Fig. 2

Histopathological and molecular features. Case #1 A A glial proliferation with oligo-like features and one microcalcification (HPS, magnification × 400). B Diffuse expression of Olig2 (magnification × 400). C Diffuse synaptophysin immunoreactivity without true neuropil islands (magnification × 400). D 1p deletion by FISH analysis (green signal for 1q25 and orange signal for 1p36, magnification × 400). E EZHIP overexpression in all tumor cells (magnification × 400). Case #2 F A glial proliferation with astrocytic features (magnification × 400). G Diffuse expression of Olig2 (magnification × 400). H Diffuse synaptophysin immunoreactivity without true neuropil islands (magnification × 400). I Loss of the trimethylation H3K27me3 in tumor cells (magnification × 400). J EZHIP overexpression in all tumor cells (magnification × 400). Case #3 K A high-grade glial proliferation with several mitoses and necrosis (magnification × 400). L Immunoreactivity for neurofilament in a subset of tumor cells (magnification × 400). N Loss of the trimethylation H3K27me3 in tumor cells (magnification × 400). O H3K27M immunopositivity in all tumor cells (magnification × 400). Black scale bars represent 50 μm