Children & families · Conditions
Posterior fossa tumours
Tumours at the back of the brain near the cerebellum, the most common site of brain tumours in children, including medulloblastoma, pilocytic astrocytoma and ependymoma.
What is it?
The posterior fossa is the space at the back and base of the skull that contains the cerebellum (which controls balance and coordination) and the brainstem. In children, it is the most common site for brain tumours. The main types are:
• Pilocytic astrocytoma: a slow-growing, usually benign tumour, often with a cyst. When it can be completely removed, surgery alone is often curative.
• Medulloblastoma: a malignant tumour that can spread through the fluid around the brain and spine. Treatment combines surgery with radiotherapy and/or chemotherapy, and the plan is guided by the tumour's molecular group. Many children are cured.
• Ependymoma: a tumour arising from the lining of the fluid spaces. The extent of removal is very important, and radiotherapy is often given afterwards.
What symptoms can it cause?
Because these tumours often block the flow of fluid, the first symptoms are frequently those of hydrocephalus: headaches, especially in the morning, vomiting and drowsiness. Others include unsteadiness, clumsiness, a head tilt, double vision or a squint. Babies may have a quickly growing head.
How is it assessed?
An MRI scan of the brain shows the tumour, and an MRI of the whole spine checks for spread. After surgery, a sample of spinal fluid may be tested for tumour cells. Your child's case is discussed at the multidisciplinary tumour board.
What are the treatment options?
Surgery to remove as much tumour as is safely possible is usually the first step, and also provides the diagnosis. Where it helps, fluorescence (5-ALA) guided resection and intraoperative neuromonitoring are used. Depending on the tumour type, further treatment may include chemotherapy and radiotherapy with the paediatric oncology team.
Managing hydrocephalus: many children have hydrocephalus when the tumour is found. Steroids may be given to reduce swelling. Sometimes a temporary drain is placed, or an endoscopic third ventriculostomy (ETV) is performed. Often, removing the tumour reopens the fluid pathways, but some children need a long-term shunt or ETV afterwards.
When might surgery be considered?
Surgery is recommended for most posterior fossa tumours, usually soon after diagnosis, especially when there is hydrocephalus. The options, benefits and risks are discussed with you in detail.
What to expect from recovery and follow-up
Most children are in hospital for about a week or more, sometimes starting in intensive care. Some children have temporary problems with balance, swallowing or speech. A small number develop posterior fossa syndrome (cerebellar mutism), with reduced speech and irritability a day or two after surgery, which usually improves gradually over weeks to months with therapy. Follow-up includes regular MRI scans and long-term support for learning, growth and hormone function.
When to seek urgent help
If your child is very drowsy, difficult to wake, has a seizure, repeated vomiting or a severe headache, go to the nearest emergency unit or call 10177. If your child is under our care, also call the hospital switchboard and ask for Dr Labuschagne (Netcare Unitas Hospital 012 677 8000; Nelson Mandela Children's Hospital 010 133 0600).
Dr Labuschagne's publications on this topic
- Labuschagne JJ. The use of 5-aminolaevulinic acid to assist gross total resection of paediatric posterior fossa tumours. Pediatr Neurosurg. 2020.
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This page is general information for parents and caregivers. Your child's doctor will advise on what applies to your child.