What to know about Pope Leo’s planned lung nodule surgery

VATICAN CITY (AP) — Pope Leo XIV is scheduled to have an operation this week to remove “a localized nodule” in his lung that was “detected at a very early stage.” It is the first medical event of his 17-month papacy.

The Vatican said he will be admitted to Rome’s Gemelli hospital on Tuesday, and predicted a weeklong hospitalization to recover.

Here is what is known:

A nodule can be benign or malignant

A lung nodule is a small abnormal area measuring less than 3 centimeters (about 1.2 inches) across. It is sometimes detected on a CT scan performed to investigate another problem, such as trauma or a lung infection, according to the American Cancer Society. Experts say the nodule could be benign or malignant and that prompt evaluation is important.

If the nodule is cancerous and removed at an early stage, the prognosis is “excellent,” and surgery alone may be sufficient treatment, said Dr. Stephen Liu, a lung cancer expert at Georgetown’s Lombardi Comprehensive Cancer Center.

Leo, 71, is considered otherwise healthy and physically fit, both positive factors for his recovery. He said the nodule was discovered during “recent medical tests,” and the Vatican said Monday that no particular health issue prompted the checkup, describing it as “routine.”

Surgery followed by a week of recovery

The Vatican said Leo will be admitted to the hospital on Tuesday in the late morning and undergo surgery in the first days of this week. Oncologists who aren’t treating him said patients can often be discharged after just a few days, to recover further at home.

The exact date of surgery wasn’t released, but Leo had a full slate of audiences and appointments Monday morning and afternoon.

The pope will be treated at Rome’s Gemelli hospital, formally known as the Agostino Gemelli Polyclinic, a nonprofit Catholic teaching hospital that is part of the Catholic Sacred Heart University. The facility has a special apartment set up for pontiffs on the 10th floor that includes a private chapel. Leo’s immediate predecessor, Pope Francis, was treated there before his May 2025 death during a long illness prompted by a respiratory crisis.

St. John Paul II spent so much time at Gemelli that he called it “Vatican III,” after the Vatican itself and the papal summer residence at Castel Gandolfo.

Upcoming activities and trip in question

Leo has several activities scheduled this week but the Vatican on Monday canceled all his audiences through Oct. 20.

Leo also has a major trip planned Nov. 6-17 to Uruguay, Argentina and Peru. It is unclear whether the surgery and recovery will affect the ambitious itinerary, which includes a dozen flights, two helicopter rides and significant altitude changes in Peru. Leo said earlier in his remarks Sunday that he still planned to make the trip.

Pope remains in charge, even when unconscious

The Vatican has no specific rules governing who takes over if a pope becomes totally incapacitated. Even while unconscious during surgery, Leo remains pope and retains his authority.

Pope Francis remained in charge throughout his lengthy hospitalizations, as did St. John Paul II before him. Both made appointments and issued laws and statements from the hospital. A team of officials already handles day-to-day Vatican operations.

Medical advances and popes’ longer lifespans, however, have highlighted this gap in church law and prompted calls for the Vatican to prepare for a pope becoming too ill or incapacitated to govern.

Two days before revealing his planned surgery, Leo confirmed one significant appointment. On Friday, he approved Filipino Cardinal Luis Antonio Tagle as the new dean of the College of Cardinals. Tagle, 69, replaces Cardinal Giovanni Battista Re, 92, whose term Francis extended in the weeks before his death.

Tagle was designated at the last minute to stand in for Leo at Wednesday’s Mass to close out a conference on family ministry.

The dean also plays a significant role in a papal transition. He presides over the previous pope’s funeral and helps lead the cardinals’ closed-door meetings before the conclave to discuss the church’s future needs. If he is under 80 when the conclave begins, he also presides over the secret election of a new pope in the Sistine Chapel.

The Vatican released a letter Leo wrote to Re on Sunday — the day of his announcement — thanking him for his lifelong service to the church. He noted in particular the role that Re played in the recent papal transition, when he celebrated Francis’ funeral.

“I do not think I am mistaken in saying that you, Your Eminence, have been and remain one of the Holy See’s best-known and most esteemed servants,” Leo wrote.

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Barry reported from Milan

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