Hairy cell leukemia (HCL) is an unusual cancer of the blood. It affects B cells, a type of white blood cell (lymphocyte).
Leukemic reticuloendotheliosis; HCL; Leukemia - hairy cell
HCL is caused by the abnormal growth of B cells. The cells look "hairy" under the microscope because they have fine projections coming from their surface.
HCL usually leads to low numbers of normal blood cells.
The cause of this disease is unknown. It affects men more often than women. The average age of diagnosis is 55.
Blood tests and a bone marrow biopsy can detect hairy cells. Flow cytometry is needed to make the diagnosis. Sometimes, a test called tartrate resistant acid phosphatase (TRAP) is done.
Treatment may not be needed for the early stages of this disease. Some patients may need an occasional blood transfusion.
If treatment is needed because of very low blood counts, a variety of chemotherapy drugs can be used. Drugs that may be used include cladribine, pentostatin, and rituximab.
In most cases, chemotherapy can relieve the symptoms for many years. (When the signs and symptoms go away, you are said to be in remission.) Interferon can relieve symptoms but is unlikely to lead to remission.
Removing the spleen may improve blood counts, but is unlikely to cure the disease. Antibiotics can be used to treat infections. People with low blood counts will receive growth factors and, possibly, transfusions.
Newer chemotherapy treatments have greatly improved the survival of patients with hairy cell leukemia. Most patients with hairy cell leukemia can expect to live 10 years or longer after diagnosis.
The low blood counts caused by hairy cell leukemia can lead to infections, fatigue, and excessive bleeding.
There is no known way to prevent this disease.
Kantarjian H, O’Brien S. The chronic leukemias. In Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 190.
National Comprehensive Cancer Network. National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology: Non-Hodgkin’s lymphoma. 2012. Version 2.2012.