Periurethral glandular zone of prostate

The periurethral glandular zone of the prostate refers to a small group of glands and ducts embedded within the periurethral region of the prostate, immediately surrounding the proximal prostatic urethra (the segment proximal to the verumontanum). As described in McNeal's zonal anatomy model, these are tiny, rudimentary ducts whose development is thought to be limited by their intimate relationship with the periurethral smooth muscle sphincter that exists only proximal to the veru montanum.

• Location: The periurethral glands are situated along the proximal prostatic urethra, between the verumontanum and the bladder neck, embedded within the periurethral smooth muscle sphincter.

• Size and composition: They represent a very small volume of glandular tissue much smaller than the transition zone consisting of short, abortive ducts with limited branching.

• Relationship to the transition zone: Although closely related anatomically, the periurethral glands are distinct from the transition zone. The transition zone consists of two small lobules whose ducts exit the posterolateral urethral wall and curve anterolaterally, whereas the periurethral ducts are more centrally located and confined to the immediate periurethral stroma.

• Clinical significance: Along with the transition zone, the periurethral glands are the exclusive site of origin of benign prostatic hyperplasia (BPH). When hyperplasia arises specifically from the periurethral glands, it may produce what is termed "median lobe hyperplasia," which can project into the bladder neck and cause significant urinary obstruction.

• Embryologic origin: Like the transition zone and peripheral zone, the periurethral glands are derived from the urogenital sinus.