What is hairy cell leukaemia?

Hairy cell leukaemia (HCL) is a rare type of chronic leukaemia. Chronic leukaemias develop slowly, over months or years, without causing many symptoms.

Hairy cell leukaemia develops in cells called B lymphocytes. B lymphocytes are a type of white blood cell that fights infection. When you have hairy cell leukaemia, the body makes too many B lymphocytes. These B cells aren’t normal and can’t fight infections properly. It is called hairy cell leukaemia because you can see tiny hair like outgrowths on the surface of the cells if you look at them under a microscope.

HCL develops and affects you in similar ways to other types of chronic leukaemia. Many people find out they have hairy cell leukaemia by chance when they are having a blood test for something else. If you have symptoms they tend to be mild at first and build up slowly. They include tiredness, picking up infections and bruising easily.

We have a section about hairy cell leukaemia and you can find out more about its symptoms there. The main treatment for hairy cell leukaemia is chemotherapy. The treatment you have depends on how far your leukaemia has developed and on your symptoms.