Diagnosis of childhood bone cancer

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Diagnosis is the process of finding out the cause of a health problem. Diagnosing childhood bone cancer usually begins with a visit to the doctor. The doctor will ask about any symptoms you have noticed and do a physical exam. Based on this information, the doctor may refer you to a specialist or order tests, such as an x-ray, to check for bone cancer or other health problems.

The process of diagnosis may seem long and frustrating. It's normal to worry but try to remember that other health conditions can cause similar symptoms as bone cancer. It's important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of bone cancer.

The following tests are commonly used to diagnose or rule out bone cancer in children. Many of the same tests used to diagnose cancer are also used to determine the stage, which is how far the cancer has progressed. The doctor may also order other tests to check general health and to help plan treatment.

Health history and physical exam

Your child's health history is a record of symptoms, risks and all the medical events and problems that they have had in the past. The doctor will ask questions about your child's health history, including their personal or family history of certain genetic conditions.

A physical exam allows the doctor to look for any signs of bone cancer. During a physical exam, the doctor may check for any swelling or lumps and see how much the child can move the affected arm, leg or joint.

Find out more about physical exams.

X-ray

An x-ray uses small doses of radiation to make an image of the body’s structures on film. Doctors usually x-ray a bone first to find out what is wrong with the bone.

Find out more about x-rays.

Complete blood count (CBC)

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check if the cancer has spread to or is affecting the bone marrow. It is also used as a baseline that doctors can check against during treatment for bone cancer.

Find out more about complete blood count (CBC).

Blood chemistry tests

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are functioning and can help find abnormalities. Doctors can use blood chemistry tests as a baseline that they can check against during treatment.

Find out more about blood chemistry tests.

CT scan

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. A computer turns the images into detailed pictures.

A CT scan is used to check if cancer has spread to the lungs or other organs. A CT scan of the chest can be used to see if cancer has spread to the lungs. A CT scan can also be used to check spread to other organs.

Find out more about CT scans.

MRI

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.

MRI is used to:

  • get more details about the bone tumour, soft tissues around the tumour and the bone marrow cavity
  • check for spread to other organs
  • help choose sites for biopsy
  • help plan surgery

Find out more about MRIs.

PET scan or PET-CT scan

A positron emission tomography (PET) scan uses a type of radioactive sugar to look for changes in the metabolic activity of body tissues. A computer 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 the lungs, other bones or other areas of the body. It can also be used to check how chemotherapy is working.

A PET scan is often combined with a CT scan. This is called a PET-CT scan and it provides a more complete picture and 3D assessment of the tumour.

Find out more about PET scans.

Bone scan

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

Find out more about bone scans.

Biopsy

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. The report from the lab will confirm whether or not cancer cells are present in the sample.

A biopsy is the only way to make a definite diagnosis of childhood bone cancer. To help choose the best area to biopsy, doctors do an MRI or CT scan, or both.

The area where the biopsy is taken will need to be removed during surgery to remove the tumour, so planning for the biopsy and possible surgery is very important. The biopsy is usually done by the same surgeon who will do the surgery to remove the cancer, or the biopsy is done under their direction. Planning the biopsy and surgery together helps prevent complications and can mean less surgery is needed. Planning is especially important to help determine if limb-sparing surgery is a treatment option.

Surgical biopsy is the most common type of biopsy used. The surgeon cuts through the skin to reach and remove a piece of the tumour from the bone or part of the tumour that has grown into the soft tissues. Find out more about surgical biopsies.

Core needle biopsy is sometimes used. During a core needle biopsy, the doctor uses a needle to remove a small sample from the tumour. If the tumour is deep in the body, the doctor may use a CT scan to guide the needle into the tumour. This approach is recommended for tumours in certain bones, including the spine or pelvis. Find out more about core needle biopsies.

Bone marrow aspiration and biopsy may be used to see if cancer has spread to the bone marrow. During bone marrow aspiration and biopsy, the doctor removes tissues or cells from the bone marrow so they can be tested in a lab. Find out more about bone marrow aspiration and biopsy.

Cell and tissue studies

Doctors can use the following types of cell and tissue studies to help diagnose childhood bone cancer.

Cytogenetics is the analysis of a cell's 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 and predict how well the treatment will work.

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.

Find out more about cell and tissue studies.

Preparing your child for tests

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.

Questions to ask your healthcare team

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

Expert review and references

  • Abha Gupta, MD, MSc, FRCPC
  • Raveena Ramphal, MBChB, FRACP