Orbital hydatid Cyst: an unusual presentation

To describe an unusually large hydatid cyst of the orbit causing loss of vision and proptosis of the eyeball. A detailed investigation, consisting of radiological and hematological studies, was carried out to determine the cause of the proptosis. The patient underwent orbital exploration for the presumed diagnosis of orbital echinococcosis. The cyst was removed surgically. The CT scan and surgical findings of the cyst removed confirmed the diagnosis of orbital hydatid cyst. Hydatid cyst is an endemic disease in Yemen. The diagnosis of orbital hydatid cyst should be considered in the differential diagnosis of unilateral severe proptosis. The main treatment for orbital hydatid cyst is complete surgical removal of the cyst