Brain Tumors

A tumor, or neoplasm, is a mass of abnormal cells that grows at an uncontrolled pace, crowding out and destroying normal tissue. Primary brain tumors arise in various regions of the central nervous system (CNS).

Common Types of Primary Brain Tumors

Nearly half of all primary brain tumors are gliomas which arise in the supporting tissue of the brain known as glial cells. Most gliomas are malignant, or cancerous, and certain types grow faster than others. Meningiomas are benign, or non-cancerous, tumors that are confined to the protective membranes that surround the brain, known as the meninges. Primary CNS lymphoma, a type of tumor that arises in the cells of the lymphatic system, is more common in people with AIDS and other diseases that compromise the immune system.

Other Types of Primary Brain Tumors

Pituitary tumors
Pituitary tumors are benign growths that involve the pituitary gland, which regulates growth, metabolism, water balance, and menstruation. Pineal tumors, which arise in the pineal gland, may be either malignant or benign. This type of tumor may compress the area that drains cerebrospinal fluid.

Acoustic neuroma
Found in the inner ear, acoustic neuromas are benign, slow-growing tumors that originate in the cochleovestibular nerve, which affects hearing and balance. Although these tumors are slow-growing, acoustic neuromas can eventually place pressure on the cranial nerves that control facial movement, facial sensation, hearing, balance, speech, and swallowing.

Metastatic, or secondary, brain tumors
Metastatic brain tumors are malignant growths that are formed by cancer cells originating in a different region or organ in the body. Cancers of the lung, breast, skin, and kidneys are the most common cause of metastatic brain tumors.

Symptoms and Diagnosis

As brain tumors grow, depending on their location, they can disrupt sensory, motor, and cognitive function and increase pressure within the brain or other areas of the CNS.

• CNS lymphoma can cause headaches, seizures, neurologic problems, or changes in mood.
• People with an acoustic neuroma may experience hearing difficulty in one ear, as well as noise or ringing in the ear (tinnitus), dizziness, and loss of balance.
• Additional symptoms associated with the tumor's growth may include headache, facial numbness, double vision, and difficulty with speech, swallowing, and even breathing.

Brain tumors are typically diagnosed using imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI).

Treatment

Depending on their location and size, malignant brain tumors may be treated with one or a combination of techniques. Traditional surgery is preferred when the tumor can be completely removed without causing neurological damage. Radiosurgery uses a single, high dose of radiation to kill remaining tumor cells, whereas radiation therapy delivers a smaller dose of radiation to the tumor site or entire brain over a period of several weeks. Chemotherapy and immunotherapy use medications to kill cancer cells and enlist the body's immune system in fighting the disease.