Snapshot During a routine pelvic exam, a 20-year-old woman has a 1 cm cystic mass incidentally discovered on the lateral wall of the vagina. She has no past medical history. She denies any pain or symptoms associated with the cyst. Introduction Incomplete regression of wolffian mesonephric duct Submucosal along anterior or lateral wall of the upper vagina benign usually small (<2cm) and asymptomatic if larger, may cause mass effect on adjacent structures Usually isolated but possible associations with metanephric urinary system abnormalities renal agenesis ipsilateral renal dysplasia Herlyn-Werner-Wunderlich syndrome Presentation Symptoms dyspareunia difficulty inserting tampons Pelvic exam cyst on the anterior or lateral vaginal wall Histology nonmucinous cuboidal or columnar epithelium Differential diagnosis Bartholin cyst: usually posterolateral vagina urethral diverticulum Prognosis and Treatment Frequently cysts remain small and require no treatment If symptomatic, surgical excision