CNS & pituitary tumors

Gliomas, glioneuronal tumors, and neuronal tumors

Ependymal tumors


Last author update: 1 August 2012
Last staff update: 18 April 2022

Copyright: 2002-2023,, Inc.

PubMed Search: Subependymoma [title]

Eman Abdelzaher, M.D., Ph.D.
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Cite this page: Abdelzaher E. Subependymoma. website. Accessed March 30th, 2023.
Definition / general
  • Benign slowly growing neoplasm typically attached to a ventricular wall
  • Cell of origin unknown but resembles subependymal tissue
  • Slow growing; 50% have symptoms (associated with larger size or specific locations, J Neurosurg 1978;49:689)
  • Affects middle aged to elderly adults, occasionally children
  • Usually occurs in fourth ventricle (50 - 60% of cases) or lateral ventricles (30 - 40%), often as incidental finding at autopsy; also spinal cord, where it usually presents as intramedullary mass
  • WHO grade I of IV; benign behavior
Radiology description
  • Nonenhancing sharply demarcated, nodular mass
  • May be calcification or hemorrhage
  • Intraspinal examples are eccentric and show minimal to moderate enhancement
Radiology images

Case #75

Intraventricular mass

Case reports
  • Excision is usually curative, occasionally radiation therapy
Clinical images

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Fourth ventricle

Gross description
  • Well circumscribed, solid, gray white, sometimes calcified, protrudes into lateral ventricle or 4th ventricle
Microscopic (histologic) description
  • Clusters of isomorphic nuclei embedded in a dense, fine, glial fibrillary background
  • Mild nuclear pleomorphism, microcystic formations (especially in lateral ventricular tumors)
  • May be occasional ependymal pseudorosettes, hemorrhage, calcification
  • Rarely osseous metaplasia in childhood tumors (Neurol India 2003;51:98)
  • No / rare mitoses
  • No necrosis no / rare endothelial proliferation
  • Classify as mixed ependymoma subependymoma if prominent ependymal component and grade based on ependymoma component
Microscopic (histologic) images

Contributed by Eman Abdelzaher, M.D., Ph.D., David Taylor, M.D., Nazila Azordegan, M.D. and Case #75

Bland nuclei, microcysts

Case #75




Dot-like perinuclear (EMA)

40x (EMA)

Cytology description
  • Microcystic formations, loose fibrillary networks and nuclear clusters with mild pleomorphism (Acta Cytol 2001;45:636)
Positive stains
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