The patient went on to have a resection. 

Histology

Microscopic Description: 

Sections show the specimen to consist predominantly of necrotic tissue, in areas containing viable glioma that is high grade. The tumor cells display small cell morphologic characteristics, possible oligodendroglial features, and astrocytic elements with a fibrillar appearance. Mitotic figures are identified. Vascular proliferation is observed, including glomeruloid aggregates proliferating capillaries. As previously mentioned, tumor necrosis is extensive. Abnormally large ectatic vascular structures are also seen and are consistent with a vascular malformation. Several vessels are thrombosed.

Final Diagnosis: Glioblastoma WHO Grade IV

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.