Mycotic infrarenal aortic aneurysm due to mycobacterium after intravesical treatment for bladder cancer

, is a common adjuvant therapy for bladder cancer with a low incidence of serious adverse events. The case described herein illustrates a rare complication of intravesical Bacillus Calmette-Guerin instillation that resulted from invasion of the mycobacterium into tissue outside of the bladder lining, also known as microbial dissemination, leading to infection of the aortic wall and development of a mycotic aneurysm, and highlights the therapeutic challenges presented by the aortic pathology in this clinical scenario.