The commonest benign brain tumours we see are meningiomas, pituitary tumours and schwannomas, which usually grow very slowly, and may become two to four centimetres in size before they are detected. They may compress adjacent structures, such as specific nerves (hearing, vision, eye movements), or the brain surface, giving rise to focal deficits (difficulty dressing, word finding), or seizures (fits). For many, all that is necessary is to watch the rate of growth of the tumour with serial scans, but sometimes the tumours need to be removed. Some are better treated with focussed radiotherapy (stereotactic radiotherapy), or occasionally a combination of surgery and radiotherapy.
If operation is necessary there are three main routes used to access the tumour.
Transphenoidal– an approach through the nose used to remove most pituitary tumours.
Transcranial– an approach through the skull, taking a disc of bone out, to gain access to the tumour, removing the tumour, then replacing the bone and closing the scalp, commonly used in the removal of a meningioma.
Translabarynthine– an approach just behind the ear, when hearing has already been lost, to remove a tumour of the inner ear such as a vestibular schwannoma.
Malignant brain tumours are often diagnosable from the short history and the appearances of the CT or MR scan, and are best treated in the multidisciplinary setting of the Edinburgh Centre for Neuro-oncology, at the Western General Hospital, Edinburgh.