Fine needle aspiration cytology of granulomatous prostatitis induced by BCG immunotherapy of bladder cancer.

Six patients treated with intravesical bacillus Calmette-Guérin (BCG) for superficial bladder cancer had granulomatous prostatitis demonstrated histologically by transperineal needle biopsy. Four of the six patients also underwent transrectal fine needle aspiration (FNA) for cytologic study. The diagnosis of granulomatous prostatitis was made cytologically in all four without knowledge of the histologic findings. Granulomatous prostatitis appears to be common following intravesical BCG treatment; these cases show that FNA cytology can be recommended as a method for diagnosing this complication.