Immunohistochemical Expression of CD10 in Cutaneous Basal and Squamous Cell Carcinomas.

Background : CD10 is a zinc-dependent metallopeptidase known as common acute lymphoblastic leukemia antigen (CALLA). Although CD10 expression has been investigated in some cutaneous tumors, to our knowledge, data regarding its expression in cutaneous epithelial neoplasms are very limited. We aimed to determine the immunohistochemical expression of CD10 in basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) and to associate it with the available clinicopathological parameters in both tumors. Patients and Methods : This study included 16 SCC and 21 BCC cases (17 solid type, 2 morphea type and 2 adenoid basal types). BCC cases were divided into 12 cases with microscopic infiltrative base and 9 cases with well-circumscribed base. The localization of anti-CD10 to the tumor and/or stromal cells was determined in each case. Results : Positive CD10 staining was identified as brown cytoplasmic, with or without cell membrane staining. In all the 16 SCC cases, tumor cells failed to stain with CD10 in contrast to the stromal cells that showed CD10 expression in 13 cases (81%). In BCC cases, the expression of CD10 was noted in tumor cells in 10 cases (47.6%) and in stromal cells of 20 cases (95.24%). Most of CD10+ (7/10) BCC showed well-circumscribed deep margin, however, most of CD10- cases (9/11) showed infiltrating base (p=0.030). BCCs with infiltrating deep margins (12 cases) tended to show CD10 negative basaloid cells (9/12) and CD10 positive stromal cells (12/12) (p=0.0003). Conclusion : From our results we suggest that CD10 might be a useful immunohistochemical marker to differentiate between BCC and SCC. At least, if tumor cells were CD10 positive, this would favor BCC over SCC. Absence of CD10 in all the SCC and in infiltrating BCC together with its overexpression in the surrounding stromal cells might confer invasive properties to such tumors. However, its relation to other poor prognostic factors needs larger studies to be confirmed. Key Words : CD 10 -Immunostaining -Skin.