What is Waldenström macroglobulinaemia (WM)?

WM (sometimes called lymphoplasmacytic lymphoma) happens when certain blood cells called plasma cells develop in an unusual way in your bone marrow.

Plasma cells are blood cells that release antibodies to help you fight infection. They develop from a type of white blood cell called B lymphocytes (or B cells). These cells are made in your bone marrow (a soft, spongy substance found inside some of your bones).

If you have WM, some of your B cells don’t change into plasma cells, and instead make cells known as lymphoplasmacytic (LPL) cells. In WM, these can cause two main problems in your body: 

  • If too many LPL cells build up in your bone marrow, they can stop healthy blood cells being made. LPL cells can also clump together in your lymph nodes (glands), your spleen (a fist-sized organ on the left side of your body, behind your ribs), and other organs.
  • LPL cells release a large amount of a protein called immunoglobulin M or IgM (also called paraprotein). This makes your blood thicker (known as hyperviscosity) and can stop it from flowing easily through some of your blood vessels.

Download our fact sheet on WM

What causes Waldenström macroglobulinaemia (WM)?

WM is very rare. Around 350 people are diagnosed with WM in the UK each year. There’s no clear cause of WM, but certain factors can affect how likely you are to develop it: 

  • Age – WM usually affects adults over 65 years old. 
  • Sex – It’s more common in men than women. 
  • Family history – You’re more likely to develop the condition if you have a relative with WM, although this is very rare. Your risk may also be higher if you have a family history of autoimmune conditions (where your body mistakenly attacks healthy cells, such as Sjögren syndrome), or certain infectious diseases. 
  • Ethnicity – People from a white European background tend to have a higher risk of developing WM. 

For general information about slow-growing non-Hodgkin lymphomas, download our booklet Low-grade non-Hodgkin lymphoma (NHL) or order a printed copy.

What are the symptoms of Waldenström macroglobulinaemia (WM)?

The most common symptoms of WM include: 

  • extreme tiredness (fatigue) 
  • long-lasting or frequent infections. 

If too many LPL cells have built up in your bone marrow, you may experience: 

  • anaemia (not enough red blood cells in the blood) 
  • breathlessness 
  • bruising or bleeding
  • pancytopenia (a condition where you don’t have enough red blood cells, white blood cells or platelets). 

If you have a lump in your lymph nodes, spleen or other organs, you may also experience swellings in your neck, armpits or groin (known as lymphadenopathy). 

If you have too much IgM in your blood, causing it to become thick, you may also suffer from: 

  • headaches 
  • dizziness 
  • confusion 
  • nosebleeds 
  • blurred vision 
  • kidney problems. 

Other symptoms 

B symptoms - People with WM may also have certain symptoms known as B symptoms, which can include unexplained weight loss, heavy sweating and fever (high temperature). 

Neuropathy – Large amounts of IgM in the blood can cause damage to your nerves, known as neuropathy. This can lead to pain or numbness, often in the legs and feet. 

Asymptomatic WM 

Some people have no symptoms when they are diagnosed. This is known as asymptomatic or smouldering WM.

How is WM diagnosed?

To find out if you have WM, you may need to have blood tests, urine tests, CT scans, a bone marrow biopsy, and cytogenetic testing of blood or bone marrow samples.

Find out more about blood cancer tests and diagnosis.

How is WM treated?

The type of treatment you’ll need will depend on how far your WM has developed. 

Watch and wait 

If you don’t have many symptoms when you’re diagnosed, and the WM isn’t affecting your general health or wellbeing, you may not need treatment straight away. Instead, you’ll be put on ‘watch and wait’ and have regular check-ups every three to six months. 

Plasma exchange

If there’s a large amount of IgM in your blood and it becomes too thick, plasma exchange treatment (also called plasmapheresis) can be used to help thin your blood to help it flow better through your blood vessels. 

This treatment takes a few hours each time and uses a machine called a cell separator to remove the IgM from your blood. 


If you do need treatment, chemotherapy is the main treatment type for WM. Chemotherapy uses anti-cancer drugs to kill cancer cells or stop them growing. 

There are many different drugs used in chemotherapy. The drugs you get will depend on how well your body can cope with the treatment and how fast the cancer is growing. You may be given any of the drugs listed below. They may be given in combination (more than one given at once). 

  • Rituximab is used in most drug combinations for WM. This drug targets your B cells and helps your immune system to destroy the LPL cells. When this treatment is combined with chemotherapy, it’s called chemoimmunotherapy. 
  • Steroids (such as prednisolone or dexamethasone) can also be given to make the chemotherapy work better. 
  • Alkylating agents (such as bendamustine or cyclophosphamide) help to stop the LPL cells growing and dividing by interfering with DNA inside the cell. DNA is present in every cell of your body and controls what each cell does. 
  • Anti-metabolites (such as fludarabine) stop cells making and repairing DNA. This means that the LPL cells can’t grow and divide. 
  • Bortezomib is a drug that makes proteins build up in a cell, causing the cell to die. LPL cells are sensitive to this drug, so it can be used to stop them growing. 

Other drugs 

Your doctor may give you other drugs that help support your chemotherapy and keep you as healthy as possible during your treatment. Some of these drugs are given through one of your veins (intravenously) or injected just under your skin (subcutaneously). 

New drugs called targeted therapy drugs can block specific proteins in cancer cells to stop them growing. An example is ibrutinib. Ibrutinib capsules are taken once a day and are swallowed with a glass of water. This treatment can be used for people who are unable have chemoimmunotherapy, or for people who have previously received other treatments for WM. 

Stem cell transplant 

If the WM doesn’t respond well to chemotherapy or chemoimmunotherapy, or if the disease comes back quickly, you may be offered a stem cell transplant. 

For more information on stem cell transplants, download our booklet The seven steps: blood stem cell and bone marrow transplants or order a printed copy.

Although a stem cell transplant can be a very effective treatment, it does carry some risks, and it’s not suitable for everyone with WM. Talk to your healthcare team about which treatments are an option for you. 

Our Treatment decisions fact sheet will help you understand why treatments may or may not be available to you. 


After treatment, you’ll need to have follow-up appointments with your GP or hospital haematology department to check the levels of IgM in your blood. This can be done through a blood test. You and your doctors will also need to look out for any new symptoms. 

What’s the outlook? 

Around six in ten people with WM who have no symptoms when they’re diagnosed will go on to develop symptoms within five years. 

Your personal outlook will depend on a range of things, such as your age at diagnosis, and the level of platelets and IgM in your blood. If this is something you want to know more about, speak to your healthcare team, as they know your individual situation. New drugs and drug combinations are improving outlook all the time, both for people starting their first treatment and for people whose WM has come back. 

Download our fact sheet on WM

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