Brain Tumor Fact Sheets

• Meningiomas are tumors that grow on the delicate outer covering of the brain. This covering is called the meninges.
• Meningiomas account for approximately 33.8% of all primary brain tumors, making them the most common type. This number is probably low as some meningiomas may never be diagnosed. Two percent of routine autopsies reveal undiagnosed primary brain tumors.
• Meningiomas account for approximately 20.7% of all intracranial tumors in males and 43.7% in females. Meningiomas are more common in women than in men, with 74% of all diagnosed meningiomas occurring in women.
• The prevalence of meningioma is estimated to be approximately 70.6 in 100,000 in the United States with over 206,856 individuals currently diagnosed with this tumor.
• The Central Brain Tumor Registries of the United States predict that within the U.S. over 21,270 new cases of meningioma will be diagnosed.
• This type of primary brain tumors grow slowly in the brain and usually do not spread to other parts of the body. Meningiomas can grow anywhere on the brain's meninges, and as a result can affect sensory (sight, hearing, touch) and cognitive (memory, judgment) functioning.
• Meningiomas often do not cause symptoms until the tumor is quite large, often resulting from the tumor compressing parts of the brain. Symptoms of meningioma patients may include: headache, vision problems, behavioral changes, and seizures. A patient may have subtle symptoms for a long period of time before the meningioma is diagnosed.
• Meningiomas may be categorized as benign (90%), atypical/borderline (7–8%) and malignant (2–3%). Within the benign category, there are several subtypes: syncytial, fibrous and transitional. With the exception of malignant meningioma, these classifications are imprecise with respect to prediction of patient outcome or response to treatment.
• Meningiomas occur most often in patients between the ages of 40 and 70 years old. Meningiomas are rare in children and only 2.5% of all meninigomas occur in childhood and adolescence (Age 0–19).
• The cause of meningiomas is unknown. Risk factors for meningiomas include prior radiation exposure to the head, and a genetic disorder called neurofibromatosis type 2 (NF2), which affects the nervous system and the skin. Many patients with meningiomas have no risk factors.
• Surgery often is the best treatment option for meningioma. The location of the tumor may make surgery impossible or may prevent complete removal of the tumor. Other treatment options include radiation and radiosurgery, which is the precise delivery of radiation to the tumor using special procedures.
• Meningiomas can recur despite successful surgery. The recurrent tumor may be a faster growing, higher-grade tumor. Chemotherapy and biological agents are being studied for the treatment of recurrent meningiomas.

Download "Your Meningioma Diagnosis" (PDF, 17KB)

Read the Brigham and Women's Department of Neurosurgery Meningioma FAQ's

Medical content reviewed September 8, 2002 by Elizabeth Noll, Director of Neurosurgical Research Affairs, Brigham and Women's and Children's Hospital.

Statistics were updated July 2010 based on CBTRUS Statistical Report of 2010.

• GBMs are malignant tumors that commonly invade adjacent tissue and spread through the CNS. “Astrocytoma grade IV,” “glioblastoma multiforme,” “glioblastoma,” and “GBM” are different names for the same tumor.
• GBMs most frequently arise in the white matter of the frontal lobes of the brain, but can occur anywhere in the cerebral hemispheres.
• GBMs represent about 17.1% of all primary brain tumors and about 70.5% of the astrocytomas. They are most common in older adults.GBMs occur only very rarely in children; only about 2.8% of pediatric brain tumors are GBMs.
• GBMs account for 2.9% of all intracranial tumors in males and 1.9% in females.
• There are about 104,652 people currently diagnosed with GBM, with an additional 10,761 expected new cases in 2010.
• GBM grow very quickly, so the first symptoms are usually caused by increased pressure in the brain. Headaches, seizures, memory loss, and changes in behavior are the most common presenting symptoms.
• GBMs are slightly more common in women than in men, with 57% of all diagnosed GBMs in women.
• GBMs are the most diverse in the type of cells that can be found in the tumor. This makes it one of the most difficult brain tumors to treat because while one cell type may be responsive to treatment and die off, other cell types may not respond to the therapy.
• If a GBM is in an accessible location, the first step in treatment is surgery. Unfortunately, since cells of the tumor invade other areas of the brain, surgery is usually not enough to fully treat a GBM. It is almost always recommended that surgery be followed up with radiation therapy.
• Chemotherapy could be given before, during, or after radiation. Chemotherapy might be used in children under the age of 3 to delay radiation, which can have severe effects on a child’s growing brain.
• Recurrent tumors can often be treated with additional surgery, chemotherapy, and/or radiation therapy.

Medical content was reviewed by Dr. Peter Black of Brigham and Women's Hospital, December 2003.

Statistics updated July 2010 based on CBTRUS Statistical Report of 2010.

• Pituitary tumors are growths, usually benign, occurring within the pituitary gland. Also known as pituitary adenomas, these tumors can be broken down into two types: secreting and non-secreting. Secreting tumors produce excessive amounts of hormones such as prolactin, growth hormone, or thyroid stimulating hormone. Non-secreting tumors fail to release any hormones.
• The pituitary gland is a small organ located in the center of the brain behind the nose. The pituitary gland’s functioning role is secretion of the hormones that control muscle and bone growth, along with sexual development. Many of the hormones secreted by the pituitary gland control the activities of other organs in the body.
• Pituitary tumors are the third most common type of primary brain tumors in adults and account for 12.7% of all intra-cranial tumors. These tumors most frequently affect adults between the ages of 20 and 55.
• Pituitary tumors account for approximately 13.4% of all intracranial tumors in males and 12.2% in females.
• Since most pituitary tumors are benign (99.53% are non-malignant), they grow slowly and do not metastasize, or spread to other parts of the body. They are basically growths found in or around the pituitary gland. Symptoms resulting from a pituitary tumor may include vision loss, headaches, nausea, vomiting, or any of the problems caused by the production of too many hormones such as heat or cold intolerance, abnormal growth, high blood pressure, loss of menstrual periods in women, or breast enlargement and secretion.
• Treatment of pituitary tumors may include surgical removal of the tumor; drug therapy, using medicine to block the pituitary gland from producing too many hormones; or radiation therapy, using high-doses of Xrays to kill tumor cells. Surgery is the most common treatment and they are best treated when they are found and diagnosed early. Transsphenoidal surgery is often used for pituitary adenomas because it is less invasive. It involves making an incision in the upper gum line or nasal cavity and removing the tumor through the base of the skull.
• There is a chance of recurrence with pituitary tumors. Follow-up MRI scans and appointments with your neurosurgeon may be necessary.
• The cause of pituitary tumors is unknown. They are usually curable; however, prognosis depends on the type of tumor and the patient’s age and general state of health.

For more information: Pituitary Network Association, pna@pituitary.org

Medical content was reviewed by Dr. Peter Black of Brigham and Women's Hospital. December 2003.

• This is the most common type of glioma, and develops from the star-shaped cell known as an astrocyte.
• Astrocytoma account for approximately 6.8% of all primary brain tumors.
• These can form anywhere in the brain and at times in the spinal cord.
• They are most commonly found in the frontal or temporal lobes in the cerebrum.
• These primary brain tumors can be benign or malignant.
• Grading is very important in defining a brain tumor. Astrocytomas are graded 1–4.
• A grade 1 tumor means that the cells within the tumor resemble normal brain cells very closely and are usually slow growing and unlikely to spread.
• A grade 4 tumor means that the tumor cells are very abnormal when compared to normal brain cells. Grade 4 astrocytomas are also known as glioblastomas and are very malignant.
• There are 3 types of astrocytomas:
  • Low-Grade Astrocytomas: present in both children and adults
  • Anapalastic Astrocytoma: this is a mid-grade tumor that can spread to surrounding areas
  • Glioblastoma Multiforme: This is a high-grade very aggressive tumor that can spread rapidly to neighboring brain tissue.
• Symptoms in children can include movement disorders.
• Treatment generally includes surgical removal, possibly followed by radiation therapy.

Medical content was reviewed by Dr. Alex Golby of Brigham and Women's Hospital, February 2004.

• A rare type of primary brain tumor (2.1% of all primary brain tumors) that develops from cells called oligodendrocytes that produce the fatty covering of nerve cells.
• This tumor is found primarily in the cerebrum, in the frontal or temporal lobes.
• Oligodendrogliomas are divided into two types; a well-differentiated tumor, which grows slowly, and second type known as an anapalastic oligodendrogliom, which grows faster.
• Oligodendroglioma is a type of glioma which is graded 1-4. This grading defines how abnormal the cells are and how rapidly they grow. Grade 1 is the least malignant, while grade 4 is very malignant.
• More common in adults but can present in children, occurs more often in men than women.
• Those with a slow growing oligodendroglioma may have a tumor for many years before becoming symptomatic.

Symptoms vary depending on where in the brain the tumor is situated. Oligodendrogliomas are most often found in the frontal or temporal lobes where symptoms include gradual changes in mood and personality, one-sided paralysis (hemiparesis), coordination and speech issues as well as memory loss.

Medical content was reviewed by Dr. Dong Kim of Brigham and Women's Hospital, March 2004.

• A rare type of glioma (1.9% of all primary brain tumors) that grows from the ependymal cells, which line the pathways that carry and produce cerebrospinal fluid.
• There are three classifications for ependymomas; supratentorial (at the front of the head), infratentorial (back of the head) and spinal (myxopapillary) ependymoma.
• These primary brain tumors can occur in all age groups. Tumors that grow at the base of the brain (posterior fossa) are more often found in children.
• Patients with supratentorial tumors might suffer from a variety of symptoms including weakness in the arms or legs, visual impairment such as blurred vision or seizures.
• Patients with infratentorial tumors can present with difficulty walking, coordination problems, neck pain and neck stiffness.
• Other symptoms may include swelling of the nerve at the back of the eye (papilloedema), rapid and jerky eye movements (nystagmus), irritability, nausea, vomiting and headache.

Medical content was reviewed by Dr. Mark Johnson of Brigham and Women's Hospital, March 2004.

• A rare benign tumor (0.7% of all primary brain tumors) which occurs near the base of the skull near the pituitary region.
• These primary brain tumors result from the growth of cells that during early fetal development fail to migrate to their designated area.
• These tumors do not generally spread, but can disrupt adjacent areas of the brain through local growth.
• Due to their location and symptoms, these tumors can sometimes be difficult to diagnosis, and are often mistaken for pituitary tumors.
• The tumor can sometimes block the flow of spinal fluid, and can lead to hydrocephalus (a build up of spinal fluid within the brain).
• Symptoms can include headaches, decreased vision, (especially peripheral vision), obesity and delayed development due to hormonal abnormalities.

Medical content was reviewed by Dr. Mark Johnson of Brigham and Women's Hospital, July 2004.