There are many different types of brain tumors, as well as different treatment options for each kind.

Brain tumors can be cancerous or benign. Both cancerous and benign brain tumors can press on surrounding brain tissue, causing serious disruptions in behavior and function. Though benign tumors will not spread to other organs, if they press on surrounding tissues they can still be life threatening.

Brain tumors are classified by the type of brain cells in which they begin, the location in the brain where they grow, and their grade. Brain tumor grades indicate how fast the tumor is likely to grow and how abnormal the cells look under a microscope when a pathologist examines them. Learn more about brain tumor grades.

Astrocytic tumors arise in astrocytes, which are cells that help nourish and repair neurons (nerve cells that send signals throughout the nervous system). Most astrocytic tumors can spread and infiltrate normal brain tissue, making it hard to completely remove them via surgery. Several subtypes of this tumor exist:

• Anaplastic astrocytoma is a grade III tumor that grows at a moderate rate.
• Brain stem glioma develops in the part of the brain that connects to the spinal cord and is often of high grade and hard to cure. It occurs often in children but also sometimes in middle-aged adults.
• Diffuse astrocytoma spreads readily but is often low grade.
• Glioblastoma is a grade IV, fast-growing tumor that is the most common malignant brain tumor in adults. It is also known as glioblastoma multiforme.
• Pilocytic astrocytoma is slow growing and rarely causes death. It occurs commonly in children and young adults as well as people with neurofibromatosis type 1.
• Pineal astrocytic tumors form in or around the pineal gland (a gland that produces a hormone responsible for the sleep-wake cycle). These tumors are rare and may be of any grade.

Oligodendroglial tumors begin with cells called oligodendrocytes, which make a substance that forms a protective sheath around neurons (nerve cells) and their extensions (axons). These tumors are often difficult to thoroughly remove because of how their ability to blend into normal surrounding brain tissue.

• Oligodendroglioma is a slow-growing, grade II tumor that most often forms in the larger, outer part of the brain that controls many of the body’s overall functions (the cerebrum).
• Anaplastic oligodendroglioma is an aggressive, grade III tumor.

Mixed gliomas are formed from both oligodendrocyte cells and astrocyte cells.

• Oligoastrocytoma is a grade II tumor that grows slowly.
• Anaplastic oligoastrocytoma is grade III, and its cells differ very much from normal cells.

Craniopharyngiomas are rare, slow-growing tumors that form at the base of the brain, near the pituitary gland. They can affect vision and the production of hormones and are most common in children.

Embryonal cell tumors or medulloblastoma form in immature cells in the cerebellum during early development and are fast growing. They occur most often in children or young adults.

Ependymal tumors (ependymoma) begin in the ventricles (fluid-filled spaces) in the central part of the brain. They usually do not infiltrate normal brain tissue, so surgery can remove and cure some of these tumors. But those that spread along pathways where cerebrospinal fluid flows can be difficult to treat. Anaplastic ependymoma is a high-grade, aggressive form of this tumor.

Germ cell tumors arise from germ cells, which are precursors of eggs or sperm. These tumors usually form in the center of the brain and can spread to other areas of the brain. Most occur in children and people with Klinefelter syndrome.

Lymphomas of the brain or central nervous system form in lymphocytes, which are white blood cells that defend against infection. Primary lymphomas that form in the central nervous system are rare. These are fast-growing tumors that can be hard to treat.

Meningiomal tumors form in the meninges, which are thin tissues that cover the brain and spinal cord. Most are grade I (slow-growing and benign). Higher-grade meningiomal tumors grow quickly and are quite rare.

Pineal parenchymal tumors form in the pineal gland but are different from pineal astrocytic tumors. A pineocytoma is slow growing and most often forms in adults, while a pineoblastoma forms most often in children and is rare, high grade, and likely to spread.

Schwannomas develop in Schwann cells, found in nerves in the ear and elsewhere in the skull. When these tumors arise from the nerves near the cerebellum that are responsible for balance, they are called acoustic neuromas or vestibular schwannomas. These tumors are very curable if removed early but can be life-threatening if they grow big enough to press on the cerebrum and other major parts of the brain.

Recurrent brain tumors are those that recur, or come back after removal. Many brain tumors recur, even years after the first tumor is found. Tumors may recur at the same place or in other parts of the brain or central nervous system.

Learn more about brain tumors:

• Brain Tumor Symptoms
• Brain Tumor Risk Factors
• Brain Tumor Grades