23rd July 2024

Hairy cell leukaemia

Hairy cell leukaemia (HCL) is an uncommon B-cell lymphoproliferative malignancy, which is distinct from CLL.

Median age of presentation of 50-55 years and there is a strong male predominance.

Patients generally present with symptoms related to BM failure or splenomegaly.

Diagnosis usually requires blood tests, blood film and immunophenotyping (CD19, CD20 and CD22 positive). BM biopsy is usually not possible due to increased BM fibrosis from HCL invasion.

Image Source: Wikimedia Commons (2015). Hairy Cell Leukaemia, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Hairy_Cell_Leukaemia.jpg (Accessed: 16 January 2024).

As with CLL, asymptomatic patients are managed with observation and can be observed for months or years. Symptomatic patients (significant cytopenia, symptomatic splenomegaly or lymphadenopathy or significant constitutional symptoms) are treated with purine analogues first line. These have a very high response rate and most patients with HCL survive >10 years after diagnosis.