Abstract
This case report presents a 66-year-old male with a complex medical history, including testicular cancer, chronic obstructive pulmonary disease, obstructive sleep apnea, tobacco use disorder, erectile dysfunction, and obesity. The patient exhibited recurrent gross hematuria, leading to a comprehensive workup. Cystoscopy revealed a bladder tumor, prompting transurethral resection and mitomycin C instillation. Subsequent intravesical Bacillus Calmette-Guérin (BCG) therapy was initiated but resulted in severe sepsis during maintenance. Despite initial suspicion of BCG-induced sepsis, further evaluation suggested a reaction with chemical cystitis. Treatment involved brief antimicrobial therapy, and the patient's condition improved. This case highlights the challenges in managing BCG therapy complications, emphasizing the need for prompt intervention, careful monitoring, and consideration of risk factors. Patient education and vigilant follow-ups are crucial for addressing potential long-term effects.