# Invasive Mycobacterium bovis Infection Outside the Genitourinary Tract Following Bacille Calmette-Guerin Therapy for Non-muscle Invasive Bladder Cancer

## TL;DR

This paper reports two cases of severe infections caused by BCG therapy for bladder cancer, highlighting the need for careful patient evaluation and aggressive treatment.

## Contribution

The paper contributes two detailed clinical cases of disseminated BCG infection and emphasizes management strategies for such rare but serious complications.

## Key findings

- Two patients developed invasive Mycobacterium bovis infections following BCG therapy for bladder cancer.
- Effective treatment required a combination of anti-tubercular drugs and surgical intervention in some cases.

## Abstract

Bladder cancer significantly impacts global health, particularly non-muscle-invasive bladder cancer (NMIBC), which is typically treated with transurethral resection of bladder tumor (TURBT) and intravesical Bacillus Calmette-Guérin (BCG) therapy. While there is evidence that BCG can effectively prevent tumor recurrence and progression, it can cause adverse effects, including disseminated infection, necessitating the exclusion of active tuberculosis and the assessment of immunosuppressive conditions before treatment. We present two cases of disseminated BCG infection. The first involves an 85-year-old male who developed an abscess in his right thigh post-BCG therapy, successfully treated with isoniazid (INH), ethambutol, and rifampin. The second case is a 63-year-old male who, three years post-BCG therapy and abdominal aortic aneurysm repair, developed a right psoas abscess and a mycotic aneurysm. He was also treated with ethambutol, INH, and rifampin, in addition to surgical intervention. Effective management of BCG-related infections requires early identification of Mycobacterium bovis, a multidisciplinary approach, thorough pre-treatment evaluations, and aggressive treatment strategies, including anti-tubercular drugs and surgical intervention as necessary.