Basal cell carcinomas of covered and unusual sites of the body

Background The concept of unusual site for a basal cell carcinoma (BCC) has to be defined because there is much confusion about it. Basal cell carcinomas of covered areas of the body are sometimes considered as unusual because of their location. In this study an attempt is made to define what is an unusual site for a BCC according to experience and the problems encountered are briefly discussed. Methods A total of 1050 histologically-confirmed primary BCCs were studied. Age, sex and site of presentation were considered. Results Eighteen cases were recorded, localized on hand, axilla, areola or nipple, buttock, perineal, and genital regions. Conclusions Unusual location has been arbitrarily defined in the past according to the incidental percentage, to a mathematical index of density, to the literature reports. All these criteria suffer more or less from some discrepancy, but in our opinion all these should be considered for a definition. Our results, moreover, suggest that only the above described sites should be considered.