Prostate

Abstract

The normal prostate weighs 20 g by early adulthood and is best thought of as having an inverted pyramid shape, with anterior, posterior and lateral surfaces, a narrow apex anteroinferiorly and a broad base superiorly which lies against the bladder neck. It is related anteriorly to the symphysis pubis, laterally to the anterior fibres of the levator ani muscle and posteriorly to the seminal vesicles and rectum, separated from the latter by Denonvilliers’ fascia. The prostate is surrounded by an ill-defined fibrous capsule which blends with the pelvic fascia. Numerous neurovascular bundles are found within this connective tissue. At the apex, skeletal muscle fibres of the urethral sphincter are admixed with occasional benign prostatic glands and, at the base, fibres from the bladder detrusor muscle blend imperceptibly with the prostate capsule. At these points the boundaries of the organ are particularly obscure, rendering difficult in resection specimens the interpretation of capsular penetration by carcinoma and capsular incision during surgery. Adipose tissue is occasionally found just inside the prostatic capsule.