Abstract
A 56-year-old woman was admitted to hospital because of left lower abdominal pain and vomiting. Abdominal computed tomography showed retrograde invagination of the sigmoid colon. Thus, a retrograde intussusception caused by a sigmoid colon cancer was diagnosed. Emergency surgery was performed. The sigmoid colon was invaginated into the oral colon in a retrograde fashion, and repositioning was impossible ; therefore, Hartmann's procedure was used. The resected specimen included a type 1 tumor at the sigmoid colon. Histological examination revealed the tumor to be a moderately differentiated tubular adenocarcinoma. The pathogenesis of retrograde intussusceptions is uncertain ; reverse peristalsis of the intestine is caused by movement of a pedunculated or subpedunculated tumor. The sigmoid colon in our case was very long. Thus an increase in abdominal pressure due to constipation may have caused the intussusception.
