Renal Tuberculosis Following Intravesical Bacillus Calmette–Guérin (BCG) Immunotherapy for the Treatment of Bladder Cancer

INTRODUCTION: Non-muscle-invasive bladder cancer (NMIBC) is usually effectively treated with transurethral resection (TUR), most often followed by intravesical instillation of bacillus Calmette-Guérin (BCG) or intravesical chemotherapy. Although the precise mechanism of BCG immunotherapy is still unclear, a local immune response is presumed. However, a number of severe side effects and complications are related to intravesical immunotherapy. AIM: Aim of this report is to present rare case of the renal granulomatous disease in a patient previously treated with intravesical instillation of BCG immunotherapy, following TURBT. In addition, we performed review of previously reported cases of renal granulomas following intravesical BCG immunotherapy. CASE REPORT: A 79-year-old man was presented to Urology Clinic due to clinically verified tumor of the urinary bladder. After transurethral resection of bladder tumor, histopathological analysis revealed the diagnosis of papillary urothelial high-grade pT1 carcinoma. Intravesical BCG immunotherapy was initiated, according to protocol currently used in our institution. Upon completion of therapy with BCG, we re-examined the patient and, using ultrasound, found a change in the right kidney, resembling moth bites not seen on CT scan before TURBT. Additionally, CT-guided core-needle biopsy of the affected kidney was performed, and the specimen was sent for histopathological analysis, which revealed chronic necrotizing granulomatous inflammation. Antituberculotic therapy was initiated for 6 months. Upon completion of antituberculotic therapy, control CT-scan was performed at follow-up, indicating regression of changes on the right kidney. CONCLUSION: This case report emphasizes the importance of consistent implementation of follow-up protocol and the identification of lesions during the asymptomatic period and enables the proper treatment of the disease. To reduce the incidence of adverse effects of BCG treatment for bladder tumors, an individualized approach is needed.