Leukemia - Eosinophilic: Diagnosis

Approved by the Lineagotica Editorial Board, 08/2017

ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. Use the menu to see other pages.

Doctors use many tests to diagnose eosinophilia. Although a patient’s signs and symptoms may cause a doctor to suspect eosinophilic leukemia, it is diagnosed only by testing a patient’s blood and bone marrow. Doctors may also do tests to learn which treatments could work best.

This list describes options for diagnosing eosinophilic leukemia. Not all tests listed below will be used for every person. Your doctor may consider these factors when choosing a diagnostic test:

  • The type of leukemia suspected

  • Your signs and symptoms

  • Your age and medical condition

  • The results of earlier medical tests

The main criteria for diagnosing eosinophilic leukemia are:

  • An eosinophil count in the blood of 1.5 x 109 /L or higher that lasts over time

  • No parasitic infection, allergic reaction, or other causes of eosinophilia

  • Problems with the functioning of a person’s organs because of the eosinophilia

In addition to a physical examination, the following tests may be used to diagnose eosinophilic leukemia:

  • Blood tests. The diagnosis of eosinophilic leukemia begins with a test called a complete blood count (CBC). A CBC measures the number of different types of cells in a person's blood. If the blood contains many eosinophils (see criteria above), eosinophilic leukemia is suspected.

  • Bone marrow aspiration and biopsy. These 2 procedures are similar and often done at the same time to examine the bone marrow. Bone marrow has both a solid and liquid part. A bone marrow aspiration removes a sample of fluid with a needle. A bone marrow biopsy is the removal of a small amount of solid tissue using a needle.

    A pathologist then analyzes the sample(s) to determine the number and type of abnormal cells. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. A common site for a bone marrow aspiration and biopsy is the pelvic bone, which is located in the lower back by the hip. The skin in that area is usually numbed with medication beforehand. Other types of anesthesia (medication to block awareness of pain) may also be used.

    Many immature cells, called blasts, in the bone marrow are a sign of acute rather than chronic eosinophilic leukemia. Acute eosinophilic leukemia is not covered in this article and is treated similarly to AML.

  • Molecular testing. Your doctor may recommend running laboratory tests on the eosinophils to identify specific genes, proteins, and other factors unique to the leukemia. If many eosinophils are found, a molecular genetic analysis should be done to test for a genetic mutation that makes an abnormal protein known as FIP1-like-1/platelet-derived growth factor alpha or FIP1L1-PDGFRa. The types of molecular testing that may be used include:

  • Immunophenotyping, which is the examination of the proteins on the surface of the leukemia cells. It helps the doctor confirm the exact type of leukemia.

  • Cytogenetics, which is the examination of the leukemia cells for abnormalities in the long strands of genes called chromosomes. It also helps the doctor confirm the diagnosis and may help to determine the person’s chance of recovery.

Results of these tests will also help decide whether your treatment options include a type of treatment called targeted therapy (see Treatment Options).

  • Computed tomography (CT or CAT) scan. A CT scan creates a 3-dimensional picture of the inside of the body using x-rays taken from different angles. A computer combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. A CT scan shows enlarged lymph nodes or a swollen spleen or liver and can be used to measure the size of these organs. Sometimes, a special dye called a contrast medium is given before the scan to provide better detail on the image. This dye can be injected into a patient’s vein or given as a pill to swallow.

  • Evaluation of the heart. People who have many eosinophils for a long time often have problems with heart function and rhythm. The doctor may recommend an electrocardiogram (ECG or EKG) and/or an echocardiogram (ECHO). An EKG is a noninvasive test that looks for abnormal heart rhythms or heart damage. An ECHO is a noninvasive test that looks at the structure and function of the heart using sound waves and an electronic sensor.

After diagnostic tests are done, your doctor will review all of the results with you. If the diagnosis is eosinophilic leukemia, these results also help the doctor describe the disease.

The next section in this guide is Stages. It explains the system doctors use to describe most cancers and how this differs for eosinophilic leukemia. You may use the menu to choose a different section to read in this guide.