Diagnostic tactics of hematocolpos following imperforate hymen mimicking a large ovarian cyst: A case report and a literature review

Background Imperforate hymen is a rare congenital defect of female genital tract resulting from the failure of embryologic canalization. This condition typically goes undiagnosed until menarche, when accumulated menstrual blood in the vagina leads to hematocolpos. Initial symptoms can include back pain, tenesmus, constipation, cyclic pelvic and abdominal pain, and difficulty urinating in conjunction with irregular menstruation. Case presentation This report presents a case of a 13-year-old female patient presenting with persistent lower abdominal pain without a history of menstruation. Initial transabdominal ultrasound due to its unspecific nature, suggested the presence of a large left ovarian cyst and a right ovarian cyst. Following the physical examination, MRI was performed in order to avoid misdiagnosis and to differentiate the mass. The MRI sequences depicted a right ovarian cyst and a dilated vaginal cavity with a hemorrhagic component (hematocolpos). Following the diagnosis, hymenotomy was performed with cross incisions and evacuation of 500 ml of hemolyzed brown blood was carried out. Post-operative ultrasound examination showed resolution of the space occupying mass which was previously mistaken as a left ovarian cyst. Conclusion This case study highlights the critical importance of a thorough physical examination and the use of MRI as a definitive secondary diagnostic tool when ultrasound findings are doubtful in young girls presenting with a pelvic mass and amenorrhea, to ensure prompt and accurate surgical management.