A rare case of hydrometrocolpos from persistent urogenital sinus in patient affected by adrenogenital syndrome

Persistent urogenital sinus (PUGS) is a congenital pathological condition characterized by an abnormal communication between the urethra and vagina, which has an estimated incidence of 0.6/10,000 female births. It could be the only known malformation or part of a syndrome. PUGS is commonly shown by a pelvic mass, related to a distended bladder, hydrometrocolpos which is due to an obstruction leading to the dilation of the vagina and uterus (i.e., imperforate hymen, transverse vaginal septum or atresia, and PUGS) or both. We present a case of female patient with classical congenital adrenal hyperplasia, diagnosed on the 7th day of life, with ambiguous genitalia, untreated surgically only with hormone therapy by parental decision. The patient, at the age of 5 years and 5 months, came to our observation for a pelvic ultrasound, which revealed retrovesical neoformation with anechoic content and regular walls. We performed the ultrasound examination that showed the dilation of the cervix and the vaginal canal with anechoic finely corpuscolated content in the declining portion, compatible with hydrometrocolpos from probable persistence of the urogenital sinus. The voiding cystourethrography (VCUG) confirmed the ultrasound diagnosis, with evidence of urogenital sinus. In conclusion, ultrasound is the first diagnostic tool, but need to be completed by other technical procedures, which VCUG or magnetic resonance imaging to observe the site of fusion of the urinary and genital tract.