Contribution of the BRAF mutation analysis in calcified thyroid nodules

OBJECTIVE. The aim of this study was to evaluate the diagnostic contribution of BRAF ^V600E mutation analysis from the fine-needle aspiration (FNA) specimens of calcified thyroid nodules. SUBJECTS AND METHODS. From January 2008 to December 2008, 139 patients with 139 calcified thyroid nodules prospectively underwent BRAF ^V600E mutation analysis and ultrasound-guided FNA. At ultrasound, the patterns of calcification were classified into microcalcification, macrocalcification, and rim calcification. The performance of FNA alone then FNA plus BRAF ^V600E mutation analysis for the diagnosis of calcified thyroid nodules was compared on the basis of surgery, repeated FNA, or imaging follow-up for at least 1 year. RESULTS. Of 139 calcified nodules, 92 (66%) malignancies were detected, which included 91 papillary thyroid carcinomas and one follicular thyroid carcinoma. The malignant rates based on calcification type were 80% (63 of 79) for microcalcifications, 59% (19 of 32) for macrocalcifications, and 36% (10 of 28) for rim calcifications. The BRAF ^V600E mutation was identified in 50% of all nodules and in five (25%) of 20 nodules with indeterminate or nondiagnostic cytology. Adding BRAF ^V600E mutation analysis to FNA compared with FNA alone improved the negative predictive value of 83.9 to 92.2% (p = 0.034) but not the sensitivity, specificity, positive predictive value, and accuracy. CONCLUSION. The BRAF ^V600E mutation analysis from FNA specimens for calcified thyroid nodules may be performed for a greater negative predictive value and unveil the malignancy in 25% of indeterminate or nondiagnostic cytology.