Loss of bullous pemphigoid antigen in peritumoral lacunas of basal cell carcinomas.

Peritumoral lacunas of basal cell carcinoma (BCC) were for a long time misinterpreted as fixation artifacts. However, recent studies showed that they might be considered as a dynamic process related to degenerescence for the palisade cells. We studied three antigens of the epidermal basement membrane zone--type IV collagen, laminin, and bullous pemphigoid antigen--by indirect immunofluorescence in six cases of basal cell carcinoma. We could observe that type IV collagen as well as laminin were expressed as a linear continuous staining pattern surrounding each of the BCC buds. When there was a peritumoral lacuna, only the stroma side of the lacuna was stained. Bullous pemphigoid antigen showed either a linear continuous or discontinuous staining pattern along the basement membrane zone of the carcinomatous buds. At the site of a peritumoral lacuna bullous pemphigoid antigen abruptly disappeared. The loss of bullous pemphigoid antigen might be related to the lacuna formation.