Monarch Disease Ontology id MONDO_0003878 (malignant choroid melanoma) can be described as follows. A uveal melanoma that arises from the choroid. It is the most common primary malignant intraocular tumor. It usually affects Caucasians of northern European descent. It usually remains asymptomatic for a long period. When signs and symptoms occur, they include blurred vision, visual field loss, floaters, and ocular pain. Tumor size is the most important factor that relates to prognosis. Also known as: choroid malignant melanoma, choroid melanoma, choroidal melanoma, malignant melanoma of choroid, malignant melanoma of the choroid, melanoma (disease) of optic choroid, melanoma of choroid, melanoma of the choroid.