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This information is about a rare type of chronic leukaemia known as hairy cell leukaemia. You may find it helpful to read it with our information about chronic lymphocytic leukaemia (CLL)|, which discusses some of the issues facing people living with leukaemia|.
Leukaemia| is a cancer of the white blood cells. Usually, people with leukaemia have more white blood cells than normal. These leukaemia cells behave differently from healthy white blood cells.
To help you understand leukaemia and its treatment, it’s useful to know a bit about your blood, what it does and how it's made.
Blood cells are made in the bone marrow| (the spongy part inside some bones). All your blood cells are made from special cells called stem cells, which grow and develop in the bone marrow. When they are mature, blood cells are released into the blood to carry out different functions:
The lymphatic system
View a large copy of the diagram of the lymphatic system|
Lymphocytes (white blood cells) travel around the blood and the lymphatic system, the body’s natural defence against infection. The lymphatic system is made up of a collection of lymph nodes (glands) linked by a network of lymphatic vessels. Lymph nodes are found all over the body.
The tonsils (glands at the back of the throat), thymus and spleen are also part of the lymphatic system. The spleen is an organ on the left side of the tummy underneath the ribs. It produces small numbers of lymphocytes, stores blood cells and destroys older, damaged blood cells.
Hairy cell leukaemia is rare. It occurs mostly in people aged 40–60 and is more common in men than in women. HCL usually develops very slowly, so the term 'chronic' is used to describe it.
HCL affects a type of white blood cell called a B‑lymphocyte. When this cell is examined under a microscope it looks as if it has hair-like outgrowths (projections) on its surface. This is where HCL gets its name from.
When a person has leukaemia, their bone marrow makes too many immature white blood cells that don't work properly. Over time these abnormal white cells fill up the bone marrow, reducing the number of normal white blood cells, red blood cells and platelets that can be made.
In HCL, the abnormal white blood cells also build up in the spleen and cause it to grow bigger. An enlarged spleen may remove normal blood cells from the bloodstream. This can also reduce the number of red blood cells and normal white blood cells in the blood.
The causes of HCL are unknown. It is not infectious and cannot be passed on to other people.
Because HCL usually develops slowly it may not cause any symptoms for a long time. It's sometimes discovered by chance when a blood test is taken for another reason, such as part of a routine health check.
HCL can cause symptoms such as weight loss, waekness, frequent infections and breathlessness.
Some people see their doctor because they feel tired or look pale due to a lack of red blood cells (anaemia).
Some people get repeated infections because they have a shortage of healthy white blood cells that normally fight off infections.
People who have an enlarged spleen| may feel a tender lump on the left side of their abdomen.
These symptoms can be caused by other conditions but should always be checked by your doctor.
When your GP gets the results of your blood test, you will be referred to a hospital for specialist advice and treatment. You will usually see a haematologist (a doctor who specialises in blood disorders). The haematologist will take your full medical history, carry out a physical examination and take further blood tests.
The blood tests will show the number of abnormal white blood cells, and the typical appearance of 'hairy' cells may also be seen in the blood sample. People with HCL may also have low numbers of platelets and red blood cells. Other blood tests are usually done to check your general health.
The spleen becomes enlarged in most people with HCL. Your specialist will usually be able to feel this when examining you.
Your specialist will usually take a sample of your bone marrow to examine under a microscope. This helps provide more specific information about the condition.
The sample is usually taken from the back of your hip bone (pelvis). You will be given an injection of local anaesthetic to numb the area. The doctor will then pass a needle through the skin into the bone and draw a small sample of liquid marrow into a syringe (bone marrow aspirate). After this, the doctor will take a small core of marrow from the bone (a trephine biopsy). Both samples will be looked at later under the microscope.
The test can be done on the ward or in the outpatients department. The whole procedure takes about 15–20 minutes. It may be uncomfortable when the marrow is drawn into the syringe, but this should only last for a few seconds.
You may feel bruised and have an ache for a few days after the test. This can be eased with mild painkillers|.
Treatment for HCL is very effective. But as it's a slow‑growing condition you may not need treatment straight away. You will be monitored by having regular blood tests.
Your doctor will recommend treatment when your blood tests show that the number of abnormal white cells is increasing, or if you start to get symptoms.
There are different treatments for HCL but chemotherapy is the most effective and most commonly used.
Chemotherapy can nearly always get rid of all signs of the leukaemia (known as remission). A remission can last for many years. If HCL comes back, further treatment with chemotherapy is given to get it into remission again.
Other treatments can also be used in addition to chemotherapy. You may have a combination of treatments. A drug called interferon, which is a type of immunotherapy, may be used. Another newer treatment that is sometimes given is a monoclonal antibody drug called rituximab (Mabthera®). Rarely, an operation is done to remove the spleen.
Chemotherapy| is the use of anti-cancer (cytotoxic) drugs to destroy the leukaemia cells. The drugs most commonly used to treat HCL are cladribine| and pentostatin|.
Chemotherapy makes you more prone to getting infections|. Always let your doctor or nurse know if you have any signs of an infection so it can be treated straight away. Your specialist may prescribe antibiotics to help prevent infections.
Tell your doctor or specialist nurse about any side effects you have. There are often ways in which they can be treated or reduced. Our general information on chemotherapy has more detailed information about possible side effects.
This drug is often given as a drip (infusion), every day for seven days. It can also be given over five days either as an injection into a vein (intravenous) or as an injection given just under the skin (subcutaneous).
Common side effects include a high temperature (fever) and infection. Other possible side effects include headaches, weakness|, feeling sick (fatigue)|, skin rashes and aching muscles.
The drug is given as an injection into a vein (intravenous) usually every two weeks.
Side effects include infections and feeling sick (nausea), which can usually be well controlled with anti-sickness drugs|. Other possible side effects include skin rashes, high temperatures (fever) and temporary changes to the way the kidneys work.
Interferon| is a type of immunotherapy, which means that it can boost the body’s own immune system to destroy the leukaemia cells.
A short course of interferon may sometimes be given before chemotherapy to improve a low blood count that is causing problems with infection.
Interferon is given as an injection under the skin. The most common side effects are flu-like symptoms such as chills, a high temperature, and aching joints and muscles.
Monoclonal antibodies| are drugs that recognise, target and stick to particular proteins on the surface of cancer cells. They can stimulate the body’s immune system to destroy these cells.
A monoclonal antibody called rituximab| may be given on its own if chemotherapy is no longer working or with chemotherapy for HCL that has come back. It's given as a drip into a vein (infusion).
For some people who have an enlarged spleen, removing it can help reduce symptoms. This operation is rarely needed as chemotherapy works so well.
Treatment usually gets HCL into remission, which can last for many years. However, as it tends to come back your doctors will monitor you with blood tests during your remission. If you feel unwell at any time between appointments, it's important to let your doctor know as soon as possible.
If the leukaemia comes back, your doctor will discuss another course of treatment with you. Doctors cannot predict how long the leukaemia will stay in remission, but with current treatments HCL can be controlled for long periods of time.
Research into treatments for HCL is ongoing and advances are being made. Your doctor may invite you to take part in a clinical trial| to compare a new treatment against the best available standard treatment.
Your doctor must discuss the treatment with you and have your informed consent before entering you into a trial.
Before any trial is allowed to take place, it must be approved by a research ethics committee, which protects the interests of those taking part.
You may decide not to take part or to withdraw from the trial at any stage. You will then receive the best standard treatment available.
Everyone has their own way of dealing with their illness and the different emotions| they experience. Some people find it helpful to talk things over with family and friends or their doctor or nurse. You can also contact our cancer support specialists| or the organisations listed here for more information and support.
Leukaemia & Lymphoma Research| provides a patient-information service and booklets on leukaemias and their treatment.
This section has been compiled using information from a number of reliable sources, including:
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.