Sen. Ted Kennedy has been diagnosed with a malignant brain tumor and will remain hospitalized for at least several days as he and his family determine his treatment options.
The Massachusetts Democrat suffered a seizure Saturday and has since been hospitalized at Massachusetts General Hospital in Boston. He has been talking and joking with family and friends while undergoing a battery of tests that revealed the malignant tumor, a glioma in the left parietal lobe, according to the hospital.
"He has had no further seizures, remains in good overall condition and is up and walking around the hospital," Drs. Lee Schwamm and Larry Ronan said in a joint statement released by the hospital.
"The usual course of treatment includes combinations of various forms of radiation and chemotherapy," they said. "Decisions regarding the best course of treatment for Sen. Kennedy will be determined after further testing and analysis."
Kennedy, the second-longest serving senator in U.S. history, has represented Massachusetts in the Senate since 1962.
"Tough days ahead," a Kennedy family friend told ABC News, "but [Sen. Kennedy] is in fighting mood."
Another Kennedy family member is bringing in another doctor for further evaluation, saying, "This is not a good time."
In an interview with ABC News' Jake Tapper for "World News With Charles Gibson", Sen. Barack Obama, D-Ill., who has received Kennedy's endorsement for president, said, "It's heartbreaking. Ted Kennedy is not only a giant of the Senate, but he's a good friend. You couldn't have a better supporter than Ted Kennedy."
Obama talked with Vicki Kennedy, the senator's wife, Saturday and said he was more optimistic after that converstion.
"The news came in today and it's a lot worse, but he's a fighter. He's been fighting on behalf of working families all his life. … It's a testament to how beloved he is that you are seeing well wishes from across the aisle from everyone in political life and Massachusetts."
In a statement released to the press, Sen. Hillary Clinton, D-N.Y., in Kentucky for an election night rally, said, "Ted Kennedy's courage and resolve are unmatched, and they have made him one of the greatest legislators in Senate history. Our thoughts are with him and Vicki and we are praying for a quick and full recovery."
Mrs. Kennedy informed Senate Majority Leader Harry Reid, D-Nev., Tuesday afternoon of Kennedy's diagnosis. Reid, in turn, informed the Senate Democratic caucus at its weekly luncheon on Capitol Hill.
Fighting back tears at a press conference following the luncheon, Sen. Chris Dodd, D-Conn., described by Reid as Kennedy's closest friend in the Senate, said, "We're confident he's going to be back."
Sen. Robert C. Byrd, a West Virginia Democrat and the most senior member of the Senate, openly wept while speaking from his desk on the Senate floor.