BRAF and pleomorphic xanthoastrocytoma: Among the 37 (of 46, 80%) cases with sufficient tumor tissue for molecular analysis: 22 (of 37, 59%) were positive for BRAF V600E mutation, including 16 classic PXA and 6 PXA with anaplastic features, and 15 (41%) cases were negative for BRAF V600E mutation, including 7 classic PXA and 8 PXA with anaplastic features.