A brain tumor is a growth of abnormal cells or normal cells in an inappropriate place in the brain. A primary brain tumor is one that starts in the brain, rather than cancer in another part of the body that has spread to the brain. Primary tumors can be grouped into non-cancerous (benign) and cancerous (malignant). Malignant brain tumors are commonly called brain cancer and they are usually invasive and life-threatening.

Brain tumors also may be metastatic or secondary brain tumors. These tumors are formed from cancer cells that begin growing elsewhere in the body and travel to the brain, usually through the bloodstream. Metastatic brain tumors are always cancerous and commonly come from cancers of the lung or breast or from melanomas. They are more common than primary brain tumors.

Unlike some other cancers, there are very few associated risk factors or causes for brain tumors.  Individuals who have received radiation therapy to the head for some other forms of cancer are at risk for developing brain tumors later in life. Some inherited syndromes, such as neurofibromatosis, are associated with brain tumors. Also, individuals with immune system disorders have a greater chance of developing brain lymphomas.

Symptoms of a brain tumor usually appear gradually and worsen over time. The symptoms will vary depending on the location and severity of the tumor. Common symptoms can include headaches, vision problems and possibly seizures as the condition progresses. However, the early symptoms of a brain tumor can be related to a number of non-threatening medical conditions.

Brain tumors are diagnosed through a series of tests and procedures. Imaging tests such as CAT scan or MRI are commonly used as the first test to identify the presence and location of a tumor. A biopsy is used as the definitive means to diagnose a brain tumor. The tissue sample from the biopsy will reveal whether the tumor is benign or malignant, the type of cells in the tumor and the severity or grade of the tumor.

Treatment for brain tumors can include surgery, radiation therapy and chemotherapy. Surgery is usually the first line of treatment with the goal of removing as much of the tumor as possible without causing severe damage to the nearby tissues. Radiation therapy may be used before surgery to shrink the size of a tumor or after surgery to destroy any remaining cancer cells. Chemotherapy also may follow surgery to destroy remaining cancer cells, particularly if the cancer has spread in the body. Treatment for brain tumors varies greatly depending on a number of factors. A combination of all three treatments in some form or another is commonly used for cancer.

Because there is no known cause of brain tumors, there is no way to clearly prevent them. The prognosis or recovery from a brain tumor is dependent on many factors, including the type and grade of the tumor, the response to treatment and the age and general health of the patient. Many tumors can be completely cured, though others have a poorer prognosis and higher chance for recurrence.