Transrectal ultrasound appearance of prostatic granulomas secondary to bacillus Calmette-Guerin instillation

Purpose: To our knowledge the transrectal ultrasound appearance of prostatic granulomas occurring after intravesical bacillus Calmette-Guerin (BCG) therapy has not been thoroughly described. Materials and Methods: A total of 13 men with a history of transitional cell carcinoma of the bladder treated with intravesical BCG underwent transrectal ultrasound followed by prostate biopsy and/or cystoprostatectomy. Results: Of the 13 patients studied 9 (69.2%) had intensely hypoechoic lesions anteriorly in the transition zone of the prostate on ultrasound images. The lesions were histologically proved to be necrotizing granulomas. Conclusions: Prostatic granulomas secondary to BCG instillation appear as distinct, intensely hypoechoic anterior lesions within the transition zone of the prostate. Prostatic adenocarcinoma arising in the transition zone is usually not visible and would not be easily confused with granulomas. However, since transitional cell carcinoma involving the prostate can appear hypoechoic in the transition zone, transrectal or transurethral tissue sampling may be indicated.