An Orbital Malignant Melanoma Arising in Cellular Blue Nevus in a Patient with Nevus of Ota.

Melanomas arising from orbital melanocytic proliferations are exceedingly rare. Many questions remain regarding their development and malignant transformation. We report on a 45-year-old Caucasian woman with a nevus of Ota that presented with visual disturbances involving her right eye and was found to have a biopsy-proven cellular blue nevus in the orbital space. Five years later, she presented with proptosis and worsening symptoms. Biopsy at that time showed a cellular blue nevus with areas of melanoma. We conclude that patients with a nevus of Ota or an orbital cellular blue nevus, particularly Caucasians, should be monitored for ocular/orbital involvement and followed closely for signs of rapid growth. There may be a progressive evolution to melanoma from a blue nevus.