Bone & joints

Other nonneoplastic

Epidermoid inclusion cyst

Topic Completed: 1 June 2005

Minor changes: 10 August 2021

Copyright: 2003-2021,, Inc.

PubMed search: epidermoid inclusion cyst [title]

Nat Pernick, M.D.
Page views in 2020: 1,872
Page views in 2021 to date: 1,939
Cite this page: Pernick N. Epidermoid inclusion cyst. website. Accessed October 25th, 2021.
Definition / general
  • Due to squamous epithelium embedded within bone
  • Benign, resembles cutaneous lesion
  • Ages 25 - 50 years
  • Sites: skull, distal phalanx, less commonly in toes
Radiology description
  • Well defined, radiolucent lesion, often associated with soft tissue swelling
Case reports
  • Excision, not amputation
Microscopic (histologic) description
  • Cyst wall composed of keratinized stratified squamous epithelium with keratin debris
  • No skin appendages
Differential diagnosis
Back to top
Image 01 Image 02