ABSTRACT
BACKGROUND: An accessory ovary is a rare congenital anomaly of the female reproductive tract. This report illustrates a case of a cyst arising from an accessory ovary complicated by torsion. CASE: A 39-year-old nulliparous woman presented with lower abdominal pain and was found on physical examination to have an 8-cm mass anterior to the uterus. Ultrasonography of the pelvis showed a 9.3×6.7 cm cystic lesion with a solid component anterior to the uterus suggestive of a left ovarian cyst. Laparoscopy was performed for presumed ovarian torsion. Torsion of a tumor arising from an accessory ovary was found intraoperatively. CONCLUSION: Patients suspected to have ovarian torsion should have emergency surgery for diagnosis and attempted ovarian preservation. Physicians should consider complications of paraovarian anomalies in the differential diagnosis.