BOSTON, Massachusetts (CNN) - The hospital treating Sen. Edward Kennedy said Tuesday that the Democratic senator has a malignant brain tumor.
The tumor was the cause of his seizure on Saturday, according to a statement from the doctors treating the 76-year-old at Massachusetts General Hospital.
While such tumors are usually treated by a combination of radiation and chemotherapy, Kennedy's doctors said "decisions regarding the best course of treatment for Senator Kennedy will be determined after further testing and analysis."
"Senator Kennedy will remain at Massachusetts General Hospital for the next couple of days according to routine protocol."
Kennedy "remains in good overall condition and is up and walking around the hospital," the statement said.
He was airlifted to Massachusetts General Hospital on Saturday, and has remained hospitalized since then.
(updated with additional information 1:30 p.m.; full hospital statement after the jump)
Drs. Lee Schwamm and Larry Ronan of Massachusetts General Hospital, where Kennedy is being treated, released this statement Tuesday:
"Over the course of the last several days, we've done a series of tests on Senator Kennedy to determine the cause of his seizure. He has had no further seizures, remains in good overall condition, and is up and walking around the hospital. Some of the tests we had performed were inconclusive, particularly in light of the fact that the Senator had severe narrowing of the left carotid artery and underwent surgery just 6 months ago.
"However, preliminary results from a biopsy of the brain identified the cause of the seizure as a malignant glioma in the left parietal-lobe. The usual course of treatment includes combinations of various forms of radiation and chemotherapy. Decisions regarding the best course of treatment for Senator Kennedy will be determined after further testing and analysis. Senator Kennedy will remain at Massachusetts General Hospital for the next couple of days according to routine protocol. He remains in good spirits and full of energy."