Find out more about the symptoms, diagnosis and treatment of this type of non-Hodgkin lymphoma.
Update Date: 25.10.2025
Small lymphocytic lymphoma (SLL) is a type of lymphoma. Lymphoma is cancer that affects the lymphatic system. The lymphatic system is made up of organs, glands, tubelike vessels and clusters of cells called lymph nodes. It's part of the body's germ-fighting immune system.
There are many types of lymphoma. Lymphoma types are often divided into two categories: Hodgkin lymphoma and non-Hodgkin lymphoma. Small lymphocytic lymphoma is a type of non-Hodgkin lymphoma.
Small lymphocytic lymphoma can affect the lymph nodes, spleen, blood, bone marrow and other parts of the body. It usually grows slowly. Treatments usually can't cure small lymphocytic lymphoma, but they may control it for a long time. People with this type of cancer often have a good prognosis.
Not everyone needs treatment right away for small lymphocytic lymphoma. When needed, treatments for small lymphocytic lymphoma may include a "watch and wait" approach, targeted therapy, chemotherapy, immunotherapy and radiation therapy. Other treatment options may include bone marrow transplant, also known as bone marrow stem cell transplant, CAR-T cell therapy and clinical trials.
Some people wonder how small lymphocytic lymphoma relates to another disease called chronic lymphocytic leukemia. Healthcare professionals often mention these together because they are thought to be the same disease. However, in small lymphocytic lymphoma, the cancer cells are most often found in the lymph nodes. In chronic lymphocytic leukemia, the cancer cells are most often found in the blood and bone marrow.
Small lymphocytic lymphoma symptoms may not happen right away. Symptoms might develop as the cancer progresses. When symptoms happen, they may include:
Make an appointment with a healthcare professional if you have any symptoms that worry you.
It's not clear what causes small lymphocytic lymphoma. Cancer happens when cells develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells. In small lymphocytic lymphoma, the cancer cells can build up in the lymph nodes, spleen, blood, bone marrow and other parts of the body.
Small lymphocytic lymphoma gets its name from the kind of cell that makes up this cancer. This cancer starts in germ-fighting white blood cells called lymphocytes. When healthcare professionals look at the cells with a microscope, the cancer cells appear round and small. These are sometimes called smudge cells.
Factors that may increase the risk of small lymphocytic lymphoma include:
Small lymphocytic lymphoma may cause complications such as:
Diagnosis of small lymphocytic lymphoma often begins with a physical exam. The exam checks for swollen lymph nodes in the neck, underarms and groin and an enlarged spleen or liver. Other tests and procedures include blood tests, imaging tests and taking a sample of tissue for lab testing.
Tests and procedures used to diagnose small lymphocytic lymphoma include blood tests that:
Your healthcare professional may suggest a lymph node biopsy or a biopsy of other tissue to look for cancer cells. A biopsy is a procedure to remove a sample of tissue for testing in a lab. A lymph node biopsy involves removing all or part of a lymph node. A sample may be taken from other parts of the body depending on symptoms and imaging test results. In the lab, tests may show whether you have small lymphocytic lymphoma.
Imaging tests make pictures of the body. They can show the location and extent of small lymphocytic lymphoma. Your healthcare team may use a CT scan to help diagnose small lymphocytic lymphoma. If you've been diagnosed with small lymphocytic lymphoma, a positron emission tomography (PET) scan may be used to see if your cancer has transformed into a more aggressive type, such as diffuse large B-cell lymphoma. This is known as Richter syndrome.
Bone marrow aspiration and biopsy are procedures that involve collecting cells from the bone marrow. The cells are sent for testing. A healthcare professional may recommend this test only if your diagnosis can't be confirmed with blood tests or other biopsies.
Lymphoma cells collected from a biopsy or a bone marrow aspiration and biopsy go to a lab for testing. In the lab, specialized tests look for specific things about the cells. The healthcare team uses the results to decide on the type of lymphoma that you have.
To decide whether the cells are small lymphocytic lymphoma cells, the healthcare professionals in the lab look for:
Treatments for small lymphocytic lymphoma may include a "watch and wait" approach, targeted therapy, chemotherapy, immunotherapy and radiation therapy. Other treatment options may include bone marrow transplant, also known as bone marrow stem cell transplant, CAR-T cell therapy and clinical trials. Which treatment is right for you depends on whether you have symptoms and the extent of your cancer, called the stage. Your healthcare team also considers how quickly the cancer is growing, your overall health and what you prefer.
If your small lymphocytic lymphoma doesn't cause symptoms, you may not need treatment right away. Instead, you may have checkups every few months. The checkups help your healthcare team watch your condition to see if your cancer progresses.
Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die.
Targeted therapy is often the first treatment for small lymphocytic lymphoma. You may take a combination of targeted therapy medicines. Targeted therapy also may be combined with immunotherapy. Targeted therapy also may be used when other treatments haven't worked, known as refractory small lymphocytic lymphoma, or for cancer that comes back after treatment, called relapsed small lymphocytic lymphoma.
Side effects of targeted therapy may include diarrhea, liver issues, high blood pressure, and issues with blood clotting and wound healing. Side effects also may include fatigue, mouth sores and nail changes. Most side effects go away after treatment is done.
Chemotherapy treats cancer with strong medicines. There are many chemotherapy medicines. Most chemotherapy medicines are given through a vein. Some come in pill form.
Chemotherapy may be a treatment for small lymphocytic lymphoma. You may take several chemotherapy medicines at one time. Chemotherapy also may be combined with immunotherapy. Chemotherapy may be the first line treatment for older adults or others who can't tolerate targeted therapy. Chemotherapy also may be used for small lymphocytic lymphoma that has transformed into a more aggressive cancer.
Side effects of chemotherapy depend on the medicines you're given. Common side effects are nausea and hair loss. Serious long-term complications can happen, such as heart disease, lung damage, infertility and developing another kind of cancer, called a secondary cancer.
Immunotherapy for cancer is a treatment with medicine that helps the body's immune system kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells.
Immunotherapy may be combined with targeted therapy or chemotherapy to treat small lymphocytic lymphoma. Immunotherapy also may be used for small lymphocytic lymphoma that has transformed into a more aggressive cancer.
Side effects of immunotherapy may include constipation, cough, fatigue, diarrhea, headache, muscle spasms and nausea.
Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points in your body. Radiation therapy is sometimes used to treat early-stage small lymphocytic lymphoma.
Radiation therapy side effects include fatigue and skin irritation at the site where the radiation is aimed. Other side effects depend on where the radiation is aimed. Radiation to the neck can cause dry mouth and damage the thyroid. Radiation to the chest can damage the heart and lungs.
A bone marrow transplant, also called a bone marrow stem cell transplant, involves putting healthy bone marrow stem cells into the body. These cells replace cells hurt by chemotherapy and other treatments. Stem cells can come from your own body, called an autologous transplant. Stem cells also can come from a donor, called an allogeneic transplant.
A bone marrow transplant may be done for relapsed or refractory small lymphocytic lymphoma. A bone marrow transplant also may be an option for small lymphocytic lymphoma that has transformed into a more aggressive cancer. Chemotherapy is typically done before the transplant to suppress the immune system and bone marrow.
Short-term side effects of a bone marrow transplant may include upset stomach, vomiting and not feeling hungry. They also may include fatigue, mouth sores, hair loss and skin reactions. Long-term side effects may include infertility, secondary cancers, organ damage, weakness in the bones or muscles, and cataracts.
Chimeric antigen receptor (CAR)-T cell therapy trains the immune system cells to fight lymphoma. This treatment begins with removing some white blood cells, including T cells, from the blood.
The cells are sent to a lab. In the lab, the cells are treated so that they make special receptors. The receptors help the cells recognize a marker on the surface of the lymphoma cells. Then the cells go back into the body. They find and destroy lymphoma cells.
CAR-T cell therapy may be an option for some people with refractory or relapsed small lymphocytic lymphoma. CAR-T cell therapy also may be an option for small lymphocytic lymphoma that has transformed into a more aggressive cancer. CAR-T cell therapy is typically used after at least two other treatments have been tried.
Side effects of CAR-T cell therapy may include fever, upset stomach, headache and confusion. They also may include dizziness, rash, rapid heartbeat, trouble breathing and low blood pressure.
Clinical trials are studies of new treatments. These studies provide a chance to try the latest treatments. The risk of side effects might not be known. Ask your healthcare team if you can be in a clinical trial.
After treatment is complete, you may have frequent follow-up appointments to see if the cancer has come back, known as a relapse. You may have repeat blood tests to check for a relapse.
Treatments for small lymphocytic lymphoma may have complications, including:
With time, you'll likely find what helps you cope with the uncertainty and worry of a cancer diagnosis. Until then, you may find that it helps to:
Ask your healthcare team about your cancer, including your test results, treatment options and, if you want, your prognosis. As you learn more about small lymphocytic lymphoma, you may become more confident in making treatment decisions.
Keeping your close relationships strong can help you deal with your small lymphocytic lymphoma. Friends and family can provide the practical support you may need, such as helping take care of your home if you're in the hospital. And they can serve as emotional support when you feel overwhelmed by having cancer.
Find someone who is willing to listen to you talk about your hopes and worries. This person may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.
Ask your healthcare team about support groups in your area. Other sources of information include the National Cancer Institute, the American Cancer Society, Blood Cancer United and the Lymphoma Research Foundation. Find support online through Mayo Clinic Connect, which is a community where you can connect with others for support, practical information and answers to everyday questions.
Make an appointment with a healthcare professional if you have any symptoms that worry you.
If your healthcare professional thinks you might have small lymphocytic lymphoma, you may be referred to a doctor who specializes in diseases of the blood and bone marrow, called a hematologist.
Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.
For small lymphocytic lymphoma, some basic questions include:
Don't hesitate to ask other questions.
Be prepared to answer questions, such as:
If you're diagnosed with small lymphocytic lymphoma, the next step is to determine the cancer's extent, called the stage. Imaging tests, blood tests and biopsies may be used to determine the stage of small lymphocytic lymphoma. Your healthcare team uses the cancer stage to help create your treatment plan.
The stages of small lymphocytic lymphoma range from 1 to 4:
Survival rates are different for each person with small lymphocytic lymphoma. Healthcare professionals use something called prognostic risk categories. These categories group people into different levels of risk to show how the disease might act and what survival chances look like. Prognostic risk categories for small lymphocytic lymphoma include low, intermediate, high and very high. If you are in the low-risk group, your cancer is likely slow-growing, and your chances of living longer are better. If you are in the very high-risk group, your cancer is more serious, and your survival chances are lower. Your risk category is determined by:
For example, someone in the low-risk category for small lymphocytic lymphoma has a five-year survival rate of about 93%. As the risk gets higher, the survival rate gets lower. The five-year survival rate for someone in the very high-risk category for small lymphocytic lymphoma is about 23%.
Keep in mind that survival statistics take five years to collect. The most recent survival rates include people who had treatment for small lymphocytic lymphoma more than five years ago. These people may not have had access to the latest treatments. Over the last few decades, small lymphocytic lymphoma death rates have been falling and survival rates have been increasing.
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