Basement membrane continuity in benign, premalignant and malignant epithelial conditions of the uterine cervix.

The pattern of basement membrane deposition in the uterine ectocervix was assessed in benign, premalignant and malignant conditions, using an indirect immunoperoxidase technique to detect laminin, an intrinsic basement membrane component. A semi-quantitative approach was used to assess the frequency of small breaks in the basement membrane. The cervical squamous epithelium in benign epithelial conditions has an almost completely continuous basement membrane, but the development of viral atypia or cervical intraepithelial neoplasia (CIN) is associated with the appearance of small basement membrane breaks. There is a correlation between increasingly severe CIN and increasing numbers of breaks, and there is a concurrent increase in the numbers of subepithelial inflammatory cells. The development of invasive neoplasm is associated with a sudden change to a fragmented pattern of basement membrane deposition, a finding which is of potential diagnostic use.