1. Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
2. General, Visceral and Thoracic Surgery Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
3. General, Vascular and Visceral Surgery Clinic, Itzehoe Medical Center, Itzehoe, Germany
4. General, Visceral Thoracic and Vascular Surgery Clinic, Regio Clinic Pinneberg, Pinneberg, Germany
5. General, Visceral and Tumor Surgery Clinic, Albertinen Hospital, Hamburg, Germany
6. Department of General and Abdominal Surgery, Schoen Clinic Hamburg Eilbek, Hamburg, Germany
7. Department of Pathology, Academic Hospital Fuerth, Fuerth, Germany
8. Institute of Pathology, Clinical Center Osnabrueck, Osnabrueck, Germany