PRESUMED RETINAL PIGMENT EPITHELIUM TUMOR ORIGINATING FROM UNILATERAL RETINAL PIGMENT EPITHELIUM DYSGENESIS

To describe a patient with a presumed retinal pigment epithelium (RPE) tumor originating from unilateral RPE dysgenesis.

Case report.

A 30-year-old woman with an unremarkable medical and ocular history was referred for an evaluation of progressive central metamorphopsia in her left eye. Visual acuity was 20/20 in her right eye and 20/25 in her left eye. Funduscopic examination of the left eye revealed an elevated mass within an area of unilateral RPE dysgenesis showing hyperpigmentation and hypopigmentation with scalloped margins. Fundus autofluorescence of the lesion showed a marginal pattern of hyperautofluorescence and hypoautofluorescence that was the inverse of the fluorescein angiography pattern. A well-circumscribed subretinal mass appeared to originate from the unilateral RPE dysgenesis lesion with surrounding subretinal fluid extending beneath the fovea. Ultrasonography showed medium-to-high reflectivity of the mass with no evidence of choroidal involvement. Optical coherence tomography showed a subretinal hyporeflective mass consistent with a tumor of RPE origin. The tumor appeared to invade the overlying retina where fluorescein angiography showed hyperfluorescent leakage and OCT angiography showed retinal vascular deformation. Indocyanine green angiography showed no evidence of choroidal neovascularization. Findings in the right fundus were normal. Over a 5-month follow-up, intravitreal anti-vascular endothelial growth factor therapy induced a resolution of subretinal exudation and modest reduction in tumor thickness.

To the authors' knowledge, this is the first report of a presumed RPE tumor described as originating from unilateral RPE dysgenesis. Multimodal imaging was crucial for establishing the diagnosis and showing that the patient's visual symptoms were a product of the exudation produced by the tumor's invasion of the retina.