Solar keratosis can be distinguished from superficial basal cell carcinoma by expression of bcl-2

Criteria for the histological diagnosis of solar keratosis (SK) and superficial basal cell carcinoma (SBCC) are well defined. On occasion, however, the distinction can be difficult, particularly when evaluating small-punch or superficial shave biopsies in which the overall global architectural pattern of the lesion is not represented. As bcl-2 expression has been established in basal cell carcinoma, this study was undertaken to determine whether it could be employed as a basis for distinguishing SBCC from SK. Ten cases each of typical SBCC and SK were studied. Every example of SBCC showed strong uniform expression of the bcl-2 gene product Bcl-2, whereas all examples of SK were uniformly negative. It is suggested, therefore, that this simple technique is a reliable method for distinguishing these two closely related but disparate lesions.