CNS tumor
Cysts
Epidermoid cyst


Topic Completed: 1 February 2012

Minor changes: 1 September 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Epidermoid cyst [title] central nervous system

Eman Abdelzaher, M.D., Ph.D.
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Cite this page: Abdelzaher E. Epidermoid cyst. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorepidermoidcyst.html. Accessed September 21st, 2020.
Definition / general
  • Benign cyst lined by keratinized stratified squamous epithelium and lacking skin adnexa (eMedicine: Brain Epidermoid Imaging)
  • More common than dermoid cyst (1% of intracranial masses)
Terminology
  • Also called epidermoid or epidermoid tumor
Sites
  • Occurs throughout neuriaxis
  • Favored site: cerebellopontine angle
  • Other sites: brainstem, cranial diploe, intraspinal, pineal gland, sella, temporal lobe
  • Rarely undergoes malignant degeneration
Radiology description
  • Discrete, extra-axial with signal characteristics reflecting keratinous contents
  • Diffusion MRI helps distinguish from arachnoid cysts
Radiology images

Images hosted on other servers:

Cerebellopontine angle

Case reports
Gross description
  • Well defined round mass, thin walled, pearly white
Microscopic (histologic) description
  • Fibrous wall lined by keratinizing squamous epithelium; contains anucleate squames but no skin adnexae and no hair
Positive stains
Differential diagnosis
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