Problems in the differential diagnosis of choroidal nevi and malignant melanoma. XXXIII Edward Jackson Memorial lecture.

Failure to appreciate the variability in the natural course of choroidal nevi (benign melanomas) has caused the adoption of a misleading cytologic classification of malignant melanomas. This classification is not based on adequate clinical observation, reliable cytologic criteria for malignancy, or sufficient autopsy information. The available evidence suggests that spindle A tumors are benign and that spindel B tumors, although capable of local destruction of the eye, metastasize infrequently. The risk of observation of small melanocytic tumors must be weighed against the risk that early enucleation or other forms of therapy may not favorably affect prognosis. The clinical observations to date at the Bascom Palmer Eye Institute indicate that the risks of observation are low.