Self-resolving vaginal cyst in a neonate: a case report

Interlabial cysts in newborns are rare and typically benign, with causes ranging from simple retention cysts to congenital anomalies or malignancies. We report the case of a full-term newborn girl presenting with a 10 mm × 15 mm golden-colored, thin-walled cyst located anterior to the vaginal introitus. The urethral meatus was normally positioned and the infant exhibited normal voiding patterns without urinary obstruction. Over the course of 4 weeks, the cyst regressed significantly in size without intervention. The differential diagnosis included hymenal cysts, paraurethral gland cysts, prolapsed urethra, neonatal prolapsed ectopic ureterocele, Gartner duct cysts, hydrometrocolpos, botryoid rhabdomyosarcoma and other congenital anomalies. Physical examination is often sufficient for diagnosing simple cysts, while imaging modalities such as ultrasonography or MRI are reserved for atypical cases or suspected urinary tract anomalies. This case underscores the importance of careful differentiation between benign, self-resolving cysts and more complex conditions requiring medical or surgical intervention. Clinicians should remain vigilant for signs of associated anomalies or complications, ensuring timely and appropriate management.