Brain cancer after surgery. Coloured magnetic resonance imaging (MRI) scan of a section through the head of a 59-year-old male patient with glioblastoma multiforme, showing some improvement in the disease affecting the white matter after surgery. Glioblastoma multiforme is a malignant (cancerous) tumour that arises from astrocytes, one of the support cells of the brain. It is an aggressive cancer with a poor prognosis. Here, the cancer in the right temporo-parietal cavity (lower right) has largely improved. However, a small lesion is still evident and a new area of potential disease (green) is now evident in the cortex of the occipital lobe.