Intraepidermal Basal Cell Epithelioma

IN THE PAST, the basal cell epithelioma has been discussed in great detail by a multitude of writers, who have centered their attention chiefly on the usual varieties, in all their clinical manifestations. For the most part, differences in the clinical picture have accompanied, with minor variations, approximately the same differences in the microscopic picture. In the following paper we present a rather rare type of basal cell epithelioma, namely, intraepidermal basal cell epithelioma. The first known case of intraepidermal basal cell epithelioma was described by Borst.1While studying routine serial sections taken for biopsy from the border of an ulcer of the lower lip, he noted a peculiar formation within the epidermis. The usual microscopic picture of basal cell epithelioma was seen at the ulcerated portion, and at points quite distant from this area, but within the boundaries of the epidermis, were islands of abnormal cells. The cells