CNS tumor
Mesenchymal tumors
Solitary fibrous tumor / hemangiopericytoma


Topic Completed: 1 August 2014

Revised: 3 January 2019, last major update August 2014

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

PubMed Search: Hemangiopericytoma CNS

Jesse L. Kresak, M.D.
Anthony T. Yachnis, M.D.
Page views in 2018: 6,094
Page views in 2019 to date: 1,709
Cite this page: Kresak J. Solitary fibrous tumor / hemangiopericytoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorHPC.html. Accessed December 10th, 2019.
Definition / general
  • Grade II or III of IV
    • Most are grade II
    • Criteria for grade III include > 5 mitoses/10 HPF with "moderate to high" nuclear atypia and "moderate to high" cellularity
  • < 1% of all primary CNS tumors
  • 60% men, mean age 45 years
  • Usually single mass attached to meninges of brain or spinal cord (resembles meningioma radiographically)
  • Recently reported overall survival (OS) 84 months, 5 year survival 94% and 10 year survival 72%, (World Neurosurg 2014;81:556)
  • 41% recur, 12 - 20% metastasize to extra or intracranial sites (World Neurosurg 2014;81:556)
  • May invade through neighboring bone
Terminology
  • Hemangiopericytoma is still current terminology in the CNS and is a distinct neuropathologic entity (not lumped together with solitary fibrous tumor)
  • Formerly called angioblastic meningioma
Sites
  • Dural based
  • Often supratentorial
  • 10% spinal
Radiology description
  • Often homogenously enhancing and well demarcated from adjacent brain - resembles meningioma
Radiology images

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Vividly enhancing mass, various images

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Extra-axial mass, various images

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Tumor mass in the left cerebellum

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Resection cavity with residual tumor tissue

Prognostic factors
  • Grade III associated with worse overall survival
  • No statistical significance between grades II and III in regards to metastatic potential or local recurrence (J Clin Neurosci 2014;21:1310)
Case reports
Treatment
Gross description
  • Dural based, gray to red
  • May be well circumscribed from brain parenchyma
  • Size can vary widely
Microscopic (histologic) description
  • Sheets of cells with uniform hypercellularity, cells are homogeneous with moderate amount of cytoplasm, round to oval nuclei and moderate pleomorphism
  • Monomorphous cellular spindle cell tumor with round to oval nuclei
  • Intratumoral staghorn vessels
  • May have storiform pattern
Microscopic (histologic) images

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H&E, CD34

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Staghorn vessels

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20x, vague "storiform" pattern

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40x


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CD34

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Reticulin stain

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Prior embolization

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Sheets of tumor cells


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Irregular blood vessels

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Irregular blood vessels (not CNS)

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CD34+ and CD31 negative

Cytology description
  • Cohesive clusters, does not squash well
  • Individual cells, when present, are round to ovoid "naked nuclei"
Cytology images

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Squash prep, low power

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Squash prep, higher power

Positive stains
Negative stains
Electron microscopy description
  • Extensive basement membrane around every cell
  • Small bundles of intermediate filaments
  • No desmosomes
  • No gap junctions
Differential diagnosis
Additional references
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