['The periurethral glands are known to produce prostate specific antigen (PSA). With ultra-sensitive assays now routinely available, it is necessary to determine if the periurethral glands significantly influence serum PSA concentration after radical prostatectomy.', 'Serum PSA levels of 46 men, 51 to 89 years old (median age 67) who underwent radical cystoprostatectomy and total urethrectomy, were compared with those of 92 men 46 to 91 years old (median age 67) who underwent radical cystoprostatectomy only. All men had transitional cell carcinoma of the bladder without gross or microscopic evidence of prostate cancer and all underwent ileal conduit diversion. Serum was obtained at least 1 year postoperatively. Each specimen was analyzed using the Tosoh, Immulite, and Yu and Diamandis ultra-sensitive PSA assays with analytical detection limits of 0.02 ng./ml., 0.004 ng./ ml. and 0.002 ng./ml., respectively.', 'Median PSA for the radical cystoprostatectomy with urethrectomy group was 0.00 ng./ml. (range 0.00 to 0.14) for each of the 3 assays. For the radical cystoprostatectomy only group the median Tosoh and Immulite PSA assay levels were 0.01 ng./ml. (range 0.00 to 0.22), and median Yu and Diamandis PSA assay level was 0.00 ng./ml. (range 0.00 to 0.31).'] Do the periurethral glands significantly influence the serum prostate specific antigen concentration?