Congenital simple hamartoma of the retinal pigment epithelium: What is the probable cause?

Congenital simple hamartoma of the retinal pigment epithelium is localized to the retinal tissue only with variable amount of surface extension. With consistent morphological and OCT features of the lesion around fovea, it appears that some of the embryologically undifferentiated ectopic progenitor cells destined for RPE within the retinal tissue may not undergo any further differentiation due to lack of necessary homeostatic factors leading to only hyperplasia and accumulation of the cells within the retina leading to simple hamartoma.