Brain Tumors

Brain Tumor

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

The symptoms of brain tumors depend on their size and location in the brain. Symptoms often are caused by damage to vital tissue and pressure on the brain as the tumor grows within the limited space in the skull. They may be caused by swelling and a buildup of fluid around the tumor, a condition called edema. Symptoms also may be due to hydrocephalus, which occurs when the tumor blocks the flow of cerebrospinal fluid and causes a build-up in the ventricles. If a brain tumor grows very slowly, its symptoms may not appear for some time.

The most frequent symptoms of brain tumors include:

• Headaches that tend to be worse in the morning and ease during the day
• Seizures or convulsions
• Nausea or vomiting
• Weakness or loss of feeling in the arms or legs
• Stumbling or lack of coordination in walking
• Abnormal eye movements or changes in vision
• Drowsiness
• Changes in personality or memory
• Changes in speech

These symptoms may be caused by brain tumors or by other problems. Diagnostic tests can be performed to determine if the cause of your symptoms is a brain tumor and if it is a primary or secondary one.

Primary Brain Tumors

Tumors that begin in brain tissue are known as primary brain tumors and are classified by the type of tissue in which they originate. The most common brain tumors are gliomas, which begin in the glial or supportive tissue. There are several types of gliomas:

• Astrocytomas — These tumors arise from small, star-shaped cells called astrocytes. They may grow anywhere in the brain or spinal cord. In adults, astrocytomas most often arise in the cerebrum. In children, they occur in the brain stem, the cerebrum and the cerebellum. A grade III astrocytoma is sometimes called anaplastic astrocytoma. A grade IV astrocytoma is usually called glioblastoma multiforme.
• Brain stem gliomas — These tumors occur in the lowest, stem-like part of the brain. The brain stem controls many vital functions. Most brain stem gliomas are high-grade astrocytomas.
• Ependymomas — These tumors usually develop in the lining of the ventricles. They may also occur in the spinal cord. Although these tumors can develop at any age, they are most common in childhood and adolescence.
• Oligodendrogliomas — These tumors occur in the cells that produce myelin, the fatty covering that protects nerves. These tumors usually arise in the cerebrum. They are rare, grow slowly and usually do not spread into surrounding brain tissue. They occur most often in middle-aged adults but have been found in people of all ages.

There are other types of brain tumors that do not begin in glial tissue. Some of the most common are described below:

• Medulloblastomas — These tumors were once thought to develop from glial cells. However, recent research suggests that these tumors develop from primitive or developing nerve cells that normally do not remain in the body after birth. For this reason, medulloblastomas are sometimes called primitive neuroectodermal tumors (PNET). Most medulloblastomas arise in the cerebellum; however, they may occur in other areas as well. These tumors occur most often in children and are more common in boys than in girls.
• Meningiomas — These tumors grow from the meninges, or membranes that enclose the brain and spinal cord. They are usually benign. Because these tumors grow very slowly, the brain may be able to adjust to their presence. Meningiomas often grow quite large before they cause symptoms. They occur most often in women between 30 and 50 years of age.
• Schwannomas — These tumors are benign and begin in Schwann cells, which produce the myelin that protects the acoustic nerve, or the nerve of hearing. They occur mainly in adults. These tumors affect women twice as often as men.
• Craniopharyngiomas — These tumors develop in the region of the pituitary gland near the hypothalamus. They are usually benign but are sometimes considered malignant because they can press on or damage the hypothalamus, a region of the brain, and affect vital functions. These tumors occur most often in children and adolescents.
• Germ cell tumors — These tumors arise from developing sex cells or germ cells. The most frequent type of germ cell tumor in the brain is the germinoma.
• Pineal region tumors — These tumors occur in or around the pineal gland, a tiny organ near the center of the brain. The tumor can be slow growing (pineocytoma), or fast growing (pineoblastoma). The pineal region is very difficult to reach, and these tumors often cannot be removed.

Secondary Brain Tumors

Metastasis is the spread of cancer. Cancer that begins in other parts of the body may spread to the brain and cause secondary tumors. These tumors are not the same as primary brain tumors. Cancer that spreads to the brain is the same disease and has the same name as the original or primary cancer. For example, if lung cancer spreads to the brain, the disease is called metastatic lung cancer because the cells in the secondary tumor resemble abnormal lung cells, not abnormal brain cells.

Treatment for secondary brain tumors depends on where the cancer started and the extent of the spread as well as other factors, including the patient's age, general health and response to previous treatment.

Reviewed by health care specialists at UCSF Medical Center.
Last updated July 31, 2007