Neuroblastoma is a rare cancer that mostly affects young children. It develops from nerve cells called neuroblasts.
These cells are found in a chain running down the back of the chest and stomach (abdomen).
In many cases, neuroblastoma first develops in the adrenal glands (the two small glands above the kidneys) and can spread to other areas such as the bones, liver and skin.
Neuroblastoma affects around 100 children each year in the UK. It usually affects children under the age of five, and can even occur before a child is born.
The cause is unknown. There are very rare cases where children in the same family are affected, but it does not generally run in families.
Signs and symptoms
The symptoms depend on where the cancer is and whether it has spread.
It's often hard to diagnose neuroblastoma in the early stages, as initial symptoms are common ones – for example, aches and pains, loss of energy and loss of appetite.
A relatively late sign is a lump or swelling in the abdomen, as this is where the cancer commonly starts. This is easy to miss in a young child. This lump can cause constipation and difficulty passing urine, as well as general pain and discomfort.
Other signs can include:
- a lump in the neck
- bone pain and difficulty walking, if the bones are affected
- numbness, weakness or loss of movement in the child’s lower body, if the cancer has affected the spinal cord
- pale skin, bruising, bleeding and frequent infections, if the cancer has affected the bone marrow
- bluish lumps in the skin and the appearance of "black eyes"
A number of tests may be carried out if it's thought your child may have neuroblastoma.
These tests may include:
- urine analysis tests to check for certain chemicals found in the urine that are produced by neuroblastoma cells
- scans of various parts of the body to look for areas affected by the cancer – such as ultrasound scans, computerised tomography (CT) scans and magnetic resonance imaging (MRI) scans
- a special type of scan involving an injection of a substance that is taken up by neuroblastoma cells anywhere in the body, called an mIBG scan
- a biopsy (removal of a tissue sample for microscopic examination) will allow the cancer to be identified – the sample is typically removed under general anaesthesic using a special needle
If the lump is in one place and safe to remove with surgery, however, then a preliminary biopsy is not necessary.
Once these tests have been completed, it will usually be possible to confirm a diagnosis of neuroblastoma and what "stage" it is at (see below).
Stages of neuroblastoma
As with most cancers, neuroblastoma is defined by stages that reflect the condition's spread. There are many staging systems, but the most widely used until recently is shown first, with the more recently agreed stages in brackets:
- Stages 1 and 2 (L1) – the cancer is in one site and has not spread
- Stage 3 (L2) – the cancer has spread to local structures, but not to distant parts of the body
- Stage 4 (M) – the cancer has spread to distant parts of the body
- Stage 4s (Ms) – this special stage is for tumours diagnosed in babies under the age of 12 months; although it may have spread to other parts of the body, the outlook is fairly good, because it can get better on its own
Treatment and outlook
The outlook for neuroblastoma is generally better if the child is younger and the cancer is confined to one site.
Babies with Stage 4s neuroblastoma who have no symptoms may not need treatment, as the cancer may go away on its own.
Depending on the stage, chemotherapy is usually given to shrink the tumour before it is surgically removed, followed in some cases by radiotherapy to kill any remaining cancer cells.
Almost half of neuroblastoma cases are an aggressive form and, despite very intensive treatment, the cancer may return. In these cases, further treatment will often be necessary.