Primary orbital hydatid cyst in an elderly patient.

Background: Orbital hydatidosis is rare, accounting for only 1% of all hydatid cysts. Herein we report a case and review the sparse literature.
Methods: Case report and review of pertinent literature.
Results: A 74-year-old farmer presented with progressive proptosis and loss of vision of the left eye. Evaluation revealed a hydatid cyst of the orbit. Orbital hydatidosis is usually unilateral and unaccompanied by cysts elsewhere in the body. Most affected are children and young adults. Although there is no gender predominance, orbital hydatidosis may affect the left eye preferentially. Onset is usually insidious over several months. Serologic testing is unreliable, and imaging by computed tomography or magnetic resonance imaging is now standard. Surgical resection is curative, but albendazole must be administered postoperatively if there is spillage intraoperatively.
Conclusions: Hydatid cysts should be included in the differential diagnosis of unilateral proptosis in patients from regions where echinococcosis is endemic.