CNS tumor
Dermoid cyst

Topic Completed: 1 February 2012

Revised: 31 December 2018, last major update February 2012

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

PubMed Search: Dermoid cyst [title] central nervous system

Eman Abdelzaher, M.D., Ph.D.
Page views in 2019: 4,793
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Cite this page: Abdelzaher E. Dermoid cyst. website. Accessed July 13th, 2020.
Definition / general
  • Developmental lesions arising from embryologic displacement of ectoderm into meninges, ventricles or rarely parenchyma (eMedicine: Imaging in CNS Dermoid Tumors)
  • Benign cyst lined by keratinizing squamous epithelium and cutaneous adnexa
  • Uncommon; much less common than epidermoid cyst
  • Usually affects children
  • Distribution more restricted than epidermoid cysts, usually affects midline (mostly fontanelle or posterior fossa as midline cerebellar lesions or within the 4th ventricle), may affect spinal canal
  • May have sinus tract to skin surface in nasofrontal or occipital regions
  • May rupture and cause chemical meningitis
Radiology images

Images hosted on other servers:

Well defined lesion

Gross description
  • Thick walled with greasy pilosebaceous contents
Microscopic (histologic) description
  • Fibrous wall lined by keratinizing squamous epithelium with skin adnexa, cyst contains squames, hair, sebum
  • Hair shafts highlighted with polarized light
  • May be hair matrix differentiation (shadow cells)
  • Rupture may cause granulomatous inflammation with foreign body giant cell reaction
Microscopic (histologic) images

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Posterior fossa dermoid cyst

Epidermal and dermal lining

Positive stains
Differential diagnosis
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