Pope Leo XIV has been diagnosed with lung adenocarcinoma after undergoing successful surgery to remove the lower lobe of his right lung, the Vatican announced.
The 71-year-old pontiff underwent a 90-minute operation on Tuesday at Rome's Gemelli Hospital, where doctors removed the affected lobe after detecting a suspicious nodule during a routine health examination.
The Vatican reported no surgical complications and said the Pope spent a peaceful night recovering.
The Vatican said the operation involved removing the entire lower lobe to maximise the likelihood of eliminating cancerous tissue.
Leo is expected to remain hospitalised for approximately one week, while his official schedule has been cleared until October 20.
The pontiff disclosed the planned procedure during Sunday prayers in St Peter's Square, explaining that doctors had identified the growth early and considered it contained.
Further examinations confirmed the suspected malignancy, while additional tests are underway to determine whether the disease has spread.
Cardinal Pietro Parolin, the Vatican's secretary of state, acknowledged concern over the unexpected diagnosis but expressed confidence in the Pope's recovery.
Catholics gathered outside Gemelli Hospital to offer prayers, while religious leaders internationally welcomed the successful operation.
Lung adenocarcinoma develops in glandular cells lining the lungs and accounts for approximately 40% of lung cancer cases.
It is the most common subtype of non-small cell lung cancer and can develop without noticeable symptoms.
Surgical removal is generally preferred when cancer remains confined to a single lung lobe.
Additional treatments, including chemotherapy, radiotherapy, immunotherapy or targeted medication, may be considered depending on disease progression.
The Vatican has not disclosed the tumour's size, lymph node involvement or whether further treatment will be necessary.
Consequently, the Pope's individual prognosis remains uncertain.
The diagnosis also raises questions about Leo's planned November visit to Latin America, particularly Peru, where he previously served as a missionary and bishop.
Preparations continue in Chiclayo, where officials anticipate approximately 1.5 million visitors for his expected return.