Pope Leo XIV has been diagnosed with a lung nodule, which was detected during a routine health check. The exact size of the nodule is not publicly known, but it was described as being detected at a very early stage and well localized, suggesting it has not spread. Doctors have advised the pope to have the nodule removed. Lung nodules are often found incidentally during chest X-rays or CT scans, especially in asymptomatic patients. Smaller nodules, defined as being less than 3 centimeters (1.1 inches), are less likely to cause symptoms such as chest pain or shortness of breath.
According to a 2019 paper in the Annals of Thoracic Medicine, incidental findings of lung nodules in asymptomatic individuals are increasingly common. Biopsies to determine if a nodule is malignant can be challenging due to the small size of many nodules, and the risks associated with surgical diagnosis may outweigh the benefits given the low prevalence of malignancy in small nodules, as noted in a 2017 paper in the European Respiratory Review.
Most early-stage lung nodules are benign, and it is possible for individuals to have multiple benign nodules. The pope is expected to need a week to recover after his operation, and he is scheduled to travel to Uruguay, Argentina, and Peru from November 6-17.
Lung nodules are defined as white spots or lesions on the lung, appearing as white or gray on CT scans due to their density compared to surrounding tissue. They can arise from various causes, including old infections, inhaled foreign particles, inflammation, scar tissue, and cancer. Nodules larger than 3 centimeters are classified as masses, which can obstruct airways and lung function.
The risk of malignancy increases with the size of the nodule. For instance, nodules smaller than 2 millimeters have a very low cancer risk, while nodules measuring 8 to 10 millimeters have a 9%-10% risk, and those larger than 1 centimeter have a 15% risk. Density also plays a crucial role in assessing malignancy, with solid and subsolid nodules being the two main categories. Subsolid nodules, which include pure ground-glass and part-solid types, have a higher likelihood of being malignant, according to a 2026 review in the New England Journal of Medicine.
Lung nodules are detected in about 30% of chest CT scans, a figure that may be increasing due to advancements in scanning technology and artificial intelligence. While most lung nodules are benign, they can be precursors to lung cancer, which remains the most common cancer type and cause of cancer-related deaths worldwide. The World Health Organization's International Agency for Research on Cancer estimates that in 2024, nearly 2.65 million people will be diagnosed with lung cancer, with over 1.8 million fatalities attributed to the disease.