Huge solitary primary pelvic hydatid cyst presenting as an ovarian malignancy: case report.

Hydatid disease is a zoonotic parasitic infection caused by Echinococcus granulosus. Echinococcus cysts are found mostly in the liver (60%) and lung (15%), but they can be located in any part of the body. However pelvic echinococcosis as the primary site is rarely seen. We report the case of a large echinococcal cyst localized in the lower pelvis. A 76-year-old woman was admitted to an emergency department with urinary retention for ten days. Ultrasonography and other imaging modalities revealed a mass with solid and cystic components in pelvic localization. This unusual presentation in an elderly postmenopausal woman was initially considered as an ovarian malignancy until surgical exploration and microscopic studies confirmed the diagnosis of echinococcosis. Antihelminthics were administered postoperatively and the patient is now being closely followed up. Gynecologists should be aware of the possibility of a primary hydatid cyst of the pelvic cavity and should be considered in the differential diagnosis of cystic pelvic masses, especially in areas where the disease is endemic.