Intramural hydatid cyst of descending aorta complicated by false aneurysm.

Hydatid disease is caused by the larval stage of Echinococcus granulosus, and the resultant fluid-filled cysts almost invariably affect the liver. Primary involvement of the aortic wall is very rare. We report a case of hydatid disease presenting as a huge cyst invading the wall of the descending aorta and complicated by a false aneurysm. Diagnostic problems and operative management are reviewed.