Immunohistochemical stainning for CD10 in differential diagnosis of basal cell carcinoma and trichoepithelioma

Objective To investigate the significance of immunohistochemical stainning for CD10 in differential diagnosis of basal cell carcinoma(BCC) and trichoepithelioma(TE).Methods CD10 protein immunohistochemistry was performed on paraffin-embedded biopsies of 96 BCC and 46 TE diagnosed by routine microscopy.The cases were analyzed for pattern of CD10 expression by tumor cells and surrounding stroma.Results Expression of CD10 by basaloid cells was identified in 95 of 96 BCC(99%).Stromal positivity was also identified in five cases of BCC.No BCC demonstrated stromal expression alone.On the other hand,all of 46 TE(100%) showed positive stromal immunoreactivity around basaloid nests.Of these,36 cases also demonstrated positivity of the papilla,and six also showed local positivity of the basaloid cells.No TE demonstrated epithelial expression alone.Conclusion This study demonstrates a significant difference in CD10 staining pattern between TE and BCC.Thus,CD10 may be a useful adjunct marker in distinguishing BCC from TE.