From the Guidelines
The peripheral zone of the prostate is located at the posterior and lateral aspects of the prostate gland, surrounding the distal urethra. This zone is the largest part of the prostate gland, making up approximately 70% of the glandular tissue in adult men 1. The peripheral zone extends from the base of the prostate, near the bladder, to the apex, the lower portion of the prostate, and forms the bulk of prostatic tissue that can be felt during a digital rectal examination.
Key Characteristics of the Peripheral Zone
- It is the most common site for prostate cancer development, with about 70-80% of prostatic adenocarcinomas originating in this region 1.
- The peripheral zone tends to be the primary site affected by chronic prostatitis.
- Understanding the location of the peripheral zone is crucial for physicians performing prostate examinations, interpreting imaging studies, and planning treatments for prostate conditions.
Clinical Significance
The location of the peripheral zone is significant because it is the area targeted during transrectal ultrasound-guided prostate biopsy, which is the most common method for obtaining prostate tissue for diagnosis of prostate cancer 1. A standard biopsy scheme consists of at least 8 to 12 cores of tissue targeting the peripheral zone at the apex, mid gland, and base, as well as laterally directed cores on each side of the prostate.
Biopsy Schemes
- Extended biopsy schemes have been proven to identify more cancer at initial biopsy compared to sextant biopsies, decreasing the false negative rate from 20% to 5% 1.
- Saturation biopsy, taking tissue from more than 20 locations, may be considered in men with persistently elevated PSA levels and multiple previous negative prostate biopsies 1.
From the Research
Location of the Peripheral Zone of the Prostate
- The peripheral zone of the prostate is located laterally and distally to the verumontanum, forming a disc of tissue whose ducts radiate laterally from the urethra 2.
- It constitutes over 70% of the glandular prostate and is the most frequent site of cancer, with almost all carcinomas arising in this zone 2.
- The peripheral zone is distinct from the central zone, which constitutes 25% of the glandular prostate and has ducts that arise close to the ejaculatory duct orifices 2.
- The relationship between the peripheral zone and other regions of the prostate, such as the transition zone and the anterior fibromuscular stroma, is important for understanding the anatomy and function of the prostate 2, 3.
Anatomical Relationships
- The peripheral zone is separated from the central zone by a distinct border, and its lateral border fuses with the proximal peripheral zone border to form a complete disc of secretory tissue oriented in a coronal plane 2.
- The peripheral zone is also related to the seminal vesicles, which may share a common embryological origin with the central zone 3.
- The anatomy of the peripheral zone is important for understanding the development and progression of prostate cancer, as well as the effects of different treatments on the prostate and surrounding tissues 4, 5, 6.