Keratoacanthoma

Keratoacanthoma
Keratoacanthoma
SpecialtyDermatology, plastic surgery
Types
  • Giant keratoacanthomas
  • Subungual keratoacanthoma
  • Multiple keratoacanthomas (Ferguson–Smith syndrome)
  • Keratoacanthoma centrifugum marginatum
  • Generalized eruptive keratoacanthoma of Grzybowski
Risk factorsUltraviolet radiation, immunosuppression, genetics
Diagnostic methodTissue biopsy
Differential diagnosisSquamous cell skin cancer
TreatmentSurgery (excision, Mohs surgery)

Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) rapidly-growing skin tumour that is believed to originate from the hair follicle (pilosebaceous unit) and can resemble squamous cell carcinoma.[1][2]

The defining characteristic of a keratoacanthoma 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. Keratoacanthoma is commonly found on sun-exposed skin, often face, forearms and hands.[2][3] It is rarely found at a mucocutaneous junction or on mucous membranes.[2]

Keratoacanthoma may be difficult to distinguish visually from a skin cancer.[4] 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 keratoacanthoma 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.[5][6][7][8]

  1. ^ Zito, Patrick M.; Scharf, Richard (2018), "Keratoacanthoma", StatPearls, StatPearls Publishing, PMID 29763106, retrieved 17 September 2018
  2. ^ a b c Joseph A. Regezi; James Sciubba; Richard C. K. Jordan (2012). "6. Neoplasms". Oral Pathology - E-Book: Clinical Pathologic Correlations. Elsevier Saunders. p. 155. ISBN 978-1-4557-0262-6.
  3. ^ Schwartz RA. The Keratoacanthoma: A Review. J Surg Oncol 1979; 12:305–17.
  4. ^ "Keratoacanthoma | DermNet New Zealand". www.dermnetnz.org. Retrieved 17 September 2018.
  5. ^ Ko CJ, Keratoacanthoma: facts and controversies. Clin Dermatol. 2010; 28(3):254–61 (ISSN 1879-1131)
  6. ^ "Keratoacanthoma: Background, Pathophysiology, Etiology". Medscape. 14 August 2018.(subscription required)
  7. ^ Kossard S; Tan KB; Choy C; Keratoacanthoma and infundibulocystic squamous cell carcinoma. Am J Dermatopathol. 2008; 30(2):127–34 (ISSN 1533-0311)
  8. ^ Weedon DD, et al. Squamous cell carcinoma arising in keratoacanthoma: a neglected phenomenon in the elderly. Am J Dermatopathol. 2010; 32(5):423–6