Concurrent Clostridium septicum bacteremia and colorectal adenocarcinoma with metastasis to the brain – A Case Report

There is a known relationship between Clostridium septicum bacteremia and colorectal malignancies. C. septicum is a gram-positive, anaerobic, spore-forming bacterium that can survive the acidic colorectal tumor microenvironment, where it is thought to enter the blood by tumor-mediated epithelial tissue damage. While in circulation, C. septicum can release exotoxins which may lead to life-threatening sepsis. The patient in this case presented with a mild fever, abdominal pain, and left hand weakness. Imaging of the head and abdomen revealed a right frontal lucency and wall thickening of the ascending colon. Two colonic adenocarcinomas were found and removed via an exploratory laparotomy and right hemicolectomy. The blood culture was positive for C. septicum. Brain MRI confirmed a right frontal mass concerning for metastasis. Here, we discuss the relationship between colonic cancers and Clostridium septicum bacteremia.