CNS tumor
Neuroepithelial tumors of uncertain origin
Astroblastoma

Author: Eman Abdelzaher, M.D., Ph.D. (see Authors page)

Revised: 29 August 2017, last major update March 2013

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Astroblastoma [title]

Cite this page: Abdelzaher, E. Astroblastoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorastroblastoma.html. Accessed October 20th, 2017.
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
Epidemiology
  • 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-)
Grading
  • 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
Treatment
  • 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

Images hosted on PathOut server:

Case of the Week #312:


EMA

GFAP

Trichrome



Images hosted on other servers:

Well differentiated and malignant tumors

Well developed perivascular pseudorosettes

Short and thick cytoplasmic processes

Fibrovascular stroma


H&E

GFAP+

S100+, vimentin+, CAM 5.2+

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