A Rare Case of Orbital Hydatid Cyst

Background: Cystic echinococcosis, also known as hydatid disease, which is mostly caused by larval stage of Echinococcusgranulosus. The orbital localization in rare and uncommon. Preoperative diagnosis is important to prevent from complications. Case information: Here we report the case of a child admitted for chronic proptosis whose investigations concluded with an orbital hydatid cyst. Result: We describe the case of an 8-year-old child, who consulted in our ophthalmic emergency department for a painful proptosis of the right eye with a progressive decrease in visual acuity and chronic fatigue that had been evolving for 6 months. Due to this highly evocative lesion of an orbital hydatid cyst, we carried out with an ELISA and Western Blot hydatid serology which ended negative. Faced with this orbital involvement, we performed an orbital MRI which objectified two right T2-hypersignal eye cystic lesions, well-limited, exerting a mass effect on the optic nerve and responsible of a grade 2 exophthalmos. We also performed a biological assessment including hemogram, renal and hepatic function that had been normal. The patient remained under medical treatment with albendazole before and after surgery. Conclusion: Orbital involvement, although rare, should not be ignored especially when it comes to chronic proptosis with or without a visual impact in children living around dogs or breeders or in deplorable hygienic conditions.