Histologic spectrum of CNS NB-FOXR2. (A–C) The characteristic embryonal-looking areas of CNS NB-FOXR2 showed substantial variation. Areas resembling high-grade glioma may be found (D). Diffusely infiltrating tumor cells may masquerade as a glial neoplasm (E). Some tumors contained low-grade appearing regions (F), but there were nodules of embryonal cells (G). There may be genuine GFAP expression among the tumor cells (H). The typical diffuse Olig2 (I) and synaptophysin (Synap, K) expression could be patchy (J, L) instead. Scale bar: 100 microns