The doctors from Massachusetts General Hospital in Boston announced today that Senator Edward Kennedy has a malignant brain tumor.

The doctors explained that the tumor is a glioma located in the left parietal lobe of the brain.

Gliomas (primary brain tumors) start in the brain or spinal cord tissue. They can spread within the nervous system but do not spread outside the nervous system. Gliomas can be either benign (slow growing) or malignant (fast growing).

Annually, about 17,000 Americans are diagnosed with a primary brain tumor. Treatment options and survival odds depend on the tumor type, size and location, as well as the patient's age and overall health.

Saturday morning, Sen. Kennedy suffered a seizure and, after being transported by an ambulance to a local hospital located near his family's Cape Cod vacation house, he was flown to Massachusetts General Hospital where doctors began running test to determine the cause of the seizure.

The neurologist Dr. Lee Schwamm of Massachusetts General Hospital in Boston, and Dr. Larry Ronan, a primary physician there said in a press statement that the treatment of glioma requires chemotherapy and radiation therapy.

The doctors said that since Saturday Senator Edward Kennedy has had no further seizures, and he is in good overall condition and “is up and walking around the hospital."

Additional tests and analysis are required before deciding the best course of treatment, the doctors noted.

Edward “Ted” Kennedy has been in the Senate for 45 years and unsuccessfully sought the centre-left Democratic nomination in 1980. He came to the Senate in November 1962 to fill a seat earlier held by his brother John Kennedy. Senator Ted Kennedy currently serves as chairman of the Senate Committee on Health, Education, Labor and Pensions.

Last year in October, Senator Kennedy underwent surgery to clear a dangerously blocked carotid artery in his neck. The surgery was decided after a routine health check. In 1964, he was seriously injured in a plane crash, and hospitalized for several months. Ever since he has suffered from back problems.