Primary CNS lymphoma

Lymphoma is a type of cancer that starts in cells called lymphocytes. These cells are part of the immune system and help fight infection. When lymphoma starts in the central nervous system (CNS) it is called primary CNS lymphoma. This includes lymphoma that starts in the brain, spinal cord and parts of the eye.

Symptoms of PCNSL may include:

  • changes in behaviour or personality
  • numbness, tingling or weakness
  • changes in balance or movement
  • seizures (fits)
  • problems with eyesight.

Tests for PCNSL usually include a brain MRI scan and a biopsy. A biopsy is when a surgeon removes part of the tumour to check it for lymphoma cells.

The main treatment is usually chemotherapy and a targeted therapy drug called rituximab. Some people may have radiotherapy or stem cell treatment.

You may also have steroids and sometimes anti-convulsants to control symptoms caused by PCNSL.

You may be invited to join a clinical trial looking at new ways of treating PCNSL. You can talk about this with your doctor.

What is primary CNS lymphoma (PCNSL)?

It is best to read this information with our general information about primary brain tumours and 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.

The central nervous system (CNS) is made up of the brain and spinal cord and parts of the eye. The brain controls different functions of the body, including how we think, feel, learn and move. The spinal cord is a long bundle of nerves that run down the middle of the backbone (spine). Messages between the brain and other parts of the body travel through the spinal cord.

Lymphoma is a type of cancer that starts in cells called lymphocytes. These cells are part of the body’s immune system and help fight infection. When lymphoma starts in the CNS, it is called primary CNS lymphoma (PCNSL).

PCNSL usually affects a type of lymphocyte called B-lymphocytes. The most common type of PCNSL is a fast-growing non-Hodgkin lymphoma called DLBCL. PCNSL is rare and most likely to affect older people.

PCNSL may affect one or several areas of the brain, spinal cord or eye (called intraocular lymphoma).

Side view of the brain
Side view of the brain

View a large version

Read a description of this image

This information is about lymphoma that starts in the CNS. A lymphoma that starts in another part of the body but is also in the brain at diagnosis, or spreads there later, is called a secondary CNS lymphoma. It may be treated differently to PCNSL. We have more information about treating lymphoma that starts in another part of the body.

Causes and risk factors for PCNSL

Usually the cause of PCNSL is not known. People whose immune system is not working properly have a higher risk of developing PCNSL. This includes:

  • people with HIV (human immunodeficiency virus)
  • people taking drugs called immunosuppressants after an organ transplant or to treat autoimmune disease.

But most people diagnosed with PCNSL do not have immune system problems.

Signs and symptoms of PCNSL

PCNSL may cause different symptoms, depending on:

  • where the tumour is in the brain or spinal cord;
  • how slowly or quickly it grows.

The following are some possible symptoms:

  • Behaviour or personality changes. These are common in PCNSL, but changes are often slight and may only be noticed by close family or friends.
  • Numbness, tingling or weakness. Some people may have numbness or weakness on one side of the body, or tingling and weakness in the arms or legs.
  • Changes in balance or movement. If your balance and co-ordination are affected, walking may be more difficult.
  • Seizures (fits). Some people may have seizures.
  • Problems with vision. If the lymphoma starts in or near the eye, you may have eyesight changes.
  • Raised intracranial pressure. Sometimes the lymphoma can increase the pressure in the skull. This can cause headaches, vomiting and problems with your eyesight. This may happen because of swelling or blockages caused by the tumour.

We have more information about these and other symptoms of brain tumours.

Diagnosing PCNSL

Tests for PCNSL usually include a brain MRI scan and a biopsy.

A biopsy is when the surgeon removes a piece of the tumour. Then they can examine it under a microscope to look for lymphoma cells. There are different ways to take a brain biopsy. Your surgeon will explain what to expect in your situation.

We have more information about having a brain MRI scan and diagnosing brain tumours.

You may also have tests to check for signs of lymphoma in other parts of the body. These may include:

  • blood tests
  • a CT scan
  • a PET/CT scan
  • a lumbar puncture
  • bone marrow samples
  • eye tests
  • for men, an ultrasound scan of the testicles.

Your doctor will usually ask you if they can take a blood sample to check for HIV and other infections such as hepatitis B and C. When they know whether you have these infections, they can plan safer and more effective treatment for you.

Diagnosis and your right to drive

You will not be allowed to drive from the time of your diagnosis until at least two years after your treatment has ended.

If you normally drive, this change can be upsetting and frustrating. But this is a legal requirement. It is important to follow the advice you are given.

If you live in England, Scotland or Wales, you must contact the Driver and Vehicle Licensing Agency (DVLA) to tell them about your illness. If you live in Northern Ireland, contact the Driver and Vehicle Agency (DVA).

Two years after treatment, you may be allowed to start driving again. But this will depend on your symptoms and most recent scans. Ask your doctor for advice about your situation.

Treating PCNSL

Your treatment may depend on:

  • the symptoms you have
  • your general health.

When you are first diagnosed, you may have treatment to control any symptoms before you have treatment for the lymphoma. Often drugs called steroids are used to reduce pressure in the skull or spine. You may have anti-convulsant drugs to prevent seizures (fits).

The main treatment for PCNSL is usually chemotherapy. It is often given with a targeted therapy drug called rituximab. Some people may have radiotherapy after chemotherapy, or as the main treatment. Sometimes high-dose treatment with stem cell support (autologous stem cell transplant) is used.

If you have HIV, you will also have treatment to control this.

A team of specialists will plan your treatment. This will usually include:

  • a lymphoma doctor (an oncologist or haematologist)
  • doctors who specialise in treating brain conditions (neurologists or neurosurgeons)
  • a specialist nurse.

Your team will explain the aims of your treatment, what it involves, and the benefits and disadvantages. It can be difficult to decide about the treatments that are right for you, but your doctor will guide and support you. Make sure you have enough information and time to help you make any treatment decisions.

Treating symptoms

PCNSL can increase the pressure in the skull or spine. For some people, this can cause symptoms that need treatment straight away. You may be given drugs called steroids to reduce any swelling around the lymphoma. These may also shrink the lymphoma for a time.

You usually start taking steroids after you have had a biopsy. Often you will only take them for a few weeks, and you may be able to stop after you start chemotherapy.

Rarely, surgery may be used to reduce the pressure. 

If you have seizures caused by PCNSL, you may be given drugs called anti-convulsants to help prevent them.


Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. It is often the first treatment for PCNSL, and it is usually given with the targeted therapy drug rituximab.

Methotrexate is the most common chemotherapy drug for PCNSL. It can be given along with the chemotherapy drugs cytarabine or thiotepa, or with both of these drugs. A nurse will usually give your chemotherapy into a vein (intravenously).

Some people have the chemotherapy drugs temozolomide and procarbazine along with methotrexate and rituximab. You take temozolomide and procarbazine as tablets.

Targeted therapy

You usually have a targeted therapy drug called rituximab along with your chemotherapy. Rituximab attaches itself to a protein on the surface of lymphoma cells and stimulates the body’s immune system to destroy these cells.


Radiotherapy uses high-energy rays to destroy cancer cells, while doing as little harm as possible to nearby healthy cells. Radiotherapy only treats the area of the body that the rays are aimed at. It may be given after chemotherapy, or on its own if you are not well enough to have chemotherapy.

For PCNSL, radiotherapy is usually used to treat the whole brain. When lymphoma starts in the eye, radiotherapy can sometimes be given directly to the eye. Your doctor will explain what to expect. They will talk to you about any side effects and how to cope with them.

Radiotherapy can make you tired, so try to get as much rest as you can. Tiredness can continue for several months after treatment has finished. Balancing rest and activity throughout the day is important, as your body needs rest to recover from the treatment. Some people get extreme tiredness after radiotherapy to the brain. This can happen about 4 to 8 weeks after treatment. You may have very little energy, feel drowsy and spend a lot of time sleeping. It gradually gets better over a few months.

The skin on your scalp may become itchy and red or darker and you will lose the hair in the area being treated. This usually grows back again after 2 to 3 months.

Radiotherapy may cause side effects that develop months or years after treatment. These are called late effects and may include changes to your thinking, planning and memory. This can be severe and affect quality of life. Your doctor or nurse will talk to you about this before you have treatment. Not everyone will need radiotherapy. Doctors may use other treatments instead to avoid the possibility of these effects.

High-dose treatment with stem cell support (autologous stem cell transplant)

This is sometimes used to treat PCNSL. It is an intensive treatment, so it is not suitable for everyone.

Stem cells are a type of blood cell that can make all other types of blood cells.

You have treatment to get rid of as much of the lymphoma as possible. Then some of your stem cells are collected from your blood and stored. You then have high doses of chemotherapy to try to destroy any remaining lymphoma cells. After this, your stem cells are returned through a drip (like a blood transfusion). The stem cells help your blood cells recover from the effects of chemotherapy.

We have more information about high-dose treatment with stem cell support.

HIV treatment

People with HIV can usually have the same lymphoma treatment as people who do not have HIV. But there can be a higher risk of some side effects. To reduce this risk and make lymphoma treatment as effective as possible, you will have treatment:

  • to control the HIV (called anti-retroviral drugs)
  • to prevent infections.

We have more information about treating HIV and lymphoma.

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.

Recovering after treatment

After treatment for a brain tumour, it may take some time before your symptoms improve. You may have ongoing side effects or be adjusting to some physical or emotional changes caused by the brain tumour. Your healthcare team includes different professionals who can help as you recover.

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.