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Diagnosing Wilms' tumour

Your child will need a number of tests if their doctor suspects they have a Wilms’ tumour. These aren’t generally painful. But your child will have to keep still for some of them.

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.

For some types of test, your child might need sedation or a general anaesthetic. Tests for Wilms’ tumour might include:

  • blood tests
  • ultrasound of the tummy area (abdomen)
  • chest x-ray
  • CT scan
  • MRI scan
  • a biopsy - this means taking a sample of tumour cells to look at under a microscope

Blood tests

Blood tests can:

  • check your child’s general health, including liver, kidneys and heart function
  • check numbers of blood cells

How

A doctor, nurse or person specialising in taking blood (a phlebotomist) takes a small amount of blood from your child. This is usually from the back of the hand, the inside of the elbow or wrist area.

Most blood tests take 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

The phlebotomist might use a local anaesthetic (numbing spray or cream) before the test. This should mean it’s less painful for your child, although they might still feel the needle go in.

Distraction

Distraction could be singing, counting, watching something on your mobile phone or a DVD.

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.

Ultrasound of the tummy area

Ultrasound scans use high frequency sound waves to build up a picture of the inside of the body. They are used in pregnancy to check on the baby’s development.

How

Ultrasound scans are completely painless. Your child has the test in the hospital x-ray department by a person who specialises in doing them called a sonographer. First, they put some cold gel on the area of skin over where they want to scan. They gently press the microphone on your child’s skin.

The sound waves bounce off the organs inside the body, and the microphone picks them up. The microphone links to a computer that turns the sound waves into a picture on the screen. This can help doctors to understand what an unusual lump might be.

The hospital will let you know how to help your child prepare for the test. For some types of ultrasound, it helps if your child has a full bladder.

After

Your child can usually eat, drink and play as normal after an ultrasound scan.

Chest x-ray

X-rays use high energy rays to take pictures of the inside of your body. Chest x-rays can show:

  • fluid
  • signs of infection
  • an enlarged heart
  • tumours in the chest

How

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.

Photograph of Child having a chest x-ray

After

Your child can usually eat, drink and play as normal after a chest x -ray.

CT scan

CT stands for computed tomography. A CT scan uses x-rays and a computer to create detailed pictures of the inside of your body. It takes pictures of the body from different angles. A computer then puts them together to give a series of pictures. It can help doctors find out what an unusual lump might be.

The scan itself is painless. Your specialist team will let you know how:

  • to help your child prepare
  • long your child needs to not eat or drink before their sedation
  • long the scan is likely to be

How

Your child might have an injection of contrast medium (a type of dye) through a small thin tube (cannula) in their hand or arm.

Many young children have a medicine to make them feel sleepy and relaxed (sedative) to help them lie still on the couch for the scan. The couch slowly slides backwards and forwards through the hole of the scanner. The machine takes pictures as it moves.

After

Your child stays on the day unit or the children's ward for a couple of hours after the scan. This is so the team can be sure they have recovered and are awake enough from the sedation. 

The nurses on the unit usually check that your child has:

  • had something to drink
  • had something to eat or some milk
  • had a wee

This can help the nurses see if your child has recovered from the sedative drugs.

MRI scan

MRI stands for magnetic resonance imaging. An MRI scan creates pictures using magnetism and radio waves.

Photograph of a child having an MRI scan

How

It produces pictures from angles all around the body and shows up soft tissues very clearly. It can help doctors find out what an unusual lump might be. It can also measure blood flow.

Many young children have a sedative or general anaesthetic to help them lie still on the couch for the scan. Most MRI scans involve around 30 minutes of lying still. Your child might have an injection of a special dye before or during the scan to help make the pictures clearer. 

After

Your child stays on the day unit or children's ward for a couple of hours after the scan. This is so the team can be sure they have recovered and are awake enough from the sedation. 

The nurses on the unit usually check that your child has:

  • had something to drink
  • had something to eat or some milk
  • had a wee

This can help the nurses see if your child has recovered from the sedative drugs.

Scans for infants

Your doctor might suggest you give your baby a feed as normal and then wrap them in a soft towel or blanket. This can help your baby lie still for their CT or MRI scan.

Babies that have had a feed and wrap scan don't need the same level of monitoring after. This is because they haven't had any medicine to make them feel sleepy.

Biopsy

Your child’s doctor might want to take a sample of the abnormal area seen on a scan. This is called a biopsy. A specialist doctor called a pathologist looks at the cells down a microscope to find out exactly what the lump is.

How

Your child is likely to have a general anaesthetic for this test. This means they are asleep and can’t feel anything during the test. 

An experienced doctor called a radiologist, or sometimes a children’s kidney surgeon, takes a small sample of cells using a needle. The doctor uses an ultrasound scan or another type of scan to help them choose the best place to biopsy.

After

When they wake up, your child has a small dressing over the needle site. Children can usually go home the same day, unless they need to stay in hospital for other tests.

A kidney biopsy is a safe test. Your child’s doctor goes through the risks and benefits with you. The most common risks are bleeding from the site or infection. Your team gives you a telephone number to call if you have any problems at home. If in doubt, give them a call.

Getting your results

You should get your results within 1 or 2 weeks.

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 nurses on freephone 0808 800 4040 for support. The lines are open from 9am to 5pm, Monday to Friday.

Treatment

Children with Wilms’ tumour are treated in a children’s cancer centre.

Last reviewed: 
18 Dec 2017
  • Cancer in Children – Clinical Management

    MCG Stevens, HN Caron and A Biondi (Editors)

    Oxford University Press, 2012

  • Feed and Wrap MRI Technique in Infants

    NK Antonov and others

    Clinical Pediatrics, 2016. Volume 56, Issue 12

  • The role of biopsy in the diagnosis of renal tumors of childhood: Results of the UKCCSG Wilms tumor study

    M Vujanić and others

    Pediatric Blood & Cancer, 2003. Volume 40, Issue 1

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