Orbital cellulitis and massive chemosis as first sign of a cilio-choroidal malignant melanoma without extraocular extension: A case report

Purpose: To describe a case of cilio-choroidal melanoma presenting as aseptic orbital cellulitis with massive conjunctival chemosis. Methods: Case report. Results: A 51-year-old man with a left retro-iris pigmented lesion had acute lid edema, conjunctival chemosis, and extensive hyphema. Ultrasound revealed a large, lobulated, wide-base choroidal-starting lesion affecting the ciliary bodies and vitreous chamber. MRI revealed low-intermediate T2-signal and intermediate-high T1-signal, with substantial post-contrastographic enhancement. After one week of systemic corticosteroids, the chemosis reduced significantly, and the patient was referred for enucleation, even without histologic confirmation. Post-surgical histopathology found 90% necrotic tissue, few viable cells, and no scleral or vascular invasion, with genetic analysis showing monosomy of chromosome 3 and 8q gain. Conclusion: Choroidal melanoma, particularly if necrotic, may occasionally present as aseptic orbital cellulitis, even without extraocular spread.