CNS tumor
CNS cysts
Epidermoid cyst




Topic Completed: 1 February 2012

Revised: 31 December 2018, last major update February 2012

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Epidermoid cyst [title] central nervous system

Page views in 2018: 5,115
Page views in 2019 to date: 968
Cite this page: Abdelzaher E. Epidermoid cyst. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorepidermoidcyst.html. Accessed February 21st, 2019.
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

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
Microscopic (histologic) images

Images hosted on other servers:

Epidermal layer

Positive stains
Differential diagnosis