Recent advances in genomic technology and genome-wide analysis have identified key molecular alterations that are relevant to the diagnosis and prognosis of brain tumors. Molecular information such as mutations in isocitrate dehydrogenase (IDH) genes or 1p/19q co-deletion status will be more actively incorporated into the histological classification of diffuse gliomas. BRAF V600E mutations are found frequently in circumscribed low-grade gliomas such as pleomorphic xanthoastrocytoma (PXA) and extra-cerebellar pilocytic astrocytoma, or epithelioid glioblastomas (E-GBM), a rare variant of GBM. This mutation is relatively rare in other types of diffuse gliomas, especially in adult onset cases. Here, we present an adult onset case of IDH wild-type/BRAF V600E-mutated diffuse glioma, evolving from grade III to grade IV. The tumor displayed atypical exophytic growth and had unusual histological features not fully compatible with, but indicative of PXA and E-GBM. We discuss differential diagnosis of the tumor, and review previously described diffuse gliomas with the BRAF V600E mutation.
Keywords: Anaplastic astrocytoma; BRAF mutation; Glioblastoma.