1. Section of Colon and Rectal Surgery, Department of Surgery, MedStar Washington Hospital Center, Washington, DC 20010, USA
2. Department of Surgery, MedStar Washington Hospital Center, Washington, DC 20010, USA
3. Department of Pathology, MedStar Washington Hospital Center, Washington, DC 20010, USA
4. Georgetown University School of Medicine, Washington, DC 20057, USA
5. Department of Surgery, MedStar Georgetown University Hospital, Washington, DC 20057, USA
6. Department of Radiology, MedStar Washington Hospital Center, Washington, DC 20010, USA