• To the left is a tumor as seen with colonoscopy.
• Below left is an X-Ray showing the typical 'napkin-ring' appearance with barium contrast.
• Directly below is a surgical specimen showing the tumor with the region of narrowing, ulceration and hemorrhage.
• Larger, right-sided lesions often present with symptoms of anemia because of the slow blood loss (months-years).
• Left-sided tumors more often present with visible blood in the stool or constipation.

Photo courtesy of Harvard Medical School and Brigham and Women's Hospital, Boston, MA