When a pathologic classification of tumors is studied, one notes a gap and a discrepancy in the part concerned with epidermal neoplasms. The following is a portion of the classification as usually given : Certain tumors produced by dysgenesis of various glandular and follicular structures in the skin are called benign epitheliomas (multiple benign cystic epithelioma, acanthoma adenoides cysticum, syringo cyst adenoma, tricho-epithelioma papillosum multiplex), the designation depending on the histologic picture and the supposed origin. One might consider the possibility that benign epidermal neoplasms do not occur, but this idea is not in keeping with the primitive nature of epithelial tissue, especially that of the epidermis, and for this reason benign epidermal neoplasms should be as frequent as the benign neoplasms of some of the tissues aforementioned. Gans1 stated that no sharp line can be drawn between benign and malignant epithelial tumors, but he did not mention benign