Anaplastic oligoastrocytoma is a brain tumor that forms when two types of cells in the brain, called oligodendrocytes and astrocytes, rapidly increase in number to form a mass. These brain cells are known as glial cells, which normally protect and support nerve cells in the brain. Because an oligoastrocytoma is made up of a combination of two cell types, it is known as a mixed glioma. An oligoastrocytoma is described as anaplastic when the tumor grows quickly and the cancer cells within the tumor have the potential to spread into surrounding brain tissue or to more distant parts of the body. Oligoastrocytomas usually occur in a part of the brain called the cerebrum and are diagnosed in adults between the ages of 30 and 50. The exact cause of this condition is unknown.

The symptoms of oligoastrocytoma depend on the size of the tumor and its exact location in the brain. The most common symptoms include headaches, seizures, and changes in personality.

Treatment of anaplastic oligoastrocytoma depends on the size and location of the tumor. If possible, treatment begins with surgery to remove as much of the tumor as possible. Chemotherapy or radiation therapy may be needed following surgery to destroy any remaining cancercells.