Tests for childhood acute lymphoblastic leukaemia (ALL)
Your child will need a number of tests if their doctor suspects they have leukaemia. These aren't generally painful. But your child will have to keep still for some time. So, for some types of tests, your child might need to be drowsy (
) or asleep ().
The team caring for your child are used to helping children have these tests. They will do everything they can to prepare them, and you.
Your child might have one or more of the following:
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blood tests
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a bone marrow aspirate and trephine - this is a sample of cells from the bone marrow, and a sample of the bone marrow itself, to see if there are leukaemia cells there
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a spinal fluid test (lumbar puncture)
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genetic tests
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a chest x-ray
Blood tests
A blood test is an important test for acute lymphoblastic leukaemia. It can check:
- the number of blood cells, this is often called a blood count, or full blood count
- if any of the cells look like leukaemia cells
- your child’s general health, such as how well their liver and kidneys are working
How do they take blood?
A doctor, nurse or takes a small amount of blood from your child. This is usually from a vein in the back of the hand or the inside of the elbow.
Most blood tests are over in a couple of minutes.
The specially trained staff will help your child feel as comfortable as possible. Things that can make it easier for your child include:
Local anaesthetic
Your child might have a before the test. This is usually a cream that is put on about 30 to 60 minutes in the area they will take the bloods. Or they might use a cold spray. This should mean it’s less painful for your child, although they might still feel the needle go in.
Distraction
Distraction could include:
- singing
- counting
- using bubbles
- reading them a story
- using books that have pop ups or music
- watching something on your mobile phone or a tablet
If your child has blood tests at the hospital they might have a health play specialist. They can help your child cope and distract them while having the blood test. This can help your child feel less anxious and scared.
Sitting with your child
Holding your child while they are having their blood test can make them feel safe and secure. And you can give them a cuddle afterwards if you’re unable to hold them during their test.
After their blood test
Your child can usually eat, drink and play as normal after a blood test.
Bone marrow tests
Your child has this test to check whether there are leukaemia cells in the bone marrow. And what type of leukaemia it is. Bone marrow is spongy tissue and fluid that is inside your bones. It makes your .
How does your child have a bone marrow test?
A doctor or specialist nurse removes a sample of bone marrow fluid (called a bone marrow aspirate). Or a small piece of bone marrow (called a trephine). Your child might have both tests at the same time.
This sample is usually taken from the back of their hip. In small infants they might have it from their shinbone (tibia). This information is about a child having it from their hip bone.
Doctors send the sample to the laboratory. A specialist doctor called a pathologist looks at the cells or tissue under a microscope.
Most children usually has this test under general anaesthetic in theatres. Some older children may have it performed under sedation and local anaesthetic.
After the bone marrow test
Your child returns to the children’s ward after the test. Their nurse will look after them closely when they return and take regular measurements such as their:
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heart rate
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breathing rate
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blood pressure
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oxygen levels
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temperature
This is to make sure they are recovering from the sedation or anaesthetic. The nurses also usually check that your child has:
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had something to drink
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had something to eat or some milk
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had a wee
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a clean and dry dressing over the site of the test
A bone marrow biopsy is a safe test. Your child’s doctor or nurse talks with you about any possible problems they might have after it.
Spinal fluid test (lumbar puncture)
A lumbar puncture is a test to check the fluid that circulates around the brain and spinal cord. This is called cerebrospinal fluid or CSF. A lumbar puncture checks for leukaemia cells in the CSF. Using a special needle your child’s doctor, or specialist nurse, takes a sample of the CSF from their lower back.
Your child’s team will talk you through the benefits and risks of having a lumbar puncture. There is a risk of bleeding and infection, but this is very rare.
How does your child have a lumbar puncture?
Most children have a general anaesthetic for this test. But occasionally some older children might be able to have local anaesthetic for their lumbar puncture.
Sometimes the area where the needle goes in, is numbed with a local anaesthetic. If your child has this test under local anaesthetic they might feel some pressure and a slight soreness when the local anaesthetic needle goes in.
The doctor or nurse puts the lumbar puncture needle in through the skin. If your child has a local anaesthetic they wait for the area to get numb first.
The lumbar puncture needle goes into the small of the back and into the space around the spinal cord.
Once it's in the right place, the fluid drips out into a pot. You also usually have intrathecal chemotherapy at the same time. This is an injection of methotrexate chemotherapy into the spinal fluid. It helps to treat and prevent any cancer cells spreading to the cerebrospinal fluid.
The doctor or nurse takes the needle out and puts a dressing or plaster on your child’s back.
After the lumbar puncture
After the lumbar puncture your child returns to the children's ward. Their nurse will look after them closely when they return and take regular measurements such as their:
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heart rate
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breathing rate
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blood pressure
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oxygen levels
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temperature
This is to make sure they are recovering from the anaesthetic. The nurses also checks that your child has:
- had something to drink
- had something to eat or some milk
- had a wee
- a clean and dry dressing over the site of the test
The area might be a little sore or bruised that lasts for a couple of days.
Your child will need to lie flat for about an hour after the procedure to help prevent headaches and to help ensure the chemotherapy goes to all areas of the .
Let your child’s healthcare team know if they get symptoms such as:
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a severe headache
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being sick
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their eyes are sensitive to bright light
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tingling or numbness in their legs
Your child usually has a bone marrow aspirate and lumber puncture together.
Genetic tests
There are different tests that look for changes in the and of your child’s leukaemia cells. Genes are coded messages made of that tell our cells how to behave. Chromosomes are made of a very long strand of DNA and contain many genes. These tests are sometimes called cytogenetic or molecular studies.
Fluorescence in situ hybridisation (FISH)
FISH is a test that looks for chromosome changes in cells. It can help your child’s doctor work out which treatment they need.
This test can check if they have the chromosome change that causes Philadelphia positive ALL. But there are also many other chromosome changes that are important in helping their doctor understand more about their leukaemia.
We also have a 2 minute video that explains what Philadelphia positive leukaemia is.
The human body is made up of trillions of cells. Inside each cell is a nucleus and within the nucleus are the cell’s chromosomes. There are 23 pairs in total.
Chromosomes are made up of DNA, which gives the instructions that tell a cell what to do. Sections of DNA are called genes. They carry the information that makes you you. For example, they tell your body what colour your hair will be or what colour your eyes will be.
Genes also tell your cells when to divide and grow, and when to die.
When cells divide to make new cells, they make exact copies of the chromosomes.
In Philadelphia chromosome positive leukaemia an abnormal change happens to chromosomes 9 and 22. Part of chromosome 9 breaks off where the gene ABL1 is located and part of chromosome 22 breaks off where the BCR gene is located. The broken parts swap places creating a new gene on chromosome 22.
This new chromosome is called the Philadelphia chromosome and the new gene is called BCR-ABL1. This new gene tells the cell to make a large quantity of a protein called tyrosine kinase which encourages leukaemia cells to grow.
There are targeted cancer drugs that can block the protein and stop the leukaemia from growing. These drugs are called tyrosine kinase blockers. You take them as tablets.
For more information about your type of leukaemia and treatments go to CRUK.org/about-cancer/leukaemia.
Polymerase chain reaction (PCR)
PCR are tests that can pick up abnormal genes. It can tell if your child has Philadelphia positive ALL. This helps your child’s doctor work out the treatment they need. In leukaemia, it can also monitor how well the treatment is working.
Gene panels
A lot is known about the gene changes that can be seen in leukaemia cells. Doctors now commonly look for these gene changes in the DNA from your child’s leukaemia cells. This is called a gene panel.
Whole genome sequencing (WGS)
The aim of this test is to look for changes (mutations) in their genes. This test can help to identify children with specific gene changes that might be missed by the standard panels which cause them to not respond to treatment as well. Understanding these changes can help doctors find out what treatment will work best for them.
These tests are done at specialist laboratories around the UK. They are called genomic laboratory hubs.
For this test your child’s doctor sends some leukaemia cells from the bone marrow and also either a blood sample or a small amount of skin (skin biopsy). The skin biopsy is usually taken at the same time as their bone marrow test.
Chest x-ray
X-rays use high energy rays to take pictures of the inside of your body. Chest x-rays can show:
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fluid
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signs of infection
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an enlarged heart
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enlargement of the lymph glands in the chest, where leukaemia cells have collected
How does your child have an x-ray?
There is no special preparation for an x-ray. Your child usually has a chest x-ray standing up against the x-ray machine if they are old enough to stand. They have it lying on the x-ray couch if they are younger or unable to stand.
X-rays are painless and quick. Your child won’t feel or see anything. You are usually able to stay in the room when your child is having their x-ray. You need to wear a lead apron to protect you from the small amount of radiation.
Your child’s specialist makes sure the benefits of having an x-ray outweighs the risks of the small amount of radiation.
After the x-ray
Your child can usually eat, drink and play as normal after a chest x-ray.
Other tests
Your child might have other tests depending on what symptoms they have. These tests might include:
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a CT scan
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an MRI scan
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an ultrasound scan
Getting your child’s results
You get your child's test results quite quickly usually within 48 hours if not sooner. But some more complex tests such as looking for changes (abnormalities) in your child's can take a couple weeks or even longer.
Waiting for test results can be a very worrying time. You might have contact details for a children’s cancer specialist nurse and you can contact them for information if you need to. It can help to talk to a close friend or relative about how you feel.
You can also contact the Cancer Research UK information nurses for support on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.
Treatment
Get more information on treating childhood acute lymphoblastic leukaemia
