Obstructive Colitis with Minor Perforation Induced by Double Sigmoid Adenocarcinoma.

A 72-year-old women was referred to our hospital because of lower left abdominal pain. Computed tomography showed prominent sigmoid colon dilation and double tumors on both the oral and anal sides. Surgical resection revealed an expanded sigmoid colon involved in double cancer that showed strong adhesion to the surrounding tissues. The pathological findings revealed obstructive colitis and minor perforation in the dilated colon. The minor perforation was considered to have been caused by fecal impaction in the closed cavity between the two tumors, resulting in an increase in colon pressure.