Article ID: 24-00059
Zinner syndrome (ZS) is a rare urogenital anomaly characterized by cystic seminal vesicles, obstructed ejaculatory duct, and ipsilateral renal agenesis, complicating diagnosis and management due to its rarity and nonspecific symptoms. ZS incidence is 0.0021%, with symptoms typically appearing in the 2nd and 3rd decades of life, including dysuria, urinary frequency, perianal pain, and infertility. MRI is the gold standard for diagnosis, while surgery is reserved for symptomatic patients. Mildly symptomatic patients receive conservative management, including antibiotics and regular monitoring.
We report the first case of ZS in Indonesia, involving a 36-year-old male presenting with perineal pain similar to an episode a decade earlier. MRI revealed right kidney agenesis, ejaculatory duct obstruction, a 4.95 cm cyst on the right seminal vesicle, and a right ectopic ureter. Semen analysis was unremarkable. Diagnosis of ZS was confirmed, and the patient opted for conservative management.
This case highlights the importance of diagnosing ZS in underrepresented regions, where limited awareness and access to advanced tools delay identification. The conservative approach reflected the patient’s preference to avoid surgical risks while achieving effective symptom relief through tailored, patient-centered care. Clinicians should consider ZS in cases of unilateral renal agenesis with cystic pelvic masses.
Zinner syndrome (ZS) is a rare congenital anomaly resulting from abnormal Wolffian duct development between the 4th and 13th gestational weeks, characterized by seminal vesicle cysts, ejaculatory duct obstruction, and ipsilateral renal agenesis1,2). Symptoms, including dysuria, perineal pain, and infertility, typically arise in the second or third decades of life. However, nonspecific presentations and the rarity of ZS often delay diagnosis1,3,4).
Imaging advancements, particularly MRI, have significantly improved diagnostic accuracy, offering detailed visualization of cysts and associated anomalies. Transrectal ultrasound (TRUS) and CT urography further aid in evaluating the reproductive and renal systems5). Management strategies focus on symptom relief and fertility preservation. Minimally invasive techniques, such as laparoscopic or robot-assisted vesiculectomy, are preferred for symptomatic cases due to their precision and faster recovery times. Conservative approaches, including α1-adrenoceptor antagonists or cyst drainage, may be considered for milder cases, though recurrence is common5,6).
Globally, only about 200 cases of ZS have been reported, emphasizing the need for greater awareness and research5). For regions like Indonesia, integrating these global learnings into local healthcare practices could significantly improve outcomes for patients with ZS. Collaborative efforts to enhance imaging capabilities and expand access to minimally invasive surgical techniques are recommended to address current limitations. This report highlights a delayed ZS diagnosis in a 36-year-old male with recurrent perineal pain after a decade of being symptom-free.
A 36-year-old man presented in 2023 with perineal pain radiating to the base of his penis, worsening over four days, accompanied by dysuria, but no flank pain, hematuria, fever, or urinary frequency. Rectal examination revealed a smooth, cystic, tender 4 cm extraluminal mass. Hematology, renal function tests, PSA, and urinalysis were normal. The patient had a similar episode 10 years prior. A non-contrast MRI performed 10 years ago, taking approximately 45 minutes, revealed right kidney agenesis and a 4 cm tortuous cystic lesion in the right seminal vesicle (Figure 1). The patient’s symptoms improved significantly within one week of initiating analgesics and antibiotics.
At present, transabdominal pelvic ultrasound (PUS) confirmed the absence of the right kidney with mild compensatory hypertrophy of the left kidney, as well as a lobulated cystic lesion in the right seminal vesicle (Figure 2). Follow-up imaging included an MRI in 2023, which reaffirmed right kidney agenesis, ejaculatory duct obstruction, and a cystic lesion in the right seminal vesicle (Figure 3). These findings align with reports of Zinner syndrome (ZS) described in global case studies, which typically present with unilateral renal agenesis and seminal vesicle cysts causing genitourinary symptoms.
The patient was diagnosed with ZS and treated with IV ketorolac, oral cefixime, and diclofenac sodium. His pain significantly reduced after two weeks. Semen analysis revealed normozoospermia, and the patient, who has a 7-year-old son, chose nonsurgical management with regular monitoring due to his personal concerns about further childbearing despite no signs of secondary infertility.
A detailed follow-up plan was established to mitigate risks of complications, including biannual evaluations with symptom assessment, physical examination, and imaging (MRI or US) to monitor cyst size and detect complications like infection or obstruction. An annual semen analysis will monitor fertility, complemented by counseling sessions or family planning. The patient was instructed to promptly report pain, dysuria, or other urinary symptoms for early detection of potential complications. As part of the screening process, an abdominal ultrasound was conducted on the boy, revealing no renal agenesis or other abnormalities.
Informed consent to publish this case and related material was obtained from both the patient and his wife. The process was straightforward, with both parties expressing support for publication after receiving clear explanations about confidentiality measures and the contribution their case could make to medical knowledge. No challenges were encountered during the consent process.
MRI 10 years ago (A) Coronal T2WI MRI showing the absence of the right kidney;(B) sagittal and (C) coronal T2WI MRI showing a slightly hypointense cystic appearance (red arrow) and tortuous tubular cystic lesion (white arrow) converging into the right seminal vesicle. The left seminal vesicle appears normal.
(A) Abdominal ultrasound showing the absence of the right kidney in the hepatorenal fossa;(B) mild compensatory hypertrophy of the left kidney, measuring 13.5 × 6.5 cm;(C) lobulated cystic lesion in the right seminal vesicle (white arrow) converging towards the central part of the prostate;(D) the point of ejaculatory duct obstruction where the hypoechoic area is no longer visible distally (red arrow).
MRI in 2023 (A) Coronal T2WI MRI confirming right kidney agenesis;(B) sagittal T2WI (left) and axial T1WI MRI (right) showing the cystic lesion in the right seminal vesicle, with the largest anteroposterior diameter measuring 4.95 cm;(C) coronal T2WI FS (left) and T1WI FS MRI (right) showing a tortuous tubular cystic structure (red arrow) converging into the cyst in the seminal vesicle (white arrow).
Zinner syndrome (ZS), first documented in 1914, has an incidence of approximately 0.0021%7,8). It involves unilateral renal agenesis, ipsilateral seminal vesicle cysts, and ejaculatory duct obstruction9). Other abnormalities, such as ureterocele, testicular or epididymal abnormalities, and hypospadias, may also occur10). During the 6th and 8th gestational weeks, disruptions in ureteric bud migration and separation from the mesonephric duct result in renal agenesis and ejaculatory duct atresia. Consequently, seminal vesicles without adequate drainage can develop cysts7,9). When the ureteric bud arises distal to the urogenital sinus, an ectopic ureter may drain into seminal vesicle cysts, as seen in our case9).
Genetic predispositions have been explored, with Dai et al. identifying mutations in BMP4, RPGRIP1L, SEC63, and SETD2 in two cases. However, due to the small sample size, further studies are needed to establish statistical significance and clinical relevance11).
Symptomatic ZS is reported in 80.8% of cases, often presenting in the 2nd and 3rd decades of life1,9,10,12). Common symptoms include dysuria, urinary frequency, perineal pain, abdominal discomfort, and urinary urgency resulting from seminal vesicle cyst enlargement1,13). Another pooled analysis published in 1998 by Van den Ouden reported epididymitis, pain after ejaculation, and scrotal pain14). Discomfort during ejaculation in ZS is thought to result from increased seminal vesicle pressure during orgasm caused by semen buildup from ejaculatory duct blockage15). Other less common presentations include hematuria, recurrent urinary tract infections, hematospermia, and prostatitis9,11). While a small number of patients exhibit cryptorchidism, its relationship to congenital dysplasia remains unclear11). Large cysts can pose additional complications, such as obstructing the bladder outlet or impeding colonic function13).
ZS diagnosis is based on clinical symptoms and imaging examinations11). MRI is the gold standard due to its excellent soft tissue resolution and ability to delineate complex anatomy9). It is the only imaging modality capable of distinguishing seminal vesicle cysts from other pelvic cystic masses, primarily by identifying a convoluted tail connecting the anomaly to the seminal vesicle. It also can detect ectopic ureteric orifices, differentiating it from other imaging methods7). However, MRI has limitations, including its high costs and limited accessibility in resource-limited settings such as Indonesia. As an alternative, transrectal ultrasound (TRUS) provides a cost-effective and reliable method for evaluating seminal vesicle cysts and ejaculatory duct obstruction, particularly where MRI is unavailable7). US typically reveals kidney absence on the affected side and identifies the seminal vesicle cyst as an anechoic pelvic mass with irregular, thickened walls7). Internal echoes may indicate infection or hemorrhage10). TRUS is often preferred for adults over transabdominal pelvic ultrasound (PUS) due to higher accuracy8). However, PUS was chosen in our case for initial evaluation due to its non-invasive nature.
In addition to diagnostic assessments, we conducted a semen analysis to rule out secondary infertility. This step is crucial, as up to 45% of males with ZS experience infertility attributed to ejaculatory duct obstruction. The precise pathophysiology remains incompletely understood due to the unexpected occurrence of azoospermia in cases of unilateral ejaculatory duct obstruction, which is part of the ZS triad. One hypothesis suggests that unilateral obstruction initiates an autoimmune response, leading to the production of anti-sperm antibodies that target and eliminate sperm in the contralateral testis. Another hypothesis proposes that prolonged obstruction prompts the generation of reactive oxygen species, inducing apoptosis in germ cells2,16).
Surgical intervention is the primary treatment option for ZS and is limited to symptomatic individuals9). The main objectives of surgical intervention in ZS patients are to alleviate discomfort resulting from the mass effect of seminal vesicle cysts and to safeguard the contralateral ejaculatory duct to preserve fertility8). The potential of α1-adrenoceptor antagonists like silodosin to suppress seminal vesicle contractions, while also inducing relaxation in the smooth muscles of the urethra and prostate, could play a role in alleviating discomfort linked to ejaculation15). Following surgical intervention, research indicates a significant enhancement in semen parameters, with reported improvements ranging from 63-83% in individuals with ejaculatory duct obstruction2). Various surgical approaches are employed, including open exploration with vesiculectomy, transperitoneal or transrectal cyst aspiration, and transurethral cyst deroofing8). While cyst aspiration and sclerotherapy offer the advantages of convenience and reduced trauma, they are associated with incomplete treatment and a higher recurrence rate11). Complete surgical removal of the cyst and affected seminal vesicle is widely acknowledged as a fully effective remedy for symptomatic cases. Recently developed robotic-assisted approaches provide a minimally invasive option, marked by enhanced visualization, reduced hospitalization duration, decreased incidence of pre- and post-operative complications, and accelerated recovery7).
Conservative management was chosen due to the patient’s concerns about potential surgical complications, including damage to surrounding structures, prolonged recovery time, and infertility risks. The mild presentation and significant symptom improvement with medical therapy indicated that surgery was unnecessary. Additionally, a risk-benefit assessment deemed the risks of surgical intervention, such as bladder neck or rectal injury and symptom recurrence, as outweighing the benefits in this stable patient4,10,11).
This case highlights the importance of considering ZS in young male patients presenting with genitourinary symptoms and the need for accessible diagnostic tools in Indonesia. Training programs for clinicians should emphasize the clinical and imaging features of ZS to improve early diagnosis. Limitations of this report include reliance on a single imaging modality for initial diagnosis, which may introduce bias. Future studies should explore genetic contributions to ZS to enhance understanding and guide management.
This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
