Pope Leo XIV is scheduled to undergo surgery this week to remove a “localized nodule” “discovered at a very early stage” in his lung. This was his first medical incident in 17 months as pope.
The Vatican said he would be taken to Rome’s Gemelli hospital on Tuesday and was expected to recover within a week.
Here’s what we know about the nodules and what we know about Pope’s case:
What are pulmonary nodules? Are they cancerous?
A pulmonary nodule is a small abnormal area less than 3 centimeters (about 1.2 inches) in diameter. According to the American Cancer Society, this condition is sometimes detected in CT scans done to investigate other problems, such as trauma or lung infection. Experts say that nodules may be benign and not cancerous, or they may be malignant and cancerous, and timely evaluation is important. According to the American Lung Association, most nodules (about 95%) are benign. It was unclear whether the pope had his nodule biopsied after the test.
What causes nodules?
According to the American Lung Association, nodules can be caused by a variety of factors, including irritants like smoking, air pollution, and diseases like rheumatoid arthritis and cancer. They may also be caused by previous infections and scar tissue from previous histoplasmosis or tuberculosis infections.
Leo, 71, is considered otherwise healthy and in good health, which are positive factors in his recovery. He said the nodule was discovered during a “recent medical examination” and the Vatican said on Monday that no special health problem prompted the examination, describing it as a “routine examination.”
What are the risks associated with nodules?
Many factors influence the risk of lung cancer, such as the size, density and location of the nodule, as well as the patient’s age, smoking status and family history of cancer.
If the nodule is cancerous and removed early, the prognosis is “very good” and surgery alone may be enough to treat it, said Dr. Stephen Liu, a lung cancer specialist at Georgetown Lombardi Comprehensive Cancer Center.
Pope to undergo surgery, then recover for a week
The Vatican said Leo would be admitted to hospital on Tuesday morning and undergo surgery in the first days of this week. The oncologist who treated him said the patient can usually be discharged from the hospital after a few days to further recover at home.
An exact date for the surgery has not yet been announced, but Leo had a large number of visitors and appointments Monday morning and afternoon.
The pope will receive treatment at Rome’s Gemelli Hospital, formally known as Agostino Gemelli Polyclinic, a nonprofit Catholic teaching hospital affiliated with the Catholic University of the Sacred Heart. The facility houses a special apartment for the pope on the tenth floor, which includes a private chapel. Leo’s predecessor, Pope Francis, was treated there in May 2025 during a long illness caused by a respiratory crisis.
St. John Paul II spent so much time in Gemelli that he called it “Vatican III”, after the Vatican itself and the papal summer residence of Castel Gandolfo.
Pope Leo’s upcoming schedule and problematic travel
Leo has several activities planned this week.
In addition to regular meetings, he will celebrate a public Mass on Wednesday to conclude a weeklong family ministry conference. It was unclear whether anyone else would celebrate Mass.
Leo is also planning a major trip to Uruguay, Argentina and Peru from November 6-17. It’s unclear whether surgery and recovery will affect the ambitious itinerary, which includes more than a dozen flights, two helicopter tours and significant elevation changes in Peru. Leo said in a speech earlier Sunday that he still planned to make the trip.
After two days of voting, Robert Francis Prevost became the first pope from the United States. But what does his name “Leo” mean?
If the Pope becomes incapacitated, who will take over?
The Vatican has no specific rules governing who takes over if a pope becomes completely incapacitated. Even while unconscious during the operation, Leo remained Pope and retained his authority.
Throughout his lengthy hospitalization, Pope Francis has remained in power, as has his predecessor, St. John Paul II. Both made appointments and issued hospital laws and statements. A team of officials is already responsible for the day-to-day running of the Vatican.
However, advances in medicine and the longevity of the pope have highlighted this flaw in canon law and prompted calls for the Vatican to prepare for a pope who becomes seriously ill or incapacitated.
Two days before the planned surgery was announced, Leo confirmed an important appointment. On Friday, he approved Cardinal Luis Antonio Tagle of the Philippines as the new rector of the College of Cardinals. Tagle, 69, succeeds Cardinal Giovanni Battista Re, 92, whose term was extended by Francis just weeks before his death.
Deans play an important role during papal transitions. He presided over the funerals of former popes and helped preside over closed meetings of cardinals before conclave to discuss the church’s future needs. If he was under 80 when the conclave began, he would also preside over the secret election of a new pope in the Sistine Chapel.
The Vatican released a letter Leo wrote to Ray on Sunday, the day he made the announcement, thanking him for his lifetime of service to the church. As he celebrated Francis’ funeral, he singled out Ray’s role in the recent papal transition.
Leo wrote: “I do not think I was wrong in saying that, Your Excellency, you have been and remain one of the most well-known and respected servants of the Holy See.”
___
Barry reported from Milan.