Unusual misdiagnosis of choroidal melanoma.

A papillary, white mass observed in a 45-year-old man was diagnosed as an optic nerve glioma. The histological examination revealed a juxtapapillary amelanotic choroidal malignant melanoma, extending over the optic disc and infiltrating the optic nerve. This clinical picture is quite infrequent in malignant melanoma of the choroid.