Background: Intravesical administration of Bacillus Calmette-Guérin (BCG) has been used effectively for treatment of superficial carcinoma of the bladder. Although well tolerated in the majority of patients adverse local and systemic side effects have been described.
Case Report: We report the case of a 58 year old man who developed granulomatous prostatitis and interstitial pneumonitis following intravesical instillation of BCG for recurrent superficial bladder cancer. Prostate biopsies showed tuberculoid granulomatous inflammation, whereas mycobacterial cultures of sputum were negative. A high resolution computed tomography
scan revealed interstitial fibrosis with reticular pattern. The patient received antituberculous treatment and corticosteroids with complete remission.
Conclusions: This was a rare presentation of granulomatous prostatitis and interstitial pneumonitis following immunotherapy with BCG. Both a hypersensitivity reaction and an infection mechanism should be considered in this particular case.

Keywords: BCG Vaccine, Bladder Neoplasms, Prostatitis