Diagnosis of childhood bone cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing cancer often means first ruling out other health conditions that share similar symptoms with cancer. It can be a very worrying time for you, your child and your loved ones. Sometimes this process is quick. Sometimes it can feel long and frustrating. But itʼs important for doctors to get all the information they need before making a diagnosis of cancer.

Diagnosing childhood bone cancer usually begins with a visit to your child’s doctor. The doctor will ask about any symptoms your child has and do a physical exam. Based on this information, the doctor may refer your child to a specialist or order tests to check for bone cancer or other health problems.

The following tests are usually used to diagnose bone cancer in children. Many of the same tests used to diagnose cancer are also used to find out the stage of the cancer (how far the cancer has spread). The doctor may also order other tests to check general health and to help plan treatment.

Your child’s health history is a record of the symptoms and risks and all the medical events and problems that they have had in the past. The doctor will ask questions about your childʼs health history, including their personal or family history of certain genetic conditions such as familial retinoblastoma or Li-Fraumeni syndrome.

A physical exam allows the doctor to look for any signs of childhood bone cancer. During a physical exam, the doctor may:

• check for pain, swelling or a lump around a bone
• look at how much a leg, arm or joint can move

Find out more about physical exams.

An x-ray uses small amounts of radiation to make an image of parts of the body on film. It is usually the first test done to look for bone cancer.

Find out more about x-rays.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

An MRI is used to confirm the diagnosis of a bone tumour found on an x-ray. Doctors can also use it to see if the cancer has spread into other parts of the bone or surrounding tissues.

Very young children may be sedated with a general anesthetic to keep them still during the procedure. This means they will be asleep during the scan.

Find out more about MRIs.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. Computer software turns the images into detailed pictures.

A CT scan may be used if an MRI can’t be done. Doctors may use a CT scan to confirm the diagnosis of a bone tumour found on an x-ray.

A CT scan of the chest is used to see if cancer has spread to the lungs.

Find out more about CT scans.

During a biopsy, the doctor removes tissues or cells from the body so that they can be tested in a lab. A report from a pathologist will show whether or not cancer cells are found in the sample. Doctors will do a biopsy to confirm the diagnosis of bone cancer and find out which type of tumour it is.

A surgical biopsy uses surgery to remove tissue from a lump to look at under a microscope. It’s the most common type of biopsy used for childhood bone cancer. This test may also be called an open biopsy.

A core biopsy uses a hollow needle or probe to remove tissue from the body.

A bone marrow aspiration and biopsy uses a needle to remove a sample of bone marrow. Bone marrow is the soft and spongy tissue inside the bones. This procedure may be used to see if cancer has spread to the bone marrow.

Doctors often use an x-ray, MRI or CT scan to guide them during a biopsy.

Find out more about biopsies.

A positron emission tomography (PET) scan uses radioactive materials called radiopharmaceuticals to look for changes in the metabolic activity of body tissues. Computer software analyzes the radioactive patterns and makes 3D colour images of the area being scanned.

A PET scan may be used to see if bone cancer has spread to other bones or other areas of the body.

A PET scan may be combined with a CT scan (called a PET-CT scan) to give your healthcare team more information.

Find out more about PET scans.

Cell and tissue studies look closely at the cells of a tumour to determine the type of bone cancer. Cells can be taken from tissue removed during a biopsy or surgery.

Cytogenetics is the analysis of a cellʼs chromosomes, including their number, size, shape and arrangement. Cytogenetic techniques show chromosomal abnormalities, which help doctors confirm the diagnosis and identify the type or subtype of bone cancer. The results of cytogenetic studies also help doctors plan treatment.

Immunophenotyping is the study of proteins expressed by cells. It uses a very specific antigen-antibody reaction to identify specific proteins in tissues or cells. It uses antibodies marked with a fluorescent label that bind only to specific proteins. The fluorescent label and the pattern of proteins that are expressed allow doctors to identify the cancer cells so that they can diagnose the specific type or subtype of bone cancer.

Molecular testing analyzes a cell’s genetic material to look for genetic changes, such as mutations, to identify the type of bone cancer and how it behaves. This helps doctors confirm the diagnosis and plan treatment, such as if targeted therapy can be used.

One of the changes that doctors look for with childhood Ewing sarcoma is a chromosomal abnormality called a translocation. A translocation happens when a piece of a chromosome changes places with a piece from another chromosome. Ewing sarcoma tumours have a translocation in which a piece of chromosome 11, or sometimes chromosome 21, changes places with a piece of chromosome 22.

Find out more about cell and tissue studies.

A bone scan uses bone-seeking radioactive materials called radiopharmaceuticals and a computer to create a picture of the bones. It’s used to find out if bone cancer has spread to other bones.

Find out more about bone scans.

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working and can help find problems. Blood chemistry tests are done to give your healthcare team information about your child’s general health. They are usually done before treatment, such as chemotherapy, is given.

Find out more about blood chemistry tests.

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to give your healthcare team information about your childʼs general health. It’s used as a baseline that doctors can check against during treatment for bone cancer.

Find out more about a complete blood count (CBC).

Children react to having these tests in different ways. Preparing your child for tests can help. Find more information on helping your child cope with tests and treatments.

To make the decisions that are right for your child, ask the healthcare team questions about diagnosis.