CNS tumor
Astrocytic tumors
Astrocytoma - general

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

Revised: 2 October 2017, last major update August 2017

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PubMed Search: Astrocytic tumors CNS

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Cite this page: Abdelzaher, E. Astrocytoma - general. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorastrocytomageneral.html. Accessed December 14th, 2017.
Definition / general
  • See also WHO classification of CNS tumors
  • Astrocytic gliomas are the most common primary brain tumors and account for up to two thirds of all tumors of glial origin (Recent Results Cancer Res 2009;171:3)
  • Both adults and children are affected
  • Comprise a heterogeneous group of neoplasms yet, they can be broadly categorized into infiltrative (diffuse) astrocytic neoplasms and localized astrocytic neoplasms
  • In the past, all astrocytic tumors (diffuse and localized) were grouped together regardless of their dissimilar biological behavior (Acta Neuropathol 2007 Aug;114:97)
  • Recently, the 2016 CNS WHO classification grouped all diffuse gliomas (astrocytic or oligodendroglial) together based on an integrated phenotypic and genotypic classification; this approach sharply separates localized astrocytic neoplasms from diffuse gliomas (Acta Neuropathol 2016;131:803)
  • The diffuse gliomas include the WHO grade II and grade III astrocytic tumors, the grade II and III oligodendrogliomas, the grade IV glioblastomas, and the diffuse gliomas of childhood
  • Gliomatosis cerebri is now regarded as a growth pattern found in many diffuse gliomas rather than a distinct entity (Acta Neuropathol 2016;131:803)
  • Localized astrocytic tumors comprise a group of slowly growing circumscribed neoplasms that frequently have BRAF alterations (pilocytic astrocytoma, pleomorphic xanthastrocytoma) or TSC1 / TSC2 mutations (subependymal giant cell astrocytoma) (Acta Neuropathol 2016;131:803)
WHO 2016 classification
  • Diffuse astrocytic and oligodendroglial tumors
    • Diffuse astrocytoma, IDH mutant
      • Gemistocytic astrocytoma, IDH mutant
    • Diffuse astrocytoma, IDH wildtype
    • Diffuse astrocytoma, NOS
    • Anaplastic astrocytoma, IDH mutant
    • Anaplastic astrocytoma, IDH wildtype
    • Anaplastic astrocytoma, NOS
    • Glioblastoma, IDH wildtype
      • Giant cell glioblastoma
      • Gliosarcoma
      • Epithelioid glioblastoma
    • Glioblastoma, IDH mutant
    • Glioblastoma, NOS
    • Diffuse midline glioma, H3 K27M mutant
    • Oligodendroglioma, IDH mutant and 1p/19q codeleted
    • Oligodendroglioma, NOS
    • Anaplastic oligodendroglioma, IDH mutant and 1p/19q codeleted
    • Anaplastic oligodendroglioma, NOS
    • Oligoastrocytoma, NOS
    • Anaplastic oligoastrocytoma, NOS

  • Other astrocytic tumors (localized)
    • Pilocytic astrocytoma
      • Pilomyxoid astrocytoma
    • Subependymal giant cell astrocytoma
    • Pleomorphic xanthoastrocytoma
    • Anaplastic pleomorphic xanthoastrocytoma
Gross images

Images hosted on other servers:

Diffuse glioma (diffuse astrocytoma)

Localized astrocytoma (pilocytic astrocytoma)

Microscopic (histologic) description
  • Refer to respective tumor sections for details
Microscopic (histologic) images

Images hosted on other servers:

Diffuse glioma

Localized astrocytic tumor (pilocytic astrocytoma)

Positive stains