Chronic contained rupture of abdominal aortic aneurysm mimicking a retroperitoneal tumor: A case report

Abstract

BackgroundChronic contained rupture (CCR) of abdominal aortic aneurysm (AAA) is a rare subtype of AAA rupture with a chronic course. CCR-AAA may mimic other diseases in terms of symptoms and morphology. Case reportA 64-year-old man was incidentally found to have an AAA and a retroperitoneal mass lesion on computed tomography (CT) during his medical checkup. He had no history of abdominal or back symptoms and was hemodynamically stable. Contrast-enhanced CT revealed a nubby cauliflower-like, nonenhanced mass in the retroperitoneum continuous with the aneurysm. Magnetic resonance imaging revealed the mass to have an internal low-signal area branching off from the abdominal aorta on a T1-weighted image. Positron emission tomography-CT revealed enhanced fluorine-18-fluorodeoxyglucose accumulation on the margin of the mass. The differential diagnoses included CCR-AAA, infectious aortic aneurysm, or AAA with a retroperitoneal malignant tumor. The mass lesion was resected at the same time as the open AAA repair. Histopathological examination revealed that the mass comprised granulation tissue associated with ruptured AAA and did not include a malignant tumor. The patient was diagnosed with CCR-AAA based on these results and had an uneventful postoperative course. ConclusionsReaching a definitive diagnosis of CCR-AAA based on preoperative examinations was difficult, and simultaneous mass resection was required. Because CCR-AAA can rupture completely, mass resection may be helpful option for early diagnosis and patient salvage.