Diagnosis of neuroblastoma
Diagnosing neuroblastoma 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 neuroblastoma 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 neuroblastoma. It’s important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of neuroblastoma. If the doctor thinks your child has neuroblastoma, your child’s care will be managed by a healthcare team that specializes in caring for children with cancer.
The following tests are commonly used to rule out or diagnose neuroblastoma. Many of the same tests used to diagnose cancer are also used to determine the stage, which is how far the cancer has progressed. Your child’s doctor may also order other tests to check the child’s general health and to help plan treatment.
Health history and physical exam
Your child’s health history is a record of symptoms, risk factors and all the medical events and problems the child has had in the past. In taking a health history, the doctor will ask if there is a family history of neuroblastoma and if the child has a personal history of:
- symptoms that suggest neuroblastoma
- certain genetic conditions, such as neurofibromatosis type 1 (von Recklinghausen disease), Hirschsprung’s disease, Beckwith-Wiedemann syndrome, DiGeorge syndrome or nesidioblastosis (a condition of the pancreas)
A physical exam allows the doctor to look for any signs of neuroblastoma. During a physical exam, the doctor may:
- check for lymph nodes that are larger than normal, or enlarged
- feel the abdomen for a growth or enlarged liver
- check the skin for bluish movable lumps under the skin
- check the head and neck for any lumps or swelling
- check if the eyeballs are bulging (called proptosis) and if there is bruising around the eyes (called periorbital ecchymosis)
A neurological exam allows the doctor to check the function of the brain, spinal cord and nerves. It usually involves a series of questions and tests to measure mental status, coordination, movement and how well the muscles, senses and reflexes are working.
Find out more about physical exam.
A urine test, or urinalysis, is done to see if certain chemicals are in the urine. Some neuroblastoma cells make chemical substances called catecholamines. When these chemicals break down, they form homovanillic acid (HVA) and vanillylmandelic acid (VMA). Higher than normal levels of these acids in the urine may be a sign of neuroblastoma. Doctors also use HVA and VMA levels to check how well the neuroblastoma responds to treatment.
A urinalysis may also be done to check kidney function.
At some centres, a small amount of urine (10–20 mL) will be collected. Other centres may need you to collect and save the child’s urine over a 24-hour period.
Find out more about urinalysis.
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.
Blood chemistry tests may also be used in staging neuroblastoma. Doctors can also use blood chemistry tests as a baseline to check against during treatment.
Find out more about blood chemistry tests.
Blood tests for ferritin levels
The body stores iron as ferritin. Iron is a part of hemoglobin (a protein in red blood cells) and it is used to transport oxygen in the blood. Ferritin levels are checked to help doctors diagnose neuroblastoma and determine a prognosis.
Complete blood count (CBC)
A CBC measures the number and quality of white blood cells, red blood cells and platelets. Doctors use the results of a CBC as a baseline that they can check against during treatment.
Find out more about complete blood count (CBC).
Tumour marker tests
Tumour markers are substances in the blood that may mean neuroblastoma is present. They are usually proteins shed by the tumour cells.
The following tumour markers may be measured with neuroblastoma. These tests are used at some centres to check a child’s response to treatment and may also be used to help diagnose neuroblastoma.
Neuron-specific enolase (NSE) levels can be higher when a neuroblastoma is present. NSE is an enzyme made by neural cells and neuroblastoma tumours.
GD2 is a cell membrane ganglioside found on the surface of a neuroblastoma cell. GD2 is thought to make tumours grow faster.
Chromagranin A levels can be higher when a neuroblastoma is present. Chromagranin A is a protein made by neuroblastoma cells.
Lactate dehydrogenase (LDH) levels can be higher if a neuroblastoma is present. LDH levels may reflect the overall amount of tumour present in the child and whether it is actively growing. However, LDH levels are not specific for neuroblastoma.
Find out more about tumour marker tests.
An MIBG scan is an imaging test. It uses the radiopharmaceutical metaiodobenzylguanidine (MIBG) to find the neuroblastoma tumour and to see if the disease has spread to other tissues or bones. Doctors can also use MIBG scans to see if the tumour is responding to treatment.
About 10% of children with neuroblastoma have tumours that don’t take up MIBG, which means they can’t be found with an MIBG scan. These tumours are called MIBG negative. Whether or not a tumour takes up MIBG dye does not affect a child’s prognosis or treatment.
MIBG scans may not be available at all centres. Find out more about MIBG scan.
Bone marrow aspiration and biopsy
During a bone marrow aspiration and biopsy, the doctor removes tissues or cells from the bone marrow so they can be tested in a lab. A bone marrow aspiration and biopsy may be used to see if neuroblastoma has spread to the bone marrow. Usually the bone marrow tests are bilateral (performed from both sides).
Find out more about bone marrow aspiration and biopsy.
An x-ray uses small doses of radiation to make an image of the body’s structures on film. A chest or abdominal x-ray may be used to check for a mass in the chest or abdomen.
Find out more about x-ray.
A computed tomography (CT) scan uses special x-ray equipment to make 3-D 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 of the primary tumour may be done to show the size of the tumour and if it is touching or next to vital structures. This can help doctors decide whether or not it can be removed with surgery. CT scan may also be used to see if the cancer has spread to any organs or tissues.
Find out more about CT scan.
Magnetic resonance imaging (MRI) uses powerful magnetic forces and radio-frequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3-D pictures.
MRI can be used to find the tumour and determine its size. This can help doctors decide whether or not it can be removed with surgery. An MRI may also be used to see if tumours near the spinal cord are pressing on nerves.
Find out more about MRI.
Ultrasound uses high-frequency sound waves to make images of structures in the body. An ultrasound can be used to examine the abdomen to look for a tumour or find out what is causing swelling. It can also be used to examine organs that may be affected by neuroblastoma, such as the kidneys, spleen or liver.
Find out more about ultrasound.
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.
The type of biopsy done depends on where the neuroblastoma is in the body.
Incisional biopsy is a type of surgical biopsy. It may be done to remove part of the tumour through an incision, or cut.
Core needle biopsy may be used to remove part of the tumour using a needle. The doctor may use a CT scan or ultrasound to guide the needle during the biopsy.
A lumbar puncture, or spinal tap, removes a small amount of cerebrospinal fluid (CSF) from the spine so it can be examined under a microscope.
A lumbar puncture may be used to stage neuroblastoma. It is done to see if neuroblastoma has spread to the brain and spinal cord (called the central nervous system, or CNS).
Find out more about lumbar puncture.
Lymph node exam and biopsy
Doctors usually examine and take biopsy samples of enlarged lymph nodes. They will use a CT scan to get a 3-D image of lymph nodes that they can’t feel. This helps doctors decide whether or not to biopsy the lymph nodes.
Lymph node biopsy may be done if an enlarged lymph node is the only possible area where the tumour has spread or if it would be difficult or risky to biopsy the primary tumour.
Fine needle aspiration (FNA) may be done to remove tissue or fluid from a lymph node. The doctor uses a thin needle to draw a sample from the lymph node.
Core needle biopsy may be used to remove tissue from a lymph node. The doctor uses a needle to collect a sample from the lymph node. The needle is slightly larger than the type used in an FNA.
Incisional biopsy is a type of surgical biopsy. It may be used to remove part of a lymph node so it can be examined.
Excisional biopsy is another type of surgical biopsy. It may be done to remove the entire lymph node so it can be examined. This is the most common type of biopsy used to check lymph nodes for neuroblastoma. It can be done at the time of surgery to remove or biopsy the main tumour.
Molecular genetic methods
Molecular genetic methods are used in combinations with cell and tissue studies. They look at abnormalities in chromosomes (the part of a cell that contains genetic information) or the DNA of cells and tissue. Doctors use these methods to identify changes to the chromosomes and genes, such as duplications, translocations, mutations and deletions.
For neuroblastoma, molecular studies can help doctors determine if the cancer cells have the amplification (or many copies) of the MYCN gene, which is an oncogene. Molecular studies can also show DNA ploidy, or the amount of DNA content. Both are useful in determining prognosis for neuroblastoma.
Find out more about molecular genetic methods in 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 is used to see if neuroblastoma has spread to the bones (called bone metastasis). A bone scan may be done if a child has bone pain or if blood tests suggest a problem with the bones.
Find out more about bone scan.