Prostatic involvement in bladder cancer. Prostate mapping in 20 cystoprostatectomy specimens.

Twenty prostate glands from patients with either high-grade papillary tumors (19 patients, 15 of whom also had peripheral carcinoma in situ) or multifocal carcinoma in situ (1 patient) of the bladder who underwent cystoprostatectomy were studied histologically by mapping. Prostatic duct involvement by urothelial carcinoma was noted in nine patients, two with extensive involvement and seven with focal involvement confined to periurethral ducts. Carcinoma in situ of the bladder was observed in each of the nine patients and intraepithelial permeation appeared to be the predominant manner of spread of cancer cells into the prostate. The prostatic involvement was clinically silent and it may be a potential source of failure of conservative modalities of treatment of high-grade bladder cancer. A routine diagnostic transurethral prostatic biopsy may be recommended in the workup of patients with carcinoma in situ and high-grade carcinomas of the bladder. An incidental observation was the presence of 14 occult prostatic adenocarcinomas.