Pope Leo was diagnosed with lung cancer after surgeons removed a part of his right lung on Tuesday, the Vatican said in a medical bulletin, marking a significant health setback for the 71-year-old pontiff.The pope has lung adenocarcinoma, a common form of cancer, with tissue tests conducted during the operation confirming what doctors had suspected from preparatory examinations, the bulletin said.Leo was admitted to Rome's Gemelli hospital on Tuesday for surgery to remove the growth that docto...