[BCG infection following intravesicular immunotherapy for bladder cancer]

Bacille of Calmette et Guérin (BCG) immunotherapy is the most effective treatment for non-muscle-invasive bladder cancer. Yet, potentially severe localized or systemic mycobacterial infections can happen.

In a patient who underwent BCG instillation for bladder cancer, the diagnosis of BCG infection is usually suggested by more than 3 days of high-grade fever and systemic and/or local symptoms with no other plausible alternative diagnosis. BCG infection can be localized (usually to the genitourinary tract, the bones or blood vessels) or systemic (mainly with pulmonary and hepatic involvements). The presence of granuloma in tissue biopsies (other than from the genitourinary tract) supports the diagnosis. The advent of polymerase chain reaction has recently improved the sensitivity of microbiological investigations. The management of BCG infection is not well established but relies on broad-spectrum antimycobacterial therapy (with the exclusion of pyrazinamide), glucocorticoids (in the context of general symptoms refractory to antimicrobial therapy alone) and occasionally surgery.

BCG infection is a rare but not exceptional complication of BCG immunotherapy with heterogeneous clinical presentation. Prospective studies are warranted in order to improve treatment outcomes.