Glioblastoma : Endothelial Hyperplasia
Besides necrosis with nuclear pseudopalisading, the presence of endothelial proliferation is another histologic hallmark of glioblastomas. The image shows glomeruloid vessels (vessels with multiple lumina) and endothelial multilayering as a result of endothelial hyperplasia. These changes are driven by Vascular Endothelial Growth Factor (VEGF) secreted by the tumor in response to hypoxia. Note the focus of necrosis on the lower left.