Lower urinary tract obstruction due to anterior bladder neck midline prostatic cyst in a young man: A case report

Abstract

Obstructive lower urinary tract symptoms in young men can occasionally be attributed to rare intra-prostatic cystic lesions. This case reports a 27-year-old man presenting with sudden onset voiding difficulty, diagnosed with a midline prostatic cyst at the anterior bladder neck, a rare location. The cyst was successfully treated with bipolar transurethral endoscopic resection, resulting in the resolution of urinary symptoms without retrograde ejaculation which is a common complication that is a central concern in the literature regarding the choice of surgical modality.

1. Introduction

Obstructive lower urinary tract symptoms represent a distinct clinical challenge in young men, rarely attributable to intra-prostatic cystic lesions.

Prostatic cysts are a rare entity with a prevalence close to 1 %, can be categorized based on their size, connection to the urethra or seminal vesicles, and the presence or absence of semen within the cyst.¹ These cysts are asymptomatic in 95 % of cases and often discovered incidentally. When symptomatic, they can cause dysuria, urinary obstruction, pain, hematuria, hemospermia, ejaculation disorders, or recurrent epididymitis.²

Occasionally, cysts are found in the intraprostatic midline, most frequently in a posterior position.¹ However, midline prostatic cysts (MPC) located on the anterior aspect of the bladder neck are exceedingly rare and pose a diagnostic and therapeutic challenge.¹

The case presented here concerns a MPC located on the anterior aspect of the bladder neck and responsible for urinary obstructive trouble in a young man.

This case report also highlights an interesting observation regarding the absence of retrograde ejaculation following endoscopic resection, challenging the common assumption that such procedures typically result in this complication and needs others more invasives approaches like a suprapubic trans -vesical access.

2. Case presentaion

A 27-year-old man presented to the urology department with a history of voiding difficulty that had appeared suddenly 1 month previously.

He reported a weak urine stream without sensation of poor bladder emptying, neither hematuria nor hemospermia.

He had no history of chlamydia or gonococcal urethritis, and no history of bladder catheterization or endoscopic urinary tract surgery.

He had no history of urinary complaints prior to this episode.

On uroflowmetry, the patient presented a flattened curve with maximum urine flow at 3.1ml/s for a volume of 111ml urinated, with micturition time increased to 66 seconds (Fig. 1).

Fig. 1.

Uroflowmetry.

Urine-culture and screening for sexually transmitted diseases were negative.

In this clinical context, a cystoscopy was performed demonstrating the presence of a cystic lesion causing obstruction localized at the anterior wall of the bladder neck mimicking “a posterior median lobe” or suggesting an intravesical cyst (Fig. 2). The rest of the examination was unremarkable.

Fig. 2.

Cystoscopy: * showing MPC at bladder neck in retrovision.

Further workup by pelvic MRI (Fig. 3) described a cystic lesion with thin walls, purely fluid T2 hypersignal and absence of diffusion restriction at the bladder neck. The formation measured 12 mm transverse diameter x 14.9 mm anteroposterior diameter x 11.1 mm height (estimated volume 1.032 cc).

Fig. 3.

MRI: white arrow showing anterior MPC.

A marsupialization by bipolar transurethral endoscopic resection was easily performed with complete resection of the cystic lesion in the operating room (Fig. 4).

Fig. 4.

Transurethral endoscopic resection in the operating room. A: anterior; P: posterior.

Anatomopathological findings revealed a histological image associating: a prostatic-type polyp corresponding to prostatic ectopy with a cystic structure bordered by a non-atypical urothelium and whose wall contained no muscle, compatible with a midline prostatic cyst.

The postoperative course was unremarkable, with a return to normal mictiometry and resolution of obstructive urinary disorders without retrograde ejaculation during follow-up.

3. Discussion

Prostatic cysts are a rare and unusual entity with a prevalence close to 1 %. They are asymptomatic in 95 % of cases and usually discovered incidentally.¹

They may be symptomatic depending on their size and location and involve: dysuria, lower urinary tract symptoms, bladder voiding obstruction, rectal or suprapubic pain, hematuria or hemospermia, ejaculation disorders or recurrent epididymitis.²

Several classifications have been proposed to differentiate the origin of these midline prostatic cysts. It was initially believed that they were all linked to incomplete regression of the Mullerian duct remnant. Subsequently, a differentiation was made between Mullerian duct remnant, originating from the mesoderm with the presence of spermatozoa in the cyst, and utricular cyst originating from the exoderm, communicating with the prostatic urethra and without spermatozoa inside.³

More detailed classifications have followed, such as these 4 categories: Type 1 MPC, which has no communication with urethra (traditional prostatic utricle cyst); Type 2a MPC, which also has no communication with the urethra [cystic dilatation of prostatic utricle (CDU)]; Type 2bCDU, which has communication with the seminal tract; and Type 3 cystic dilatation of the ejaculatory duct.¹

However, all these classifications are of very limited interest and are not used in clinic given the similarity of the clinic and management of all those types of cystic lesion.

Detection of prostatic cystic lesions is easy thanks to the accessibility of imaging. Conventional imaging with transrectal ultrasound, pelvic CT-scan/MRI, and cystoscopy may be useful to exclude other associated urological lesions and to establish the therapeutic strategy according to the cyst localization.1, 2, 3, 4

The majority of MPCs are located posteriorly. Only a dozen cases in the literature report an anterior location on the anterior wall of the bladder neck, as described in this case, representing a diagnostic and therapeutic challenge sometimes due to the difficulty of access (intra-vesical cyst suspected by cystoscopy).⁴

Several treatment modalities are described depending on the clinical case. The simplest technique, probably to be recommended due to its routine use and low complication rate, is transurethral endoscopic resection with unroofing of the lesion.^1,2,4,5

Other methods such as transrectal aspiration or percutaneous suprapubic approaches have also been described, especially in young men with challenging lesions in the bladder neck that may compromise antegrade ejaculation after treatment with transurethral resection.^1,4,5

Cases similar to the one presented have been treated by a percutaneous suprapubic approach with insertion of a transvesical resectoscope, as well as by transverse laser incision of the anterior MPC with a cystoscope using the retrovision.¹

An interesting observation from this case is the absence of retrograde ejaculation postoperatively, despite the endoscopic resection performed. This could be explained by the fact that the resection did not involve the bladder neck sphincter extensively, which is crucial in maintaining antegrade ejaculation. Instead, a partial resection might have spared enough of the bladder neck structures to preserve this function, highlighting the importance of tailored surgical approaches in young patients to avoid compromising their sexual health.

4. Conclusion

Midline prostatic cysts are an unusual benign entity in the urology clinic and should be considered in the differential diagnosis of obstructive lower urinary tract symptoms in young men. They are easy to detect thanks to the accessibility of routine imaging and cystoscopy. The position at the anterior wall of the bladder neck can represent a therapeutic challenge due to access difficulties. The simplest therapeutic modality appears to be transurethral resection with unroofing. However, the risk of retrograde ejaculation needs to be discussed with the patient, especially young patients. This case demonstrates that a careful and tailored surgical approach can avoid the complication of retrograde ejaculation, preserving the patient's sexual health and quality of life. Alternative approaches such as suprapubic or retrovision laser incisions may be considered to minimize this risk in suitable cases.

CRediT authorship contribution statement

Laurenzo Milone: Writing – review & editing. Tania Oliveira-e-Silva: Writing – review & editing. El Hajj Houssein: Investigation. Kim Karim Entezari: Supervision.

Declaration of competing interest

None.