[Mycotic aneurysm of the iliac artery disclosed by an abdominal mass].

Background: Mycotic aneurysms are classic complications of infective endocarditis. Their diagnosis can be difficult when they are located in deep vessels.

Case report: A 8 year-old boy was admitted for psoitis, tenderness of the left iliac fossa and a palpable mass. He was treated with antibiotics for 2 months for infective endocarditis, but vomiting and fever began after 3 weeks of therapy. Blood cultures showed Staphylococcus epidermidis. Ultrasonography of the mass showed findings compatible with an abscess but sampling of its contents showed blood. Immediate Doppler echography showed that the mass was an aneurysm of the left iliac artery. This diagnosis was confirmed by CT scan and aortography. The aneurysm was excised and a satisfactory repair was made using a Gore-tex graft.

Conclusion: Although this mass had no clinical vascular characteristics, its origin should have been recognized because of the history of infective endocarditis and a better analysis of the ultrasonographic findings.