Herlyn-Werner-Wunderlich syndrome with a protruding hymen over the vaginal introitus in a neonate

- Herlyn-Werner-Wunderlich syndrome is a rare, congenital Müllerian anomaly.
- The trilogy is uterus didelphys, obstructed hemivagina, and ipsilateral renal agenesis.
- Presentation is usually cyclical abdominal pain and a vaginal mass after menarche.
- Resection of hymenal or vaginal septum at an early stage can relieve acute symptoms.