Objective: To evaluate the risk of dying of metastatic choroidal melanoma in patients with small, indeterminate, pigmented lesions of the uveal tract.
Methods: A cohort of 1063 consecutive patients were evaluated in the Ocular Oncology Clinic of the Massachusetts Eye and Ear Infirmary between January 1976 and June 1996 with definite choroidal nevus (n = 256), indeterminate lesions (n = 334), or small melanoma (n = 373). Deaths occurring up to December 1998 were identified through active follow-up or by a search of the National Death Index. Cumulative death rates were compared among diagnostic groups using the Kaplan-Meier method.
Results: Mean lesion diameter was 4.6 mm in the nevi, 7.0 mm in the indeterminate lesions, and 8.1 mm in the small melanomas. Patients ranged in age from 3 to 95 years (median, 64 years). A total of 15 deaths due to ocular melanoma were ascertained (median follow-up of survivors, 8.2 years), 13 in the melanoma group and 2 in the indeterminate lesion group; actuarial tumor-specific death rates at 10 years after evaluation were 5% (95% confidence interval, 3%-8%) and 1% (95% confidence interval 0%-3%), respectively. No deaths due to ocular melanoma occurred in the nevus group.
Conclusions: These data document the very low malignant potential of most indeterminate melanocytic lesions of the choroid and support the current practice of monitoring these tumors, with treatment provided when growth and other signs of malignant transformation are observed.