Hairy cell leukaemia

Hairy cell leukaemia is a rare type of chronic (long-term) leukaemia.


Hairy cell leukaemia is a rare type of chronic (long-term) leukaemia.

The condition gets its name from the fine, hair-like strands that develop around the outside of the cancerous cells, visible under a microscope.

It is not known what causes hairy cell leukaemia.


Leukaemia is cancer of the white blood cells.

All the body's blood cells, including red and white blood cells and platelets, are produced by bone marrow. Bone marrow is a spongy tissue found inside the bones. It also produces special cells called stem cells.

In leukaemia, the cancer begins in the stem cells and causes them to produce more white blood cells than are needed. Over time, the build-up of cancerous white blood cells disrupts the normal balance of cells in the blood.

This means your body does not have enough red blood cells, which carry oxygen around the body, or platelets, which help stop bleeding. This can lead to symptoms of anaemia, such as tiredness and feeling faint, as well as increasing the risk of excessive bleeding.

Also, as the white blood cells are not properly developed, they are less effective at fighting bacteria and viruses, making you more vulnerable to infection.

Hairy cell leukaemia

Symptoms of hairy cell leukaemia develop slowly and are similar to those of other types of leukaemia. They include:

  • weight loss
  • pale skin, weakness, tiredness and breathlessness (due a lack of red blood cells)
  • frequent infections (due to a lack of infection-fighting white blood cells)

The abnormal white blood cells can accumulate in your spleen, causing it to increase in size.

If your spleen is enlarged, it may remove normal blood cells from your bloodstream. This can lead to a further reduction in the number of normal red and white blood cells and platelets in your blood.

You may have a sore lump on the left side of your abdomen (tummy). If this is the case, you should visit your doctor so the lump can be examined.


If your doctor suspects leukaemia, they may refer you to a haematologist (a specialist in blood disorders).

Blood tests are carried out which will indicate the number of abnormal white blood cells you have. If you have hairy cell leukaemia, it is likely your red blood cell and platelet counts will be low.

A bone marrow sample may also be taken which will give the haematologist more detailed information about your condition.


As hairy cell leukaemia develops slowly, immediate treatment may not be needed. You will have regular blood tests to monitor your condition.

Your doctor may recommend treatment if the number of abnormal white blood cells increases or if you develop symptoms.

A number of different treatments are available for hairy cell leukaemia. Chemotherapy is usually effective at destroying the cancerous cells, and is the most commonly used treatment.

Other treatments are sometimes used in combination with chemotherapy. A medicine called interferon may be used as part of a treatment known as immunotherapy.

A medicine called rituximab may also be used. In rare cases, where the spleen is severely affected, surgery may be needed to remove it.


As with most types of cancer, the outlook for hairy cell leukaemia will depend on how far the condition has advanced at the time of diagnosis and how well it responds to treatment.

As hairy cell leukaemia is a rare type of cancer, it is difficult to accurately predict how it will affect individuals in the long-term.

Want to know more?

  • Cancer
  • Cancer Research UK: hairy cell leukaemia
  • Macmillan: hairy cell leukaemia
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