It is generally acknowledged that the two layers of the prostatoperitoneal fascia of Denonvillier, which lie as a transverse aponeurosis interposed between the posterior surface of the prostate and seminal vesicles and the anterior surface of the rectum seem to act as a protective barrier to neoplastic infiltration. Young,1 in a study of 111 cases of primary prostatic carcinoma, observed only one instance in which invasion occurred through this fascia into the rectal mucosa with ulceration. Ackerman and del Regato,2 in discussing primary rectal carcinoma, state that true invasion of the prostate occurs only rarely because "Denonvillier's fascia usually provides protective check to intraprostatic invasion."
At the same time, it is not a rare clinical experience in urological practice to encounter a patient two or three years following performance of an abdominoperineal resection for rectal carcinoma because of dysuria, hematuria, or symptoms of bladder-neck obstruction. Such a patient