Figure 1. Schematic of the zonal anatomy of the human prostate.

As indicated, each zone houses distinct sections of the prostatic urethra. The central zone, where little if any disease develops, houses the ductal tube from the vesicular seminalis. The peripheral zone, the primary site of pre-cancerous and cancerous lesions, houses the descending penile urethra. The transition zone, the only site of benign prostatic hyperplasia, houses the transitional urethra composed of descending bladder and prostatic urethral sections. The verumontanum is the junction between the ejaculatory ducts and the prostatic urethra.