Contribution of the BRAF mutation analysis in calcified thyroid nodules

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.

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.

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.

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.