Malignant disease - Brain tumours

Question 1

Brain Tumours

Answer 1

• brain tumours in children are almost always primary and 60% are infratentorial.
• most common solid tumour in children and are the leading cause of childhood cancer deaths in the UK

The types of brain tumour are:

• Astrocytoma (∼40%) – varies from benign to highly malignant (glioblastoma multiforme)
• Medulloblastoma (∼20%) – arises in the midline of the posterior fossa. May seed through the CNS via the CSF and up to 20% have spinal metastases at diagnosis
• Ependymoma (∼8%) – mostly in posterior fossa where it behaves like medulloblastoma
• Brainstem glioma (6%)
• Craniopharyngioma (4%) – a developmental tumour arising from the squamous remnant of Rathke pouch. It is not truly malignant but is locally invasive and grows slowly in the suprasellar region

Question 2

Clinical features

Answer 2

Signs and symptoms are often related to evidence of raised intracranial pressure but focal neurological signs may be detected depending on the site of the tumour (see below). Spinal tumours, primary or metastatic, can present with back pain, peripheral weakness of arms or legs or bladder/bowel dysfunction, depending on the level of the lesion

Question 3

Investigations

Answer 3

Brain tumours are best characterised on MRI scan. Magnetic resonance spectroscopy can be used to examine the biological activity of a tumour. Lumbar puncture must not be performed without neurosurgical advice if there is any suspicion of raised intracranial pressure

Question 4

Management

Answer 4

Surgery is usually the first treatment and is aimed at treating hydrocephalus, providing a tissue diagnosis and attempting maximum resection. In some cases the anatomical position of the tumour means biopsy is not safe, e.g. tumours in the brainstem. Even tumours which are histologically ‘benign’ can cause major challenges to survival. The use of radiotherapy and/or chemotherapy varies with tumour type and the age of the patient.