Monoclonal antibody Ber EP4 distinguishes basal-cell carcinoma from squamous-cell carcinoma of the skin.

Twenty-two cases of basal-cell carcinoma (BCC) and 21 cases of squamous-cell carcinoma of the skin (SCC) were stained for Ber EP4 using indirect immunofluorescence and avidin-biotin-peroxidase techniques. The results showed that all BCCs were diffusely and intensely labeled, whereas none of the SCCs expressed Ber EP4, irrespective of their histological type or grade of differentiation. This difference may prove useful in (a) histologically differentiating between these two neoplasms; and (b) in clarifying the histogenesis of neoplasms considered to be intermediate between BCC and SCC, or derived from BCC. In addition, because significant differences between the staining of hair follicles and BCC were noted, evaluation for Ber EP4 expression could assist in distinguishing between BCC and hair follicles in Mohs micrographic sections.