CNN

Robert Novak

WASHINGTON (CNN) – Washington journalist Bob Novak, 77, has a brain tumor, he announced Monday.

"I will be suspending my journalistic work for an indefinite but, God willing, not too lengthy period," Novak, a long-time Washington insider, said in a written statement.

He does not yet know whether the tumor is malignant or benign, and is waiting for a biopsy in the next few days, said his assistant, Kathleen Connolly.

He is alert and talking, and personally wrote the statement, which was posted on the Web site Human Events, she said.

"He seemed fine," she said. Novak became ill on Sunday while on a family trip to Cape Cod, Massachusetts, she said. A family member called 911 and he was taken to Brigham and Women's Hospital in Boston, where the tumor was diagnosed.

Novak, a syndicated columnist, was at the center of the scandal over the outing of CIA agent Valerie Plame Wilson in 2003, ultimately leading to the resignation of Vice President Dick Cheney's chief of staff, Lewis "Scooter" Libby. Novak published a column revealing her CIA status days after her husband debunked a key Bush administration justification for the invasion of Iraq.

Intentionally revealing the identity of an undercover CIA agent can be a crime. No one was ever prosecuted for the leak itself - which turned out to have come from former Deputy Secretary of State Richard Armitage. Libby was convicted of obstructing an investigation into the leak.