Brain Tumors

Astrocytoma

These tumors arise from star-shaped brain cells called astrocytes. Astrocytomas can arise anywhere in the brain, but in adults they usually arise in the largest part of the brain known as the cerebrum. In children, they develop in the cerebellum, brain stem, and cerebrum. Astrocytomas are graded from I to IV with the least aggressive designated grade I and the most aggressive, or rapidly growing, designated grade IV. Grades I and II astrocytomas are called low grade astrocytoma.Grade III astrocytomas are sometimes also called anaplastic astrocytomas and grade IV astrocytomas are usually referred to as glioblastoma multiforme or GBM.

Schwannoma

This is a tumor that arises from the Schwann cell. These cells are present in nerves, including those that control balance and hearing. One common site of schwannoma growth is on the vestibular nerve, which carries signals from the inner ear to the brain stem. Tumors arising in this location are called acoustic neuroma (AN), although a more correct name is vestibular schwannoma (VS). These tumors occur most often in adults and produce progressive hearing loss in one ear. Some patients with a genetic condition called neurofibromatosis or NF have vestibular schwannomas on both sides (see picture). Patients with this genetic disorder may have schwannomas in other locations and can develop meningiomas as well.

Ependymoma

This tumor arises from cells that line the ventricles, which are the fluid-filled spaces within the brain, or from the central canal of the spinal cord. They more commonly occur in children and young adults and can develop either in the ventricles or within the substance of the brain.

Glioblastoma multiformeGlioblastoma

is the most common and one of the most aggressive primary brain tumors. It can arise from changes in the growth pattern of either a low grade astrocytoma or an anaplastic astrocytoma. Alternatively, GBM may arise de novo without any prior history of a lower grade primary brain tumor. Because of its aggressive nature, treatment of glioblastoma usually involves a combination of surgery, radiation therapy and chemotherapy.

Grade 3 astrocytoma

Brain stem glioma

This type of tumor is usually an astrocytoma that is distinguished by the specific brain location in which it arises. Brain stem gliomas are most frequently diagnosed in young children and in middle-aged adults. They can produce serious neurologic symptoms due to their location in close proximity to critical brain structures. Treatment usually involves a combination of radiation therapy and chemotherapy. Surgical treatment is possible only rarely.

Craniopharyngioma

CraniopharyngiomatThis tumor (pictured left) grows at the base of the brain and arises from the band of tissue that connects the brain and the pituitary gland. Craniopharyngiomas occur in both adults and in children and generally consist of solid tumor tissue and a fluid-filled cyst. Treatment usually involves microneurosurgery; however, radiation therapy and gamma knife (radiosurgery) may be used in some cases as well.

Pituitary Adenoma

These are common tumors that arise from the pituitary gland located at the base of the brain. If they grow large enough, they can compress the optic nerves causing serious vision problems. Such tumors are called macroadenomas (pictured right) . Smaller tumors are known as microadenomas. Some pituitary tumors produce excessive amounts of hormones that can disrupt the bodyﾒs metabolism. Pituitary tumors compress the normal pituitary gland and can adversely affect its function. Some pituitary tumors can be treated medically with drugs like bromocryptine and octreotide. Others must be treated surgically. For some patients, conventional radiation therapy and gamma knife (radiosurgery) can be used effectively as well.