BRAF and perineurioma: Further support for the notion that BRAF mutations occur only in the epithelial component and not in the stromal component came from a study by Groisman et al. who demonstrated BRAF mutations (using direct sequencing) in 5 of 8 serrated perineuriomas while none of 12 cases of non-serrated perineuriomas harboured a BRAF mutation [5].