The hymen is normally a perforate membrane seen at the vaginal introitus where it separates the vestibule externally from the vagina internally. Imperforate hymen refers to the congenital absence of a hymenal orifice. This condition may present in infants or young children as a smooth, glistening membrane protruding from the introitus due to the buildup of vaginal secretions known as a mucocolpos. More commonly, it presents in adolescent girls with the accumulation of menstrual blood and secretions behind the hymen, known as a hematocolpos. The fluid collection can become large enough to compress the bladder neck and cause urinary retention. Occasionally, the accumulated blood spilling into the peritoneal cavity through the fallopian tubes results in free pelvic fluid and signs of peritonitis. On examination, hematocolpos is evident as a smooth, dome-shaped, bluish-red bulging membrane at the introitus. A large, smooth, cystic mass can often be palpated anteriorly on digital rectal examination.
Management and Disposition
Refer to a gynecologist for definitive treatment of imperforate hymen and other abnormalities of the vaginal outlet. Incision of the hymen to allow drainage of the hematocolpos may be needed emergently in patients with severe pain and/or signs of peritonitis.
An imperforate hymen commonly presents in adolescent girls with primary amenorrhea and recurrent abdominal pain.
Refer preadolescent patients to a pediatric gynecologic practitioner when possible.
Imperforate Hymen. A bulging mass at the introitus is seen in this patient with abdominal distention and amenorrhea. The imperforate hymen was diagnosed, with subsequent incision and drainage of the hematocolpos. (Photo contributor: Mark Eich, MD.)