RARELY, the cornea may be the site of a primary malignant melanoma. In such instances the tumor arises from the Schwannian cells of the corneal nerves or in the basal cells of the corneal epithelium. Reese1 states that the basal cells of the corneal epithelium are potential melanoblasts, and this is evidenced by the melanin which these cells show in Stähli pigmented lines, in Hudson lines, and as an occasional sequela of irradiation. Reese1 published a photograph of a malignant melanoma of the cornea in an 89-year-old man who had noted a progressively enlarging lesion for two years. Serial sections in this case showed no connection with the limbus.
The cornea is more commonly invaded by a malignant melanoma which has arisen in the region of the limbus, this invasion usually taking place between the epithelium and Bowman's membrane, with subsequent invasion of the substantia propria.
DAVIES WS, BAILEY WH. MALIGNANT MELANOMA OF THE CORNEAReport of a Case. AMA Arch Ophthalmol. 1954;52(6):923-924. doi:10.1001/archopht.1954.00920050929011