2F20.1

ICD-11 MMS 2026-01

Atypical melanocytic naevus

Description

Solitary or multiple, slightly raised, pigmented lesions with irregular borders, usually measuring more than 0.6cm in greatest dimension. Morphologically, there is melanocytic atypia and the differential diagnosis from melanoma may be difficult. Patients are at an increased risk for the development of melanoma.

Index terms

  • Atypical melanocytic naevus
  • Dysplastic naevus, unspecified
  • Multiple atypical melanocytic naevi
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  • Melanocytic naevus with mild to moderate dysplasia

Inclusions

  • Dysplastic naevus, unspecified

Sibling codes

  • 2F20.0 – Common acquired melanocytic naevus
  • 2F20.2 – Congenital melanocytic naevus
  • 2F20.3 – Generalised eruptive melanocytic naevi
  • 2F20.Y – Other specific types of melanocytic naevus
  • 2F20.Z – Melanocytic naevus, unspecified

Foundation entity

Atypical melanocytic naevus – http://id.who.int/icd/entity/934048827

Allowed postcoordination axes

Part of: 2F20: Benign cutaneous melanocytic neoplasms › 02: Neoplasms