World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0003375234
Reproduction Date:

Title: Keratoacanthoma  
Author: World Heritage Encyclopedia
Language: English
Subject: Skin cancer, Squamous-cell carcinoma, Electrodesiccation and curettage, Mohs surgery, Auricle (anatomy)
Publisher: World Heritage Encyclopedia


Classification and external resources
ICD-10 D23 (ILDS D23.L71) (ICD10.v4 L85.8)
ICD-9-CM 238.2
DiseasesDB 29383
eMedicine derm/206
MeSH D007636

Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) skin tumour that is believed to originate from the neck of the hair follicle.[1]

The defining characteristic of KA is that it is dome-shaped, symmetrical, surrounded by a smooth wall of inflamed skin, and capped with keratin scales and debris. It grows rapidly, reaching a large size within days or weeks, and if untreated for months will almost always starve itself of nourishment, necrose (die), slough, and heal with scarring. KA is commonly found on sun-exposed skin, often face, forearms and hands.[2]

Under the microscope, keratoacanthoma very closely resembles squamous cell carcinoma. In order to differentiate between the two, almost the entire structure needs to be removed and examined. While some pathologists classify KA as a distinct entity and not a malignancy, about 6% of clinical and histological keratoacanthomas do progress to invasive and aggressive squamous cell cancers; some pathologists may label KA as "well-differentiated squamous cell carcinoma, keratoacanthoma variant", and prompt definitive surgery may be recommended.[3][4][5][6]


  • Classification 1
  • Cause 2
  • Diagnosis 3
  • Treatment 4
  • See also 5
  • References 6


Keratoacanthomas (molluscum sebaceum) may be divided into the following types:[7]:763–764[8]:643–646

  • Giant keratoacanthomas are a variant of keratoacanthoma, which may reach dimensions of several centimeters.[7]:763
  • Keratoacanthoma centrifugum marginatum is a cutaneous condition, a variant of keratoacanthomas, which is characterized by multiple tumors growing in a localized area.[7]:763[8]:645
  • Multiple keratoacanthomas (also known as "Ferguson–Smith syndrome," "Ferguson-Smith type of multiple self-healing keratoacanthomas,") is a cutaneous condition, a variant of keratoacanthomas, which is characterized by the appearance of multiple, sometimes hundreds of keratoacanthomas.[7]:763[8]:644
  • A solitary keratoacanthoma (also known as "Subungual keratoacanthoma") is a benign, but rapidly growing, locally aggressive tumor which sometimes occur in the nail apparatus.[7]:667,764[8]:644
Picture of the face of a patient Generalized eruptive keratoacanthomas
  • Generalized eruptive keratoacanthoma (also known as "Generalized eruptive keratoacanthoma of Grzybowski") is a cutaneous condition, a variant of keratoacanthomas, characterized by hundreds to thousands of tiny follicular keratotic papules over the entire body.[7]:763[8] :645 Treatments are not successful for many patients with Generalized eruptive keratoacanthoma. Use of emollients and anti-itch medications can ease some symptoms. Improvement or complete resolutions of the condition has occurred with the application of the following medications: Acitretin, Isotretinoin, Fluorouracil, Methotrexate, Cyclophosphamide.


Keratoacanthoma usually occurs in older individuals. As with squamous cell cancer, it seems likely that ultraviolet light from the sun causes the development of KA.[9] As with squamous cell cancer, sporadic cases have been found co-infected with the human papilloma virus (HPV).[10]

Many new treatments for Melanoma are also known to increase the rate of Keratoacanthoma, such as the B-Raf inhibitor drugs Vemurafenib and Dabrafenib.[11]


Keratoacanthoma presents as a fleshy, elevated and nodular lesion with an irregular crater shape and a characteristic central hyperkeratotic core. Usually the patient will notice a rapidly growing dome-shaped tumor on sun-exposed skin.

Skin keratoacanthoma whole slide

If the entire lesion is removed, the pathologist will probably be able to differentiate between keratoacanthoma and squamous cell carcinoma. If only part of the lesion is removed, confident diagnosis may be impossible.


Excision of the entire lesion, with adequate margin, will remove the lesion, allow full tissue diagnosis, and leave a planned surgical wound which can usually be repaired with a good cosmetic result. However, removing the entire lesion (especially on the face) may present difficult problems of plastic reconstruction. (On the nose and face, Mohs surgery may allow for good margin control with minimal tissue removal, but many insurance companies require the definitive diagnosis of a malignancy before they are prepared to pay the extra costs of Mohs surgery.) Especially in more cosmetically-sensitive areas, and where the clinical diagnosis is reasonably certain, alternatives to surgery may include no treatment (awaiting spontaneous resolution).[12]

On the trunk, arms, and legs, electrodesiccation and curettage often suffice to control keratoacanthomas until they regress. Other modalities of treatment include cryosurgery and radiotherapy; intralesional injection of methotrexate or of 5-fluorouracil have also been used.[13]

Recurrence after electrodesiccation and curettage is common; it can usually be identified and treated promptly with either further curettage or surgical excision.

See also


  1. ^ Fisher, B.K., Elliot, G.B. Keratoacanthoma: Reflections on an Unusual Lesion. Can Med Assoc J. 1965 August 7; 93(6): 272–273.
  2. ^ Schwartz RA. The Keratoacanthoma: A Review. J Surg Oncol 1979; 12:305–17.
  3. ^ Ko CJ, Keratoacanthoma: facts and controversies. Clin Dermatol. 2010; 28(3):254–61 (ISSN: 1879-1131)
  4. ^
  5. ^ Kossard S; Tan KB; Choy C; Keratoacanthoma and infundibulocystic squamous cell carcinoma. Am J Dermatopathol. 2008; 30(2):127–34 (ISSN: 1533-0311)
  6. ^ Weedon DD, et al. Squamous cell carcinoma arising in keratoacanthoma: a neglected phenomenon in the elderly. Am J Dermatopathol. 2010; 32(5):423–6
  7. ^ a b c d e f Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.
  8. ^ a b c d e James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
  9. ^ Schwartz RA (February 2004). "Keratoacanthoma: a clinico-pathologic enigma". Dermatol Surg 30 (2 Pt 2): 326–33; discussion 333.  
  10. ^ Niebuhr M, et al. Giant keratoacanthoma in an immunocompetent patient with detection of HPV 11. Hautarzt. 2009; 60(3):229–32 (ISSN: 1432-1173)
  11. ^ Niezgoda, Anna; Niezgoda, Piotr; Czajkowski, Rafal (2015) Novel Approaches to Treatment of Advanced Melanoma: A Review of Targeted Therapy and Immunotherapy BioMed Research International
  12. ^ Keratoacanthoma. Désirée Ratner. 2004. accessed 23 June 2015
  13. ^ Keratoacanthoma. Désirée Ratner. 2004. accessed 23 June 2015
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.