Highlights:
- Pope Leo diagnosed with common form of lung cancer
- Doctors removed lower lobe of pope's right lung in surgery
- Procedure lasted 90 minutes, with no complications, Vatican says
Pope Leo was diagnosed with lung cancer after surgeons removed part of his right lung on Tuesday, the Vatican said in a medical bulletin, marking a significant health setback for the 71-year-old pontiff.
The pope has lung adenocarcinoma, a common form of cancer, with tissue tests conducted during the operation confirming what doctors had suspected from preparatory examinations, the bulletin said.
Leo was admitted to Rome's Gemelli hospital on Tuesday for surgery to remove the growth that doctors had discovered during a recent routine health check.
The pope's lead surgeon, Dr Stefano Margaritora, and his personal physician, Dr Luigi Carbone, said in a statement that the procedure lasted about 90 minutes and was successful, with no complications.
"In order to make the procedure curative, the lower lobe of the right lung was removed using a video-assisted technique," they said, making clear that the aim was to eliminate all cancerous tissue.
Human lungs have five lobes – three in the right lung and two in the left.
A medical expert said that, to assess the pope's case, they would need to know the size of the tumour and whether the cancer had spread to his lymph nodes, information the Vatican did not immediately provide.
"While we have the diagnosis, we do not yet have the stage. This is critical to prognosis and treatment," said Dr Stephen Liu, a lung cancer expert at Georgetown University in Washington and division chief of haematology-oncology at MedStar Georgetown University Hospital.
"If this is a small lung cancer with no lymph nodes involved, surgery itself is likely to be curative," he told Reuters. "But if final analysis reveals a greater extent of cancer involvement, this indicates a poorer prognosis."
Resting in his hospital room
The pope regained consciousness normally after the operation and later returned to his hospital room, where he was resting, the medical bulletin said.
The Vatican said earlier this week that he was expected to remain in hospital for about a week and all his public events had been cancelled until 20 October.
Leo left the Vatican ahead of the surgery shortly before 1 pm (1100 GMT) in Rome and was seen waving from the back of a black SUV as his convoy drove about 9 km (5.6 miles) north of the Vatican to the Gemelli hospital.
Upon arrival at the hospital, Leo shook hands with several officials, walked in front of a waiting crowd of well-wishers, some of whom shouted "Auguri" (best wishes), and entered through the main entrance.
Leo, elected by the world's cardinals in May 2025, is relatively young for a Church leader. He enjoys sports, including tennis, and is not known to be a smoker or to have had recent health issues.
The late Pope Francis, Leo's predecessor, was hospitalised several times as he grew frail in his later years. He died aged 88 in April 2025.
Leo, who spoke in a firm, clear voice at his only public event on Monday, keeps a very busy schedule. He is due to make an 11-day tour of Uruguay, Argentina and Peru from 6 to 17 November, but it was not clear whether the trip would still go ahead.
Typhoid fever
The pope is the ultimate earthly authority for the world's 1.4 billion Catholics and does not have a deputy who steps in when he is sick. When a pope is incapacitated, the business of the Vatican's vast bureaucracy carries on as usual, with decisions requiring papal approval put on hold.
Leo, born in Chicago in 1955 as Robert Prevost, served for decades as a missionary and bishop in Peru before becoming pope. In 1985, when he was a young priest, he contracted typhoid fever in Chulucanas, Peru, and was hospitalised.
He recounted the experience in his only major interview as pope, in a book for Penguin Peru.
Leo said the pain was so bad that he asked God to let him die rather than continue suffering. He took his survival as a sign from God that "We need you here (on Earth)," he said.
"I never looked back," said Leo.
Reporting by Joshua McElwee; additional reporting by Cristiano Corvino and Clara Schoenthaler; writing by Keith Weir; editing by Gareth Jones and Crispian Balmer.