Analysis of differential BRAF^V600E mutational status in high aggressive papillary thyroid microcarcinoma

Papillary thyroid cancers often occur as microcarcinoma. Some papillary thyroid microcarcinoma (PTMC) have been considered to be high aggressive according to advanced disease stages, extrathyroidal extension, and severe cervical lymph node metastasis. Although several factors are thought to predict the occurrence of aggressiveness from PTMCs, the origin of aggressiveness has been rarely studied. To answer this question, the correlation between BRAF ^V600E mutation and high aggressive PTMCs was investigated. The clinicopathological characteristic of totally 64 cases of PTMCs was investigated and the BRAF^V600E mutational status of them was identified. BRAF^V600E mutation was exclusively detected in PTMCs (37.5%). The data provided no correlation between the occurrence of BRAF^V600E mutations and clinicopathological parameters, such as sex, age, and tumor-like lesions combination. The prevalence of BRAF^V600E mutation of PTMCs with high aggressiveness (advanced disease stages, extrathyroidal extension, and nodal metastasis) was significantly higher (p < 0.05) than that of PTMCs without aggressive behavior. The BRAF^V600E mutated PTMCs exhibited signs of higher aggressiveness than PTMCs without the mutation. BRAF ^V600E mutation may be a marker of high aggressiveness in PTMCs.