How is leukaemia diagnosed?

You might have a number of tests to investigate your symptoms and confirm a diagnosis of leukaemia, including: 

• medical history and physical examination
• blood tests to check blood cell counts, related infections ³², immunophenotyping ³³ and genetic tests ³⁴
• removal of a small piece of bone marrow usually from the pelvis (aspiration, biopsy or trephine)to be examined under a microscope and sometimes other laboratory tests such as immunophenotyping and genetic tests ³⁵
• chromosome testing – the genetic changes that occur in leukaemia often involve chromosome changes, which can be seen under a microscope or using laboratory tests
• removal of fluid from the spinal cord using a needle (known as a lumbar puncture or spinal tap)to check if the leukaemia has spread to this area
• imaging tests, such as X-rays, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, ultrasound or bone scan – these tests are mostly used to look for infections or other problems related to leukaemia, rather than for a diagnosis of leukaemia
• sometimes a positron emission tomography (PET) scan may be used with a CT scan and an injection of radioactive glucose solution – this makes the cancer cells easier to see on the scan because they take up more glucose compared to normal cells ³⁶
• removal of a small piece of tissue from a lymph node (biopsy) – however this isn’t commonly used to diagnose leukaemia. 

Other tests may include: 

• blood tests to check levels of an enzyme called lactate dehydrogenase – this enzyme is usually higher in people with AML ³⁷
• blood or bone marrow test for human leukocyte antigen (HLA) – if a stem cell transplant is an option for treatment, this test is used to make sure the donor is a suitable match ³⁸
• gated heart pool scan – this involves being injected with a radioactive substance to see how well the heart is pumping blood ³⁹. 

Many people with a chronic form of leukaemia (CLL and CML) do not have symptoms when it is diagnosed. Instead, the leukaemia is detected during blood tests for other reasons. 

Staging 

If you are diagnosed with leukaemia, you might have more tests to determine the stage of the disease and whether the cancer has spread to other parts of the body. These tests may include an Xray of the chest, CT scan, lumbar puncture and tests of the blood and bone marrow ⁴⁰. Knowing the stage of the disease helps your medical team plan the best treatment for you. 

Staging of leukaemia is different to staging of other types of cancer (staging of other types of cancer is usually based on the size and spread of tumours, but leukaemia doesn’t usually form tumours, and it spreads through the bone marrow and blood). 

There is no standard staging system for acute forms of leukaemia (ALL and AML) – these are described as being untreated, in remission (the symptoms have reduced or disappeared) or recurrent (the symptoms are still present, have come back or are increasing) ⁴¹.  

Doctors in Australia use different systems to classify and treat different types of leukaemia.  

Treatment for acute lymphoblastic leukaemia (ALL) is based on: 

• the subtype of ALL
• the unique set of proteins on the surface of the cells (immunophenotypes). 

Treatment for acute myeloid leukaemia (AML) is based on ⁴²: 

• the subtype of AML – there are over 20 subtypes based on the type of myeloid cell affected (one subtype of AML affects a type of myeloid cell called promyelocytes – this is called acute promyelocytic leukaemia, or APML, and is treated differently to other subtypes of AML) ⁴³
• whether there are particular genetic changes in the leukaemia cells
• whether the leukaemia started from a blood disorder called myelodysplasia
• whether more than one type of blood cell has abnormal changes. 

Treatment for chronic lymphoblastic leukaemia (CLL) is often based on a staging system called the Binet system ⁴⁴: 

• Stage A – a high number of white blood cells but less than 3 enlarged areas of lymph tissue (this may include lymph nodes, liver, spleen, or a combination).
• Stage B – a high number of white blood cells and 3 or more enlarged areas of lymph tissue.
• Stage C – a high number of white blood cells with a low number of red blood cells (anaemia) or low number of platelets (thrombocytopenia) or both. 

Treatment for chronic myeloid leukaemia (CML) is based on the number of certain immature white blood cells (myeoblasts) in the blood or bone marrow ⁴⁵: 

• Chronic phase – white blood cell count is increased and a small number of immature cells (blast cells) are found in the blood and bone marrow.
• Accelerated phase – the leukaemia may suddenly change and progress quickly (this may happen after several years). The spleen may become enlarged and white blood cell count may increase quickly.
• Blast phase – the number of blast cells increases, symptoms get worse, and blast cells may spread to other organs. Bleeding, infections and anaemia may also occur. 

When planning treatment options for the different types of leukaemia, doctors also consider: 

• how far the leukaemia has spread in the body
• how well your body will respond to treatment (your general health and other factors that may affect treatment).