The prostate gland is a walnut-shaped organ that lies at the base of the bladder in men. It serves as an accessory reproductive organ that produces a thin, milky fluid that helps to sustain sperm cells following ejaculation. The size of the prostate is usually expressed in cubic centimetres (cc); a normal prostate is about 20cc1,2. Approximately one third of the prostate is composed of the anterior or ventral fibromuscular and non-glandular region; the remainder is glandular, with three histologically different zones: peripheral (~65%), central (~25%) and transitional (~2%).
Prostatic fluid also contains an enzyme called prostate-specific antigen (PSA). Serum PSA levels are commonly used for the early detection of prostate cancer, but can also be used to assess the progression of BPH.
For the detection of non-palpable prostate cancer, it is generally agreed that prostate biopsies should be performed when the PSA level is over 10 ng/mL and probably when it is above 4gn/mL.87