Facts about CLL

Confirming Your Chronic Lymphocytic Leukemia Diagnosis

Diagnosing chronic lymphocytic leukemia (CLL) involves a series of blood tests, and sometimes a bone marrow biopsy, which shows if you have cancer. The biopsy gives details about the type and subtype of cancer you have.

At Fred Hutchinson Cancer Center, our experts check and confirm your cancer type and the molecular features of your subtype. We also look for factors that tell us if your CLL is likely to get worse (called high-risk disease). This information matters in planning your personalized care.

Hematopathologists are lab experts who look at samples of your blood under a microscope. They can see important details by carefully studying your blood. At Fred Hutch, our hematopathologists are very experienced in identifying CLL.

Staging CLL and Risk Level

Staging means finding out how much CLL is affecting your body. Knowing the stage of your cancer helps your physicians predict if your disease will get worse and if you need treatment.

For CLL, doctors use a staging system called the Rai system. Your Rai stage is based on the levels of your blood cells and if some organs are enlarged. This gives your doctor information about the risk that your CLL will get worse and need treatment.

Doctors use Roman numerals 0 (zero), I (one), II (two), III (three) and IV (four) to name the stages. Stage 0 is the least advanced, and stage IV is the most advanced. All stages can be treated.

  • Stage 0, low risk: You have a higher-than-normal level of lymphocytes in your blood.
  • Stages I and II, intermediate risk: You have a higher-than-normal level of lymphocytes in your blood. Your lymph nodes are larger than normal. Your liver or spleen is also larger.
  • Stages III and IV, high risk: You have a higher-than-normal level of lymphocytes in your blood. You do not have enough red blood cells or platelets. (Your lymph nodes, spleen or liver may or may not be larger than normal.)

Types of Treatment for CLL

Unlike most cancers, CLL is a long-term condition that may not need to be treated for many years. When it is time for treatment, doctors have more options today than ever before to control the disease or put it into remission. 

Staging Tests

To figure out the stage of your CLL and predict the outlook for your disease, you may need blood and bone marrow tests and imaging tests.

Blood and marrow tests show your levels of lymphocytes, red blood cells and platelets.

Imaging tests show if lymph nodes or other organs are bigger than normal.

Blood tests to stage CLL include:

  • Complete blood count (CBC)
  • Peripheral blood smear
  • Immunophenotyping
  • Flow cytometry
  • Cytogenetic tests
  • Fluorescent in situ hybridization (FISH)
  • Polymerase chain reaction (PCR)
  • Beta2 microglobulin
  • Lactate dehydrogenase (LDH)

Bone Marrow Aspiration and Biopsy

Some patients may need a bone marrow aspiration and biopsy. After numbing the area so there is no pain, a physician uses a hollow needle to take a sample of marrow (bone marrow aspiration) and a small piece of bone (bone marrow biopsy). A pathologist checks these samples for signs of cancer. Many of the same tests done on your blood can also be done on your marrow.

Imaging Tests to Stage CLL may include:

  • CT (computed tomography) scan
  • MRI (magnetic resonance imaging)
  • PET-CT (positron emission tomography-computed tomography) scan
  • Ultrasound

Fred Hutch has researched and treated of CLL for decades.


There are many resources online for learning about your disease. Health educators at the Fred Hutch Patient and Family Resource Center have compiled a list of trusted sources to help you get started.

Whether you are newly diagnosed, or going through treatment, or know someone with cancer, our staff are available to tailor personalized resources and answer questions about support options in the community. 

Cancer Research Organizations

Our list of online resources provides accurate health information from reliable and reputable sources, like the National Cancer Institute (NCI), the American Society of Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN).


American Cancer Society

American Cancer Society (ACS): Overview of Chronic Lymphocytic Leukemia (CLL)

If you have CLL or a caregiver for someone who does, knowing what to expect can be helpful. Here you can find out all about CLL in adults, including risk factors, symptoms and how they are found and treated.

American Society of Clinical Oncology

American Society of Clinical Oncology (ASCO): Guide to Chronic Lymphocytic Leukemia

This is Cancer.Net's Guide to CLL. Here you can learn more about CLL, treatment, the latest research and clinical trials.

National Comprehensive Cancer Network

National Comprehensive Cancer Network (NCCN) Guidelines for Patients: Chronic Lymphocytic Leukemia

This step-by-step guide to the latest advances in cancer care features questions to ask your physician, patient-friendly illustrations and glossaries of terms and acronyms.