Basement membranes in progressing intraepithelial cervical neoplasia. An ultrastructural and immunohistochemical study with antibodies against human type IV collagen and laminin.

The occurrence and location of basement membranes (BM) and their constituents were studied in benign, inflammatory, dysplastic and malignant conditions of the uterine cervix by light and electron microscopy and by immunohistochemical analysis with antibodies against human laminin and type IV collagen. The normal squamous epithelium showed a thin subepithelial BM band, which was preserved in dysplasia. Severe inflammatory conditions affecting the epithelium caused disruption and fragmentation of the BM. Well-differentiated carcinomas were frequently surrounded by a BM, whereas anaplastic tumors had a disrupted and fragmented BM, and similar material was also seen in the tumor tissue itself. Thus the presence of a continuous BM seems to be only a relative criterion in distinguishing between benign and malignant conditions.