Skin - Nonmelanocytic tumors
Cysts
Keratinous cyst

Author: Ghassan Tranesh, M.D. (see Authors page)
Editor: Hong Qu, M.D.

Revised: 4 October 2016, last major update January 2015

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Keratinous cyst [title]

See also: epidermal, trichilemmal

Cite this page: Keratinous cyst. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumornonmelanocytickeratinouscyst.html. Accessed December 3rd, 2016.
Definition / General
  • Cysts containing keratin and lipid debris from sebaceous secretions
  • May be painful if ruptured
Terminology
  • Also called infundibular cyst; most probably arise from infundibular portion of hair follicles
Epidemiology
  • Young and middle-aged adults are most often affected
  • No gender preference
Sites
  • Face, neck, and upper trunk (may be due to damage to pilosebaceous unit)
  • Also labia majora and scrotum
Clinical Features
  • Smooth dome-shaped swellings, vary from a few millimeters to a few centimeters
  • Lesions of palm, sole or other sites may contain HPV 57 or 60
Treatment
  • Excision if symptomatic
Clinical Images

Images hosted on other servers:

Various images

Gross Description
  • Cyst with creamy contents
Micro Description
  • Cyst containing laminated keratin
  • May have disruption of cyst wall, acute inflammation, intense foreign body giant cell reaction