'Shadow sign' in congenital hypertrophy of the retinal pigment epithelium of young myopic pigmented patients.

PURPOSE Congenital hypertrophy of the retinal pigment epithelium (CHRPE) may simulate choroidal melanoma in certain cases. We report unique clinical features we have observed in cases of CHRPE in young myopic pigmented patients.METHODS Patients who were referred for evaluation of a suspicious choroidal lesion and found to have a CHRPE lesion with the clinical appearance of lesion elevation and a subretinal fluid-like 'shadow sign' were included. Patient and lesion characteristics were tabulated. Available images, including fundus photography, ultrasonography, optical coherence tomography (OCT), and fluorescein angiography (FA) were reviewed.ResultsSix patients were included. The 'shadow sign' was anterior to the CHRPE lesion in all cases. The mean age of the patients was 27.3 years. The ethnicities of the patients were Chinese (n=1), Hispanic (n=3), or African-American (n=2). Five of six patients were myopic.CONCLUSIONS Although most CHRPE lesions appear flat on ophthalmoscopy, lesions in young myopic patients of pigmented ethnicities may appear elevated with a 'shadow sign' due to 'dark without pressure.' This new finding may be related to the vitreoretinal interface in young myopic pigmented patients and must be distinguished from true subretinal fluid and lesion thickness, which are often observed in choroidal melanoma.