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Classic hairy cell leukemia

Disease definition

A rare, slowly progressive, chronic leukemia characterized by presence of abnormal B-lymphocytes (medium sized with abundant irregular pale cytoplasm, hair-like cytoplasmic projections/ruffled cytoplasmic border, a round or bean-shaped nucleus and absent nucleoli) in the blood or bone marrow, spleen and peripheral blood pancytopenia, notable monocytopenia, and marked susceptibility to infection. The characteristic immunophenotype is CD11c+, CD25+, CD103+ and CD123+ with a BRAF mutation in most cases.


Classification level: Disorder
  • Synonym(s):
    • HCL-C
    • Leukemic reticuloendotheliosis
  • Prevalence: 1-9 / 100 000
  • Inheritance: Unknown 
  • Age of onset: Adult
  • ICD-10: C91.4
  • ICD-11: 2A82.2
  • OMIM: -
  • UMLS: C0023443
  • MeSH: D007943
  • GARD: 6560
  • MedDRA: 10019053

Detailed information

Article for general public


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