Melanocytoma of the optic disc.

The common perception that melanocytomas of the optic disc do not affect visual function is one that must be challenged. We report two cases of melanocytoma of the optic disc that show that visual function can be significantly affected. The benign nature of optic disc melanocytomas in contrast to the urgency needed in optic nerve malignant melanomas makes the differential diagnosis even more critical. In addition, recent reports have documented malignant transformation of melanocytomas. Therefore, close observation and proper diagnostic work-up of any suspicious optic nerve head tumor is essential.