The role of BRAF^v600e mutation and ultrasonography for the surgical management of a thyroid nodule suspicious for papillary thyroid carcinoma on cytology

Background: This study was designed to investigate the role of BRAF ^V600E mutation status in cytology specimens and ultrasonography (US) when planning surgery for thyroid nodules with cytologic results suspicious for papillary thyroid carcinoma (PTC). Methods: From July 2008 to November 2008, 91 consecutive patients with cytologic results of suspicious for PTC underwent thyroidectomy. Before surgery, all patients received US-guided fine needle aspiration biopsy (US-FNAB) solely for the purpose of BRAF^V600E mutation analysis of thyroid nodules suspicious for PTC on cytology. BRAF ^V600E mutations were tested by direct sequencing. We investigated the role of BRAF^V600E mutation and US in planning the thyroid surgery. Results: Of 91 nodules suspicious for PTC, 42 (46.2%) were positive for the BRAF^V600E mutation and confirmed to be PTC by histopathology. The positive predictive values of BRAF^V600E mutation was 100%. Of the 49 nodules without the BRAF^V600E mutation, 42 (85.7%) proved to be PTC. Thirty-nine of 42 (92.9%) PTCs were suspicious for malignant features on US. Two of seven (28.6%) benign lesions showed probably benign features. The sensitivity, positive predictive value, and accuracy of US in thyroid nodules without BRAF^V600E mutations was 92.9% (39/42), 88.6% (39/44), and 83.7% (41/49), respectively. Conclusions: The BRAF^V600E mutation is a useful molecular marker for preoperative diagnosis of PTC and an indicator for therapeutic thyroid surgery in the nodule with cytologic results suspicious for PTC. In thyroid nodules without the BRAF^V600E mutation, suspicious malignant features on US may help in planning the extent of thyroid surgery.