CNS tumor
Diffuse astrocytic and oligodendroglial tumors

Topic Completed: 1 March 2012

Revised: 2 January 2019, last major update March 2012

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Gliosarcoma CNS

Eman Abdelzaher, M.D., Ph.D.
Page views in 2019: 3,279
Page views in 2020 to date: 2,517
Cite this page: Abdelzaher E. Gliosarcoma. website. Accessed August 6th, 2020.
Definition / general
  • Rare biphasic subtype of glioblastoma, with alternating glial and mesenchymal differentiation (glioblastoma and sarcoma)
  • WHO grade IV
  • May be well circumscribed and resemble meningioma radiologically
  • May progress to pure sarcoma (GFAP-)
  • Rarely expresses epithelial markers or lipid
Radiology description
  • Predominantly sarcomatous tumors appear well demarcated with homogeneous contrast enhancement, may mimic meningioma
Radiology images

Images hosted on other servers:

Various images

Before surgery

Case reports
Gross description
  • Firm, well circumscribed mass (resembling meningioma or metastasis)
Microscopic (histologic) description
  • Glioblastoma (occasionally oligodendroglioma, rarely ependymoma) plus regions of sarcoma resembling fibrosarcoma or malignant fibrous histiocytoma rich in reticulin (collagen+, GFAP-)
Microscopic (histologic) images

Images hosted on other servers:

Various images

With prominent smooth muscle component

Reticulin stain

EGFR, p53

2A: Biphasic with epithelioid and spindle cells
2B: Markedly increased nuclear Ki67 staining
2C: Epithelioid component has strong GFAP staining
2D: Spindle cells SMA+, surrounded by reticulin fiber

Cytology description
  • Highly cellular
  • High grade tumor with mesenchymal and glial components
  • Mesenchymal features may be fibrosarcoma, rhabdoid, osteoclastic giant cell, undifferentiated or heterologous elements
  • Rich arborizing vessels, high mitotic rate, necrosis
  • Glial component has pleomorphic round / oval nuclei, gemistocytes in fibrillary stroma (Diagn Cytopathol 2004;30:77)
Differential diagnosis
  • Glioblastoma: may have desmoplasia but spindled areas lack features of malignancy
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