Congenital Vaginal Atresia with Uterovaginal Hydrocolpos Causing Giant Abdominal Cyst in a Neonate: A Case Report

Background Congenital vaginal atresia is a rare genital tract malformation that is often diagnosed during adolescence or adulthood. Neonatal cases pose particular diagnostic challenges due to their susceptibility to misdiagnosis, which may result in significant long-term consequences for fertility and quality of life. Case presentation This case describes a 2-day-old female neonate who presented with abdominal distension and persistent irritability. Initial ultrasonography misdiagnosed the condition as an intestinal duplication cyst; however, emergency surgical exploration confirmed congenital vaginal atresia with massive hydrometrocolpos. Transvaginal catheter drainage was subsequently performed, and postoperative follow-up demonstrated marked reduction of fluid accumulation. Conclusions This case underscores the critical need to consider congenital vaginal atresia and its complications in neonates presenting with nonspecific abdominal symptoms. Early recognition of this rare condition is essential to prevent diagnostic delays, reduce misdiagnosis-related morbidity, and optimize long-term reproductive and functional outcomes.