Expression of the BRAF L597Q mutation in sporadic neurofibromas of the upper extremity

Exp Mol Pathol. 2017 Dec;103(3):276-278. doi: 10.1016/j.yexmp.2017.11.010. Epub 2017 Nov 21.

Abstract

The pathogenesis of neurofibromas is poorly understood outside of neurofibromatosis (NF). The BRAF proto-oncogene has been implicated in malignant peripheral nerve sheath tumors (PNSTs), however its role in neurofibromas has not been described. In this study, we identify a BRAF mutation in a 61-year old non-NF patient with a history of sporadic and recurrent neurofibromas localized to the right upper extremity. Despite repeat resections to establish local control, he developed median nerve neuropathy secondary to a 13×4cm plexiform neurofibroma. Genetic sequencing of the neurofibroma revealed the expression of a novel BRAF L597Q mutation. This study is the first to describe the BRAF L597Q mutation in PNSTs and the first to implicate a BRAF mutation in neurofibroma biology. We hypothesize that BRAF mutations may identify a molecularly-distinct subset of recurrent neurofibromas and may provide potential for targeted therapeutics.

Keywords: BRAF; Neurofibroma; Peripheral nerve sheath tumors.

Publication types

  • Case Reports

MeSH terms

  • Gene Expression
  • Humans
  • Male
  • Middle Aged
  • Neurilemmoma / genetics*
  • Neurilemmoma / pathology
  • Neurofibroma / genetics*
  • Neurofibroma / pathology
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins B-raf / genetics*
  • Upper Extremity / pathology

Substances

  • MAS1 protein, human
  • Proto-Oncogene Mas
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf