Hairy cell leukemia variant

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Hairy cell leukemia variant

ORPHA:300878Disease

Also called HCL-v · Leukemic reticuloendotheliosis variant · Prolymphocytic variant of HCL · Prolymphocytic variant of hairy cell leukemia

What it is

A rare, malignant splenic B-cell lymphoma/leukemia characterized by circulating abnormal lymphocytes with intermediate morphology between prolymphocytes and hairy cells with positive expression of CD11c and negative expression of CD25, CD123 and the BRAFV600E mutation. Manifestations include splenomegaly, elevated white blood cell (WBC) count, hyper-cellular bone marrow and anemia/thrombocytopenia, but no monocytopenia.

Key facts

Prevalence
1-9 / 1 000 000 (annual incidence, United States)
Age of onset
Adult, Elderly
Inheritance
Unknown
Classified as
Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Gene

IGHV4-34Major susceptibility factor

ICD-10 codes

C91.4filed under a broader ICD-10 category — shared with 1 other rare disease

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references

MEDDRA 10019054MONDO 0017600UMLS C0349633

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

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