CNS & pituitary tumors
Cysts
Dermoid cyst
Author: Eman Abdelzaher, M.D., Ph.D.
Last author update: 1 February 2012
Last staff update: 29 July 2020
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Dermoid cyst [title] central nervous system
Table of Contents
Definition / general | Gross description | Microscopic (histologic) description | Positive stains | Differential diagnosisCite this page: Abdelzaher E. Dermoid cyst. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumordermoidcyst.html. Accessed April 24th, 2024.
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
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
Differential diagnosis
