CHOROIDAL MELANOMA MIMICKING ORBITAL INVASION: A CASE REPORT OF ORBITAL EXENTERATION AND RECONSTRUCTION

Choroidal melanoma is the most common primary intraocular malignancy in adults and may present a significant diagnostic challenge when associated with extensive orbital inflammatory changes. We report the case of a 63-year-old man presenting with progressive visual loss, ocular pain, and subsequent development of marked chemosis, inflammatory eyelid swelling, exophthalmos, and restricted ocular motility. Ocular ultrasonography revealed a choroidal mass measuring 15 × 18 mm associated with retinal detachment. Clinical and radiological findings raised suspicion of locally advanced disease with orbital involvement, while systemic staging showed no distant metastases. Following multidisciplinary evaluation, a total orbital exenteration was performed. Surprisingly, definitive histopathological examination revealed a mixed-cell uveal melanoma involving the choroid and ciliary body with intrascleral invasion, but without extrascleral or orbital tumor extension. Surgical margins were tumor-free and the lesion was classified as pT3b according to the AJCC 8th edition.  After confirmation of adequate oncological resection, the orbital defect was reconstructed using a temporalis muscle flap covered with a skin graft, with a favorable postoperative course. This case highlights the potential for severe tumor-associated orbital inflammation to mimic extrascleral extension of choroidal melanoma, emphasizing the challenge of accurately assessing local tumor spread and the importance of careful clinicoradiological correlation before considering radical surgical treatment.