Mycobacterium Bovis-Related Abdominal Aortic Aneurysm after Intravesical Bacillus Calmette-Guérin Therapy for Non-Muscle Invasive Bladder Cancer

Background: Systemic infection after intravesical Bacillus Calmette- Guérin (BCG) therapy for non-muscle invasive bladder cancer (NMIBC) is a rare complication. Case Presentation: Here, we describe an 81-year-old man with a history of multiple, recurrent NMIBC who was treated with intravesical BCG. Twelve months after his last BCG treatment, he developed back pain and constitutional symptoms. Investigations revealed a new 6.2 cm abdominal aortic aneurysm. He underwent open repair using a femoral vein conduit. Post-operatively, he was started on anti-tubercular therapy, and was discharged home with outpatient follow-up at the tuberculosis (TB) clinic. Discussion: Mycotic aneurysms are a rare vascular complication of intravesical BCG. Maintaining a high degree of suspicion is key to early diagnosis and management.