IMPORTANCE OF BASAL MEMBRANE CONDITION IN DIAGNOSIS OF INVASIVE-CARCINOMA

The destruction of the epithelial basement membrane is widely regarded as a clear criterion for invasive malignant tumor growth. Since, howe ver, defects in the basement membrane may also occur in non-invasive c onditions,such as inflammatory and proliferative lesions, and since it has been shown that particularly in highly differentiated squamous ce ll carcinomas a continuous basement membrane is mimicked by the presen ce of isolated components, this criterion seems to be of minor value f or the diagnosis of malignancy. Despite these drawbacks, the immunoloc alization of basement membrane material may still be of differential d iagnostic significance in certain situations. This holds particularly true for invasive (ductal) bleast carcinomas, which usually completely lack a basement membrane. Accordingly, sclerosing adenosis can be dis tinguished from invasive carcinoma, as a distinction can be made betwe en neoplastic (malignant) tubular formations and reactive lesions.