The lump, called a nodule, was detected early and is “well-defined,” according to the pope. The operation is scheduled to take place in the next few days.
The 71-year-old pope made the announcement during his usual Sunday prayer at noon in St. Peter's Square.
A Vatican spokesperson confirmed the news and said recovery is expected to take a week.
The American pope has no known health problems and is physically active, with swimming and tennis on his schedule.
He has an extensive trip to Uruguay, Argentina and Peru planned for November 6-17, but it is still unclear whether the surgery will affect his travel plans.
