Central Nervous System Tumours

Key points

• • In adults most brain tumours are in the cerebral hemispheres, while in children they are more often below the tentorium in the posterior fossa.
• • Gliomas arise from glial cells, and the most malignant, glioblastoma, spreads through the brain but rarely outside it.
• • Meningiomas arise from the meninges, are usually benign and slow-growing, and press on the brain from outside.
• • Secondary (metastatic) tumours from the lung, breast and skin are actually the commonest brain tumours in adults overall.
• • Even a benign tumour is dangerous in the brain because rising pressure in the closed skull causes headache, vomiting and drowsiness.