LAUSR

BACKGROUND We present a unique case scenario of a periaortic liposarcoma masquerading as an impending rupture of an inflammatory abdominal aortic aneurysm (AAA). METHODS AND RESULTS A 57-year-old man was referred to our unit for an emergency endovascular repair of "an inflammatory AAA with computed tomography (CT) features of impending rupture." He underwent an uneventful endovascular repair with a bifurcated endograft (C3; Gore, Flagstaff, AZ). Seven weeks later, CT showed that the periaortic "mass" grew larger and asymmetric, and a CT-guided needle biopsy suggested the presence of a high-grade malignant mesenchymal tumor. He underwent laparotomy and excision of the retroperitoneal tumor en bloc with the anterior wall of the infrarenal aorta. The endograft acted as an excellent "safety net" providing adequate hemostatic control and obviating the need for aortic cross-clamping and repair of the aortic defect with a patch or tube graft. CONCLUSIONS The learning point from the present case is that when faced with an inflammatory AAA and/or retroperitoneal fibrosis, the rare possibility of a retroperitoneal neoplasm should be kept in mind.