Infected Aortic Aneurysm Mimicking Anti-proteinase 3-Antineutrophil Cytoplasmic Antibody-associated Vasculitis

Abstract

We herein report an unusual case of an infected descending aortic pseudoaneurysm with luminal pathognomonic oscillating vegetation with serological findings and clinical features mimicking anti-proteinase 3-antineutrophil cytoplasmic antibody-associated vasculitis. The positive blood cultures and imaging findings, including a pseudoaneurysm and vegetations in the aorta, suggested the presence of an infected aortic aneurysm. The patient was successfully treated with antibiotics and endovascular aortic repair. A precise diagnosis is crucial in order to avoid inappropriate therapy such as immunosuppressive treatment, which could result in life-threatening consequences in a patient with an infected aortic aneurysm.

Figure 1.

Effects of antibiotics on fever and C-reactive protein during hospitalization. The patient finally became afebrile and has C-reactive protein levels within the normal range after receiving antibiotics. CRP: C-reactive protein, DAP: daptomycin, PCG: penicillin G, TAZ/PIPC: tazobactam/piperacillin, Tx: therapy

Figure 2.

Transesophageal echocardiographic images of the descending aorta, with sectioning planes at 90° (a) and 0° (b). Many oscillating masses attached to the intima were seen in the lumen of the descending aorta.

Figure 3.

Contrast-enhanced computed tomographic images in the axial (a) and frontal (b) sections. These images show a descending aortic pseudoaneurysm and a contrast defect (arrow) beside the aneurysm that is compatible with echo-documented vegetation.

Figure 4.

A nontender hemorrhagic macular on the sole of the foot (a). Photomicrograph of the macular lesion shows microembolization with fibrin and infiltration of neutrophilic cells Hematoxylin and Eosin staining (b,c). These findings are compatible with a Janeway lesion.

Figure 5.

A transesophageal echocardiographic image of the descending aorta after the antibiotic treatment, with the sectioning plane at 90°. Many oscillating masses have disappeared.

Figure 6.

A contrast-enhanced computed tomographic image after endovascular stent graft repair. It shows a successfully occluded infected pseudoaneurysm.