Listeria Monocytogenes is a small gram-positive rod that is ubiquitous in nature and found to contaminate many foods. Clinically significant infection is rare, but mostly tends to affect those with impaired cell-mediated immunity.
An 83 year old man, with a past medical history significant for coronary artery disease with coronary artery bypass graft 20 years previously, a left nephrectomy for renal cell carcinoma with chronic renal insufficiency, and gastric arteriovenous malformations, presented to the emergency department with complaint of hemoptysis. Computed tomography and magnetic resonance imaging confirmed the presence of a large, leaking saccular aneurysm of the descending aorta. In the operating room, an eight centimeter aneurysm with localized extension into the lung parenchyma with contained rupture was discovered. The affected segment was resected and aneurysmal wall was sent for microbiologic and pathologic assessment. The aorta was repaired with a 20 millimeter tube graft. The patient recovered and was discharged to home on the eighth postoperative day.
Microscopic examination of aortic wall tissue showed an area of transmural aortic necrosis with acute inflammation. Final microbiologic results were consistent with Listeria Monocytogenes and final pathologic diagnosis of Listeria aortitis was considered. However, examination was inconclusive as to the possibility of primary aortitis versus hematogenous spread of infection. Blood cultures drawn on the third postoperative day failed to yield the pathogen and a two-dimensional echocardiogram was negative for endocarditis.
Aortitis can develop from an autoimmune or infectious cause. Among infectious agents, Staphylococcal Aureus and Salmonella are the most commonly implicated organisms. Opportunistic organisms are sometimes seen in intravenous drug abusers or immunosuppressed patients. From our review, this is one of fewer than 20 reported cases of Listeria Monocytogenes infected aneurysms worldwide, and illustrates the often aggressive course of such infection. Previous reports have noted that malignancy and immunosuppression are not predisposing factors as they are in other adult Listerial infections.
E.G. Daoud, None.