Histology

Microscopy: Diffusely infiltrating malignant glioma with a small cell astrocytic phenotype.  There are frequent mitoses, evidence of vascular proliferation and focal necrosis, including palisaded necrosis.

Immunohistochemistry:

• GFAP: positive
• IDH1-R132H mutation: negative
• P53:  only focal abnormal nuclear staining

Summary: Glioblastoma (WHO grade IV)

On imaging, restricted diffusion and enhancement, indicating this is an aggressive tumor.

Note

In a 45-year-old, this tumor has not been fully classified thus remains a "Glioblastoma NOS"  according to WHO classification. It requires IDH 1 and 2 sequencing to evaluate for non R132H and IDH2 mutations before being called an IDH-wt tumor.