Pope Leo XIV left Rome's Gemelli Hospital on Saturday, four days after surgeons removed the lower lobe of his right lung in an operation that confirmed he has lung cancer. The 71-year-old pontiff is expected to lead Sunday's Angelus prayer from the window of the papal apartment overlooking St. Peter's Square — his first public appearance since going under the knife.

The Vatican disclosed on Oct. 13 that the tumor removed from Leo's right lung was an adenocarcinoma, the most common form of non-small-cell lung cancer, after doctors spotted a nodule during a routine checkup. The roughly three-hour procedure at Gemelli was described by the Holy See Press Office as having gone smoothly, with no complications.

A Fast Recovery, With Caveats

In the days since, Vatican medical updates have charted steady progress: on Oct. 14, officials said Leo was walking, eating and undergoing respiratory physiotherapy, with post-operative blood tests and a chest X-ray within the expected range. By Oct. 15 he had resumed meeting with aides from his hospital room, and doctors reported the operated lung was healing well.

HIS POST-OPERATIVE RECOVERY ALLOWS HIM TO CARRY OUT HIS NORMAL DAILY ACTIVITIES COMPLETELY ON HIS OWN

That was the Vatican's assessment in the medical bulletin announcing Saturday's discharge, which also confirmed Leo would mark his return to public duties from the apartment window rather than in person at the square, a step down from his usual balcony appearances but one officials framed as a swift return to form for a man four days removed from thoracic surgery.

Doctors have not yet determined whether the cancer spread beyond the removed lobe, and the Vatican has said chemotherapy isn't being discussed until those results are in. That uncertainty hangs over a planned trip to Latin America scheduled for Nov. 6 through 17, which Vatican officials have so far declined to confirm or cancel.

Parishes from Rome to Chicago held prayer vigils through the week; at Holy Name Cathedral in Chicago, parishioners continued masses for the pope's recovery even after word of his discharge arrived Saturday afternoon. The Vatican says further updates on his treatment plan, and on the status of the November travel, are expected in the coming weeks.