Ocular melanocytosis and melanoma.

The hypothesis that ocular melanocytosis is a precancerous condition that may lead to a choroidal melanoma should be seriously questioned for the following reasons: The incidence of malignant degeneration in a hyperpigmented eye is unknown and overreported. If the hypothesis were correct a bilateral melanoma would occasionally occur in patients with bilateral melanosis. No such case has been reported. In patients with unilateral melanosis the blue, unaffected eye may also develop a melanoma. A 67-year-old white woman with one dark and one blue eye provided the first such instance, although previous cases may not have been reported if their histologic picture was not unusual. The incidence of melanoma in our patients with unilateral melanosis was rare compared with the many melanomas developing in normal pigmented eyes (4/418). I found no statistically significant difference in the incidence of choroidal melanomas originating in the hyperpigmented or in the blue eye in patients with unilateral ocular melanocytosis.