Glioblastoma

Glioblastoma a very common malignant brain tumour in adults.

Glioblastoma
Diagnosis in short
Glioblastoma. H&E stain.
LM	astrocytic differentiation, nuclear atypia, necrosis, microvascular proliferation, +/-pseudopalisading necrosis
LM DDx	anaplastic astrocytoma
IHC	GFAP +ve, IDH-1 -ve/+ve
Site	brain, spinal cord
Radiology	intra-axial
Prognosis	very poor
Clin. DDx	metastatic carcinoma

It was previously known as glioblastoma multiforme, abbreviated GBM.

General

• Median survival is measured in months.
• Only about 5% can expect to survive more than three years.

Microscopic

Features:

• Astrocytic tumour with:
  • Nuclear atypia.
  • Necrosis.
  • Endothelial proliferation (AKA microvascular proliferation).
  • +/-"Pseudopalisading necrosis" - tumour cells lined-up like a picket fence around necrotic areas.

Images

• www:
  • Microvascular proliferation in a GBM (ouhsc.edu).
  • Pseudopalisading necrosis in GBM (aacrjournals.org).

• 

  Extreme nuclear enlargement in a GBM - very high mag. (WC)

• 

  GBM juxtaposed with near normal white matter - high mag. (WC)

IHC

• GFAP +ve (cytoplasm).
• IDH-1 -ve.
  • +ve if developed from lower grade astrocytoma. (???)

See also

• Astrocytoma.
• Neuropathology tumours.
• Neuropathology.