[Immunohistochemical alterations in basement membrane components in skin cancer]

To investigate alterations in the basement membrane (BM) components around tumor nests, Bowen's disease (BD), actinic keratosis (AK), basal cell epithelioma (BCE), squamous cell carcinoma (SCC) were studied by double immunofluorescent staining with antibodies to laminin (LN), type IV collagen (CIV), heparan sulfate proteoglycan (HSPG), and chondroitin 6-sulfate glycosaminoglycan (C6S). In BD, all BM components were continuous on the dermo-epidermal junction. In AK, C6S was partially disrupted, but the other components were continuous. In BCE, LN and CIV were continuous around the tumor nests, but HSPG and C6S were varied. SCCs were divided into two groups by the patterns of LN, CIV, and HSPG; SCC with continuous BM components or disrupted ones. The former SCC had a tendency to show the more infiltrative growth. C6S was detected partially on the BMs of SCCs which have cytological characteristics of BD, while it was absent on those of other SCCs. The difference in the patterns of the BM components suggests variation of tumor invasion.