Acute urinary retention in an adolescent girl and important learning points

A Rare Pelvic "Mass-Querader": Acute Urinary Retention Secondary to Hematocolpos in a Preadolescent Patient

We report a case of acute urinary retention in an adolescent female secondary to hematocolpos. A 13-year-old female presented to the emergency department with acute urinary retention and suprapubic abdominal pain for 24 hours. She denied menstruation or sexual history. Bedside bladder ultrasound scan revealed 1.2 L of retained urine and a Foley catheter was placed. A formal renal ultrasound detected a debris-filled structure in the abdomino-pelvic cavity. Follow-up computed tomography of the abdomen and pelvis revealed an 8.5 cm × 9.3 cm × 12.1 cm mass-like structure in the pelvis. No formal pelvic exam was completed and the patient was taken to the operating room for exploratory laparotomy due to concern for large pelvic mass versus tubo-ovarian abscess. However, upon entering the abdominal cavity, no mass was found. At that point, an external genital exam was performed, revealing an imperforate hymen. Hymenotomy resulted in the evacuation of 2.5 L of clotted blood from the vagina and uterus. Hematocolpos resulting in acute urinary retention is exceedingly rare; however, it is an important differential diagnosis that can be ruled in or out by physical exam findings. Although it may be uncomfortable for adolescent patients and physicians, external genital exams should be conducted in young females with acute urinary retention and amenorrhea to evaluate for imperforate hymen. This can ensure appropriate treatment and avoidance of unnecessary invasive procedures.

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.