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:
Blood tests
Your doctor will take a sample of blood and send it to a laboratory for a full blood count (FBC). This will show whether leukaemia cells are present and whether the levels of different types of blood cells are different from what would be expected in a healthy person.
The blood tests will also check for infections such as HIV (human immunodeficiency virus) or hepatitis.
Learn more about blood tests.
Bone marrow tests
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. Samples of bone marrow are usually collected from the hipbone (pelvic bone) and there are 2 different ways to collect these samples.
- Bone marrow aspiration – The doctor uses a thin needle to remove a small amount of fluid (aspirate) from the bone marrow.
- 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. To help you relax, you may be offered a light sedation that you inhale (a mild pain reliever known as “the green whistle”) or is injected through a small plastic tube inserted into a vein (cannula). This 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 are sent to a laboratory. A specialist called a pathologist will do tests on the samples to work out the subtype of ALL. These tests may include:
Immunophenotyping
This test looks for certain markers that are found on the surface of leukaemia cells. Looking at the patterns of these markers can help your doctor to confirm that the leukaemia is ALL (and not AML) and to work out the subtype and the type of lymphocyte (B-cell or T-cell) affected. B–cell ALL is the most common type of ALL in adults.
Genetic tests (cytogenetics and molecular tests)
Cancer changes the genes of affected cells. These types of gene changes are not the same as genes passed through families. The fault is only in the structure of the leukaemia cells, not in normal cells.
A test called FISH (fluorescence in situ hybridisation) looks 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.
Philadelphia chromosome
Gene swap
The Philadelphia chromosome is formed when parts of 2 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.
Further tests
You may have other tests to find out more about the ALL, your general health and how well your organs are working. This may include a chest x-ray, a computerised tomography (CT) scan, ultrasound and a magnetic resonance imaging (MRI) scan. Other tests may include the following:
HLA typing
If a stem cell transplant may be an option, a 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 stem cell transplant can usually only go ahead if the donor is a close match to your HLA type. This is why your close relatives may also have an HLA test.
Gated heart pool scan
This scan is used to see how well the heart is working and whether you are fit enough for chemotherapy. A small amount of blood is taken, mixed with some radioactive material and injected back into your body. A special camera takes pictures of the blood being pumped by your heart.
Lumbar puncture
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 and brain. This fluid is called cerebrospinal fluid. A sample of cerebrospinal fluid is removed with a thin needle from a space between 2 bones in the lower back. This takes only a few minutes, but it can be uncomfortable, so your doctor will use a local anaesthetic to numb the area.
A lumbar puncture may be done under x-ray guidance if your doctor thinks the lumbar puncture may be difficult.
In some people, the back of the legs may tingle when the needle is inserted – this is harmless and doesn’t last long. You may get a headache after a lumbar puncture, but this usually improves with a few hours of bed rest. You can ask your doctor for pain relief if the headache is ongoing.
PET–CT scan
For some types of ALL, you may have 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. Leukaemia cells show up brighter on the scan because they take up more of the glucose than normal cells do.
Before having scans, tell the doctor if you have any allergies or have had a reaction to contrast during previous scans.
You should also let them know if you have diabetes or kidney disease, or if you are pregnant or breastfeeding.
→ READ MORE: Classification and prognosis
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Dr Jonathan Sillar, Haematologist, Calvary Mater Newcastle Hospital; Dr Scott Dunkley, Haematologist, Royal Prince Alfred Hospital and Chris O’Brien Lifehouse; Sharon Frazer, Consumer; Dr Robin Gasiorowski, Staff Specialist, Haematology, Concord Hospital; 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; Heather Mackay, Clinical Nurse Consultant – Haematology, Westmead Hospital; Katelin Mayer, Clinical Nurse Consultant, Cancer Outreach Team, Nelune Comprehensive Cancer Centre.
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