Hairy cell leukaemia
This information is about a rare type of chronic leukaemia known as hairy cell leukaemia. You may find it helpful to read this page with our information about chronic lymphocytic leukaemia (CLL), which discusses some of the issues about 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:
Red blood cells contain haemoglobin, which carries oxygen from your lungs to all the cells in your body.
White blood cells fight and prevent infection. There are several types of white blood cell. The two most important types are lymphocytes and neutrophils.
Platelets are very small cells that help the blood clot and prevent bleeding and bruising.
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), which are 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 (HCL)
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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.
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. 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.
Causes of hairy cell leukaemia
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The causes of HCL are unknown. It is not infectious and cannot be passed on to other people.
Signs and symptoms of hairy cell leukaemia
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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, for example as part of a routine health check.
HCL can cause symptoms such as weight loss, weakness, 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.
How hairy cell leukaemia is diagnosed
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When your GP gets the results of your blood test you'll 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.
Bone marrow sample
Your specialist will 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 a 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 as 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.
CT (computerised tomography) scan
A CT scan takes a series of x-rays, which build up a three-dimensional picture of the inside of the body. The scan takes 10-30 minutes and is painless. It uses a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. It’s important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection.
Treatment for hairy cell leukaemia
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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 monoclonal antibody drug called rituximab (Mabthera®) may be given on its own, or with or after chemotherapy. Very occasionally a drug called interferon, which is a type of immunotherapy, may be used. A small number of people may have an operation to remove the spleen (splenectomy).
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. Your specialist may prescribe antibiotics to help prevent infections. Always let your doctor or nurse know if you have any signs of an infection so it can be treated straight away.
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.
Cladribine (2-CdA, Leustat®)
This drug can be given as an injection just under the skin (subcutaneously), or as a drip (infusion) into a vein.
Common side effects include a high temperature (fever) and infection. Other possible side effects include headaches, weakness, feeling sick (nausea), 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.
After chemotherapy treatment
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For some time after treatment with cladribine or pentostatin, you’ll have lower numbers of infection-fighting white blood cells (lymphocytes) in your blood than normal. You may be given treatment to prevent certain infections. Treatment to prevent an infection is called prophylaxis.
You may be given:
an antibiotic called co-trimoxazole (Septrin®) to prevent a type of pneumonia called PCP (pneumocystis carinii)
the antiviral drug aciclovir to prevent the herpes virus (which causes cold sores) becoming active.
Your doctor will tell you when to stop taking these medicines.
People who have treatment with cladribine or pentostatin should only ever have blood or platelet transfusions that have been treated with radiation (irradiated). Your hospital team should give you a card to carry or a MedicAlert® to wear so that hospital staff are aware, in case you need blood products in an emergency.
Monoclonal antibody therapy
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).
Interferon is a type of immunotherapy, which means that it can boost the body’s own immune system to destroy the leukaemia cells.
is a type of immunotherapy, which means that it can boost the body’s own immune system to destroy the leukaemia cells.
Sometimes people who are having repeated infections are given a short course of interferon before chemotherapy. This may help improve the white blood cell count.
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.
Removing the spleen (splenectomy)
Some people who have a very enlarged spleen but only have a very small amount of leukaemia in their bone marrow may be offered an operation to remove their spleen. This may cause a remission or stabilise the leukaemia so that no further treatment is needed for months or years.
Follow-up for hairy cell leukaemia
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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.
Clinical trials for hairy cell leukaemia
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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.
Information and support
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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.
is a national group promoting the welfare of people with leukaemia and other blood disorders. Has support groups.
Leukaemia & Lymphoma Research
This information has been compiled using information from a number of reliable sources, including:
BMJ Best Practice. www.bestpractice.bmj.com (accessed September 2010).
British Committee for Standards in Haematology. Revised Guidelines for the Diagnosis and Management of Hairy Cell Leukaemia and Hairy cell Leukaemia Variant. 2012.
Lee, et al. Wintrobe’s Clinical Haematology. 12th edition. 2009. Lippincott, Williams and Wilkins.
Thank you to Dr Claire Dearden, Consultant Haematologist, and all of the people affected by cancer who reviewed this edition. Reviewing information is just one of the ways you could help when you join our Cancer Voices network.