An unusual presentation of colon cancer: purulent pericarditis and cardiac tamponade due to Bacteroides fragilis.

Extra-abdominal infections caused by colonic anaerobic organisms have been shown to be associated with colorectal cancers. We report a very unusual case of a patient who suffered from cardiac tamponade secondary to anaerobic bacterial pericarditis caused by Bacteroides fragilis as an initial presentation of colon cancer. The medical literature is reviewed.