Clostridium septicum Aortitis With Associated Sigmoid Colon Adenocarcinoma

We report an unusual case of Clostridium septicum aortitis with associated adenocarcinoma of the sigmoid colon. An 87-year-old man with multiple medical comorbidities presented with a 1-week history of severe abdominal pain in the left lower quadrant of his abdomen. Abdominal computed tomography showed, in addition to a mass in the sigmoid colon, a gas density within the wall of the abdominal aorta with extensive periaortic fat stranding and some additional gas densities in the proximal left common iliac artery. The patient refused surgery, and was treated with intravenous antibiotics. He died 5 weeks later. The development of Clostridium septicum aortitis, an extremely rare but life-threatening infection, is highly associated with an underlying colonic malignancy and demands immediate surgical intervention.