BCG pyelonephritis following intravesical therapy for transitional cell carcinoma.

Bacillus Calmette-Guerin (BCG) is a common intravesical agent utilized for superficial transitional cell carcinoma of the bladder. The potential for side effects and complications does exist secondary to the utilization of live attenuated bacteria. We present the case of a 70-year old male that developed BCG pyelonephritis and associated renal mass following the fifth of six weekly intravesical BCG therapies. The patient improved clinically and renal mass resolved following 3 months of isoniazid monotherapy without renal biopsy.