Suspected infected infrarenal abdominal aortic aneurysm with contained rupture in the setting of Escherichia coli prostatitis.

Contained rupture of a mycotic abdominal aortic aneurysm (AAA) is rare and potentially fatal. While most cases involve Salmonella or Staphylococcus aureus, Escherichia coli is an uncommon cause.A man in his early 60s presented with acute E. coli prostatitis and a prostatic abscess. Abdominal ultrasound incidentally revealed a 3.8 cm infrarenal saccular AAA suspicious for contained rupture. Contrast-enhanced CT confirmed focal aortic wall disruption without active extravasation. Intravenous ceftriaxone and vancomycin were initiated, and serial imaging demonstrated stability. After infection control, endovascular aneurysm repair (EVAR) with an Endurant II stent graft was successfully performed. Recovery was uneventful and the patient completed targeted antibiotic therapy.This case illustrates an unusual presentation of E. coli-associated mycotic aneurysm detected before frank rupture. Early imaging, infection control and multidisciplinary coordination enabled a staged strategy with a favourable outcome.