Types of Brain Tumors
There are many types of brain tumors, including primary and secondary brain tumors.
Primary brain tumors
Primary brain tumors start in the brain. They are named by the type of brain tissue in which they are found. The most common primary brain tumors are gliomas, which begin in the glial, or supportive, tissue of the brain.
These are some of the many types of gliomas. Some gliomas tend to grow slowly, while others grow and spread quickly. Some types of gliomas include:
Astrocytomas. These tumors come from the small star-shaped cells called astrocytes. They can grow anywhere in the brain or spinal cord. In adults, astrocytomas usually occur in the cerebrum. In children, they occur in the cerebellum, cerebrum, and brain stem. Most astrocytomas spread into nearby normal brain tissue and are very hard to cure with surgery. Glioblastomas are a type of astrocytoma that tend to grow very quickly.
Brain stem gliomas. These tumors of the brain stem are more common in children than in adults. Because the brain stem controls many important functions, such as breathing and heart rate, these tumors usually cannot be removed by surgery.
Ependymomas. These tumors start in cells that line the ventricles (fluid-filled spaces within the brain). They usually do not grow into nearby brain tissue, which means they can sometimes be cured with surgery.
Oligodendrogliomas. These tumors start in cells that make myelin, the fatty substance that surrounds nerve cells. Like astrocytomas, these tumors tend to spread into nearby normal brain tissue and are very hard to cure with surgery.
Optic nerve gliomas. These tumors occur in or around the nerve that sends messages from the eyes to the brain and can cause vision changes or hormonal changes (due to their location near the pituitary gland).
Other types of tumors can start in and around the brain as well:
Primitive Neuroectodermal Tumors (PNETS). These tumors occur more often in children and can occur anywhere in the brain in the primitive form of nerve cells. One type is the medulloblastoma.
Medulloblastomas. These tumors start in primitive forms of nerve cells and are found in the cerebellum. They are more common in children than in adults. They tend to grow and spread quickly, but they can often be treated effectively.
Tumors of the pineal gland. These tumors grow in and around the pineal gland, a tiny organ near the center of the brain. The tumors can be slow-growing, called pineocytoma, or fast-growing, called pineoblastoma.
Pituitary tumors. These tumors start in the pituitary gland at the base of the brain. They are almost always benign, but they can cause serious symptoms because of their location and because they sometimes secrete excess hormones.
Craniopharyngiomas. These tumors start near the pituitary gland. They are usually slow growing but can cause symptoms if they press on the pituitary or on nearby nerves.
Schwannomas. These tumors start in myelin-making cells that surround certain nerves. They are most common in the nerve in the inner ear that helps with balance, in which case the tumor is called a vestibular schwannoma or an acoustic neuroma. These tumors are usually benign.
Meningiomas. These tumors start in the outer linings of the brain and spinal cord. They are more common in adults. Most meningiomas can be removed with surgery, although some may come back.
Primary central nervous system lymphomas. Primary central nervous system lymphoma is an aggressive, rare type of tumor derived from lymphocytes, a type of immune cell. It is more common in people with a disease of the immune system, such as AIDS. But it can also be seen in otherwise healthy individuals.
Secondary brain tumors
Secondary brain tumors are also known as metastatic brain tumors. These are cancers that start in another organ and then travel to the brain. In adults, secondary brain tumors are actually more common than primary brain tumors. Cancer in the brain that has spread from these cancers is not considered brain cancer. They are still the same type of cancer as where they started. For instance, lung cancer that has spread to the brain isn’t called brain cancer; it is called metastatic lung cancer. These are the most typical cancers that spread to the brain:
Germ cell cancer