Anaplastic pleomorphic xanthoastrocytoma with leptomeningeal dissemination responsive to BRAF inhibition and bevacizumab

To the Editor: Anaplastic pleomorphic xanthoastrocytoma (PXA) was added to the 2016 WHO Classification of Central Nervous System Tumors to describe a neoplasm that is morphologically similar to grade II PXA, but with increasedmitotic activity and shorter survival.1 There is no consensus on the management of high-grade or surgically unresectable PXAs. Approximately 60% of PXAs are associated with BRAF V600 mutations.2 Growing experience supports the use of BRAFtargeted therapy for treating relapsed or refractory PXAs and anaplastic pleomorphic xanthoastrocytomas (aPXAs).3,4 Case reports suggest that BRAF inhibitors may also be effective in the management of disseminated aPXAs.5 We present case of an adolescent with a disseminated aPXA treatedwith combined antiangiogenic andBRAF-targeted therapy. A16-year-old female presentedwithprogressive fatigue, headache, and two seizures. An magnetic resonance imaging (MRI) of the brain demonstrated an enhancing solid and cystic left frontal mass (Supporting Information Figure S1A). She underwent a subtotal resection (Supporting Information Figure S1B) and the pathology revealed a high-grade glioneuronal tumor or aPXA with MIB-1 of 15%. After further molecular characterization with methylation array and mutation of BRAF V600E demonstrated in the tumor, the consensus opinion favored aPXA.6 She was treated with radiation therapy (RT), 5940