"The Holy Father has undergone respiratory physiotherapy and has begun walking around his room. He has resumed eating normally and had breakfast and lunch," their statement added. "His recovery is proceeding as expected."
The pope spent approximately three hours in the operating room, although the surgery itself lasted about 90 minutes.
Doctors said the procedure was successful and there were no complications.
"Doctors found a small lump in the lung," Leo said after an Angelus address at St. Peter's Square on Monday. "It was identified at a very early stage and well situated."
"The doctors consider it appropriate to intervene and so, following their advice, I decided to have surgery to remove it," he continued. "The surgery is already scheduled for the next few days. I thank you for your spiritual closeness and I rely on your prayer."
Fox News' Courtney Walsh, Anders Hagstrom and Jasmine Baehr contributed to this report.