Rapid detection of bacille Calmette-Guérin-associated mycotic aortic aneurysm using novel cell-free DNA assay

Intravesical instillation of bacille Calmette-Guérin (BCG), an attenuated strain of Mycobacterium bovis , is an adjuvant immunotherapy for bladder carcinoma. Typical complications include fever, malaise, and dysuria. However, more severe complications have been reported, including granulomatous pneumonitis, BCG sepsis, and vascular infections. We present a case of an infrarenal abdominal aortic aneurysm complicated by iliopsoas abscess 2 years after BCG treatment and discuss a novel diagnostic tool for mycobacterial strain identification.