Optical coherence tomography features of atypical congenital hypertrophy of retinal pigment epithelium in a patient with familial adenomatous polyposis

Purpose:To describe optical coherence tomography (OCT) features of atypical congenital hypertrophy of retinal pigment epithelium (CHRPE) associated with familial adenomatous polyposis (FAP).Methods:Case report.Results:A 34-year-old patient diagnosed with FAP was referred to our clinic for fundus examination. We characterized the lesions we found using multimodal imaging (infrared, autofluorescence, OCT and widefield and ultra-widefield fundus image). We described 3 possible stages of progression of the lesions in a single patient and we found a possible evolutionary stage with a "2 binary reflective sign".Conclusions:CHRPE lesions can show a progression from only retinal pigment epithelium (RPE) hyperreflectivity to complete outer retinal atrophy and even intraretinal RPE migration. We hypothesize that the 2 binary reflective sign could represent an hemorrhage between RPE and outer retina which could lead, together with the reduced catabolic activity of pathological RPE, to overlying retinal atrophy.