Ciliary body and choroid melanoma measuring between 2.5 mm and 10 mm in height and 16 mm or less in basal diameter (medium-sized) or more than 10 mm in height or more than 2 mm in height and more than 16 mm in basal diameter or more than 8 mm in height with optic nerve involvement (large-sized). (Collaborative Ocular Melanoma Study) [from
NCI]