The Vatican press office said the operation will be performed later in the day by a team led by Dr. Stefano Margaritora, Gemelli’s chief thoracic surgeon. All of the pope’s public engagements are canceled through Oct. 20.

Leo revealed the discovery of the nodule during his Sunday noon prayer in St. Peter’s Square, calling it “circumscribed” and detected early. “The doctors believe it’s best to take action, so, following their advice, I’ve decided to have surgery to remove it,” he said.

Dr. Lorenzo Spaggiari, director of thoracic surgery at the European Institute of Oncology in Milan, praised the Vatican’s openness. “The Holy Father is in excellent hands at Gemelli,” he said.

A lung nodule is a small, localized lesion that can be benign or malignant. The Vatican said the nodule was discovered during routine checks and is likely in an early stage. Dr. Federico Venuto, chief of thoracic surgery at Policlinico Umberto I, noted such procedures are typically minimally invasive with a low complication rate.

The Vatican denied reports that the nodule was discovered due to an inflammation or illness, stating no particular issue had prompted the tests. Cardinal Pietro Parolin, Vatican secretary of state, said the announcement came “like a bolt out of the blue” but added that the early detection was a positive sign. “Thank God it was detected immediately, so the operation could take place immediately,” he said.

Leo, who is not known to be a smoker or to have had significant health issues before, leads an active lifestyle and plays tennis. Tokyo Cardinal Kikuchi Tsutomu said the pope told him he felt fine and had decided to have the surgery immediately to avoid disrupting his upcoming travel plans to Latin America.

The Vatican confirmed that Leo will not be staying in the traditional papal suite at Gemelli, which is currently under renovation. Instead, he will be in a nearby room.

The pope is scheduled to travel to Uruguay, Argentina, and Peru from Nov. 6 to 17.

Leo’s public disclosure of his health issue contrasts with the Vatican’s historical secrecy. While Pope Francis had begun to open up about his own frailty, information was still tightly controlled. Leo’s approach suggests a shift toward greater openness.