CNS & pituitary tumors

Gliomas, glioneuronal tumors and neuronal tumors

Other astrocytic tumors

Astroblastoma, MN1 altered

Last author update: 1 March 2013
Last staff update: 6 June 2024 (update in progress)

Copyright: 2002-2024,, Inc.

PubMed Search: Astroblastoma

Eman Abdelzaher, M.D., Ph.D.
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Cite this page: Abdelzaher E. Astroblastoma, MN1 altered. website. Accessed July 14th, 2024.
Definition / general
  • Rare ( < 3% of primary brain gliomas), compact glial neoplasm with perivascular pseudorosettes formed of GFAP+ cells arranged around central, often sclerotic, blood vessels
  • Controversial entity - relationship with ependymoma is not clear
  • Usually children and young adults, median age 11 years, range 1 - 58 years
Clinical features
  • Features of astrocytoma and ependymoma; expresses nonfibrillar form of GFAP (so PTAH-)
  • No WHO grade assigned for astroblastoma or anaplastic astroblastoma
Radiology description
  • Discrete supratentorial cerebral, often superficial, contrast enhancing mass
  • Cystic change is common
Radiology images

Images hosted on other servers:

Huge well demarcated mass in frontal lobe

Prognostic factors
Case reports
  • Resection (adequate for well differentiated tumors), more aggressive treatment needed for malignant tumors
Gross description
  • Well circumscribed, peripheral, cerebral hemispheric masses
  • Firm, often cystic
Microscopic (histologic) description
  • Well circumscribed with discrete pushing borders, occasionally infiltrative in high grade lesions
  • Perivascular pseudorosettes resembling ependymoma but with thick processes from cell body to adventitia of vessel
  • Also vascular hyalinization, little fibrillar background
  • Limit diagnosis to tumors in which these features predominate (other tumors have these features focally)
  • High grade astroblastomas have hypercellular and mitotically active regions, often with vascular proliferation or necrosis with pseudopalisading; rare features are signet ring cells (Neuropathology 2002;22:200)
Microscopic (histologic) images

Case #312




Positive stains
Negative stains
Electron microscopy description
  • Abundant intermediate filaments forming bundles in tumor cytoplasm, membrane junctions and external lamina when cells are in contact with collagen fibers (Surg Neurol 1991;35:116)
Molecular / cytogenetics description
Differential diagnosis
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