Primary Orbital Hydatid Cyst: A Case Report.

Hydatid cyst is a rare parasitic infection that involved all organs. It caused by the larval stage of Echinococcus tapeworms. Hydatid cyst of the head and neck is a very rare condition, even in areas where Echinococcus infestation is endemic. Orbital hydatid cyst is extremely rare and accounts for less than 1% of all hydatid cysts. Herein a 24-year-old man with primary orbital hydatid cyst is introduced. He complained from proptosis and diplopia. MRI images revealed a lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, which displaced the optic nerve inferiorly and the globe inferolateral. The cyst was enucleated via frontotemporal craniotomy and superior orbitotomy approach. Histopathological examination of the fluid confirmed the diagnosis of hydatid cyst. Treatment of the orbital hydatid cyst is surgical excision followed by the systemic use of albendazole.