Chronic contained rupture of abdominal aortic aneurism complicated with aortic occlusion: a case report

BACKGROUND: Chronic contained rupture is a subtype of an abdominal aortic aneurysm rupture. Its diagnosis is sometimes difficult due to lack of typical symptoms. We would like to report the challenge of diagnosing chronic contained rupture of abdominal aortic aneurysm with a retroperitoneal tumor. CASE PRESENTATION: A 60-year-old man reported perceived lower abdominal pain 7 months earlier that spontaneously remitted. A contrast-enhanced computed tomography (CT) indicated an abdominal aortic aneurysm and a mass lesion surrounding the abdominal aorta and iliac arteries. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed an increased accumulation of FDG in the margin of the lesion, indicating a retroperitoneal tumor. A CT-guided biopsy revealed only retroperitoneal fibrous tissue with chronic inflammation. We were thus unable to reach a definitive diagnosis. At 1 month after the initial examination, intermittent claudication was newly observed. A follow-up contrast-enhanced CT scan revealed abdominal aortic occlusion. Mass resection and bypass surgery were performed for diagnosis and treatment. Intraoperative and pathological findings led to the diagnosis of chronic contained rupture of an abdominal aortic aneurysm. The patient was discharged 19 days after surgery. CONCLUSION: The mass peripheral to the abdominal aorta should be considered the possibility not only of tumor but also of chronic contained rupture of an abdominal aortic aneurysm.