1. Department of Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands
2. Department of Surgery, Isala Hospital, Zwolle, the Netherlands
3. Department of Surgery, Zuyderland Medical Center, Sittard-Geleen and Heerlen, the Netherlands
4. Department of Surgery, IJsselland Hospital, Rotterdam, the Netherlands
5. Department of Pathology, Amsterdam University Medical Center, VU University Medical Center, Amsterdam, the Netherlands