Adenocarcinoma of the retinal pigment epithelium.

A 57-year-old woman complaining of decreased vision for six months had a mass expanding the choroid inferonasally in the right eye. Clinical examination, ultrasonography, and fluorescein angiography were consistent with a malignant melanoma. The eye was enucleated and pathologic studies showed an adenocarcinoma of the retinal pigment epithelium (RPE). Malignant tumors of the RPE may simulate exactly choroidal melanomas clinically, but apparently have a much better prognosis, in that very few cases have been documented to produce metastatic disease. The vast majority of cases studied histopathologically, in which a diagnosis of adenocarcinoma of the RPE has been made, are low-grade malignant neoplasms with the absence of invasion beyond the choroid or lamina cribrosa at the time of enucleation.