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Chronic Lymphocytic Leukemia (CLL): Diagnosis 

How is chronic lymphocytic leukemia (CLL) diagnosed?

If your healthcare provider thinks you might have CLL, you will need certain exams and tests to make sure. Your healthcare provider will ask you about your health history, your symptoms, risk factors, and family history of disease. Your healthcare provider will also give you a physical exam. But the definitive diagnosis of CLL depends on blood work.

What tests might I need?

You may have one or more of these tests:

  • Blood tests. CLL is often found with blood tests before a person has symptoms. For these tests, blood will be taken from a vein in your arm. A complete blood count (CBC) is a blood test that reports the numbers of each type of blood cell. People with CLL have an increased count of lymphocytes, which is a type of white blood cell (WBC). Your healthcare team may also do a peripheral blood smear and flow cytometry test. These tests look closely at cells and help confirm the diagnosis of CLL.

  • Bone marrow aspiration or biopsy.This procedure is usually not needed to diagnose CLL. It is done by taking out a small amount of bone marrow (aspiration) and/or solid bone marrow tissue (core biopsy). The sample is taken from the back of the hip (pelvic) bone. For the bone marrow aspiration, the skin over the hip is numbed. A long, hollow needle is pushed into the pelvic bone. A syringe is used to pull out a small amount of liquid bone marrow. You may have some brief pain when the marrow is removed. A bone marrow biopsy is usually done just after the aspiration. A slightly bigger needle is used to take out a small core of bone and marrow. This may also cause some brief pain. The fluid and bone marrow are sent to a lab and tested for the number, size, and maturity of the blood cells and checked for abnormal cells. Other tests can also be done on these cells but they're not usually needed to diagnose CLL. 

Getting your test results

When the results of your tests are in, your healthcare provider will contact you to discuss them. They will also talk with you about other tests you may need if CLL is found. Make sure you understand the results of your tests and what follow-up you need.

Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Online Medical Reviewer: Sabrina Felson MD
Online Medical Reviewer: Todd Gersten MD
Date Last Reviewed: 1/1/2023
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