A Clinical Pitfall: Imperforate Hymen Presenting as Abdominal Distension in an Adolescent

Imperforate hymen is a rare congenital anomaly and the most common obstructive lesion of the female genital tract. Typically, the condition manifestsduring adolescence, presenting with primary amenorrhoea and cyclic pelvic pain. However, it can, on occasion, present as abdominal or pelvic masses inemergency departments. A 14-year-old female patient presented to the emergency department with lower abdominal pain and progressive visible abdominal distension. A physical examination was conducted, which revealed a tense, distended abdomen, suggesting that the patient had a full urinary bladder.Routine laboratory tests were unremarkable, with the exception of mild microcytic anaemia. Ultrasonography revealed a 9×5 cm pelvic mass of unknownorigin, raising suspicion of a gynecologic malignancy. A pelvic magnetic resonance imaging (MRI) scan revealed a smooth-walled, cystic lesion that wasobserved to be filling the vaginal cavity with hemorrhagic content. The uterus and ovaries appeared normal, which is consistent with the diagnosis of hematocolpos due to imperforate hymen. The patient underwent hymenotomy and was discharged without complications. In adolescent girls presenting tothe emergency department with abdominal distension or suspected pelvic mass, consideration should be given to the possibility of imperforate hymen,thus avoiding unnecessary oncologic workup and treatment delays.