This is a malignant melanoma arising in the choroid and elevating the retina. It will cause no symptoms unless it involves the submacular region and disturbs visual acuity. Not all choroidal melanomas have this much black pigment; some 20% have so little that they appear as yellow masses.
This is the most common primary intraocular tumor of adults, but it is still rare: only 0.5 per 100,000 are diagnosed in the United States each year. The age range is 40-75 years, with a peak at 50.
The tumor probably arises via malignant transformation of nevi, collections of melanocytes. This is why choroidal nevi, once detected on routine ophthalmoscopy, must be watched for signs of growth.
There are many lesions that resemble a choroidal melanoma, but with the aid of fluorescein angiography and ultrasound, the correct diagnosis is reached in over 98% of cases.
Treatment consists of plaque radiation for medium-sized lesions and removal of the eye (enucleation) for . Depending on the size of the tumor, whether it has extended into the sclera, and its histology (the percentage of epithelioid cells), five-year survival ranges from 55% to 80%.
What to do?
Refer non-urgently any patient who has a mass elevating the retina, pigmented or not.