Abstract: Intravesicular bacillus Calmette-Guérin (BCG) instillation is a widely used immunotherapy for superficial bladder cancer. Although this treatment is generally well tolerated with primarily local adverse effects, systemic adverse effects, including fever, pneumonitis, and hepatitis, have been reported. A disseminated infection with the development of mycotic aneurysms is very rare and results in significant morbidity and mortality.
We report an immunocompetent patient with disseminated BCG infection and mycotic aneurysms diagnosed based on imaging and a positive mycolytic blood culture and subsequently confirmed by histopathology. We review the literature of other cases of disseminated BCG infection with mycotic aneurysms and summarize the classic presentation, the treatment, and outcomes.