Bcl‐2 and CD10 expression in the differential diagnosis of trichoblastoma, basal cell carcinoma, and basal cell carcinoma with follicular differentiation

Abstract

BACKGROUND: Both trichoblastoma and basal cell carcinoma (BCC) of the skin are characterized morphologically by the proliferation of basaloid cells; however, BCCs are clinically associated with a more aggressive behavior. An accurate diagnosis of these lesions is essential for effective, timely treatment and appropriate therapeutic decisions. METHODS: This study includes 40 lesions. Bcl-2 and CD10 immunohistochemistry were performed in all cases and the patterns of expression were analyzed. RESULTS: Bcl-2 is useful for the detection of BCC with diffuse expression in nests of basaloid cells, but cannot distinguish between BCC with follicular differentiation and trichoblastoma, as both lesions show the same pattern with positive and negative areas. Conversely, CD10 expression can distinguish between trichoblastomas with peritumoral stromal staining and BCCs with epithelial staining. If both stromal and epithelial areas are stained, these cases are classified as BCC with follicular differentiation. CONCLUSIONS: CD10 is useful for distinguishing between BCC with widespread follicular differentiation and trichoblastomas.