24. Peri-urethral cyst mistaken for imperforate hymen in a patient with distal vaginal agenesis

Abstract

<h3>Background</h3> Imperforate hymen is the most common obstructive genital tract anomaly and typically presents in adolescence with primary amenorrhea, worsening pelvic pain, and a bulging hymenal membrane at the introitus. When the hymen is normally visualized, other obstructive anomalies should be considered, as establishing the correct diagnosis prior to making management decisions is paramount. We present a case of a peri-urethral cyst misdiagnosed as an imperforate hymen in a patient with vaginal agenesis, highlighting strategies for accurate diagnosis and options for management. <h3>Case</h3> An 11 year old premenarchal female presented to the Emergency Department (ED) with several months of worsening intermittent lower abdominal pain. In the ED, she had transabdominal pelvic imaging showing a large hematometrocolpos and per the provider an imperforate hymen external genital exam. After achieving adequate pain control, she was discharged to follow up with Pediatric and Adolescent Gynecology. At her follow up visit, examination findings were notable for an annular hymen with membranous tissue blocking the vagina immediately behind the hymen. On rectal exam, the hematocolpos was palpated approximately 4 cm from the introitus. The patient was started on menstrual suppression with depot leuprolide and norethindrone acetate. Follow up magnetic resonance imaging (MRI) confirmed a cyst near the introitus and distal vaginal agenesis. When the genitalia were re-examined under anesthesia, adequate labial traction revealed a peri-urethral cyst. Due to ongoing pain, interventional radiology placed a transuterine drain under ultrasound guidance. Tissue plasminogen activator (TPA) was used through the drain to thin the obstructed blood and facilitate drainage. Approximately 500 ml of blood was drained from uterus and vagina before the drain was removed. The patient remains asymptomatic and will continue menstrual suppression until she reaches an age when she can participate in post-operative care. <h3>Comments</h3> In this case, the diagnosis of distal vaginal agenesis was obscured by the presence of a peri-urethral cyst. The case illustrates the importance of thorough examination including rectal exam and pelvic MRI when the diagnosis is unclear. Vaginal dilation or use of a vaginal stent is usually required after definitive surgical management of distal vaginal agenesis and therefore it is important to consider age and maturity before any surgical decisions are made. Accurate diagnosis is of utmost importance and management efforts aimed at delaying definitive surgical management should be considered.