Carter Center spokeswoman Deanna Congileo called the procedure "elective" in a statement released Monday afternoon. She says the operation was completed without any issues and Carter's "prognosis is excellent for a full recovery."
In response to an email from The Associated Press asking how the mass was detected, what symptoms Carter had displayed, what follow-up care he will receive and what is known about the mass, Congileo said no further details would be provided.
Carter, 90, was the nation's 39th president. After leaving the White House, he founded the center in Atlanta in 1982 to promote health care, democracy and other issues globally.
He has remained active for the center in recent years by making public appearances and traveling overseas, including a May election observation visit to Guyana cut short because Carter developed a bad cold.
He completed a book tour Saturday promoting his latest work, "A Full Life: Reflections at 90," according to Julia Prosser with the publisher Simon & Schuster. He has written more than 20 books since leaving office.
The native of Plains, Georgia, is also a former Georgia governor.