Polar bear tracks retina skin#

These lacunae may show progressive enlargement, and eventually the entire lesion may become depigmented ( Figure 12.01 G). Hypopigmented or depigmented lacunae within these lesions are frequently evident, particularly in older patients ( Figures 12.01 B, D, E, and I, and 12.03 G and H). Although most CHRPE are between one and two disc diameters, some may occupy an area equal to one quadrant of the fundus ( Figure 12.01 B). There is often a halo of depigmentation just inside the outer edge of these lesions ( Figure 12.01 E and F). However, CHRPE in macula and juxtapapillary location are rare. A CHRPE may occur anywhere in the fundus. They are usually solitary but may be multiple and grouped in a pattern suggesting animal tracks ( Figure 12.01 A). Solitary-type CHRPEs are well-demarcated, slightly elevated, gray-brown to black, oval, round, or occasionally geographic lesions with smooth or scalloped margins ( Figures 12.01–12.03 ).

Solitary-Type Congenital Hypertrophy of the Retinal Pigment Epithelium (CHRPE) Melanotic Nevi of the Retinal Pigment Epithelium

It is important to realize that reactive proliferation of RPE, retinal glial cells, and retinal vascular endothelial cells can occasionally duplicate the clinical and histopathologic changes of all of the RPE hamartomatous lesions discussed in this chapter. Developmental uveal melanocytic nevi have been described in Chapter 14.

Polar bear tracks retina skin#

A nevus is a “birthmark a circumscribed malformation of the skin, especially if colored by hyperpigmentation or increased vascularity it may be predominantly epidermal, adnexal, melanocytic, vascular, or mesodermal, or a localized overgrowth of melanin-forming cells arising in the skin early in life.” Ophthalmologists have adopted the term “nevi” to refer to developmental melanocytic lesions of the uveal tract, and it has been suggested as an appropriate term to describe developmental placoid lesions of the RPE. Stedman’s Medical Dictionary defines a hamartoma as: “a focal malformation that resembles a neoplasm grossly and even microscopically, but results from faulty development in an organ it is composed of an abnormal mixture of tissue elements, or an abnormal proportion of a single element, normally present at that site, which develops and grows at virtually the same rate as normal components, and is not likely to result in compression of the adjacent tissue (in contrast to neoplastic tissue).” A choristoma is defined as a “mass formed by maldevelopment of tissue of a type not normally found at that site.” Phacoma is defined as “a hamartoma found in phacomatosis,” a group of hereditary diseases characterized by hamartomas of multiple tissues. The terms “hamartoma,” “choristoma,” “phacoma (mother spot),” and “nevus” are used to describe benign developmental tumors or placoid lesions.