Diagnostic tests for ALL
A combination of the following tests will help your doctor confirm the diagnosis and work out the subtype of acute lymphoblastic leukaemia (ALL) you have.
Learn more about these tests to diagnose ALL:
Your doctor will take a blood sample and send it to a laboratory for a full blood count (FBC). This will show whether leukaemia cells are present in the blood and whether the levels of blood cells are different to what would be expected in a healthy person.
If the blood test shows abnormalities in the number or appearance of the white blood cells, your doctor will want to check a sample of your bone marrow for signs of leukaemia. This is because blood cells develop in your bone marrow.
Bone marrow samples are usually collected in two ways:
- bone marrow aspiration – the doctor uses a thin needle to remove a small amount of fluid (aspirate) from the bone marrow, usually from the hipbone (pelvic bone)
- bone marrow biopsy or trephine – the doctor uses a slightly larger needle to remove a small amount of bone and marrow.
You will be given a local anaesthetic to numb the area, pain relief that you inhale (commonly known as the green whistle) or light sedation to help you relax. Pain medicine may make you feel drowsy, so ask a family member or friend to drive you home afterwards. Although it can take up to 30 minutes to prepare for a bone marrow test, the actual procedure takes only a few minutes.
The bone marrow samples (biopsy) are sent to a laboratory. A specialist called a pathologist will do tests on the samples to work out the subtype of acute leukaemia. These tests may include:
This test looks for markers or signals called antigens that are found on the surface of cells. Looking at the patterns of antigens can help your doctor work out whether you have ALL or AML, what subtype it is, and the type of lymphocyte cell (B-cell or T-cell) affected.
Cancer changes the genes of affected cells. These gene changes do not pass through families. They are only in the structure of the leukaemia cells, not in normal cells.
A genetic test called FISH (fluorescence in situ hybridisation) can look for abnormal chromosomes (including the Philadelphia chromosome). A test called PCR (polymerase chain reaction) looks for other common gene changes in ALL.
These tests are used to work out suitable treatment options and assess the chance of ALL coming back after a period of improvement.
Most cells in the human body have 23 pairs of chromosomes. Chromosomes are threadlike structures that contain sets of instructions known as genes.
The Philadelphia chromosome is formed when parts of two chromosomes break off and switch places. A gene from chromosome 22, called BCR, and a gene from chromosome 9, called ABL, create the BCR-ABL gene.
You may have other tests to find out more about the ALL, and to check your general health and how well your organs are working.
A chest x-ray is taken to check the heart and lungs, and to see whether there are enlarged lymph nodes in the chest. Enlarged lymph nodes are sometimes seen in people with ALL.
Human leukocyte antigen (HLA) typing
If having a stem cell transplant may be an option, your blood or bone marrow sample will be tested for human leukocyte antigen (HLA). HLA is found on most cells in your body – it helps your immune system recognise which cells belong in your body. A transplant can usually only go ahead if the stem cell donor is a close match to your HLA type. This is why your close relatives may also have an HLA test.
A blood test to check for infections such as HIV (human immunodeficiency virus) or hepatitis.
Gated heart pool scan
This scan is used to see how well the heart is working. A small amount of your blood is taken, mixed with some radioactive material and injected back into your body. A special camera known as a gamma camera takes pictures of the blood being pumped by your heart.
Once you have been diagnosed with ALL you will have a lumbar puncture. This test shows if any leukaemia cells have travelled to the fluid around your spine. The fluid is called cerebrospinal fluid (CSF).
A sample of CSF is removed with a thin needle from a space between two bones in the lower back. This takes only a few minutes, but as it can be uncomfortable, your doctor will use a local anaesthetic to numb the area.
A lumbar puncture can be done under x-ray guidance if your doctor thinks the lumbar puncture may be difficult or if the bones in your spine have broken down.
In some people, the back of the legs may tingle when the needle goes in – this is harmless and doesn’t last long. You may get a headache after a lumbar puncture. This usually improves without treatment, but ask your doctor for pain relief if it’s ongoing.
A computerised tomography (CT) scan uses x-rays and a computer to create cross-sectional pictures of the body. It can show if your lymph nodes are affected and if your spleen is enlarged.
This scan uses echoes from soundwaves to create a picture of the body’s organs on a screen.
A magnetic resonance imaging (MRI) scan uses a large magnet and radio waves to take detailed cross-sectional pictures.
For some types of ALL, you may be offered a positron emission tomography (PET) scan combined with a CT scan. Before the scan, you will be injected with a small amount of radioactive glucose solution. Cancer cells show up brighter on the scan because they take up more of the glucose than normal cells do.
Podcast: Tests and Cancer
A/Prof John Moore (Conjoint UNSW), Senior Staff Specialist Haematology, Department of Haematology and Bone Marrow Transplant, Kinghorn Cancer Centre, St Vincent’s Hospital; Glynda Blomson, Consumer; Kevin Bloom, Senior Social Worker, Haematology and Bone Marrow Transplant, Royal North Shore Hospital; Sharon Frazer, Consumer; Prof Angela Hong, Radiation Oncologist, Chris O’Brien Lifehouse, and Clinical Professor, The University of Sydney; Yvonne King, 13 11 20 Consultant, Cancer Council NSW; Karen Maddock, Clinical Nurse Consultant – Haematology, Westmead Hospital.
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