Novel anatomical findings of the prostatic gland and the surrounding capsular structures in the normal prostate.

With the increase of the patients with prostate cancer, the number of radical prostatectomy increased prominently. Meanwhile, surgeons and pathologists have difficulty regarding appropriate surgical dissection of the prostate and the pathological diagnosis. These problems are derived from uncertainty or misunderstanding about the precise anatomy. In fact, many surgeons are not confident of the structures of the prostatic gland, its surrounding capsules, and the sphincter. Here we investigated the surgical anatomy of the normal prostate to provide beneficial information regarding radical prostatectomy and subsequent pathological diagnosis. A 40 year-old cadaver with a history of sudden cardiac arrest was utilized in this study. Whole pelvic organs were extirpated en bloc and fixed in formalin. Whole mount step sections from the membranous urethra to the seminal vesicle were prepared and histologically examined. It has been reported that the prostatic parenchyma is covered with outside layer (lateral pelvic fascia) and inside layer (prostatic fascia, also known as "capsule"). Here, we show that nearly one third of the anterior surface of the apical region of the prostate (apical prostate) lacks this "capsule". The apical prostate is a mixture of striated muscles, glands, and elastic fibers. Furthermore, the glandular tissue exists within the anterior fibromuscular stroma and some region of the "capsule". Surgeons often try to preserve neurovascular bundles to maintain erectile function; however, other neural tissue was also observed over the entire surface of the prostate. Surgeons must be aware of these complicated anatomical structures when undertaking radical prostatectomy and subsequently diagnosing extra-prostatic extension.