Infectious etiologies can present as orbital mass lesions simulating orbital malignancies. Clinical manifestations can not distinguish between the etiologies of orbital lesions and imaging studies and tissue specimens are necessary to have a net diagnosis.

A 23 years old woman presented with a nonaxial proptosis since three months ago in her right eye. A multilobulated hypointense lesion in T1W MRI, hyperintense in T2W was found in further assessment. Excisional biopsy was performed and clinical pathologist reported a bilayerd cyst wall, the innermost germinal layer, and the faintly stained chitinous outer membrane. Surgical and medical management of the patient are explained here.

Complete resection of the lesion to avoid the dissemination and local recurrence of the disease, systemic anti helminthic therapy and systemic investigative workups, are the main considerations in this patients.

Hydatid disease should be kept in mind in the differential diagnosis of orbital mass lesions in endemic regions as a rare presentation of a prevalent disease.