CNS lymphoma

CNS lymphoma, or primary CNS lymphoma, is a rare cancer that affects your central nervous system (CNS). The cancer may form in your brain, spinal cord, spinal fluid or behind your eye. It can spread throughout your CNS quickly. Treatment options vary depending on your circumstances.


What is CNS lymphoma?

CNS lymphoma is a rare type of cancer that develops in your central nervous system (CNS). It may form in your brain, spinal cord, spinal fluid and (as it’s so close to your brain) your eye. It’s a type of non-Hodgkin lymphoma.

When the lymphoma starts in the CNS and isn’t found anywhere else in your body, it’s called primary CNS lymphoma. If lymphoma is found in other parts of your body, as well as your CNS, it’s called secondary CNS lymphoma.

CNS lymphoma starts in white blood cells called lymphocytes that are part of your lymphatic system. Your lymphatic system is an important part of your immune system. It helps your body fight infections and diseases.


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How common is CNS lymphoma?

CNS lymphoma is rare. There are only about 1,500 new cases of CNS lymphoma diagnosed in the United States each year. It occurs most often in people over 50, with the average age of diagnosis being 65. It’s slightly more common in men and people assigned male at birth (AMAB).

People with HIV, AIDS and other immunodeficiencies are more likely to receive a CNS lymphoma diagnosis.

Symptoms and Causes

What are the symptoms of CNS lymphoma?

Symptoms depend on where your tumor is located. A tumor is a mass of cancer cells. For instance, CNS lymphoma likely won’t cause symptoms if the tumor’s located in the membrane covering your brain and spinal cord (meninges). In contrast, a tumor near one or both eyes often causes vision changes. If the mass occurs near the area of your brain that controls movement, you could have weakness or coordination changes.

Symptoms of CNS lymphoma may include:

  • Nausea and vomiting.
  • Weakness in your arms, legs or face.
  • Weakness affecting one side of your body.
  • Hearing loss.
  • Difficulty swallowing.
  • Signs of brain pressure (headaches, confusion).
  • Vision problems (blurry vision, seeing double, floaters).
  • Changes in your mental state (memory loss, trouble speaking, feeling sluggish).
  • Seizures (that may become more frequent over several days or weeks).
  • Trouble controlling when you pee or poop (incontinence).


What causes primary CNS lymphoma?

Like other types of lymphoma, CNS lymphoma forms when cells in lymph tissue start to behave abnormally. They multiply out of control and overtake healthy cells. With CNS lymphoma, the cells that start growing abnormally are usually white blood cells (lymphocytes) called B-cells.

Researchers aren’t sure what causes a lymphocyte to transform into a cancer cell. Still, they’ve identified factors that may increase your risk of CNS lymphoma.

What are the risk factors for CNS lymphoma?

Certain conditions associated with having a weakened immune system may increase your risk of CNS lymphoma. They include:

Taking immunosuppressant drugs following an organ transplant may also increase your likelihood of developing certain cancers, including CNS lymphoma.


Diagnosis and Tests

How is CNS lymphoma diagnosed?

Your healthcare provider may recommend multiple procedures and tests to diagnose CNS lymphoma. Cancer staging also takes place during diagnosis. Cancer staging allows your provider to classify your cancer based on the tumor size, location and whether it’s spread beyond the site where the cancer started (metastasis).


Your provider will perform exams to check the health of your brain, spinal cord and eyes.

  • Physical exam: Your provider will assess your overall health by examining your body and asking questions about your medical history, lifestyle and symptoms.
  • Neurological exam: Your provider will perform a neurological exam to check how your central nervous system functions. They may check your reflexes, movement, coordination, and ability to process information and speak.
  • Eye exam: Your provider may perform various eye exams to find tumors behind your eye. A slit-lamp examination is commonly used as part of the diagnostic process with CNS lymphoma. During the procedure, your provider uses a special microscope called a slit lamp to see the parts of your eye magnified. They can also detect signs of a brain tumor behind your eye, like swollen optic nerves.

Imaging procedures

Your provider may order tests to see where cancer is located inside of your body. CNS lymphoma rarely spreads beyond your central nervous system, but it may spread quickly throughout various parts of your CNS.

  • MRI: An MRI (magnetic resonance imaging) uses magnets and radio waves to scan your body and produce a detailed image of your insides on a computer. Your provider may give you a harmless substance called gadolinium by injection to make the cancer show up better. Once it’s inside of your body, Gadolinium clusters around cancer cells, making them stand out more on the computer.
  • CT scan: A CT scan (computerized tomography) uses X-rays to scan your body and produce a detailed image of the soft tissue and bones inside of your body. A CT scan may be used to show if the cancer has spread beyond your CNS.
  • PET scan: During a PET scan (positron emission tomography), you’ll receive an injection of a radioactive tracer that travels through your body and collects near diseased cells. Meanwhile, a machine takes multiple images of the inside of your body. The tracer makes the cancer cells stand out in the images. Like a CT scan, your provider may order a PET scan to track cancer spread. Sometimes, the two procedures take place together and produce a three-dimensional (3D) image that makes abnormal cells easier to see. This is called a PET-CT scan.

Tissue and fluid samples

Your provider may take a sample of tissue or fluid to be tested in a lab for cancer cells.

  • Stereotactic biopsy: A stereotactic biopsy is also a kind of imaging procedure. During a stereotactic biopsy, a special machine scans your body to locate where the tumor is located. The image will help guide your provider as they perform a biopsy. They’ll remove a tissue sample so that it can be sent to a lab and tested.
  • Lumbar puncture (spinal tap): A lumbar puncture allows your provider to take a sample of your spinal fluid to be tested for signs of cancer. Your provider will insert a thin, hollow needle between the vertebrae in your low back to withdraw the fluid.
  • Bone marrow aspiration and biopsy: A bone marrow aspiration and biopsy allows your provider to remove a sample of bone marrow. A lab specialist called a pathologist tests the fluid and tissue inside the marrow for signs of cancer.

Lab tests

Various lab tests allow your provider to check your cells for signs of cancer.

  • CBC with differential: A complete blood count (CBC) is a blood test that provides information about your blood cells. A CBC with differential allows your provider to learn more about your white blood cells, the blood cells responsible for fighting infection.
  • Blood chemistry: A blood chemistry study provides information about levels of various substances (like proteins or enzymes) in your blood. High or low levels may be a sign that an organ isn’t working correctly.
  • HIV test: HIV infection is a major risk factor associated with CNS lymphoma. Your provider may test for signs of the virus as part of your diagnostic testing.

Management and Treatment

What are the treatments for CNS lymphoma?

There aren’t standard treatments for CNS lymphoma. Instead, your healthcare team will suggest a care plan based on various factors, including your age, your HIV/AIDS status and whether the cancer is newly diagnosed or recurrent (returned after treatment). Treatment will likely involve a combination of therapies.

Treatments for CNS lymphoma include:

  • Radiation therapy: Radiation uses strong beams of energy to kill cancer cells or prevent them from growing. One of the most common radiation treatments for symptom relief with CNS lymphoma is called whole-brain radiation. With this procedure, radiation destroys cancer cells throughout your brain. The radiation may also damage healthy cells, negatively impacting brain function. Discuss the benefits and risks of this therapy with your provider.
  • Chemotherapy: Chemotherapy uses drugs to kill cancer cells. High doses of a chemotherapy drug called methotrexate (HD-MTX) are often used to treat newly diagnosed CNS lymphoma.
  • Steroid therapy: Steroids, or corticosteroids, are drugs that can be used to reduce inflammation in your body and fight cancer cells. They can help with pain relief and reduce some side effects associated with chemotherapy treatment, like pain, nausea and vomiting.
  • Targeted therapy: Targeted therapy uses substances like proteins and antibodies to attack cancer cells. Rituximab and Ibrutinib are targeted therapy treatments that your provider may recommend to treat CNS lymphoma.

If you’re HIV-positive or have AIDS, you’ll continue antiretroviral therapy (ART) while you receive treatments for CNS lymphoma.

Your provider may recommend you take part in a clinical trial. A clinical trial is a study used to test new treatments for safety and effectiveness. Researchers are currently studying the potential of stem cell transplants and other therapies to more effectively treat CNS lymphoma. During a stem cell transplant, you receive healthy blood cells to replace blood cells that may be damaged during cancer treatments like chemotherapy and radiation.

Outlook / Prognosis

What can I expect if I’ve been diagnosed with CNS lymphoma?

CNS lymphoma is a fast-spreading cancer that often returns following treatment. Still, your prognosis depends on a variety of unique factors, including:

  • Your age.
  • Your overall health.
  • Your HIV status.
  • The location of your tumor.
  • The result of your blood chemistry studies (which can tell how the cancer may be impacting your organs).

What is the survival rate for CNS lymphoma?

Researchers report on cancer survival rates by tracking how many people with a certain cancer diagnosis are alive after a set time, usually five years. The five-year survival rate for people with CNS lymphoma under 70 is 30%. The survival timeline for people older than 70 is six to seven months.

Still, these numbers are general. They don’t factor in other specifics that affect prognosis. For instance, outcomes are generally better if you’re not immunocompromised or if the lymphoma hasn’t spread beyond your brain. Survival rates also don’t consider the impact that new treatments may have on lifespan.

Your provider is your best resource for explaining how your health and cancer will shape your care plan and likely outcomes.

Living With

What questions should I ask my doctor?

  • What healthcare providers will be on my care team?
  • What experience do you have treating CNS lymphoma?
  • Would you recommend I receive a second opinion about treatment?
  • What tests will I need to determine my care plan?
  • What are the risks and benefits associated with various treatment options?
  • How often will I need follow-up testing to see how my cancer responds to treatment?
  • Am I eligible to enroll in a clinical trial? Would you recommend I do so?
  • Would you recommend palliative care?
  • How can I manage treatment side effects?

A note from Cleveland Clinic

CNS lymphoma is a serious condition that requires close monitoring and a treatment plan designed especially for you. It’s important to work closely with a care team with experience treating lymphomas or cancers affecting the CNS. Your care team can explain your treatment options and help you weigh the benefits against potential risks or side effects. Depending on your cancer, they may recommend you participate in a clinical trial. They can connect you with palliative care to see to your comfort as you determine the next steps.

Medically Reviewed

Last reviewed on 07/05/2022.

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