Primary Orbital Melanoma: A Case Study Highlighting the Critical Importance of Timely Diagnosis and Treatment

Primary orbital melanoma (POM) is a rare malignant tumor arising from the deep pigmented layer of the eye, potentially leading to tumor extension and metastases, particularly to the liver. Although there are fewer than 100 documented cases, diagnosis is often delayed, with an uncoded management approach and generally unfavorable prognosis. We present the case of a 57-year-old patient with no significant medical history who developed a pigmented lesion at the inner canthus of the right eye. An excision in 2023 revealed a nodular melanoma, but the patient was already lost to follow-up before the final diagnosis was obtained. In 2024, he presented for exophthalmos with signs of significant tumor extension, necessitating radical treatment including right exenteration, ipsilateral lymphadenectomy, and radio-chemotherapy. Orbital melanomas, which represent about 7% of melanomas, manifest as painless tumors and can be better assessed by MRI. Differential diagnosis includes choroidal angiomas and metastatic tumors. Treatment requires a radical surgical approach, while chemotherapy is often ineffective. Mortality is primarily due to hepatic metastases. At six months post-operation, the outcome was favorable, and the patient received an ocular prosthesis.