Laparoscopic extraperitoneal excision of a symptomatic anterior midline periprostatic cyst: A case report

Abstract

Anterior midline periprostatic cysts are rare and may cause lower urinary tract symptoms due to compression of the membranous urethra. We report a 44-year-old man with progressive voiding symptoms. Perineal ultrasound and pelvic MRI revealed a 12 × 25 mm anterior midline periprostatic cyst clearly separated from the prostatic parenchyma and compressing the urethra. Because of its deep anterior location and the risk of sphincter injury with transurethral approaches, laparoscopic extraperitoneal excision was performed. The cyst was completely removed without complications, and symptoms improved markedly (IPSS 18 to 5).

Highlights

• •Anterior midline periprostatic cysts are rare causes of obstructive LUTS.
• •Extraperitoneal laparoscopy allows safe and complete cyst excision.
• •Urinary symptoms improved markedly after surgery.

1. Introduction

Cystic lesions arising in the periprostatic region are uncommon and are most frequently detected incidentally during imaging studies performed for unrelated urological conditions.¹ These lesions represent a heterogeneous group of entities that may originate from embryological remnants, obstructed glandular ducts, or acquired inflammatory processes, and may be located adjacent to, rather than within, the prostatic parenchyma 1, 2, 3.

Traditionally, cystic lesions involving the prostate and periprostatic region have been classified according to their anatomical relationship with the prostatic urethra and surrounding structures into midline, paramedian, and lateral types.^1,2 Most reported lesions are intraprostatic and located posteriorly, commonly corresponding to Müllerian duct cysts, utricle cysts, or ejaculatory duct cysts 1, 2, 3. Consequently, when symptomatic, these lesions are more frequently associated with ejaculatory disorders, infertility, or recurrent infections than with bladder outlet obstruction.

In contrast, anteriorly located midline cystic lesions situated in the periprostatic space are exceedingly rare. These lesions do not follow the typical embryological or anatomical trajectory of classical intraprostatic cysts and are more closely related to the space of Retzius and the membranous urethra 4, 5, 6. Due to their proximity to the external urethral sphincter and deep pelvic location behind the pubic symphysis, such lesions may cause significant lower urinary tract symptoms (LUTS) while simultaneously limiting the feasibility and safety of conventional transurethral or transrectal interventions.

At present, there is no consensus regarding the optimal management of symptomatic anterior midline periprostatic cysts. Available evidence is limited to isolated case reports describing heterogeneous treatment strategies, including transurethral marsupialization, transrectal aspiration, and percutaneous resection, with variable functional outcomes and potential risks of urethral or sphincter injury 4, 5, 6, 7, 8, 9.

To the best of our knowledge, laparoscopic extraperitoneal excision of a symptomatic anterior midline periprostatic cyst has not been previously reported. We present a rare case successfully managed using this approach, highlighting the distinctive anatomical characteristics, surgical rationale, and favorable functional outcomes.

2. Case presentation

A 44-year-old male with no previous history of urological disease or prior urethral intervention presented to our outpatient clinic with progressive lower urinary tract symptoms (LUTS) for approximately 6 months. His symptoms included dysuria, hesitancy, weak urinary stream, intermittency, sensation of incomplete bladder emptying, and suprapubic discomfort. These symptoms significantly impaired his daily activities and quality of life.

At presentation, the International Prostate Symptom Score (IPSS) was 18, indicating moderate-to-severe symptoms, and the quality of life (QoL) score was 4. Digital rectal examination revealed a normal-sized prostate with no palpable nodules.

Perineal ultrasonography was performed using a high-frequency linear transducer. A hypoechoic cystic lesion with irregular margins was identified in the right paramedian perineal region, measuring approximately 11.4 × 22.7 mm. The lesion contained internal septations and was located 22.1 mm anterior to the anal canal (Fig. 1A). No internal vascularity was detected on color Doppler imaging. Due to the deep pelvic location of the lesion, its anatomical origin could not be clearly determined on ultrasound examination alone. Therefore, pelvic magnetic resonance imaging (MRI) was performed for further assessment.

Fig. 1.

Imaging findings of the perineal cyst. (A) Perineal ultrasound demonstrating a well-defined cystic lesion (oval, circled) located in the perineal region. (B) Coronal T2-weighted MRI showing a cystic lesion (arrow) located anterior to the apex of the prostate, closely adjacent to but separated from the prostatic parenchyma. (C) Axial T2-weighted MRI demonstrating a right-sided cystic lesion at the prostatic apex, closely related to the membranous urethra (arrow). C: corpus cavernosum; P: prostate.

MRI demonstrated a well-circumscribed, thin-walled cystic lesion without septation, measuring 12 × 25 mm. The lesion was located in the anterior midline periprostatic region at the level of the prostatic apex, closely adjacent to but clearly separated from the prostatic parenchyma, thereby confirming its periprostatic rather than intraprostatic origin. It compressed the membranous urethra and displaced the external urethral sphincter inferiorly (Fig. 1B and C). The cyst showed homogeneous fluid signal intensity and no communication with the urethra or bladder neck. Laboratory tests revealed no signs of infection or inflammation. Serum prostate-specific antigen (PSA) level was 0.69 ng/mL. Rigid urethrocystoscopy was performed to evaluate the urethra and bladder; however, no abnormal findings were observed.

Given the cyst's atypical anterior location, its close relationship with the membranous urethra and external sphincter, and the patient's persistent symptoms, minimally invasive approaches such as transrectal aspiration or transurethral marsupialization were considered inappropriate due to limited accessibility and high risk of urethral or sphincter injury. Therefore, surgical excision via a laparoscopic extraperitoneal (preperitoneal) approach was planned.

The patient was placed in the supine position under general anesthesia. A Foley catheter (18 Fr) was inserted preoperatively to help identify and protect the urethra. Three trocars were placed: one 10-mm trocar below the umbilicus and two 5-mm trocars along the lateral border of the rectus abdominis muscles. Dissection was performed in the preperitoneal space, proceeding along the posterior surface of the transversalis fascia into the space of Retzius. The anterior space of the bladder neck and prostate was exposed, allowing direct visualization of the cyst (Fig. 2).

Fig. 2.

Laparoscopic extraperitoneal intraoperative view of the cyst. Laparoscopic extraperitoneal view showing the cystic lesion (arrow) located at the right side of the prostatic apex, within the prevesical (Retzius) space, posterior to the pubic bone.

The cyst was carefully dissected and completely excised without rupture. No communication with the urethra was identified intraoperatively. The specimen was retrieved through the 10-mm trocar and sent for histopathological examination. A closed suction drain (18 Fr) was placed in the space of Retzius to monitor for bleeding or urinary leakage.

The postoperative course was uneventful. The Foley catheter was removed on postoperative day 2, and the drain was removed on day 3 after confirming minimal output and absence of urinary leakage. Postoperative laboratory tests showed no anemia or infection, and follow-up ultrasound revealed no fluid collection in the Retzius space. Histopathological analysis showed dense fibrous tissue with scattered lymphocytes and chronic inflammatory cell infiltration. No epithelial lining or evidence of malignancy was observed, suggesting chronic fibrotic inflammatory changes.

The patient reported significant improvement in urinary symptoms immediately after catheter removal. At discharge, the IPSS had decreased to 5, and the QoL score improved to 1. At follow-up, the patient remained symptom-free, with no evidence of recurrence on imaging.

3. Discussion

Cystic lesions of the prostate and periprostatic region represent a heterogeneous group of rare entities that include utricle cysts, Müllerian duct cysts, ejaculatory duct cysts, and retention cysts of prostatic glands 1, 2, 3. Most of these lesions are located posterior to the prostate and remain asymptomatic throughout life. Symptomatic presentation is uncommon and typically associated with infection, infertility, or ejaculatory disturbances rather than obstructive urinary symptoms.

The case reported herein is unique in several aspects. First, the cyst was located in the anterior midline periprostatic region at the level of the prostatic apex, clearly separated from the prostatic parenchyma and situated within the space of Retzius. This anatomical location does not correspond to the typical embryological or anatomical trajectory of classical intraprostatic midline cysts, suggesting that it represents a distinct periprostatic cystic entity¹⁰. Similar anteriorly located cysts have been rarely described in the literature. However, most reported cases were still classified as intraprostatic lesions 4, 5, 6. Second, although most periprostatic cysts remain asymptomatic because they are small and do not produce significant compression of the urethra or sphincteric structures¹⁰, the cyst in our patient caused significant LUTS by compressing the membranous urethra and displacing the external urethral sphincter inferiorly, a mechanism that has been described in only a limited number of previous reports 4, 5, 6. Third, the lesion was successfully managed using a laparoscopic extraperitoneal approach, which has not been previously described for this condition.

A review of the literature reveals that fewer than 15 cases of symptomatic anterior midline periprostatic region requiring surgical intervention have been reported to date 4, 5, 6, 7, 8, 9. The majority of these cases were managed using transurethral techniques, including unroofing or marsupialization with monopolar, bipolar, or holmium laser energy.^5,7,8 While effective in selected cases, these approaches are associated with a potential risk of urethral stricture, bladder neck contracture, and sphincter injury, particularly when the cyst is located close to the membranous urethra.⁸

Transrectal or percutaneous aspiration, with or without sclerotherapy, has also been described; however, this approach is limited to posteriorly located cysts and is associated with a high recurrence rate due to incomplete removal of the cyst wall 6, 7, 8, 9. In the present case, the deep anterior location of the cyst behind the pubic symphysis made transrectal access impossible, while a transurethral approach carried a significant risk of iatrogenic sphincter injury and postoperative urinary incontinence.

The extraperitoneal laparoscopic approach offered several advantages. First, it provided direct access to the space of Retzius and allowed precise dissection of the cyst under direct vision, minimizing the risk of urethral or sphincter injury. Second, complete excision of the cyst wall was achieved, potentially reducing the risk of recurrence compared with aspiration or unroofing techniques. Third, this approach is familiar to urologists performing laparoscopic radical prostatectomy and can be reproduced without specialized equipment.

The excellent postoperative functional outcome in our patient, with a marked improvement in IPSS and quality-of-life scores, supports the effectiveness of this approach. Given the rarity of anterior midline periprostatic cysts, high-level evidence is unlikely to be available; however, our experience suggests that laparoscopic extraperitoneal cyst excision should be considered a safe and effective option in selected patients, particularly when minimally invasive transurethral or transrectal techniques are not feasible.

4. Conclusion

Symptomatic anterior midline periprostatic cysts are extremely rare and may cause significant lower urinary tract obstruction. Laparoscopic extraperitoneal cyst excision is a safe and effective option that allows complete cyst removal with excellent functional outcomes.

CRediT authorship contribution statement

The-May Nguyen: Writing – review & editing, Writing – original draft, Validation, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Van-Thoai Nguyen: Writing – original draft, Visualization, Methodology, Investigation, Data curation, Conceptualization. Duc-Duy Nguyen: Writing – original draft, Visualization, Validation, Investigation, Formal analysis, Data curation. Minh-Tung Do: Writing – review & editing, Writing – original draft, Visualization, Validation, Methodology, Investigation, Formal analysis, Conceptualization.

Informed consent

The patient in this study has given consent to be included.

Ethical approval

The retrospective case series study is exempt by the Institutional Review Board (IRB) of the current institution.

Data availability statement

Data could be obtained by requesting it from the corresponding author via E-mail.

Declaration of generative AI and AI-assisted technologies in the writing process

During the preparation of this work the authors used Paperpal in order to check grammar and writing. After using this tool/service, the authors reviewed and edited the content as needed and took full responsibility for the content of the publication.

Funding

This research did not receive any specific funding.

Conflict of interests

The authors declare no conflicts of interest regarding the publication of this article.