2B31.6

ICD-11 MMS 2026-01

Indeterminate cell histiocytosis

Description

A very rare dendritic cell tumour composed of spindle to ovoid cells with a phenotype that is similar to the Langerhans cells. Patients usually present with cutaneous papules, nodules, and plaques. Systemic symptoms are usually absent. The clinical course is variable.

Index terms

  • Indeterminate cell histiocytosis
  • Indeterminate dendritic cell tumour

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

Sibling codes

  • 2B31.0 – Juvenile xanthogranuloma
  • 2B31.1 – Histiocytic sarcoma
  • 2B31.2 – Langerhans cell histiocytosis
  • 2B31.3 – Langerhans cell sarcoma
  • 2B31.4 – Interdigitating dendritic cell sarcoma
  • 2B31.5 – Follicular dendritic cell sarcoma
  • 2B31.7 – Fibroblastic reticular cell tumour
  • 2B31.Y – Other specified histiocytic or dendritic cell neoplasms
  • 2B31.Z – Histiocytic or dendritic cell neoplasms, unspecified

Foundation entity

Indeterminate cell histiocytosis – http://id.who.int/icd/entity/583219258

Allowed postcoordination axes

Part of: 2B31: Histiocytic or dendritic cell neoplasms › 02: Neoplasms