The first step in diagnosing acute lymphoblastic leukaemia is to check for physical signs of the condition, such as swollen glands, and to take a blood sample.
If the blood sample contains a high number of abnormal white blood cells, it could be a sign of acute leukaemia. Your GP will refer you to a haematologist (a specialist in treating blood conditions).
Bone marrow biopsy
To confirm a diagnosis of acute leukaemia, the haematologist will take a small sample of your bone marrow to examine under a microscope.
The haematologist will use a local anaesthetic to numb the skin over a bone – usually the hip bone – before removing a sample of bone marrow with a needle. You may experience some pain once the anaesthetic wears off and some bruising and discomfort for a few days afterwards. The procedure takes around 15 minutes and you shouldn't have to stay in hospital overnight.
The bone marrow will be checked for cancerous cells and, if found, the type of acute leukaemia will be determined at the same time.
Some people with acute leukaemia will need to have a bone marrow assessment to check for cancerous cells every three months for at least two years during maintenance treatment or after having a bone marrow transplant.
A number of additional tests (described below) can be used to find out about the progress and extent of the leukaemia. They can also help guide treatment.
Cytogenetic testing involves identifying the genetic make-up of the cancerous cells. Specific genetic variations can occur during leukaemia, and knowing what these variations are can have an important impact on treatment.
Immunophenotyping is a test to help identify the exact type of acute lymphoblastic leukaemia. A sample of blood, bone marrow or another type of fluid is studied.
This testing is important as the treatment needed may be slightly different for each type.
Polymerase chain reaction (PCR)
A polymerase chain reaction (PCR) test can be carried out on a blood sample. PCR can help diagnose and monitor the response to treatment.
The blood test is repeated every three months for at least two years after starting treatment, then less often once remission is achieved.
Lymph node biopsy
If you've been diagnosed with acute leukaemia, further biopsies may be carried out on any enlarged lymph nodes that you have. These will establish how far the leukaemia has spread.
If you have acute leukaemia, a computerised tomography (CT) scan may be used to assess how far the leukaemia has spread and to check that your organs, such as your heart and lungs, are healthy.
You may have an X-ray so that the chest can be examined for any swollen lymph nodes.
A lumbar puncture may be carried out if there's a risk that acute leukaemia has spread to your nervous system.
A needle is inserted into the lower part of your spine to extract a small sample of cerebrospinal fluid (the fluid that surrounds and protects your spine), which is tested for cancer cells.