Primary orbital melanoma associated with a blue nevus.

A 43-year-old white woman presented with a sudden pain and protrusion of the right eye, along with decreased vision. Orbital CT revealed a well-demarcated lesion in the right intraconal space. After surgical excision, the histopathologic examination revealed a malignant melanoma with a predominant epithelioid cell type, probably arising in a blue nevus. The patient was treated with exenteration followed by radiotherapy.