The patient went on to have surgery. 

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 of 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

Note: This case predates the recent (2016) revision WHO classification of CNS tumors and IDH status is not available. As such, this tumor would now be classified as a glioblastoma NOS.