This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science.
This page was updated on August 11, 2022.
Leukemia has many different types. Some forms of acute leukemia are fast-growing, while other chronic forms of the disease may require less aggressive treatments. A thorough and accurate cancer diagnosis is a critical first step in developing a leukemia treatment plan. Our multidisciplinary team of leukemia experts uses a variety of tools and technologies designed for diagnosing leukemia and developing a treatment plan tailored to each patient’s needs. Throughout your treatment, we'll use imaging and laboratory tests to monitor your response to treatment and modify your plan as needed.
This article will cover:
If you’re concerned you may have leukemia or are experiencing symptoms associated with leukemia, a physical exam is often the first method your doctor utilizes to see what’s going on.
The physical exam may be focused on looking or feeling for swelling in the lymph nodes, liver and spleen. Your eyes, mouth and skin may also be examined. Your doctor may also be on the lookout for signs of infection and bruises, as frequent infections, widespread bruises and easy bleeding are associated with some types of leukemia.
A nervous system exam may also be performed, which often involves checking your balance, sensation (touching different areas of the body to make sure you have proper sensation) and reflexes (tapping certain body parts with a small rubber hammer).
Laboratory tests, and specifically blood tests, are among the most important diagnostic tools for leukemia. For some types of leukemia, such as chronic lymphocytic leukemia, blood tests may be the only test needed to confirm the diagnosis (but other tests may be used to find out more about the cancer).
To officially diagnose other types, such as acute lymphocytic leukemia, blood tests are typically followed by bone marrow tests. Most of the time, blood tests, and specifically a test called a complete blood count, are the first step in the diagnostic process.
Complete blood count (CBC): This blood test measure the amount of red blood cells, white blood cells and platelets in the blood.
Differential: A differential, or diff, analyzes how many of each type of white blood cell are present in your blood.
Peripheral blood smear: This blood test requires just one drop of blood, which is smeared or spread out across a surface and then analyzed under a microscope. The laboratory technician looks at the appearance of the blood cells, as certain changes in the look of these cells may point toward leukemia.
Leukemia blood test results
The results of a CBC, diff and peripheral blood smear are an essential part of diagnosing leukemia and, if present, determining the type of leukemia. These blood tests tend to reveal different findings depending on the type of leukemia. The findings associated with some of the main leukemia types are summarized below.
A flow cytometry test may provide valuable insight into whether the tumor cells contain a normal or abnormal amount of DNA, and the relative rate at which the tumor is growing.
This test is a very accurate indicator in determining the patient’s exact kind of lymphoma or leukemia. The test may be performed on bone marrow cells (taken during a biopsy) or blood cells (taken during a blood test). These cells are exposed to special antibodies (proteins), which will attach to specific proteins on the cells that match them. Cancer is suspected if the antibodies attach to most cells in the sample, as this indicates that the cells originated from one abnormal cell. Cancer is unlikely if different antibodies attach to different cells in the sample, as this means that there are a variety of cell types.
The process may also reveal how much DNA is in cancer cells, which indicates whether the cancer is likely to grow quickly or slowly.
A biopsy is used to determine the type of leukemia, the growth rate of the tumor, and whether the disease has spread. Common biopsy procedures for leukemia include:
Bone marrow biopsy removes a sample of bone marrow. Since leukemia begins in bone marrow, examining these cells is an important part of diagnosing leukemias. There are two types of procedures used to extract a bone marrow sample, and they are often performed simultaneously.
Lymph node biopsy removes all or part of a lymph node. This procedure is rarely needed to diagnose leukemia, as tests on the blood and bone marrow are much more important. When it’s used, however, it’s typically done because a lymph node has increased in size after diagnosis, raising concern that the cancer may have become more aggressive. There are two types of lymph node biopsies: excisional (to remove an entire lymph node) and incisional (to remove part of a lymph node). If you need to have a lymph node deep inside the body (or part of a lymph node) removed, you may be given general anesthesia for the procedure. To remove lymph nodes that are more easily accessible, you may only need local anesthetic to numb the area.
These procedures may provide information about the extent of leukemia in the body, and the presence of infections or other problems. The following imaging tests may be used to help formulate a leukemia diagnosis:
A pulmonary function test may be used to assess your lung function before or after treatment. It may help you and your care team know whether your lungs are strong enough for treatments and/or how current treatments might be affecting your lungs. There are different ways to do this, including:
A spirometry test requires you to breathe into a tube, and a computer measures how much air is exhaled with every breath. Lung plethysmography uses a machine to assess how much air you breathe in when you inhale and then with what force you breathe out when you exhale. Lung diffusion testing involves inhaling a gas through a tube, waiting a few seconds, and then exhaling. The exhaled air is kept in a tube that your doctor examines.
Also known as a spinal tap, this test may be required to determine the extent of leukemia. During this procedure, a needle is used to collect cerebrospinal fluid from the lower back. Lumbar punctures may also be used to inject medications, such as chemotherapy drugs, to treat the disease.
After you’ve undergone blood tests and/or a bone marrow biopsy to determine whether you have leukemia, your doctor may follow up with you once the results are returned from the laboratory.
Your doctor may explain the findings, including the levels of different kinds of blood cells found in your blood sample, and whether those levels are consistent with leukemia. If a bone marrow biopsy was performed, the doctor may explain whether this sample contained leukemia cells.
If diagnostic tests reveal that you have leukemia, your doctor may also tell you what type of leukemia you have. Leukemias may be acute or chronic. Chronic leukemias tend to progress slowly, while acute leukemias grow quickly. The cancer cells may look and act differently depending on the type of leukemia. These differences are important in determining an informed treatment plan, which is the next step after your leukemia is diagnosed and the type of leukemia is determined. If the preliminary tests weren’t detailed enough to determine the type of leukemia, you may need to repeat these tests or undergo additional testing.
Your care team may provide information and support, and discuss treatment options with you at each step of the way.