2A21.1

ICD-11 MMS 2026-01

Cutaneous mastocytosis

Description

Cutaneous mastocytosis is characterised by abnormal accumulation and proliferation of cutaneous mast cells. Most types are isolated but cutaneous mastocytosis can occur in association with systemic disease. Clinical forms include cutaneous mastocytoma, urticaria pigmentosa (the most frequent form), pseudoxanthomatous nodular cutaneous mastocytosis, telangiectasia macularis eruptiva perstans and diffuse cutaneous mastocytosis.

Exclusions from above levels

  • 2E03 – Malignant neoplasm metastasis in bone or bone marrow
  • http://id.who.int/icd/entity/501778925 – Malignant neoplasm metastasis in lymph nodes
  • http://id.who.int/icd/entity/97145147 – Malignant neoplasm metastasis in thymus gland

Child codes

  • 2A21.10 – Urticaria pigmentosa
  • 2A21.1Y – Other specified cutaneous mastocytosis
  • 2A21.1Z – Cutaneous mastocytosis, unspecified

Sibling codes

  • 2A21.0 – Systemic mastocytosis
  • 2A21.2 – Mast cell sarcoma
  • 2A21.3 – Extracutaneous mastocytoma
  • 2A21.Y – Other specified mastocytosis
  • 2A21.Z – Mastocytosis, unspecified

Foundation entity

Cutaneous mastocytosis – http://id.who.int/icd/entity/1300710062

Allowed postcoordination axes

Part of: 2A21: Mastocytosis › 02: Neoplasms