The patient went on to have surgery. 

Histology

Microscopic Description: Sections show a densely cellular glial neoplasm. The tumor cells have hyperchromatic, pleomorphic nuclei and abundant eosinophilic cytoplasm with fibrillary processes. There are areas where the tumor cells have scant cytoplasm and round nuclei that could represent focal oligodendroglial differentiation. Mitotic figures are frequent and there is abundant endothelial proliferation and tumor necrosis with pseudopalisading.

FINAL DIAGNOSIS: glioblastoma

Note: IDH mutation status is not provided in this case and according to the current (2016) WHO classification of CNS tumors, this tumor would, therefore, be designated as a glioblastoma NOS.