Types of Ocular Melanoma Different types of melanoma of the eye include:
UVEAL MELANOMA The uveal tract is made up of three main sections: the choroid, the iris and the ciliary body. Uveal melanoma (UM) can form in any of these layers and is named for where it forms. There are around 2,000–2,500 new cases diagnosed each year in the US.
CONJUNCTIVAL MELANOMA The conjunctiva is the clear tissue that covers the white part of the eye, as well as the inside of the eyelids. Conjunctival melanoma is very rare. About 500 people are diagnosed in the United States per year. It often appears as a raised tumor and may contain little or even no pigment. Conjunctival melanoma most commonly occurs in the bulbar conjunctiva — the mucous membrane that covers the outer surface of the eyeball. Unlike other forms of ocular melanoma that spread most often to the liver, when conjunctival melanoma spreads, it most often spreads to the lymph nodes and lungs.
Choroid
Iris
Conjunctival Melanoma
Ciliary body
Tumors
Iris
l Choroidal melanoma begins in the layer of blood vessels — the choroid — beneath the retina. l Iris melanoma occurs in the front, colored part of the eye. l Ciliary melanoma occurs in the back part of the eye — in the ciliary body. OCULAR MELANOMA VS. CUTANEOUS MELANOMA Cutaneous (skin) melanoma and ocular melanoma are distinct conditions. While conjunctival melanoma is more similar biologically and genetically to cutaneous, uveal melanoma is very different both biologically and genetically. Both forms of melanoma begin in melanocytes but, beyond that, there are many differences and only a few similarities.
Sclera
PROGNOSIS AND METASTASIS The size of the tumor and the degree
of invasion are major factors in determining the prognosis — or
outcome — in melanoma. When the disease spreads, however, it spreads differently than cutaneous melanoma. Uveal melanoma tends to spread through the blood, while cutaneous and conjunctival melanoma tend to spread through the lymphatic system. Uveal melanoma metastasizes in up to 50% of all cases and when it spreads, it spreads to the liver 85–90% of the time. Cutaneous and conjunctival melanoma are less predictable and can spread to the lymph nodes, liver, lungs, brain, bone and soft tissue.
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