Banded Structure in Cellular Blue Nevus

To the Editor.—  We wish to report a new observation—the appearance of "banded structures" in the stroma of a nerve within a cellular blue nevus. The nerve in the nevus reported herein (Figure) had both myelinated and nonmyelinated fibers. The banded structures were only seen in association with nonmyelinated nerve fibers. With higher magnification, they had a broad base, appearing to arise from the nonmyelinated nerve fiber basement membrane. The distal end was narrow and appeared to blend with stroma (Fig 1, inset). The periodicity varied from 1,600 to 1,800 Angstroms and the maximum width was 3,200 to 3,600 A. No intraperiodic bands were observed.Banded structures similar to those seen by us have been described in schwannomas and are considered to be diagnostic by some investigators.¹ The presence of such bodies within a cellular blue nevus, therefore, would seem to support the neurogenic origin of these tumors.²