Representative images showing histomorphological structures of GC. Many histological features are similar to invasive patterns of GBM (secondary structures of Scherer in Figure 2). (a) Diffuse parenchymal infiltration of GC cells without the formation of a circumscribed tumor mass. The secondary structures of Scherer are seen also in GC as follows: (b) perineuronal satellitosis (indicated by arrows), (c) subpial spread (region above black dots), and (d) invasion along the white matter tracts (indicated by arrow heads). Hematoxylin and eosin staining. Scale bar in (a), 375 μm; scale bars in (b) and (d), 50 μm; scale bar in (c), 100 μm.