ACQUIRED TUMORS ARISING FROM CONGENITAL HYPERTROPHY OF THE RETINAL PIGMENT EPITHELIUM

Abstract

Background Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is widely recognized to be a flat, stationary condition. Although it can show minimal increase in diameter, it has not been known to spawn nodular tumor that is evident ophthalmoscopically. Objectives To report 5 cases of CHRPE that gave rise to an elevated lesion and to describe the clinical features of these unusual nodules. Methods Retrospective medical record review. Results Of 5 patients with a nodular lesion arising from CHRPE, there were 4 women and 1 man, 4 whites and 1 black. Three patients were followed up for typical CHRPE for longer than 10 years before the tumor developed; 2 patients were recognized to have CHRPE and the elevated tumor concurrently. Visual acuity was decreased in 3 patients, mainly due to cystoid macular edema. The tumor was located between the equator and ora serrata in all 5 patients. There was no predilection for quadrant of the fundus. The flat part of the lesion was black and had visible lacunae in all 5 patients. The CHRPE ranged in basal diameter from 3 × 3 mm to 13 × 11 mm. The size of the elevated lesion ranged from 2 × 2 × 2 mm to 8 × 8 × 4 mm. The nodular component in all cases was supplied and drained by slightly prominent, nontortuous retinal blood vessels. Yellow retinal exudation occurred adjacent to the nodule in all 5 patients and 1 patient developed a secondary retinal detachment. Two tumors that showed progressive enlargement, increasing exudation, and progressive visual loss were treated with iodine 125–labeled plaque brachytherapy, resulting in deceased tumor size but no improvement in the visual acuity. Conclusions Congenital hypertrophy of the retinal pigment epithelium can spawn a nodular growth that slowly enlarges, attains a retinal blood supply, and causes exudative retinopathy and chronic cystoid macular edema. Although no histopathologic evidence is yet available, we believe that the tumor probably represents either an acquired adenoma or a reactive proliferation of the retinal pigment epithelium. The best treatment of these lesions is not yet established.