Malignant tumor of melanocytes of the choroid. The classic appearance of choroidal melanoma is a pigmented dome-shaped or collar button-shaped tumor with an associated exudative retinal detachment. Choroidal melanoma is usually pigmented, but can be variably pigmented and even amelanotic (non-pigmented). [ http://www.ncbi.nlm.nih.gov/pubmed/22557869 ]