Liver Abscess due to <b><i>Streptococcus intermedius</i></b> Bacteremia and Its Association with Colonic Carcinoma: Is Bacteremia with <b><i>Streptococcus intermedius</i></b> an Alert for Colonic Carcinoma?

Abstract

Liver abscess caused by some kinds of <i>Streptococcus</i> group such as <i>Streptococcus bovis</i> group has been recognized to associate with colorectal cancer. <i>Streptococcus milleri</i> group with liver abscess has not been received much attention in this point of view. Here, we report the case of a 63-year-old man who developed liver abscess with <i>S. intermedius</i>, which belongs to the <i>S. milleri</i> group. We confirmed that this case was accompanied by cecal carcinoma by colonoscopy. The tumor was a pathological lead point of intussusception of cecum. On the 26th day, open right hemicolectomy was performed. In this case, bacterial endophthalmitis was a complication due to bacteremia. The patient underwent ophthalmic surgery on the 98th day. Research investigating 16S rRNA of the mucosal colon microbiome reported that the <i>S. intermedius</i> gene was upregulated in patients with colorectal carcinoma. It is recommended that liver abscess with <i>S. intermedius</i> bacteremia should alert the clinician about the risks of carcinoma of the colon and abscess formation in distant organs. We here list the case reports of liver abscess caused by <i>Streptococcus</i> other than <i>S. bovis</i> group, which was associated with colonic carcinoma, and suggest the need for further research about <i>S. milleri</i> group.