AP:

BOSTON - Sen. Edward M. Kennedy has a malignant brain tumor. Doctors for the Massachusetts Democrat say tests conducted after Kennedy suffered a seizure this weekend show a tumor in his left parietal lobe. His treatment will be decided after more tests but the usual course includes combinations of radiation and chemotherapy.

We'll have to wait for more news, including a prognosis, but of course "malignant brain tumor" is never good news. To hear it in connection with Ted Kennedy is awful.

Update: The AP has a more detailed story up, with more on the diagnosis:

Malignant gliomas are a type of brain cancer diagnosed in about 9,000 Americans a year — and the most common type among adults. It's a starting diagnosis: How well patients fare depends on what specific tumor type is determined by further testing.

Average survival can range from less than a year for very advanced and aggressive types — such as glioblastomas — or to about five years for different types that are slower growing.