There are four important characteristics in glioblastomas:
- Severe atypia
- Many mitotic figures
- Pseudopalisading necrosis
- Microvascular proliferation
Microvascular proliferation is a phenomenon where the tumor contains small capillaries who are irregular and are comprised of atypical endothelial cells.
Pseudopalisading necrosis is a phenomenon where the tumor contains areas of necrosis, and this necrosis is surrounded by hypercellular regions.
- Age 50 – 70
Glioblastoma is a grade IV astrocytic tumor that is defined histologically be the four characteristics described above. It must be differentiated from anaplastic astrocytoma, a grade III astrocytic tumor. Anaplastic astrocytoma also shows severe atypia and many mitotic figures but no pseudopalisading necrosis or microvascular proliferation.
23. Senile plaques and neurofibrillar degeneration