Melanotic tumors of the optic nerve head. A pathologic study.

Malignant melanomas occasionally are clinically manifested as pigmented growths more or less confined to the substance of the optic nerve head. In most instances such lesions are found, on histologic examination, to be located in part within the choroid adjacent to the nerve-fiber layer as it courses backward to enter the posterior scleral foramen as the optic nerve. The involvement of the papilla in such instances is considered to be an extension of the growth from the choroid and, since the studies of Reese1in 1933, the cases have been designated "juxtapapillary malignant melanoma of the choroid." The recognition of the pathogenesis of this type of melanoma was of particular importance in making possible its differentiation from a much rarer, relatively benign pigmented tumor situated predominantly in the papilla, histologically not traceable to the choroid, and considered a primary tumor of the optic disc. Several years ago, in discussing