Fig. 3

Histopathological analyses of the resected glioblastoma. a Histopathological specimen showing nuclear pseudopalisading, which is defined as the aggregation of tumor cells around the periphery of the necrotic areas, increased mitotic activity, and vascular proliferation. Pseudopalisading necrosis and vascular proliferation are the two important hallmarks of glioblastoma [55]. Magnification, 20×. b Histopathological specimen depicting an accumulation of viable tumor cells encircling the blood vessels in a large necrotic focus. The image also shows endothelial multilayering as a result of endothelial hyperplasia. These changes are mostly driven by vascular endothelial growth factor secreted by the tumor in response to hypoxia. Magnification, 20×