What kinds of cysts occur in the prostate gland and seminal tract?
• Utricular cysts are congenital and endodermal in origin and arise from the utricle. These are seen within the midline of the prostate gland, do not extend above the superior aspect of the prostate gland, and may communicate with the posterior urethra or ejaculatory duct.
• Müllerian duct cysts are congenital and mesodermal in origin and arise from the caudal ends of the fused müllerian ducts. These are seen within the midline of the prostate gland, often have a teardrop shape, and may extend above the superior aspect of the prostate gland but do not communicate with the urethra or ejaculatory duct.
• Ejaculatory duct cysts are usually acquired secondary to partial obstruction of the ejaculatory duct and are seen in a paramedian location along the course of the ejaculatory duct.
• Seminal vesicle cysts are typically located laterally in one or both seminal vesicles. They are associated with ipsilateral genitourinary anomalies such as renal agenesis, congenital absence of the vas deferens, and ectopic ureteral insertion into mesonephric duct derivatives such as the seminal vesicle or ejaculatory duct. Seminal vesicle cysts may also occur in patients with autosomal dominant polycystic kidney disease (ADPKD).
• Cowper’s gland cysts are usually encountered in children and rarely in adults. These are typically located posterior or posterolateral to the bulbomembranous portion of the posterior urethra within the urogenital diaphragm.
• Retention cysts are usually secondary to obstruction of glandular components in the prostate gland and may occur anywhere in the prostate gland, usually off midline.
• Although cysts in the prostate gland and seminal tract are often asymptomatic, they may sometimes cause irritative or obstructive lower urinary tract symptoms secondary to compression/obstruction of the prostatic urethra or ducts and may result in hematospermia. Cysts may also get infected, and calculi or calcifications may form in the cysts.