Role of BRAFV600E mutation analysis and second cytologic review of fine-needle aspiration for evaluating thyroid nodule.

BACKGROUND

Thyroid fine-needle aspiration (FNA) is the primary diagnostic tool used for the evaluation of thyroid nodules. Although most aspirates provide diagnostic cytology, some are classified as indeterminate. The aim of this study was to determine whether the second review of FNA cytology can improve the diagnostic values and to assess the role of proto-oncogene B-Raf (BRAF) mutation testing in the diagnosis of papillary carcinoma (PC).

METHODS

Thyroid aspirates from 1060 patients were submitted for cytologic evaluation and BRAFV600E mutation analysis. A second cytologic review was performed by 2 cytopathologists in light of the mutation status.

RESULTS

Of the 313 patients who received surgery, 200 (63.9%) had been initially diagnosed as malignant by cytology. They were surgically confirmed as PCs, and the BRAFV600E mutation was detected in 82.5% of the cases. Ninety-five of 102 cases (93.1%) with indeterminate cytology turned out to be malignant, and the mutation was present in 63.3% of PCs. The sensitivity, accuracy, and negative predictive value (NPV) of the second review were better than those of initial cytologic diagnosis (P <.001). The addition of the mutation analysis significantly increased the sensitivity, accuracy, and NPV for detecting PCs compared with those of cytology alone.

CONCLUSIONS

Qualified cytologic diagnosis increases the effectiveness of FNA, forgoing the need for repeat biopsy or intraoperative frozen section evaluation. Preoperative BRAF mutation testing can supplement the routine cytology in the selection of thyroid nodules for surgery.