title: Lack of BRAF V600E protein expression in primary central nervous system lymphoma.
abstract: BACKGROUND
  Mutations in the v-raf murine sarcoma viral oncogenes homolog B1 (BRAF), most commonly of the V600E type, are present in a variety of human malignancies including malignant melanoma, papillary thyroid cancers, and hairy-cell leukemia and specific therapeutically active BRAF inhibitors exist. We aimed to investigate BRAF V600E protein expression in primary central nervous system lymphoma (PCNSL).
  
  
  METHODS
  We investigated BRAF V600E expression in formalin-fixed and paraffin-embedded surgical tissue specimens of 20 immunocompetent patients with PCNSL using the mutation-specific monoclonal mouse antibody VE1.
  
  
  RESULTS
  Ten male and 10 female patients with a median age of 60 years (range, 44 to 71 y) at time of operation were included. All cases were qualified as diffuse large B-cell lymphomas. None of the investigated cases demonstrated specific immunoreactivity for BRAF V600E mutation.
  
  
  CONCLUSIONS
  Our data provide evidence that the BRAF V600E mutation is not pathobiologically relevant in PCNSL and as a consequence is not a feasible drug target in this tumor type.
authors.affiliation: Department of Neuropathology, Institute of Neurology, Medical University of Vienna, Vienna, Austria.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Berghoff
authors.forename: David
authors.initials: D
authors.lastname: Capper
authors.forename: Matthias
authors.initials: M
authors.lastname: Preusser
mesh_terms: D000328:Adult; D000368:Aged; D016543:Central Nervous System Neoplasms / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008223:Lymphoma / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics* / Q000378:metabolism
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf