Beau Biden, a son of U.S. Vice President Joe Biden, has been hospitalized at Walter Reed Army Medical Center outside Washington, the vice president's office said on Tuesday.Biden, 46, a former Delaware attorney general, is undergoing treatment at the facility. No further details were available.After eight years as attorney general, Biden joined the investor law firm Grant & Eisenhofer in 2015.He served a yearlong tour in Iraq as a captain in the Delaware Army National Guard and underwent surgery at a cancer center in Texas last year. He suffered a mild stroke in 2010.In a message to voters posted on his website in April 2014, Biden, a Democrat like his father, said he planned to run for governor of the mid-Atlantic state.