Empyema Necessitans Following Bacille Calmette-Guérin Administration for Urothelial Carcinoma

Bacille Calmette-Guérin wash for urothelial carcinoma is a very common adjuvant treatment with a low potential for serious systemic adverse events. We present a case of a rare serious complication, empyema necessitans, following treatment with BCG. A 77-year-old patient with urothelial cancer treated with adjuvant BCG wash developed empyema due to Mycobacterium bovis related to his previous BCG exposure, which progressed to empyema necessitans treated with antituberculosis medications in conjugant with multiple thoracic drainages. Despite treatment, the patient's condition deteriorated slowly leading to death. Rare adverse events of common treatments should be considered when evaluating a patient, as BCG wash could potentially lead to empyema necessitans.