Choroidal nevus transformation into melanoma: analysis of 2514 consecutive cases.

OBJECTIVE To determine features that are predictive of growth of choroidal nevi into melanoma. METHODS This was a retrospective medical record review of 2514 consecutive eyes; Kaplan-Meier estimates and Cox regression analyses were used. RESULTS The median tumor basal diameter was 5.0 mm and thickness was 1.5 mm. Nevus growth into melanoma occurred in 2%, 9%, and 13% of eyes at 1, 5, and 10 years, respectively. Factors predictive of growth into melanoma by multivariable analysis included tumor thickness greater than 2 mm (P < .001), subretinal fluid (P = .002), symptoms (P = .002), orange pigment (P < .001), tumor margin within 3 mm of the optic disc (P = .001), ultrasonographic hollowness (P < .001), and halo absence (P = .009). A mnemonic device to recall risk factors of ocular melanoma is "To find small ocular melanoma using helpful hints," representing thickness, fluid, symptoms, orange pigment, margin, ultrasonographic hollowness, and halo absence. The median hazard ratio for those with 1 to 2 risk factors was 3; for 3 or 4 factors, 5; for 5 to 6 factors, 9; and for all 7 factors, 21. CONCLUSIONS In an analysis of 2514 choroidal nevi, factors predictive of growth into melanoma included greater thickness, subretinal fluid, symptoms, orange pigment, margin near disc, and 2 new features: ultrasonographic hollowness and absence of halo.