Detection of BRAF Mutation on Fine Needle Aspiration Biopsy Specimens Using the Colorimetric Mutation Detection Method

ABSTRACT

PURPOSE: The detection of papillary thyroid carcinoma (PTC) is increasing these days; however, there is currently no satisfactory definitive preoperative diagnostic method. Fine-needle aspiration cytology (FNAC) is now the most accurate method to diagnose PTC preoperatively. It is known that the specificity of BRAF mutation is high in papillary thyroid carcinoma. Therefore, detection of BRAF mutation using a FNAC slide can be helpful to diagnose PTC preoperatively. METHODS: 13 patients with benign disease, 36 patients with PTC and 23 patients with an indeterminate diagnosis as determined histologically on the FNAC slide were evaluated to detect BRAF mutation with using FNAC slides and intraoperative fresh tissue. RESULTS: Mutation was detected using direct sequencing and the colorimetric method. The frequency of BRAF mutation was 86.3% for all the PTC cases. The concordance between the colorimetric method and direct sequencing was 57.1%. During DNA extraction from the FNAC slide, the DNA damage is so severe that direct sequencing is succeeded in only one case. CONCLUSION: We have to take measures to overcome and prevention DNA damage during extraction. The colorimetric method is not reliable.