Pope Leo has been taken to hospital so surgeons can deal with a nodule that has been found on his lung. Details in the early announcement were sketchy, beyond confirmation that the procedure concerns the lung nodule. A lung nodule is a small growth in the lung tissue, and doctors often opt for surgery when one needs closer examination or removal. Operations involving the lungs are fairly routine, but any procedure on a sitting pope is treated as delicate news around the world. The Vatican tends to release only short statements on the pope's condition, which leaves plenty of room for speculation between updates. With the pontiff in hospital, public appointments and audiences are expected to be scaled back while he recovers. More information is likely to arrive once the operation is complete and doctors have assessed how the surgery went.