Tuesday, April 28, 2015
The Tumor Biomarker Series: BRAF
Aberrant constitutive activation of BRAF tends to be seen in cerebellar and midline pilocytic astrocyomas whereas the activating point mutation at BRAF V600E is more likely to be seen in cerebral examples. The V600E point mutation is also observed in other low-grade gliomas and glioneuronal neoplasms, including approximately two-thirds of pleomorphic xanthoastrocytomas, and lower percentages of ganglioglioma, desmoplastic infantile ganglioglioma, dysembrioplastic neuroepithelial tumor, and papillary craniopharyngioma. Although less common, diffusely infiltrative gliomas including glioblastoma, particularly the epithelioid variant, may also demonstrate the V600E point mutation -- making this biomarker potentially less useful as a diagnostic tool in distinguishing low-grade gliomas from high-grade ones.