Neurosurgery notes/Tumours/Gliomas, Glioneuronal Tumors, and Neuronal Tumors/Circumscribed astrocytic gliomas/Astroblastoma, MN1-altered

Astroblastoma, MN1-altered

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Circumscribed astrocytic gliomas

General

  • Previously MN1 alteration was was not here its newly added

Definition

  • Essential:
    • A glial neoplasm with astroblastic perivascular pseudorosettes AND
    • MN1 alteration (on chromosome 22) AND (for unresolved lesions)
      • DNA methylation profile of astroblastoma, MN1-altered
  • Desirable:
    • GFAP immunoreactivity
    • EMA immunoreactivity

Numbers

  • Rare glial neoplasm
  • Children, young adults
  • Male: female 3:7

Localisation

  • Cerebral hemispheres
    • Frontal and parietal lobes

CNS WHO grading

  • Grade: 2 or 3 (anaplastic)-No more grading now
    • 2: Ki67 <5% (presence of necrosis does not indicate higher grade
    • 3: Ki67 >10%

Origin

  • The tanycyte, a cell with features intermediate between those of astrocytes and ependymal cells,

Pathology

  • Greyish pink or tan
  • Pseudo-rosette:
    • Consistency depending on extent of collagen deposition elongated tumour cells containing abundant eosinophilic cytoplasm, with a single, prominent process extending to a central blood vessel.
  • +GFAP, S100, vimentin, EMA, cell adhesion molecules (including CD44, NCAM1, GJB1, and GJB2)
A close-up of a microscope AI-generated content may be incorrect.
  • A Central vessel of pseudorosette shows variable sclerosis.
  • B Borders of astroblastoma with brain are generally well defined.
  • C Hyaline sclerosis of central vessels is typical in astroblastomas.
  • D Tumour cells strongly express GFAP.
4.08 q033 … 1
Astroblastoma.

Genetic

  • Gain of Chr 19 and 20q

Radiological

  • Well-demarcated
  • Superficially located
  • Non-calcified
  • Solid and cystic components
    • Nodular or lobulated masses with frequent cystic change and conspicuous contrast enhancement
  • T2 hyperintense
    • Multiple areas of susceptibility artefact and little to no surrounding oedema
  • DWI
    • Restricted diffusion within the solid components and heterogenous enhancement characteristics

Treatment

  • Surgery
  • If surgery not suitable then chemo and RT

Outcome

  • High-grade histology has been found to be associated with recurrence, progression, and worse prognosis
  • Surgery GTR best predictor of survival
    • Gross total resection resulted in a
        • ㅤ
        Survival rate
        5-year
        95%
        10 year
        50%
  • Frequent local recurrence but good overall survival.