyroid nodules according to ultrasonographic features and the time of aspiration

Background. We investigated the diagnostic value of the BRAF ^V600E mutation of thyroid nodules according to ultrasonography (US) features and the time of BRAF^V600E mutation analysis. Methods. A total of 304 nodules in 295 patients (mean age, 49.4 years) were included. Thyroid nodules were classified as suspicious or probably benign on US. Group 1 (n = 168) included nodules with BRAF^V600E mutation analysis at the time of the initial US-guided fine needle aspiration biopsy (US-FNAB) and group 2 (n = 136) included nodules with analysis at the time of the repeat USFNAB. The frequency of malignancy and the BRAF^V600E mutation were compared between suspicious and probably benign nodules on US and between groups 1 and 2. Results. Of 304 nodules, 113 were malignant and 59 (52.2%) had the BRAF ^V600E mutation. Also, 58 of 196 nodules suspicious on US (29.6%) had the BRAF^V600E mutation, whereas 1 of 108 (0.9%) probably benign nodules had the BRAF^V600E mutation (P value<.0001). The BRAF ^V600E mutation was more frequently found in nodules suspicious on US than those probably benign in both groups 1 and 2 (P value<.0001 and .0058, respectively). Preoperative detection of the BRAF^V600E mutation led surgeons to perform surgery in 5.8% of 103 nodules with benign and nondiagnostic results on cytology in group 1 and 1% of 98 nodules in group 2 without treatment delay. Conclusions. The BRAF^V600E mutation analysis was a useful adjunctive diagnostic tool, especially in nodules suspicious on US, and was more effective if performed at the time of the initial US-FNAB.