1. Department of General, Visceral and Thoracic Surgery, University Medical Center Hamburg‑Eppendorf, D‑20246 Hamburg, Germany
2. Institute for Pathology, University Medical Center Hamburg‑Eppendorf, D‑20246 Hamburg, Germany
3. Institute for Pathology, University Hospital Cologne, D‑50937 Cologne, Germany
4. Department of Surgery, University Hospital Cologne, D‑50937 Cologne, Germany