Listeria Infected Pseudoaneurysm of the Superficial Femoral Artery.

We present a unique case of listeria-infected pseudoaneurysm of the superficial femoral artery. Listeria monocytogenes, a gram positive, intracellular bacterium, is widespread in the environment. The manifestation of infection in humans ranges from mild gastroenteritis to life-threatening listeriosis. The incidence in the healthy population is low (0.7 per 100,000) but rises sharply in pregnancy, the immunocompromised and patients with malignancy. Listeria rarely causes mycotic aneurysm formation, with fewer than 40 cases reported in the literature. Further investigation revealed the patient to be diagnosed with a hepatocellular carcinoma. It is likely that the two pathologies were linked. Hence, we would advocate investigation for underlying malignancy in patients presenting with a mycotic aneurysm, particularly those resulting from Listeria infection.