CASE REPORT

Technical Summary: Congenital Prepubic Sinus with Urethral-Type Differentiation

Problem Statement
Congenital prepubic sinus is a rare midline urogenital anomaly characterized by an epithelial-lined tract arising from the prepubic region, dorsal penile root, or clitoral area. The condition presents significant diagnostic and embryologic challenges due to substantial heterogeneity in tract anatomy, depth, termination, and histology. The primary clinical dilemma involves distinguishing between a superficial cutaneous sinus (resulting from midline closure defects) and an incomplete or abortive accessory urethral structure (a variant of dorsal urethral duplication). This distinction is complicated by the fact that tracts may lack patent communication with the orthotopic urethra or bladder yet still exhibit urogenital histologic features. Current literature lacks a single accepted embryologic explanation, with hypotheses ranging from defective abdominal wall closure to remnants of the primitive urogenital sinus or cloacal membrane.

Methodology
The authors present a single-patient case report of a 4-year-old male presenting with a congenital dorsal penile midline opening and intermittent local discharge. The study employed a clinical and surgical approach without routine preoperative imaging, guided by the absence of urinary leakage, double stream, or voiding difficulty.

• Clinical Assessment: Physical examination revealed a firm, cord-like subcutaneous tract extending toward the prepubic region, with a normally positioned orthotopic urethral meatus and no associated anomalies (e.g., epispadias, bladder exstrophy).
• Surgical Intervention: Under general anesthesia, the tract was explored via a local open approach. A fine probe defined the tract's course, followed by an elliptical incision and careful dissection. The tract was completely excised.
• Histopathologic Analysis: The excised specimen underwent microscopic examination to characterize the epithelial lining and surrounding tissue.
• Follow-up: The patient was monitored postoperatively for complications, recurrence, or urinary issues.

Key Results

• Anatomic Findings: Surgical exploration confirmed an approximately 4-cm tract coursing proximally along the dorsal penile-prepubic midline. Crucially, the tract ended blindly at the pubic soft tissue/pubic symphysis with no macroscopic communication to the orthotopic urethra or urinary bladder.
• Histopathologic Findings: Despite the blind-ending anatomy, histologic examination revealed an epithelial-lined tract embedded in dense fibromuscular tissue. The epithelial features were reported as compatible with urethral-type differentiation.
• Clinical Outcome: The postoperative course was uneventful. There was no urinary leakage, wound infection, or recurrent discharge during the follow-up period.

Key Contributions
This case report contributes to the understanding of congenital prepubic sinus by highlighting a specific anatomical-histological discordance: a tract that terminates blindly (suggesting a superficial defect) yet possesses histologic markers of urogenital origin (urethral-type differentiation).

• Spectrum Interpretation: The findings support a spectrum-based interpretation of the anomaly, suggesting that some prepubic sinuses represent abortive or incomplete dorsal accessory urethral tracts rather than simple cutaneous sinuses, even in the absence of functional urinary continuity.
• Diagnostic Strategy: The authors advocate for a selective imaging approach. Preoperative voiding cystourethrography or MRI is deemed reasonable only when specific indicators exist (e.g., urinary leakage, double stream, deep/complex extension). In cases with superficial palpable tracts and no urinary symptoms, direct surgical exploration is presented as a viable primary diagnostic and therapeutic step.
• Therapeutic Standard: The report reinforces complete excision as the definitive treatment, serving both to prevent recurrence/infection and to provide the necessary histopathologic material for characterization.

Significance and Claims
The authors claim that the combination of blind-ending operative anatomy and urethral-type histology in this case illustrates the developmental heterogeneity of congenital prepubic sinus. They posit that this specific pattern likely represents an incomplete dorsal accessory urethral tract that failed to establish functional continuity with the urinary system.

The paper modestly acknowledges its limitations, noting that the absence of preoperative contrast studies, intraoperative cystoscopy, and immunohistochemical staining prevents definitive proof of a microscopic connection to the urinary tract or a specific embryologic mechanism. However, the authors conclude that careful clinical assessment, selective imaging based on complexity, and complete excision with histopathologic evaluation constitute a pragmatic and effective approach to managing this rare anomaly. The case underscores that histology can reveal urogenital origins even when macroscopic anatomy suggests a superficial defect.