The Role of BRAFV600E Mutation and Ultrasonography for the Surgical Management of a Thyroid Nodule Suspicious for Papillary Thyroid Carcinoma on Cytology

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). 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. 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. 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.