[Immunohistochemical study of components of the basement membrane in odontogenic cysts].

The pattern of distribution and expression of laminin and type IV collagen was studied in ten radicular cysts, ten dentigerous cysts and ten odontogenic keratocysts, by means of the streptavidin-biotin method. The purpose of this study was to investigate changes in the distribution of components of the basement membrane in an attempt to contribute to the understanding of the differences, as to evolution and clinical behavior, between these cysts. The results revealed a weak and discontinuous linear staining, in odontogenic keratocysts, for both laminin and type IV collagen, while, in radicular cysts, staining was more intense and continuous. In dentigerous cysts, an intermediary pattern was observed, which was more similar to that observed in keratocysts. Our results suggest that, in view of the weak expression of proteins of the basement membrane observed in odontogenic keratocysts, modifications must take place in the interaction between the epithelium and the adjacent connective tissue, which could, in part, contribute to the pattern of more rapid growth exhibited by these cysts.