We evaluated 20 cases of BCC for the pattern of CD56 and cytokeratin 5/6 (CK5/6) staining, hypothesizing that these 2 stains could differentiate BCC from MCC in difficult cases.
Basaloid skin tumors, including basal cell carcinoma (BCC) and basaloid follicular hamartoma, are associated with aberrant Hedgehog (Hh) signaling and, in the case of BCC, an expanding set of genetic variants including keratin 5 (encoded by KRT5), an intermediate filament-forming protein.