Huge vaginal wall Mullerian cyst mimicking high stage pelvic organ prolapse

Vaginal Mullerian cysts are usually small and asymptomatic. Occasionally, they are enlarged and mimic other anatomical disorders, such as anterior vaginal wall prolapse, middle compartment defects (enterocele, apical vaginal wall prolapse) or urethral diverticulum.  Herein we report a female case with a huge vaginal wall Mullerian cyst which was initially misdiagnosed as stage 4 cystocele. Pelvic MRI and cysto uerthroscopy revealed no communication between the cyst and adjacent structures. The cyst was completely excised through a vaginal approach. The pathologic evaluation revealed a benign Mullerian cyst lined with mucinous epithelium. Diagnostic approach to space occupying lesions in the vaginal cavity needs assessment by history, physical examination and appropriate imaging which are essential to prevent misdiagnosis and mistreatment.