Ultrasonographic Appearance of Suspected Zinner Syndrome

Zinner syndrome (ZS) is a rare congenital condition characterized by the triad of unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ipsilateral ejaculatory duct obstruction. ZS is suspected to be caused by the malformation of the mesonephric duct during embryogenesis. The incomplete migration of the ureteric bud results in ipsilateral renal agenesis and ejaculatory duct obstruction. The remaining gonad develops with inadequate seminal fluid drainage, leading to the formation of seminal vesicle cysts. ZS is often asymptomatic, leading to challenges in diagnosis, particularly in adolescents. Symptoms can include pain, dysuria, pollakisuria, perineal pain, epididymitis, and pain after ejaculation. Imaging plays a crucial role in the diagnosis of ZS. MRI is the preferred modality due to its ability to provide detailed anatomical and soft tissue information. Ultrasonography can be used for initial evaluation, especially in adolescents, and may reveal cystic masses in the retrovesical space and an absent kidney on the affected side. Differential diagnosis includes Mullerian duct cysts and utricular cysts, which can be distinguished based on their anatomical location. Surgical intervention is the mainstay of treatment for symptomatic patients, with the goal of relieving pain and preserving fertility. Various surgical approaches, including transurethral unroofing and open surgery, can be employed. Minimally invasive procedures, such as robotics, are gaining popularity. Surgical intervention for ejaculatory duct obstruction involves transurethral resection of the ejaculatory duct. Despite surgical interventions, azoospermia may persist due to contralateral spermiogenesis impairment. Early excision of the affected duct may help prevent negative effects on the contralateral genitourinary tract.