Waldenström macroglobulinemia

It is a form of lymphoplasmacytic lymphoma — a slow-growing cancer of B cells, the white blood cells that normally make antibodies.

What makes it Waldenström is the antibody. When the abnormal cells produce a detectable antibody called IgM, the condition is given this name. Lymphoma Action reports that this accounts for 95% of lymphoplasmacytic lymphoma.

IgM is a large antibody, and the "macroglobulinemia" in the name describes exactly that: a big protein, in the blood, in quantity.

It is rare. Lymphoma Action states that fewer than 400 people are diagnosed with it each year in the UK, though the page does not give a reference year for that count. Most people are over 65, and about twice as many men as women are diagnosed.

None of the sources we read states a cause.

There is a well-characterised genetic change, and it needs stating carefully because a named gene sends people straight to worrying about their children. About 9 in 10 people with this condition have a change in a gene called MYD88, and Lymphoma Action is explicit that these changes are acquired during a person’s life. They are not inherited and they are not passed down.

Nothing in these sources supports a lifestyle, diet, stress or exposure explanation.

Many people have no symptoms at all when it is found, and the NCI notes that people without symptoms can be monitored for signs of progression rather than treated straight away.

The distinctive problem, when it comes, is caused by the antibody itself. Too much IgM can make the blood too thick to flow properly — a state called hyperviscosity.

Lymphoma Action lists what that feels like: nosebleeds, blurring or loss of vision, dizziness or headaches, and ringing in the ears. Those are the symptoms that most often bring someone in, and they are hard to attribute to a lymphoma before anyone knows there is one.

It is generally treatable but not curable, and it is managed as a long-term condition over years.

In up to 1 in 10 people it can change into a faster-growing lymphoma, which is then treated as that lymphoma.

For people without symptoms, the plan is often regular check-ups rather than treatment. Lymphoma Action goes further than most sources do and says there is a chance you may never need treatment at all.

Hyperviscosity is dealt with separately from the lymphoma, and the distinction matters. Plasma exchange removes the IgM directly: blood is taken out, passed through a machine that separates off the plasma carrying the antibody, and returned. The NCI describes it as useful for temporary, acute symptoms. It relieves the thickened blood. It does not treat the lymphoma, and it is not a cure for anything.

When drug treatment is needed, the usual first-line approach is chemotherapy together with rituximab — an antibody that targets a protein on B cells — often with a steroid.

BTK inhibitors are used largely when the disease comes back. BTK is a signalling protein B cells depend on, and blocking it starves the lymphoma cells. These are tablets taken on an ongoing basis. Availability differs between countries and, within the UK, between nations.

Another drug class, the proteasome inhibitors, is used to bring IgM levels down.

For many people the experience begins with being told they have a cancer and that the plan is to watch it. That is genuinely disorienting, and it is done because treating earlier has not been shown to help while side effects begin immediately.

The hyperviscosity symptoms — nosebleeds, blurred or lost vision, headaches, dizziness, tinnitus — can be alarming, and can go unexplained for a while before anyone connects them.

Plasma exchange is a procedure some people need repeatedly and sometimes urgently, and it sits alongside rather than inside their lymphoma treatment.

Rarity has its own weight. Fewer than 400 diagnoses a year in the UK means fewer people to talk to, fewer nearby specialists, and less familiarity among clinicians who are not haematologists.

And a BTK inhibitor changes the shape of treatment from a course to a medication you stay on, with everything that means for cost, access and side effects over years.

Almost none, and this is one of the clearest cases in the library.

EBMT’s 2025 recommendations state that an autologous transplant — the person’s own cells — should not be considered as a first-line option here. So even the transplant that involves no donor at all is not part of standard early treatment.

A donor transplant sits further out still. EBMT describes it as something that might be considered for younger people with multiple relapses, or people whose disease has not responded to treatment. That is rare and highly selected.

If you have just been diagnosed with this, nobody is starting a donor search, and you do not need to go looking for a match.