Childhood neuroblastoma – How is it diagnosed?

Neuroblastoma is a tumour that arises from specialised nerve tissue. They may occur in the neck, tissue at the back of the heart, along the side of the spinal cord in both the chest, abdomen and pelvis, or from the adrenal gland (a small  gland situated above both kidneys). 

They usually arise in children under the age of five. Symptoms vary depending on what part of the body is affected. If the tumour is in the abdomen, symptoms include pain, a mass or lump in the abdomen, changes in bowel habits, either diarrhoea or constipation, and blood in the urine. High blood pressure may also occur. 

Neuroblastoma in the chest may cause wheezing, chest pain, and changes to the eyes, including drooping of the eyelid usually on one side, and unequal pupil size. 

Other symptoms include lumps of tissue under the skin, particularly on the scalp, protruding eyeballs or proptosis, dark circles like bruises under the eyes, back pain, fever, unexplained weight loss, bleeding, and bone pain. 

The tests and procedures required to diagnose include a physical examination by a paediatric oncologist, urine and blood tests. These tumours may release certain hormones that are able to be picked up in the urine and blood. 

Imaging may reveal a mass. Imaging required depends on the location of the tumour but includes an ultrasound of the abdomen, a chest X-ray and CT scans of the brain, neck, chest, and abdomen.

Depending on the age of the child, an anaesthetic or sedation may be required. A biopsy or removal of some of the tumour tissue is required to make the diagnosis. This can be done using an ultrasound or CT scan to guide the radiologist where to insert the needle into the tumour, or a surgeon may need to do an operation to remove either the whole tumour or a small piece of the tumour. 

Additional investigations needed to stage patients include a bone marrow, bone scan, MIBG or Dotatate PET-CT scan. 

A bone scan uses nuclear imaging to diagnose or track different bone diseases. A small amount of a radioactive compound is injected into the child via a drip. A special camera is then used to assess the entire skeleton for signs that the neuroblastoma may have spread to the bones. Sedation may be required in young children.

An MIBG is also a nuclear imaging test. It’s like a bone scan but uses a different iodine-based radioactive compound to look for spread of the tumour in different areas of the body.

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