Malignant tumors in the brain are life-threatening, because of their aggressive and invasive nature. This is because the skull is a closed container, and when brain tumors take up space they compress the vital tissues and structures around them, causing serious neurological problems.
Some brain tumors are easier to remove and treat than others.
Brain tumors are classified according to the type of cell that makes up the tumor, or the cell type from which the tumor originated. An astrocyte is one type of glial cell, and the tumors that grow out of astrocytes are called astrocytomas. Meningiomas are tumors of the meninges, the membranes covering the brain. Metastic tumors are brain tumors that have originated elsewhere in body and have metastasized to the brain. In addition to being classified on the basis of cell type, malignant tumors are typically assigned a tumor grade, based on what the cancer cells look like under a microscope.