Sebaceous carcinoma: an immunohistochemical reappraisal

The rates of distant metastases and tumor death in sebaceous carcinoma (SC) have been reported to be higher than those of other cutaneous carcinomas, such as squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), regardless of whether they occur in ocular or extraocular regions. Therefore, strict differentiation of SC from SCC and BCC is required. In this article, we report immunohistochemical findings of SC and compare these data to those of SCC, BCC, and sebaceoma. An immunohistochemical study was performed using 7 antibodies [anti-carcinoembryonic antigen (CEA), anti-epithelial membrane antigen (EMA), anti-CA15-3, anti-CA19-9, anti-androgen receptor (AR), anti-epithelial antigen (Ber-EP4), and anti-adipophilin (ADP)] on 35 cases of SC (16 cases in ocular and 19 cases in extraocular regions) and 10 cases of each SCC (5 cases in ocular and 5 cases in extraocular regions), BCC (5 cases in ocular and 5 cases in extraocular regions), and sebaceoma (no cases arose on the eyelids). In summary, the typical immunophenotypes of SC were EMA+, CA15-3+, AR+, Ber-EP4-, and ADP+; those of sebaceoma were CEA-, EMA+, Ber-EP4-, and ADP+; those of SCC were CEA-, EMA+, CA19-9-, AR-, Ber-EP4-, and ADP-; and those of BCC were CEA-, EMA-, CA15-3-, Ber-EP4+, and ADP-. Other antibody tests for each neoplasm were positive in about half of the cases. The detection of AR and ADP was useful for differentiating SC from SCC, whereas the determination of EMA, CA15-3, Ber-EP4, and ADP was valuable in differentiating SC from BCC.