Diffuse choroidal melanocytoma simulating melanoma in a child with ocular melanocytosis

To report a clinicopathologic correlation of an extensive, diffuse uveal melanocytoma (magnocellular nevus) simulating diffuse choroidal melanoma in a child.

Clinicopathologic report.

A 14-year-old girl with congenital sector ocular melanocytosis was found to have progressive visual loss and a diffuse choroidal mass measuring 18 mm in basal dimension and 4 mm in thickness. There was overlying orange pigment and secondary retinal detachment. Diffuse choroidal melanoma was suspected, and the eye was enucleated. Histopathologically, the entire uveal tract was diffusely thickened because of a proliferation of benign cells typical of melanocytoma without evidence of melanoma.

Diffuse uveal melanocytoma is a rare variant of ocular melanocytosis that can cause reduced vision, overlying orange pigment, and retinal detachment, resembling a diffuse choroidal melanoma.