BÁO CÁO CA LÂM SÀNG VIÊM TỔ CHỨC HỐC MẮT DO KÝ SINH TRÙNG THELAZIA SPP.

Thelazia callipaeda is a nematode that parasitizes the eye in animals and humans, typically causing epiphora, foreign-body sensation, conjunctivitis, and keratitis, while deep tissue invasion is rare. We report a 68-year-old woman with a painful right upper eyelid mass of one month’s duration, accompanied by ptosis and limitation of upgaze. Laboratory testing revealed elevated eosinophil count and erythrocyte sedimentation rate. Orbital MRI demonstrated right preseptal orbital cellulitis with partial abscess formation. The patient received intravenous ceftriaxone and methylprednisolone, followed by anterior orbitotomy with complete excision of the lesion. Parasitologic examination identified Thelazia spp., and histopathology showed eosinophil-rich granulomatous inflammation. This case illustrates that Thelazia may cause abscess-forming orbital cellulitis and can mimic idiopathic orbital inflammation or an orbital tumor. In atypical orbital inflammation, particularly when accompanied by eosinophilia or a mass-like lesion, a parasitic etiology should be considered, and correlation of imaging with histopathology is essential for definitive diagnosis.