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Glioblastoma, IDH-wildtype is an aggressive, high-grade (CNS WHO Grade 4) astrocytic tumor that lacks mutations in IDH1/IDH2 genes, occurring predominantly in older adults.

It is the most common primary malignant brain tumor in adults and typically exhibits rapid progression, necrosis, and microvascular proliferation.

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Glioblastoma (NORD)

https://www.youtube.com/watch?v=GiV_XyyvNz8

https://www.youtube.com/watch?v=waliaz_0-54

https://youtu.be/bh5sswbaC5U

Etiopathogenesis

Cell of origin: Astrocyte or neural stem-like cell.
Genetic profile (per WHO 2021) – Diagnosis of glioblastoma can be made in:
- Histologically classic GBM: with necrosis and/or microvascular proliferation, and IDH-wildtype.
- Histologically lower-grade tumors but with molecular features of GBM:
  - TERT promoter mutation
  - EGFR amplification
  - Combined whole chromosome 7 gain / 10 loss (+7/–10)
MGMT promoter methylation: Predicts better response to temozolomide.

Clinical Features

Feature	Description
Age	Typically >55 years
Symptoms	Headache, seizures, focal neurological deficits, cognitive decline
Location	Frontal and temporal lobes are most common
Course	Rapid progression over weeks to months

Radiology

MR features:

Classic sign: “Butterfly glioma” — crosses corpus callosum into both hemispheres.

MRI Sequence	Findings
T1	Hypointense central necrotic core
T2/FLAIR	Hyperintense infiltrative margins with extensive peritumoral edema
Post-contrast T1	Thick, irregular ring enhancement around central necrosis (heterogeneous)
DWI/ADC	Restricted diffusion in solid enhancing areas (high cellularity)
Perfusion (rCBV)	Markedly elevated (due to neovascularity)
SWI	Hemorrhage, microvascular proliferation
MR Spectroscopy	↑Choline, ↓NAA, ↑lipid-lactate peaks

CT features:

Hypo- to isoattenuating mass with central hypodensity (necrosis).