He holds joint appointments as a staff surgeon in the Clinic's Transplantation Center in the Division of Surgery and in the Cleveland Clinic Cancer Center. He specializes in general thoracic surgery . He has a particular interest in minimally invasive surgery including robotic surgery, thoracoscopic and laparoscopic surgery. His clinical interests include lung cancer, esophageal cancer, malignant mesothelioma, lung volume reduction surgery, myasthenia gravis, antireflux surgery, hyperhidrosis, and lung transplantation. He has research interests in all of these areas. Dr. Mason is board certified in general and thoracic surgery.