Choroidal melanoma (see the image below) is the most common primary malignant intraocular tumor and the second most common type of primary malignant melanoma in the body. It is a subtype of uveal melanoma. Primary choroidal melanoma arises from melanocytes within the choroid. Most melanomas are believed to develop from preexisting melanocytic nevi, though de novo growth of choroidal melanomas also occurs. They may have variable coloration, ranging from darkly pigmented to purely amelanotic. Growth of choroidal melanomas can occur silently until it produces enough visual loss through various mechanisms. The tumor?s disruption of choroidal circulation and consequent ischemia typically cause degeneration of retinal photoreceptors and other retinal neurons. The retina overlying the tumor can separate into cystoid spaces and larger schisis cavities. There may be associated cystoid macular edema.
Incidence of choroidal melanoma is much higher in countries with large numbers of people of northern European descent than elsewhere in the world. Incidence of choroidal melanoma is highest around age 55 years. In Asians, although it is a very infrequent tumor, reports indicate a peak incidence at a somewhat younger age. Choroidal melanoma is exceptional in children. Choroidal melanoma is found slightly more frequently in men for all age groups, except from 20-39 years, when a small predilection exists for women.