Tumors of the Retinal Pigment Epithelium

Tumors of the retinal pigment epithelium (RPE), although relatively uncommon, can be mistaken for choroidal melanoma and are of importance to the clinician. Congenital hypertrophy of the RPE (CHRPE) is benign, typically pigmented lesions found in a solitary or grouped configuration. These must be distinguished from the bilateral, multiple, pigmented hamartomas that can be present in familial adenomatous polyposis. Congenital hyperplasia of the RPE is small, solitary, nodular lesions often located in the macula that remain stable in size. Reactive hyperplasia of the RPE, which develops in response to stimuli such as trauma, inflammation, or hemorrhage, often manifests as intraretinal pigmented spicules; however, it can also present as a localized subretinal mass. Combined hamartomas of the retina and RPE are elevated pigmented masses with variable degrees of retinal distortion and retinal vascular tortuosity that are thought to be congenital. Visual acuity varies depending on the location of the combined hamartoma as well as the degree of glial proliferation and distortion of the retinal architecture. Tumors with the ability to invade and metastasize rarely arise from the RPE.