The first step in diagnosing acute lymphoblastic leukaemia if for your GP to check for physical signs of the condition, such as swollen glands, and to take a blood sample.

A high number of abnormal white blood cells in the sample could indicate the presence of acute leukaemia and you will then be referred 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 – and then use a needle to remove a sample of bone marrow. 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 to complete 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 leaukaemia will be determined at the same time.

Further tests

There are various additional tests that can be used to help reveal more information about the progress and extent of the leukaemia. They can also provide an insight into how the leukaemia should be treated. These tests are described below.

Cytogenetic testing

Cytogenetic testing involves identifying the genetic make-up of the cancerous cells. There are specific genetic variations that can occur during leukaemia, and knowing what these variations are can have an important impact on treatment.

Immunophenotyping

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 done on a blood sample. This is an important test to 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 have been diagnosed with acute leukaemia, further biopsies may be carried out on any enlarged lymph nodes that you have. These will be able to establish how far the leukaemia has spread.

CT scans

If you have acute leukaemia, a computerised tomography scan (CT scan) may be used to check that your organs, such as your heart and lungs, are healthy.

Chest X-ray

An X-ray may be performed to examine the chest for any swollen lymph nodes.

Lumbar puncture

If it is felt that there is a risk that acute leukaemia has spread to your nervous system, a lumbar puncture may be carried out.

A lumbar puncture is a test where a needle is used under local anaesthetic to extract a sample of cerebrospinal fluid (fluid that surrounds and protects your spine) from your back. The fluid is tested to determine whether leukaemia has reached your nervous system.