Histology findings:

Microscopy: pleomorphic astrocytic tumor which diffusely infiltrates surrounding brain tissue. Predominantly composed of gemistocytic cells although some regions or more cohesive small cell apearance. Microvascular proliferation and intrinsic tumor necrosis identified.

Immunohistochemistry:
GFAP positive
MIB1 high index proliferation
ATRX positive (not mutated)
IDH1 negative (not mutated)
H3K27M negative
P53 focal upregulation
NeuN and synapthophysin in surrounding cortical tissue but negative within the tumor
MGMT 1.1% (unmethylated)

Comment: left temporal glioblastoma, WHO grade 4, IDH1 wild-type, unmethylated

Discussion:

New onset seizures in adults >40 years old merit neuroimaging with trauma, vascular disease and tumors common causative conditions.

Although there are a variety of smaller low grade tumors typically considered epileptogenic, high grade tumors such as glioblastoma should be in consideration. Small cortical lesions can initially present with seizures rather than the headaches or focal neurological deficits larger lesions elicit.