Basal cell carcinoma on the vermilion lip: a study of 18 cases.

B asal cell carcinoma (BCC) involving the vermilion border and mucosal surface of the lips is rare, whereas these sites are more frequently involved by squamous cell carcinoma (SCC). The epithelium of the lip is divided into 4 regions: the skin; the vermilion border; the outer mucosa (vermilion); and the inner mucosa. The vermilion border contains the orbicularis oris muscle without a subcutaneous fat layer. It is devoid of hair follicles and sweat glands. During the aging process the upper lip lengthens, the teeth wear down, and the angle of the jaw opens, resulting in a reduction in the amount of outer mucosa, which is exposed to the sun. We present 18 cases of BCC, which involved predominantly the vermilion lip. In our study, we use the term “vermilion lip” to include the vermilion border and the outer mucosal surface of the lip (Fig 1). The clinical presentation and histopathology of these cases were reviewed and characterized. (Figs 2-7).