Astrocytoma.pdf

Astrocytoma is a type of glioma, a primary brain tumor that originates in brain tissue. There are two main types of glioma: astrocytoma and oligodendroglioma. Astrocytomas are rare, with less than 15,000 new cases diagnosed in the US each year, and have no known causes except for previous high-dose radiation exposure. Gliomas are characterized by invasive growth, forming roots that invade surrounding brain tissue, and cannot be surgically cured. Tumors are identified by histology and molecular-genetic expression, and are graded based on their aggressiveness. Higher grade tumors tend to be more aggressive, and some astrocytomas can be tested for certain proteins and genes, such as IDH and MGMT, which can influence treatment options. The most common type of astrocytoma is glioblastoma, a grade 4 tumor with approximately 12,000 diagnosed per year in the US. Other less common types of astrocytoma include pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and diffuse midline glioma.