Neuropathology IIIa

• Pilocytic astrocytoma (kids) has rosenthal fibres ( bipolar hair cells ) & eosinophilic granules
• Diffuse astrocytoma has naked nuclei & glomeruli bodies
• Oligodendroglioma affects the frontal & temporal lobes
• Ependymona has periventricular true & pseudo - rosettes
• Wet keratin appearance is for craniopharyngioma
• Metastasis to the brain has dirty necrosis & peri - tumoural oedema
• Diffuse astrocytomas (Glioblastomas) is due to loss of function mutations in tp53 & Rb
• Gliobastoma has cystic degeneration & haemorrhage
• Glioblastoma multiforme has butterfly, pseudo - palisading necrosis
• MIB-1 (Ki-67) is a proliferative marker & can be used in anaplastic astrocytoma
• DNTs are localised in the superficial temporal lobe and have floating neurons within the myxoid fluid
• Medulloblastoma

  • MYC amplications - poor outcome
  • mutations in sonic hedgehog pathway = good prognosis
• Medulloblastoma has homer - wright rosettes
• Primary CNS lymphoma has Necroses ( EBV [+] tumours) and Perivascular accumulation of neoplastic cells
• Germ cell tumours are localised to the pineal & supra - sellar regions