Iris melanoma arising from sector congenital ocular melanocytosis in a child.

PURPOSE: To report a clinicopathologic correlation of a melanoma arising from iris component of ocular melanocytosis in a child.

METHODS

A 13-year-old boy developed a progressive iris nodule arising from sector iris pigmentation that was a component of congenital ocular melanocytosis involving the iris, ciliary body and choroid. The tumor was examined clinically and with ultrasound biomicroscopy (UBM), removed by peripheral iridocyclectomy, and studied histopathologically.

RESULTS

Clinically, the pigmented nodule was 3 mm in diameter, located within the sector iris pigmentation, and was 2.4 mm in thickness as measured by UBM. Histopathologically, it was composed predominately of spindle B melanoma cells with adjacent spindle and dendritic melanocytes compatible with iris melanocytosis.

CONCLUSION

Although highly unusual, melanoma can arise in the sector iris pigmentation that is often a component of congenital ocular melanocytosis. Even young patients with ocular melanocytosis should be examined periodically for development of melanoma in the ciliary body and choroid.