After his weekend seizure, Senator Ted Kennedy has been diagnosed with a malignant brain tumor, according to the Associated Press, which quotes the senator’s doctors.

AP reports:

The usual course of treatment includes combinations of radiation and chemotherapy, but Kennedy’s treatment will be decided after more tests.

“He has had no further seizures, remains in good overall condition, and is up and walking around the hospital,” said a joint statement issued by Dr. Lee Schwamm, vice chairman of the Department of Neurology at Massachusetts General Hospital and Dr. Larry Ronan, Kennedy’s primary care physician.

Kennedy’s wife and children have been with him each day since he was hospitalized but have made no public statements.

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.

Kennedy is 76. Anyone who’d like to send a goodwill message can do so on the senator’s official website.

He and his niece Caroline, JFK’s daughter, both endorsed Barack Obama in January.

Update: In response to the news, Obama called Kennedy a “beloved friend” and said “he deserves the kind of support he’s been giving others for so long.”

John McCain praised Kennedy saying, “I have described Ted Kennedy as the last lion in the Senate. And I have held that view because he remains the single most effective member of the Senate.”

President Bush and Hillary Clinton have also expressed support and good wishes.