2C31.1

ICD-11 MMS 2026-01

Keratoacanthoma

Description

Keratoacanthoma is a relatively common keratinocytic epidermal tumour which shows resemblances to squamous cell carcinoma of the skin, from which it may be difficult to distinguish either clinically or histopathologically. It is characterised by rapid growth over a few weeks to months, followed by spontaneous resolution over 4-6 months. Because it is not possible to predict its benign behaviour with complete certainty during its initial growth phase, the designation "Well-differentiated squamous cell carcinoma (keratoacanthoma type)" is also used.

Coding note from above levels

For use of this category, reference should be made to the mortality coding rules and guidelines in the Reference Guide.

Index terms

  • Keratoacanthoma
  • KA - [keratoacanthoma]
  • Well-differentiated squamous cell carcinoma (keratoacanthoma type)
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  • Giant keratoacanthoma
  • Multiple keratoacanthomas
  • Generalised eruptive keratoacanthomas
  • Grzybowski syndrome
  • Familial multiple keratoacanthomas
  • Ferguson-Smith multiple keratoacanthomas
  • Multiple self-healing squamous epitheliomas of Ferguson-Smith
  • Muir-Torre syndrome

Exclusions from above levels

  • 2E08 – Malignant neoplasm metastasis in skin
  • 2E64 – Carcinoma in situ of skin
  • http://id.who.int/icd/entity/1965082709 – Malignant mesenchymal neoplasms
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  • http://id.who.int/icd/entity/879154182 – Neoplasms of central nervous system or related structures
  • http://id.who.int/icd/entity/944754984 – Neoplasms of haematopoietic or lymphoid tissues

Sibling codes

  • 2C31.0 – Verrucous squamous cell carcinoma of skin
  • 2C31.Z – Cutaneous squamous cell carcinoma

Foundation entity

Keratoacanthoma – http://id.who.int/icd/entity/516478127

Allowed postcoordination axes

Part of: 2C31: Squamous cell carcinoma of skin › 02: Neoplasms