There is no standardized staging system for brain cancer, but a grading system is used to determine the seriousness of a tumor. A grade IV brain tumor grows very quickly and easily spreads malignant cells to other parts of the brain, according to Johns Hopkins Medicine.
Grade IV tumors are also called high-grade tumors, reports the National Cancer Institute. When a pathologist looks at this type of tumor under a microscope, the cells appear very abnormal. In some cases, a grade IV tumor has some dead cells in it. Most grade IV tumors cannot be cured.
Nine different types of tumors form in the brain: astrocytic tumors, mixed gliomas, oligodendroglial tumors, medulloblastomas, ependymal tumors, pineal parenchymal tumors, germ cell tumors, craniopharyngioma and meningeal tumors. Each tumor affects a different type of cell or different part of the brain, according to the National Cancer Institute. Astrocytic tumors, for example, affect cells called astrocytes. Meningeal tumors grow in the lining covering the spinal cord and brain.
The National Cancer Institute reports that symptoms of a brain tumor vary based on the tumor's type, size, grade and location. Some of the symptoms associated with brain tumors include nausea and vomiting, loss of appetite, headaches that go away after vomiting, weakness, seizures, personality changes, vision problems, loss of balance, speech problems, difficulty walking, hearing problems, and unusual sleepiness.