Skin nonmelanocytic tumor
Adnexal tumors - hair follicles

Topic Completed: 1 June 2012

Revised: 9 May 2019

Copyright: 2002-2016,, Inc.

PubMed Search: Trichilemmoma [title]

See also: Trichilemmal carcinoma

Christopher S. Hale, M.D.
Page views in 2018: 13,685
Page views in 2019 to date: 12,801
Cite this page: Hale C. Trichilemmoma. website. Accessed October 21st, 2019.
Definition / general
  • Also called tricholemmoma
  • Benign
  • Derived from the outer root sheath of hair follicle
  • Cowden's syndrome: multiple trichilemmomas, multiple hamartomas in skin, oral mucosa, breast, thyroid and intestines, as well as malignancies at these sites
Clinical images

Images hosted on PathOut server:

Knee, courtesy of Mark R. Wick, M.D.

Gross description
  • Warty papule on face
Microscopic (histologic) description
  • Lobular or plate-like growth of pale pink, glassy cells
  • Often palisading at periphery, thickened basement membrane, occasional central keratinization
  • Desmoplastic variant simulates malignancy
Microscopic (histologic) images

Images hosted on PathOut server:

Courtesy of Mark R. Wick, M.D.

Images hosted on Flickr:





Differential diagnosis
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