Brain cancer. Magnetic resonance imaging (MRI) scan of a sagittal section through the left hemisphere of the brain of a 35-year-old male patient, showing the presence of a large lesion (dark, upper centre), suggestive of a primitive neuroectodermal tumour. Primitive neuroectodermal tumours are rare malignant (cancerous) tumours that usually occur in children and young adults under 25-years-old. The overall 5 year survival rate is about 53 percent. Here, the diagnosis was confirmed through biopsy of the affected tissue.