Uncommon BRAF mutations in the follicular variant of thyroid papillary carcinoma: New insights

Mutational analysis is reshaping the practice of fine-needle aspiration cytology for the diagnosis of thyroid nodules. The v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) valine (V) to glutamic acid (E) substitution at codon 600 (BRAF(V600E)) is the most effective diagnostic/prognostic marker and is used mainly for papillary thyroid carcinomas (PTCs). Although BRAF(V600E) represents 95% of all BRAF mutations, uncommon BRAF mutations have been identified in thyroid carcinomas. For the current study, the authors evaluated morphologic (plump pink cells and sickle-shaped nuclei) anti-BRAF(V600E) antibody (VE1) immunocytochemical and molecular findings of BRAF mutations in PTCs and in the follicular variant of PTC (FVPC).