Skin - Nonmelanocytic tumors
Adnexal tumors - hair follicles

Author: Christopher Hale, M.D. (see Authors page)

Revised: 6 October 2016, last major update June 2012

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

PubMed Search: Trichilemmoma [title]

See also: Trichilemmal carcinoma

Cite this page: Trichilemmoma. website. Accessed October 16th, 2018.
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