Incarcerated prolapsed ureterocele masquerading as a vulvar mass after midurethral sling surgery: a case report with systematic review.

Background: Incarcerated prolapsed ureterocele (IPU) after midurethral sling (MUS) surgery is extremely rare and may be misdiagnosed as a vulvar or interlabial mass because of its atypical presentation and altered postoperative anatomy. Methods: We report the clinical presentation, multimodal ultrasonographic findings, surgical management, and follow-up of a patient with IPU after MUS surgery. A systematic review was conducted in accordance with the PRISMA framework using major medical databases to identify previously reported cases. Fifteen cases were identified from the literature; together with the present case, 16 cases were included in the analysis. Results: The patient presented with a vulvar mass after MUS surgery, and the diagnosis was difficult because of altered postoperative pelvic anatomy. Multimodal ultrasonography demonstrated a characteristic dumbbell sign, showing continuity between the intravesical and prolapsed components, and dynamically clarified the relationship between the prolapsed ureterocele and the sling in the postoperative setting. In the 16 included cases, prolapsed ureterocele was an uncommon but important differential diagnosis in women presenting with an interlabial or vulvar mass, especially when accompanied by urinary symptoms. Imaging was essential for diagnosis, and surgical treatment was generally associated with favorable outcomes. Conclusion: IPU after MUS surgery is a rare but clinically important condition that should be considered in the differential diagnosis of postoperative vulvar or interlabial masses. Multimodal ultrasonography can provide dynamic assessment of ureterocele anatomy and its relationship to the sling, while CT and MRI remain useful complementary modalities in selected cases.