Brain Tumours in Children

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Brain tumours in children are abnormal growths of cells in the brain or spinal cord. They are the most common solid tumours in children and can be either benign (non-cancerous) or malignant (cancerous). The tumour can affect brain function depending on its size, location, and rate of growth. Brain tumours in children differ biologically from those in adults and require specialised treatment approaches.

Aetiology

The exact cause of brain tumours in children is not well understood, but several factors may increase the risk:

• Genetic predisposition: Certain genetic conditions, such as neurofibromatosis, tuberous sclerosis, Li-Fraumeni syndrome, and Von Hippel-Lindau disease, increase the risk of brain tumours.
• Radiation exposure: Previous exposure to ionising radiation, especially for the treatment of other cancers.
• Family history: A family history of brain tumours or other cancers.
• Environmental factors: Though not well established, some studies suggest environmental exposures may contribute to the risk.

Pathophysiology

Brain tumours arise from the uncontrolled proliferation of abnormal cells within the brain or spinal cord. These tumours can originate from various types of brain cells, including glial cells (leading to gliomas) or embryonal cells (leading to medulloblastomas, the most common malignant brain tumour in children). As the tumour grows, it can compress surrounding brain structures, increase intracranial pressure (ICP), and disrupt normal neurological function.

Risk Factors

• Genetic syndromes such as neurofibromatosis or Li-Fraumeni syndrome.
• Previous exposure to radiation therapy.
• Family history of brain tumours or other cancers.
• Environmental exposures (less established in children).

Signs and Symptoms

Symptoms of brain tumours in children vary depending on the location and size of the tumour, but some common symptoms include:

• Headaches: Often worse in the morning and associated with nausea or vomiting. Morning headaches are a classic sign of increased intracranial pressure.
• Nausea and vomiting: Frequently seen with increased intracranial pressure, especially when associated with early morning symptoms.
• Seizures: New-onset seizures in a child without a history of epilepsy can be a sign of a brain tumour.
• Visual disturbances: Blurred vision, double vision, or loss of vision, often caused by increased pressure on the optic nerve.
• Balance and coordination problems: Difficulty walking, unsteady gait, or clumsiness, especially if the tumour is located in the cerebellum.
• Behavioural changes: Irritability, personality changes, or developmental regression.
• Weakness or sensory changes: Weakness in the arms or legs, changes in sensation, or difficulty moving certain parts of the body.
• Increased head size (in infants): In younger children, a growing head circumference may be a sign of increased intracranial pressure due to a brain tumour.

Investigations

• Neuroimaging: MRI is the preferred imaging technique to visualise brain tumours and assess their size, location, and involvement of surrounding structures. CT scans may be used if MRI is unavailable.
• Electroencephalogram (EEG): May be used to assess abnormal brain activity, particularly in children presenting with seizures.
• Blood tests: To assess overall health and rule out other causes of symptoms. Certain tumour markers may be tested in specific cases.
• Biopsy: In cases where the tumour is accessible, a biopsy may be performed to confirm the diagnosis and classify the tumour.
• Lumbar puncture: If the tumour is suspected to involve the cerebrospinal fluid, a lumbar puncture may be performed to detect malignant cells.

Management

The treatment and management of brain tumours in children depend on the type, size, location, and grade of the tumour. Multidisciplinary care involving neurosurgeons, oncologists, and paediatricians is essential.

First-line Treatment:

• Surgery: Surgical resection is the main treatment for many brain tumours. The goal is to remove as much of the tumour as possible while minimising damage to surrounding brain tissue.
• Chemotherapy: May be used either before surgery to shrink the tumour or after surgery to kill remaining cancer cells. It is also a treatment option for inoperable tumours.
• Radiation therapy: Often used for malignant brain tumours but is typically avoided in very young children due to potential long-term side effects on brain development.

Supportive Care:

• Management of increased intracranial pressure: Corticosteroids (e.g., dexamethasone) may be used to reduce swelling around the tumour and alleviate symptoms.
• Anticonvulsants: To manage or prevent seizures in children with brain tumours.
• Rehabilitation: Physiotherapy, occupational therapy, and speech therapy may be needed to support recovery and manage long-term effects.

Referral:

• 2-week wait (2WW) referral: Any child presenting with concerning neurological symptoms such as persistent headaches, morning vomiting, or new-onset seizures should be referred urgently under the 2-week wait cancer pathway for neuroimaging and specialist evaluation.
• Children with brain tumours should be managed by a multidisciplinary paediatric neuro-oncology team for optimal care.

References

1. NICE (2024). Brain Tumours in Children: Diagnosis and Management Guidelines. Available at: NICE Guidance
2. Cancer Research UK (2023). Paediatric Brain Tumours. Available at: Cancer Research UK
3. British Medical Journal (2023). Management of Brain Tumours in Children. Available at: BMJ