Brain tumour. Section through a brain showing a large tumour (dark, right) in one of the temporal lobes. This is a glioblastoma, a relatively common brain tumour arising from astrocyte cells in the brain. Astrocytes are a type of glial cell, which support the brain's nerve cells. A glioblastoma is a fast-growing and malignant tumour. In common with other types of brain tumour, symptoms may include headaches, muscle weakness, epileptic seizures, sensory disturbances and speech difficulties. If the tumour is not accessible by surgery, radiotherapy and chemotherapy (anti- cancer drugs) may effect a cure, but the prognosis is usually bleak.