A brain tumor is an abnormal growth of cells within the brain, which can be cancerous or non-cancerous (benign). Brain tumors can be grouped by the type of cell involved (such as meningioma, astrocytoma, lymphoma, etc.) or by the location in the brain. Metastasized cells may grow in one or several areas of the brain. Almost half of all brain tumors are non-cancerous (benign), slow growing and respond well to treatment. A primary malignant brain tumour is a cancer which arises from a cell within the brain. The cells of the tumour grow into and damage normal brain tissue. Also, like benign brain tumours, they can increase the pressure inside the skull. However, unlike most other types of malignant tumours, primary brain tumours rarely spread (metastasise) to other parts of the body. A secondary malignant brain tumour means that a cancer which started in another part of the body has spread to the brain. Many types of cancer can spread (metastasise) to the brain. The most...