Meningioma brain tumour, gross specimen. The front of the brain is at right. The tumour is at centre right at the optical chiasma, on the underside of the brain. A meningioma is a slow- growing benign (non-cancerous) tumour of the meninges, the three protective membranes that surround the brain and spinal cord. Its prevalence increases with age, and it is more common in women than men. As it grows it causes an increased pressure within the skull, which can lead to headaches, nausea and visual disturbances. Other symptoms depend upon the tumour’s location. Treatment is most often with surgical removal of the tumour, which leads to a complete cure..