Imperforate hymen presenting as chronic low back pain.

Imperforate hymen in an adolescent usually presents with cyclic abdominal pain or with pelvic mass associated with primary amenorrhea. We present a 13-year-old girl with chronic lower back pain of 6 months' duration as the only complaint. On physical examination, multiple trigger points were detected in the quadratus lumborum and gluteus medius muscles bilaterally. Abdominal ultrasound revealed hematometrocolpos secondary to an imperforate hymen. Hymenectomy was performed, with complete resolution of the back pain. Myofascial pain syndrome with a viscerosomatic reflex is a possible explanation for the clinical presentation of our patient.