Some types of primary brain tumors include astrocytomas, oligodendrogliomas, ependymomas, meningiomas and schwannomas, explains the Department of Neurological Surgery at the University of Pittsburgh. There are also germ cell tumors, pineal tumors and craniopharyngiomas, as well as secondary brain tumors, which are cancerous tumors that begin elsewhere in the body, and then eventually spread to the brain.
A primary brain tumor originates inside the brain rather than traveling to the brain from another part of the body, notes the Department of Neurological Surgery at the University of Pittsburgh. Within the category of primary brain tumors, gliomas, which are tumors that first begin developing in the supportive tissue called the glial tissue, are the most common. Astrocytomas, oligodendrogliomas and ependymomas are examples of gliomas. An astrocytoma stems from a type of cell called an astrocyte, while oligodendrogliomas come from the cells responsible for making the fatty myelin that protects nerves. Ependymomas usually affect children and teenagers, and they may grow inside the ventricles or in the spinal cord.
The medical community classifies brain tumors affecting the pineal gland based on how fast they grow, states the Department of Neurological Surgery at the University of Pittsburgh. A pineocytoma is the name for a pineal tumor that grows slowly, while fast-growing pineal tumors are called pineoblastomas. Because the pineal gland is in the middle of the brain, doctors are often unable to reach pineal tumors to remove them.