Chronic myeloid leukaemia diagnosis

How is CML diagnosed?

When you see your doctor they will probably take a full medical history, asking questions about your general health and any illness or surgery you have had previously, and give you a full physical examination and order further tests. CML is diagnosed by examining samples of your blood and bone marrow.

Full blood count

The first step in the diagnosis is a simple blood test called a full blood count (FBC) or complete blood count (CBC). This involves a sample of blood from a vein in your arm being sent to the laboratory for investigation. Many of the white blood cells may be abnormal leukaemic blast cells and the presence of these blast cells suggests you have CML. A CML diagnosis needs to be confirmed by examining the cells in your bone marrow.

Bone marrow examination

If the results of your blood tests suggest that you might have CML, a bone marrow biopsy may be required to help confirm the diagnosis. A bone marrow biopsy involves taking a sample of bone marrow (usually from the back of the hip bone) and sending it to the laboratory for examination under the microscope. The bone marrow biopsy may be done in the haematologist’s rooms, clinic or day procedure centre and is usually performed under local anaesthesia with sedation given either by tablet or through a small drip in your arm.

The sample of bone marrow is examined in the laboratory to determine the number and type of cells present and the amount of haemopoiesis (blood forming) activity taking place there. The diagnosis of CML is confirmed by the detection of the Philadelphia (Ph) chromosome or the bcr-abl gene in the bone marrow cells. Other findings may include a very active marrow filled with large numbers of mature and immature white cells and platelets.

Further testing

Once the diagnosis of CML is made, blood and bone marrow cells are examined further using special laboratory tests. These include cytogenetic tests. These tests provide more information about the exact type of disease you have, the likely course of your disease and the best way to treat it.

Other tests

These may be conducted to provide information on your general health and how your vital organs are functioning. These include a combination of further blood tests and imaging tests (x-rays, scans and ECG). These results will provide a baseline of your disease and general health which will be compared with later results to assess how well you are progressing and responding to treatment.