Malignant melanoma of the choroid is the most common eye tumor. It arises in the choroid of the eye (see Anatomy section) and may be very slow growing or may quickly grow. The most common eye abnormality confused with a malignant melanoma is a nevus (freckle) of the choroid. A nevus, like a melanoma, can be pigmented or non-pigmented and has characteristic findings such as orange material or drusen overlying it, is usually flat, and is benign just like the freckles on your hand.
Malignant melanomas, in an early stage, may look just like a nevus or may grow from a nevus, thus eye specialists follow nevi carefully for the development of signs of malignancy. Eye melanomas are many times confused with skin melanomas, which can be a very bad cancer. Eye melanomas, when treated early, have very high cure rates, although some vision may be lost with treatment. Eye melanomas, as mentioned above, arise in the choroid of the eye, a very vascular area. As a result, when they do spread to other parts of the body they most often move via the blood vessels, especially to the liver. Eye specialists will usually send you to see an oncologist (cancer specialist) either before or after eye treatment to look for spread to other parts of the body. The oncologist will need to follow the patient for many years to look for spread of the tumor even after it has been well treated. Even a few small cells may have escaped prior to treatment or while the tumor is regressing and may take many years to show up somewhere else in the body.
As mentioned above, a malignant melanoma may be pigmented or non-pigmented, but is usually seen as a pigmented lump under the retina in the back of the eye. Melanomas can be more flat, however, and can be very anterior and difficult to see with all of our examination techniques.
|
Malignant Melanoma of the Choroid Elevated pigmented malignant melanoma of the choroid prior to treatment with a radioactive plaque. The tumor can be associated with a retinal detachment caused by leakage of tumor vessels and an exudative retinal detachment as a result. |
The treatment of a malignant melanoma is controversial. The Collaborative Ocular Melanoma Study has been evaluating the use of radioactive plaques vs. enucleation (removal of the eye) for a number of years to determine which is best for life. The treatments that may be recommended based on the size, growth rate, location, etc., of the tumor include observation only, laser photocoagulation, a radioactive plaque, proton beam irradiation, external beam irradiation, enucleation, surgical removal of the tumor, and transpupillary thermotherapy (TTT), a type of laser treatment for melanomas.
Disclaimer Stuff: The opinions expressed in this website are those of RVT. Diagnosis and therapy should be based on a thorough examination by and recommendations of a qualified eye provider.