Basal Cell Carcinoma Arises from Interfollicular Layer of Epidermis

BACKGROUND: BCC is currently the most common type of skin cancer in humans. Although having a low-grade malignancy and metastatic potential, BCC is locally aggressive and destructive. Despite numerous studies, the origin of BCC, whether arising from the follicular or interfollicular layer, remains controversial. OBJECTIVES: This study aims to evaluate whether BCC arises from the follicular or interfollicular layer by using immunohistochemical staining. METHODS: Twenty-three specimens of superficial and nodular BCC at its very early stage were examined. The samples were immunohistochemically stained using BerEP4 antibody. The stained specimens were then examined and scored by 2 independent observers. RESULTS: BerEP4 was found to be strongly positive in all BCC lesions, including a very early lesions budding off the basal layer of the epidermis. CONCLUSION: This study confirmed that the origin site of BCC is basal layer of epidermis. This finding suggests that BCC arises from the interfollicular epidermis.