Although controversy surrounds the connection, bilaterality and numerous small presentations (sometimes referred colloquially as “animal” or “bear tracks”) seem to be the most consistent indicator for a gastrointestinal consultation. Single lesions could be present among certain at-risk patients; such extra-colonic manifestations should be followed up.2,3
Histologically, geographic CHRPE lesions displace the overlying photoreceptor cells, resulting in a scotoma.5 The present case was not evaluated perimetrically because the lesion was well anterior of the equator. CHRPE lesions have been reported to change over time.
Central presentations may interfere with visual acuity.6-8 In the periphery, they may remain stable with the exception of depigmented appearance, as this case illustrates.
Related: Imaging a choroidal nevus
1. Shields CL, Mashayekhi A, Ho T, Cater J, Shields JA. Solitary congenital hypertrophy of the retinal pigment epithelium: clinical features and frequency of enlargement in 330 patients. Ophthalmology. 2003 Oct;110(10):1968-76.
2. Nusliha A, Dalpatadu U, Amarasinghe B, Chandrasinghe PC, Deen KI. Congenital hypertrophy of retinal pigment epithelium (CHRPE) in patients with familial adenomatous polyposis (FAP); a polyposis registry experience. BMC Res Notes. 2014 Oct;18(7):734.
3. Chen CS, Phillips KD, Grist S, Bennet G, Craig JE, Muecke JS, Suthers GK. Congenital hypertrophy of the retinal pigment epithelium (CHRPE) in familial colorectal cancer. Fam Cancer. 2006;5(4):397-404.
4. Parisi ML. Congenital hypertrophy of the retinal pigment epithelium serves as a clinical marker in a family with familial adenomatous polyposis. J Am Optom Assoc. 1995 Feb;66(2):106-12.
5. Tzu JH, Cavuoto KM, Villegas VM, Dubovy SR, Capo H. Optical Coherence Tomography Findings of Pigmented Fundus Lesions in Familial Adenomatous Polyposis. Ophthalmic Surg Lasers Imaging Retina. 2014 Jan-Feb;45(1):69-70.
6. Zucchiatti I, Battaglia Parodi M, Pala M, Bandello FM. Macular congenital hypertrophy of the retinal pigment epithelium: a case report. Eur J Ophthalmol. 2010 May-Jun;20(3):621-4.
7. Shields CL, Materin MA, Walker C, Marr BP, Shields JA. Photoreceptor loss overlying congenital hypertrophy of the retinal pigment epithelium by optical coherence tomography. Ophthalmology. 2006 Apr;113(4):661-5.
8. Nishikatsu H, Shiono T. Congenital hypertrophy of the retinal pigment epithelium in the macula. Ophthalmologica. 1996;210(2):126-8.