Malignant transformation of choroidal nevus to melanoma. A, Small choroidal nevus. B, After an observation period of 13 months, the nevus has expanded its borders and acquired surface lipofuscin. C, A different patient with a small peripapillary choroidal nevus. D, The nevus shown in part C demonstrated substantial growth and emergence of surface lipofuscin after an observation period of 6.5 years.