A 3 week-old-female newborn, was referred to our institution with vaginal swelling and lower abdominal mass. Genital examination revealed the presence of a bulging swelling at the vaginal introitus that completely obstructs the vagina. Routine investigations including renal function tests were all within normal limits. Abdominal ultrasound revealed the presence of a huge fluid-filled cystic abdominal mass with bilateral hydroureteronephrosis. A provisional diagnosis of hydrocolpos secondary to imperforate hymen with pressure effect on the lower urinary tract was made. The baby was taken to the operative room, hymenotomy through a simple hymenal incision and subsequent drainage of the accumulated vaginal fluid was made (Figure 1). The baby experienced uneventful postoperative recovery, and abdominal ultrasound is done 3 weeks later, confirmed resolution of bilateral hydroureteronephrosis.
Figure 1. Bulging imperforate hymen. Note drainage of the cloudy white fluid “ hydrocolpos” at the beginning of hymenotomy.
What is the diagnosis?