Splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a rare type of non-Hodgkin lymphoma (NHL). It develops when the body makes abnormal B-cells – the lymphoma cells. B-cells are white blood cells that fight infection. The lymphoma cells build up in the spleen, bone marrow and blood.

Many people have no symptoms when SMZL is first diagnosed. If you have symptoms, they may include:

  • pain in the upper part of the tummy
  • tiredness
  • breathlessness
  • bruising or bleeding easily
  • night sweats
  • high temperatures (fevers)
  • weight loss.

If you have an operation to remove your spleen, it will be tested for SMZL. If not, doctors diagnose SMZL with blood tests, scans and a bone marrow sample.

SMZL develops slowly and people do not always need treatment straight away. If you are not having treatment, you will have regular check-ups.

Treatment is usually with a targeted therapy drug called rituximab. You may have this with chemotherapy drugs and steroids. Some people have their spleen removed and others have radiotherapy.

You may be invited to join a clinical trial looking at new ways of treating SMZL. Your doctor will talk to you about clinical trials.

What is splenic marginal zone lymphoma (SMZL)?

It is best to read this information with our general information about non-Hodgkin lymphoma (NHL). If you have any more questions, you can ask your doctor or nurse at the hospital where you are having treatment.

SMZL is a slow-growing type of NHL. It develops when B-cells (also called B-lymphocytes) become abnormal. B-cells are white blood cells that fight infection.

The abnormal B-cells (lymphoma cells) build up in the spleen, bone marrow and blood.

The spleen is an organ in the upper part of the abdomen, on the left-hand side. It is normally about the size of a clenched fist. It helps us to fight infection and removes old and damaged blood cells from the bloodstream.

The bone marrow is in the middle of bones. It is where blood cells are made.

The lymphatic system
The lymphatic system

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Causes and risk factors for SMZL

SMZL is rare. It is not usually clear why SMZL develops in most people. But some cases may be linked to long-term infection with the hepatitis C virus (HCV). SMZL lymphoma is not infectious and cannot be passed on to other people. It is most common in people over the age of 65.

We have more information about risk factors for lymphoma.

Signs and symptoms of SMZL

Many people will have no symptoms when SMZL is first diagnosed. It is sometimes discovered during an examination of your tummy (abdomen) or when blood tests are done for some other reason.

The spleen may become bigger (called splenomegaly) if lymphoma cells build up there. This can cause discomfort or pain in the upper part of the abdomen.

Some people with SMZL have low numbers of blood cells in their blood. The main cause is usually an enlarged spleen removing too many blood cells. It can also happen if lymphoma cells build up in the bone marrow. These cells take up space, which makes it difficult for the bone marrow to make enough blood cells.

If you have too few blood cells, you may:

  • feel tired
  • become breathless when moving around
  • bruise or bleed easily.

Sometimes the lymphoma cells make an abnormal protein called a ‘globulin’ or a ‘paraprotein’. This is found in the bloodstream. This protein can make the blood thicker and more slow-moving than normal. This can cause headaches, confusion, nosebleeds and blurred vision.

B symptoms

Some people with lymphoma have:

  • drenching night sweats
  • high temperatures (fevers) with no obvious cause
  • unexplained weight loss.

These are called B symptoms.

Diagnosing SMZL

If you have an operation to remove the spleen, it will be sent to a laboratory and tested for SMZL. For people who do not have this operation, SMZL is diagnosed through a combination of:

  • blood tests
  • scans
  • a bone marrow sample.

Other tests may be done to check for signs of infection with hepatitis C virus.

Doctors use these tests to find out more about the lymphoma.

Staging and grading SMZL


The stage describes which areas of the body are affected by lymphoma. This information helps doctors plan the right treatment for you.

The stage of a lymphoma is usually described using numbers from 1 to 4:

  • Stages 1 and 2 are also called early-stage, limited or localised lymphoma.
  • Stages 3 and 4 are also called advanced lymphoma.

As well as giving each stage a number, doctors also add the letters A or B. A means you do not have B symptoms. B means you do have B symptoms.


Non-Hodgkin lymphomas are divided into two groups:

  • Low-grade (indolent) lymphomas, which usually grow slowly.
  • High-grade (aggressive) lymphomas, which grow more quickly.

SMZL is a low-grade lymphoma and usually develops slowly. Sometimes it can change (transform) to become a high-grade lymphoma.

Treating SMZL

SMZL usually develops slowly. Some people may not need treatment for months or years. This is called watch and wait

If you don’t need treatment immediately, you will have regular check-ups at the hospital. Your specialist will examine you and do blood tests. This is to check the levels of your red blood cells, white blood cells and platelets (a full blood count – FBC).

Treatment depends on the stage of the lymphoma and whether you have symptoms that are causing problems. The most common treatments are surgery or the targeted therapy rituximab, on its own or with chemotherapy.

Unfortunately, SMZL usually cannot be cured. For most people, the aim of treatment is to get rid of as much of the lymphoma as possible. If there are no signs of SMZL after treatment, this is called a complete remission.

If SMZL comes back after treatment, further treatment can often successfully get the lymphoma into remission again.


The drug rituximab is often used with chemotherapy to treat this type of lymphoma. It works by targeting proteins on the surface of B-cell lymphocytes. This makes the body destroy these cells.

Rituximab is given as a drip into a vein or an injection under the skin.


Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. It is an important treatment for SMZL and can often get the lymphoma into remission. It is usually given in combination with rituximab.

Chemotherapy can be given as tablets or into a vein (intravenously). You may be given just one type of chemotherapy drug. Or you may be given two or more chemotherapy drugs (combination chemotherapy).

Chemotherapy treatments for SMZL include:

  • R-CVP – which includes rituximab, the chemotherapy drugs cyclophosphamide and vincristine, and prednisolone (a steroid). It's given as a drip into a vein, usually once every three weeks
  • R-CHOP – which includes rituximab, prednisolone and the chemotherapy drugs vincristine, cyclophosphamide and doxorubicin.
  • R-chlorambucil – which includes rituximab and chemotherapy tablets called chlorambucil.
  • R-bendamustine – which includes rituximab and the chemotherapy drug bendamustine given as a drip into a vein.

There are other chemotherapy drugs and combinations that can be used to treat SMZL. Your specialist will be able to tell you which treatment is the most appropriate for you.


Steroids are drugs that are often given with chemotherapy to treat lymphomas. They help make chemotherapy more effective. They also help you feel better and can reduce feelings of sickness.

Surgery to remove the spleen (splenectomy)

An operation to remove the spleen may sometimes be useful in this type of lymphoma. If the spleen is not too large, this operation can be done using laparoscopic surgery (sometimes called keyhole surgery). Instead of making one large cut, the surgeon makes 4 or 5 small cuts (incisions). A flexible tube with a camera and light on the end is put into the tummy area through one of these cuts. This lets the surgeon see inside the tummy to operate. The surgeon uses specially designed instruments to remove the spleen.

The spleen helps to protect the body from bacterial infections. If you do not have a spleen, you will still be able to cope with most infections. But it is possible that a serious infection could develop quickly.

At least 14 days before an operation to remove the spleen, you will need to have vaccinations to boost your ability to fight certain infections.

Your doctor will talk to you about some things you should do. It is important to:

  • Have vaccinations as advised by your medical team.
  • Carry a card or wear a medical alert bracelet to tell people you do not have a spleen. This is in case there is a medical emergency.
  • Remind your doctor and dentist that you do not have a spleen.
  • Contact your doctor immediately if you have any signs of infection.
  • Try to avoid cuts, scratches and insect bites. Contact your doctor for advice about any cuts, scratches or bites. If you are bitten or scratched by an animal, including by a cat or dog, contact your doctor straight away for advice.
  • Ask your doctor for advice before travelling abroad to countries where you may need vaccinations or anti-malarial medicines.
  • Take any medicines that your doctor prescribes for you. You may be advised to take daily antibiotics for the first few years after your operation.


Radiotherapy uses high-energy rays to destroy cancer cells. You may have low doses of radiotherapy to the spleen. This treatment may be used if the enlarged spleen is causing symptoms, but you are not well enough to have surgery or chemotherapy.

Clinical trials

Your lymphoma doctor may talk to you about having treatment as part of a clinical trial. Clinical trials test new treatments or new ways of giving treatments.

Follow-up after treatment

After treatment, you will have regular check-ups. These appointments are a good opportunity for you to talk to your doctor or nurse about any concerns you have. Your doctor will want to know how you are feeling generally, and to check you are recovering from any side effects of treatment. We have more information about follow-up.

Getting support

Everyone has their own way of dealing with illness and the different emotions they experience. You may find it helpful to talk things over with family and friends or your doctor or nurse. You can also call our cancer support specialists free on 0808 808 00 00. The organisations below also offer information and support:

  • Bloodwise offers support and information to people affected by blood cancers, including lymphoma.
  • Lymphoma Action gives emotional support, advice and information on all aspects of Hodgkin lymphoma and non-Hodgkin lymphoma. It has a national network of people with lymphoma, and local groups.