Zinner syndrome mimicking bladder outlet obstruction managed with aspiration.

Zinner syndrome is a rare cystic malformation of seminal vesicle which consists a triad of unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction. The usual presentation is between the third and fourth decades of life, with infertility being the most common complaint. Ultrasound, cystoscopy, and magnetic resonance tomography (MRI) can easily detect this condition. Treatment option varies according to the presenting symptoms of the patient. We present a case of a 19-year-old male with recurrent episodes of urinary tract infection (UTI) and poor urinary stream. On ultrasound examination, the patient was found to have absent right kidney with a cystic swelling noted to be arising from prostate or seminal vesicle region which was further confirmed on MRI examination. Cystoscopy reveals a bulge on the right side of the verumontanum abutting the neck of the bladder. An ultrasound-guided aspiration of the cyst was performed which relieved the symptoms of the patient. Cystic abnormalities of the seminal vesicle are very uncommon. Symptomatic cases may present as recurrent UTI, infertility, bladder outlet obstruction, and painful ejaculation. Surveillance may be the option in the absence of clinical manifestations. Interventions such as image-guided aspiration or surgical procedures are appropriate when conservative measures prove ineffective. Copyright:

INTRODUCTION

There are various congenital abnormalities noted in the urogenital system ranging from innocuous condition such as duplication of the ureter to life-threatening condition such as bilateral renal agenesis.[1] The most common organ affected with malformations is the ureter in the urogenital tract. Congenital malformations of the seminal vesicle are very uncommon. Malformations of seminal vesicle range from complete absence of the seminal vesicle to solid and cystic enlargement.[2]

Most of the malformations are cystic in nature due to collection of inspissated material in the seminal vesicle following obstruction of the ejaculatory duct. Malformation occurs due to insults between 4 and 13 weeks of gestation. Zinner syndrome is a cystic malformation of the Wolffian duct, a male counterpart of Mayer–Rokitansky–Küster–Hauser syndrome seen in women, seen in 0.005% of all the cases.[34] It consists a triad of ipsilateral seminal vesicle cyst, ejaculatory duct obstruction, and most commonly unilateral renal agenesis. The usual age of presentation is the third or fourth decade of life.[5] Most of the patients are asymptomatic which are detected incidentally. Other patients present with chief complaints of infertility, dysuria, urgency, prostatism, and painful ejaculation due to obstruction of the ejaculatory ducts and distension of the seminal vesicle.

CASE REPORT

A 19-year-old unmarried male patient presented to the outpatient department with complaints of recurrent episode of urinary tract infections (UTIs). The patient also complained of poor urinary stream which slightly improved on straining from the past 1 year. The patient was average built, and clinical parameters were normal. Abdominal examination and the external genitalia were normal, and Vas deferens was palpable bilaterally. On digital rectal examination, there was a soft, smooth, nontender bulge just above the prostrate. Laboratory investigations were in the normal range. Urine culture was sterile. Uroflometry done initially showed a maximum flow rate of 7 ml/min.

Computed tomography (CT) scan already done from outside revealed absent right kidney and well-defined peripherally enhancing cystic lesion with hyperdense contents arising likely from the seminal vesicle. Ultrasound examination of the abdomen showed absent right-sided kidney with mild degree of cystitis. Transrectal ultrasonography showed a cystic lesion of size 5 cm × 4 cm, with internal echoes arising from the right seminal vesicle abutting the prostrate and urinary bladder posteriorly. Both the testes were of normal size. MRI scan showed a well-defined paramidline cystic lesion of size 5.67 cm × 4.22 cm [Figure 1], with hyperintensity on T1- and T2-weighted images. The swelling was indenting the base of bladder superiorly [Figure 2] and the right side of the prostate and seminal vesicle inferiorly with inspissated secretions within [Figure 3].

Figure 1

MRI scan (transverse section) showing seminal vesicle cyst compressing the urinary bladder

Figure 2

MRI scan (sagittal section) showing seminal vesicle cyst

Figure 3

MRI scan (transverse section) showing seminal vesicle cyst

Cystoscopy was performed which shows a smooth bulge present at the bladder neck from the right side, crossing the midline [Figure 4]. Serum prostate-specific antigen was normal. Semen analysis showed oligospermia with reduced motile spermatozoa.

Figure 4

Cystoscopy view of seminal vesicle cyst bulging on the right side right side

After discussing the condition and future outcomes, the patient did not agree for surgical removal, henceforth, transrectal ultrasound-guided aspiration was done yielding 8 ml thick viscid content with no sperms on microscopic examination. The swelling decreased in size and maximum flow rate improved to 23 ml/min. The patient followed up for 4 months and is healthy with adequate urinary stream and flow rate maintained at 19 ml/min.

DISCUSSION

Congenital malformations of the urinary tract have been seen to be known to affect multiple organs. Congenital anomalies of the kidney and urinary tract describe the various conditions in the pediatric age group.[1] This includes ureteral duplications (1% of population),[6] horseshoe kidney (1 in 500 people),[7] obstructive renal dysplasia (3.7% of population),[8] and ADPK (1 in 1000 individuals).[9]

The mesonephric duct plays an important role in the development of the urogenital system. It is a paired organ which, in males, gives rise to hemitrigone, bladder neck, urethra, seminal vesicle, vas deferens, efferent ducts, epididymis, paradidymis, and appendix epididymis under the influence of testosterone and anti-Mullerian hormone. This development takes place in the first 3 months of pregnancy, and any insult seriously hampers the development of the kidney, ureter, seminal vesicle, and vas deferens. Cystic malformation of the seminal vesicle is very uncommon. It occurs due to impaired development of the distal part of mesonephric ducts causing obstruction of the ejaculatory ducts and dilatation of seminal vesicle. It is also associated with renal agenesis due to involvement of the ureteric bud.[1]

Zinner first described his findings in 1914 as a triad of unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction.[2] Zinner syndrome is a cystic malformation of the Wolffian duct, a male counterpart of Mayer–Rokitansky–Küster-Hauser syndrome seen in women. Casey et al. also reported a pentad including cystic dysplasia of rete testis, seminal vesicle cyst, ipsilateral renal agenesis, partial hemitrigonal development, and epididymal dilatation in a radiological study.[10] About 100 cases of Zinner syndrome have been reported so far.[2]

Most of the patients with cyst size <5 cm are asymptomatic.[11] Other patients manifest at the reproductive age group, with infertility as the most common presentation.[12] The various other manifestations reported till date include infertility, UTIs, painful ejaculations, epididymitis, prostatitis, and bladder outlet obstruction.[21314]

Most of the cysts are discovered by ultrasonography and digital rectal examination. Clinical presentation depends on the size and location of the cyst; however, cyst reaching up to 12 cm has been reported.[15]

The diagnostic workup of these patients includes transrectal ultrasonography, CT scanning, cystoscopy, and MR imaging. Intravenous urography can be used to see the cystic mass impinging on the bladder. MR scanning can best identify the renal agenesis and associated cystic mass.[1617] Transrectal ultrasound can also determine the size and location of the cyst.[5] A seminal vesicle cyst may show anechoic contents or contain debris due to previous hemorrhage or infection but is limited by its small field of view. MRI is the best investigation due to greater tissue contrast resolution. It gives detailed pelvic anatomy and differentiation of cystic masses, therefore providing a definitive diagnosis. Seminal vesicle cysts appear low attenuation on T1-weighted images and high attenuation on T2-weighted images.[5]

All the patients undergoing treatment should undergo infertility workup before any treatment is offered. Surveillance may be the option in the absence of clinical manifestations. Intervention or surgical procedures are appropriate when conservative measures prove ineffective. There are various treatment options that include antibiotic therapy for infected inspissated collection and UTIs, percutaneous image-guided aspiration, sclerosant injection, transurethral resection of the ejaculatory ducts or surgery.[5181920] Recently, robot-assisted laparoscopic surgery is also reported for Zinner syndrome. There is no current preferred method of treatment due to paucity of the literature and limited number of cases reported. Minimally invasive options should be preferred to open surgery; however, size of the cyst and complaints may decide the course of the treatment.[19] The method of treatment depends on the symptoms of the patient. Only the symptomatic cases are treated. The percutaneous method of aspiration of cyst was reported by Kajita et al. which was found to be effective in Zinner syndrome patient.[20] The same method was adopted in our case. Open surgery was found to effective by Van den Ouden et al. with complete resolution of symptoms. The cure rate of 80% was found in transurethral unroofing of the cyst.[21] Laparoscopic surgery with transperitoneal approaches was also found to be having a successful outcome.[22] Major consideration of surgery is preserving the fertility of the patient. Due to proximity of the vital pelvic structure, more minimally invasive procedures are devised.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

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