Abstract
BACKGROUND: Echinococcosis, commonly known as hydatid disease, is a zoonotic infection resulting from the tapeworm Echinococcus granulosus. The occurrence of hydatid cysts in the orbital region is uncommon, representing less than 1% of all reported hydatid cases. This report details a unique case of an intramuscular hydatid cyst in the orbital region that led to compressive optic neuropathy. CASE PRESENTATION: A 22-year-old male from Kabul, Afghanistan presented with a five-month history of progressive proptosis in his left eye, associated with a gradual decrease in vision over the past three weeks. The left eye exhibited upward globe dystopia, ocular motility limitation, mild conjunctival injection, and chemosis. Diagnosis was achieved through imaging and histopathological examination. Treatment involves surgical removal of the cyst and prolonged albendazole therapy. The postoperative course showed significant improvement in the patient's condition and restoration of his vision. CONCLUSIONS: Despite its rarity, this case underscores the importance of awareness and knowledge of hydatid disease among physicians, especially those working in endemic areas. It emphasizes the importance of including hydatid disease in the differential diagnosis of orbital masses, particularly in endemic regions.