How is chronic lymphocytic leukemia (CLL) diagnosed?

If your healthcare provider thinks you might have CLL, you will need certain exams and tests to be sure. Your healthcare provider will ask you about your health history, your symptoms, risk factors, and family history of disease, and will also conduct a physical exam.

What tests might I need?

You may have one or more of the following tests:

• Blood tests. CLL is often found with blood tests before a person has symptoms. Tests can look at the numbers of different types of blood cells. People with CLL often have too many lymphocytes. This is a type of white blood cell.

• Bone marrow aspiration and/or biopsy. This procedure is done by taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (core biopsy). The sample is often taken from the back of the hip (pelvic) bone. For the bone marrow aspiration, the area over the hip is numbed. A thin, hollow needle is put 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. The biopsy may also cause some brief pain. The fluid and bone marrow are examined for the number, size, and maturity of the blood cells and for abnormal cells. Other tests can also be done on these cells but they are not usually needed to diagnose CLL. 

How blood or bone marrow is tested

Tests can be done on blood (or less often, bone marrow) samples to diagnose CLL and help determine how quickly it is likely to grow. The tests include:

• Flow cytometry and immunohistochemistry. These tests use chemicals and dyes to look for certain substances on the surface of the leukemia cells. This is called immunophenotyping. These tests are used to diagnose CLL.

• Cytogenetics. These tests look for changes in the chromosomes of cells from samples of blood, bone marrow, or lymph nodes. For example, in CLL, part of a chromosome may be missing or there may be extra copies of a chromosome. This test usually takes a few weeks because the cells need time to be grown in the lab.

• Fluorescent in situ hybridization (FISH). This test uses special fluorescent dyes that only attach to certain parts of chromosomes. It can be used to look for certain changes in genes and chromosomes that are found in CLL cells from blood or bone marrow samples. The FISH test is very accurate and gives results more quickly than standard cytogenetic tests.

Getting your test results

When the results of your tests are in, your healthcare provider will contact you to discuss them. He or she 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.