Meningioma brain tumour. Coloured magnetic resonance imaging (MRI) scan of an axial section through the brain of an 87-year-old female patient with a large (6.5 cm) cystic meningioma (top, highlighted) affecting the ventricular structures. A meningioma is a slow-growing, usually benign (non-cancerous) tumour that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumour pressing on nearby tissue. Here, it has caused problems with coordination, leading to walking disorders and falls.