What is uveal melanoma?
Melanoma is a cancer of melanocytes, the body’s pigmented cells. Uveal melanoma is the most common primary eye cancer. Affecting the iris, ciliary body or choroid, uveal melanoma is exceedingly rare. It affects about 6 in 1 million people, with only a few thousand cases developing in the United States every year. It does not run in families and is not associated with skin melanoma or sunlight exposure. Uveal melanoma is thought to arise from a preexisting non-cancerous nevus. However, choroidal nevi are extremely common and carry a minimal risk of progressing to cancer.
How is uveal melanoma diagnosed?
Most patients with uveal melanoma have no symptoms since the tumor develops silently within the eye without vision loss. It is usually diagnosed as part of a dilated eye exam. Workup includes fundus photography, Optomap imaging, ultrasonography, and occasional biopsy.
How is uveal melanoma treated?
Once diagnosed, patients are referred to a radiation oncologist for a metastatic work up, including blood work, CT scan, and PET scan. However, it is rare for patients to present with metastases. Genetic testing, performed with a needle biopsy at the time of treatment, can help in predicting the risk for later metastases.
There are multiple ways to treat uveal melanoma including transpupillary thermotherapy (TTT), plaque brachytherapy, proton beam radiotherapy and removal of the eye (enucleation). Small tumors are usually treated with TTT or radiation while larger tumors are treated with enucleation.
The treatment goals, in decreasing order of importance, are to save the patient, then save the eye, then save the vision. In general, larger tumors are associated with worse vision and decreased life expectancy. Smaller tumors are often cured, and eyes with tumors located away from the optic nerve and macula often maintain good long-term vision. Yearly monitoring of the liver and lungs is recommended to detect metastases.