Choroidal melanocytic lesions in children: focal aggregates and melanocytosis

To investigate prevalence and age of onset of choroidal melanocytic lesions (other than nevi) in pediatric patients.

The pooled data of participants 6 months to 18 years of age in the Sydney Paediatric Eye Disease Study, the Sydney Myopia Study, and the Sydney Adolescent Vascular Eye Disease Study were reviewed retrospectively to identify children with choroidal melanocytic lesions. The clinical features and prevalence by age were assessed.

From the pooled sample of 5,533 unique children, 39 cases of focal melanocytic aggregates and 22 cases of choroidal melanocytosis were identified, with overall prevalence of 0.70% and 0.40%, respectively. There was a statistically significant trend toward increased prevalence with increasing age. Both focal melanocytic aggregates and choroidal melanocytosis tended to be bilateral (100% and 86% respectively), brown in color, and temporally located in all cases. Amelanotic variants were not identified. Focal melanocytic aggregates were small (0.15-0.5 mm), whereas choroidal melanocytosis varied in size (5.0-20 mm). All focal melanocytic aggregates were characteristically located 4-5 mm temporal to the center of the fovea and were associated with linear nervelike (11 [28%]) or tortuous vessel like structures (10 [26%]).

In this study, pooled data from large population studies revealed morphologic patterns of choroidal melanocytic lesions, other than nevus, that correlate with described clinical appearance in adults. The association of focal melanocytic aggregates with nervelike structures supports their embryologic origin along the migration path of uveal melanocytes.