Diagnostic utility of BRAF V600E mutation testing in thyroid nodules in elderly patients

摘要

Thyroid cancer is a rare disease characterized by the subtle appearance of a nodule. Fine-needle cytology (FNC) is the first diagnostic procedure used to distinguish a benign from a malignant nodule. However, FNC yields inconclusive results in about 20% of cases. BRAF V600E mutation is the most frequent genetic alteration in papillary thyroid carcinoma (PTC); its high prevalence makes this oncogene a useful marker to refine inconclusive FNC results. However, the prevalence of the BRAF V600E mutation depends on detection methods, geographical factors, and age. The aim of this study is to determine the prevalence of BRAF V600E mutation and its utility as a diagnostic tool in elderly subjects. FNC from 92 PTC patients were subjected to the analysis of BRAF mutation by pyrosequencing and direct sequencing; age-dependent prevalence was also determined. BRAF mutation analysis was successful in all FNC specimens. BRAF V600E was documented in 62 (67.4%) and in 58 (63.0%) PTCs by pyrosequencing and direct sequencing, respectively. BRAF V600E prevalence did not correlate with patient's age at diagnosis. Twenty out of 32 PTCs (62.5%) were correctly diagnosed by BRAF mutation analysis in inconclusive FNC results. Detection of BRAF V600E in cytology specimens by pyrosequencing is a useful diagnostic adjunctive tool in the evaluation of thyroid nodules also in elderly subjects.