1. Division of Thoracic Surgery, IRCCS Azienda Ospedaliero Universitaria di Bologna, 40100 Bologna, Italy
2. Alma Mater Studiorum, University of Bologna, 40064 Bologna, Italy
3. Pathology Unit, IRCCS Azienda Ospedaliero Universitaria di Bologna, 40100 Bologna, Italy
4. Division of Thoracic Surgery, Cantonal Hospital of Lucerne, 6000 Lucerne, Switzerland
5. Department of Thoracic Surgery, Imperial College Healthcare NHS Trust, London W2 1NY, UK