One of America's best-known political figures, Massachusetts Senator Edward Kennedy, has been diagnosed with a malignant brain tumor. VOA's Michael Bowman reports from Washington, the diagnosis comes days after the 76-year-old Democratic senator suffered a seizure and was rushed to a hospital in his home state.

Doctors in Massachusetts say they have identified the cause of Senator Kennedy's seizure: a malignant tumor on the left side of his brain that was discovered through a biopsy.

Kennedy, America's second-longest serving senator and the younger brother of President John Kennedy, will undergo further tests to find out more about the tumor and determine a course of treatment. For now, doctors say the senator is alert and in good spirits. Possible treatments for the tumor include radiation, chemotherapy, and surgery.

Reaction from across the country - and across America's political spectrum - has been swift. The White House says President Bush is "deeply saddened" by the news and will keep the senator in his prayers.

House Speaker Nancy Pelosi says Americans have received word of the diagnosis with "great concern."

"I have confidence, though, because Senator Kennedy has been a fighter all his life," she said. "He is a fighter: a fighter for our children, for our workers, for our seniors. I know that that fighting spirit will hold him in good stead in the challenge that he faces now."

Several of Kennedy's senate colleagues expressed hope and confidence that he would recover fully and return to his duties in Congress.

Edward Kennedy was first elected to the Senate in 1962 to fill the seat vacated by then-President John Kennedy. He unsuccessfully ran for president in 1980, challenging President Jimmy Carter's nomination for a second term. Widely regarded as one of America's most left-leaning legislators, Kennedy has been a champion of civil rights and governmental activism on behalf of the poor and disadvantaged in society.

This year, he made headlines as an early endorser of Democratic presidential aspirant Barack Obama.