Uveal melanomas may arise in the iris, ciliary body or choroid. Choroidal melanomas are the most common and usually display a discoid, collar-button or mushroom-shaped growth pattern. Uveal melanomas are composed of spindle and epithelioid cells and are classified histopathologically as either spindle-cell-type or mixed-cell-type tumours.The most important factors predicting clinical behaviour and underlying biology are cell type, cytomorphometric features, largest tumour dimension, scleral invasion and mitotic figures. Other valuable prognostic factors are tumour-infiltrating lymphocytes and macrophages, and the presence of vascular loops.