Histopathological characteristics of epithelioid glioblastoma (e-GB) in children. Several cytological phenotypes characterize these tumors, including epithelioid (a), rhabdoid (b), and astrocytic/gemistocytic (c). e-GBs resemble classic glioblastomas in some areas (d; all H&E, ×200). Immunoreactivity for GFAP was variable in tumor cells (e; anti-GFAP antibody, ×200). Homozygous deletion of CDKN2A was evident in two patients (f; iFISH: green and red fluorochromes targeted CDKN2A and the control locus on 9q, respectively)