Epithelioid glioblastoma arising from pleomorphic xanthoastrocytoma with the BRAF V600E mutation.

Pleomorphic xanthoastrocytoma (PXA) is classified by the World Health Organization as a grade II astrocytic tumor with relatively favorable prognosis among gliomas. A valine-to-glutamic acid substitution at position 600 of the serine/threonine-protein kinase BRAF (BRAF V600E) mutation, which is commonly found in PXA, has recently been detected in approximately 50% of all epithelioid glioblastoma (GBM) cases. We herein report a case of epithelioid GBM developing at the site of a left temporal PXA 13 years after the treatment of the primary tumor. The BRAF V600E mutation was detected in both tumors. These findings suggest that epithelioid GBM may arise from a PXA with a BRAF V600E mutation.