Imperforate Hymen Causing Hematocolpos and Urinary Retention.

BACKGROUND: Acute urinary retention is rare in the pediatric population and is typically caused by an obstructing entity. It may result from hematocolpos caused by imperforate hymen. Imperforate hymen is rare, with an associated incidence of 1 in 2000 people. Nonetheless, in a pediatric age female who presents with urinary retention and who has a history of primary amenorrhea or a history of cyclical pelvic pain an examination of the external genitalia should be performed to rule out this condition. CASE REPORT: A 12-year-old girl presented to the emergency department with urinary retention and was discharged with a diagnosis of urinary tract infection. She returned the following day to the emergency department with worsening abdominal pain. A computed tomography scan revealed a fluid-filled vagina measuring 12.5 cm. Her bladder measured 15.4 cm. The patient was taken to the operating room for further evaluation by the consulting gynecologist. At the time of surgery, 1000 mL of urine were evacuated after catheterization. Three hundred milliliters of chocolate-colored fluid, consistent with menstrual blood, were evacuated at time of hymenotomy. Hymenotomy was performed with a cruciate incision. No complications were encountered. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: To date, there have been >40 reported cases of imperforate hymen causing hematocolpos and subsequent urinary retention. However, given the rarity of imperforate hymen, hematocolpos leading to acute urinary retention can still be missed. Untreated urinary retention can lead to a compromise in bladder function and subsequent kidney damage.