Epidermoid inclusion cyst

Bone
Other tumors of bone
Epidermoid inclusion cyst

Author: Nat Pernick, M.D. (see Authors page)

Revised: 20 October 2016, last major update June 2005

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed search: epidermoid inclusion cyst [title]

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Cite this page: Epidermoid inclusion cyst. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/boneepidermoidcyst.html. Accessed July 14th, 2017.

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

55 year old man with work related trauma and cyst in great toe (Arch Pathol Lab Med 2003;127:e298)

Treatment

Excision, not amputation

Microscopic (histologic) description

Cyst wall composed of keratinized stratified squamous epithelium with keratin debris
No skin appendages

Microscopic (histologic) images

Images hosted on other servers:

Xray, toe, H&E

Differential diagnosis

Chondroma: proximal phalanx, spotty stippled calcifications
Dermoid cyst: contains skin appendages
Glomus tumor: sensitivity to cold, scalloped edges, very rare in bone
Osteoid osteoma: reactive sclerosis
Osteomyelitis