Glioblastoma multiforme (GBM) is characterised histologically by necrosis with a distinctive architectural pattern. This pattern is:

• A Geographic necrosis with peripheral rim of reactive gliosis
• B Cystic degeneration with eosinophilic granular bodies in the cyst wall
• C Pseudopalisading necrosis — viable tumor cells arranging around necrotic foci in a palissade pattern ✓
• D Rosette formation around necrotic vessels by tumor cells

Explanation

Pseudopalisading necrosis is the histological hallmark of GBM (WHO grade IV glioma): tumor cells radially align around areas of necrosis, forming a 'pseudopalisade' or picket fence appearance. This is believed to result from intratumoral hypoxia and vascular thrombosis, with surviving cells migrating away from dead zones. Glomeruloid microvascular proliferation is another hallmark. Eosinophilic granular bodies are characteristic of pilocytic astrocytoma.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

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Written and medically reviewed by the StethoPrep medical team.