Two cases are reported of rectal cancer associated with an abscess of Douglas' cavity due to perforation of the cancerous lesion. Case 1: A 73-year-old man was admitted because of abdominal pain and fever. An emergency operation was performed under the diagnosis of an abscess of Douglas' cavity. During surgery, we found the abscess in Douglas' cavity with reddish swelling and edema of the ileum at the location of the abscess cavity. Abscess drainage and partial ileal resection was performed. Colonoscopic examination after surgery showed advanced cancer in the rectum. Twenty-nine days after surgery low anterior resection of the rectum was performed. Case 2: A 49-year-old woman was admitted because of abdominal pain and fever. An emergency operation was conducted under the diagnosis of abscess of Douglas' cavity and rectal carcinoma. We performed abscess drainage. Colonoscopic examination after surgery showed advanced cancer in the rectum. Fourteen days after surgery low anterior resection of the rectum was performed. In both cases, the histological findings disclosed perforation at the center of the advanced cancerous lesion. In our series of 12 cases of perforated rectal carcinoma, two cases were presented with an abscess of Douglas' cavity. Rectal cancer perforations should be considered in cases with findings similar to those reported here.
