Immunoreactive elastin in benign breast tissues. An immunoperoxidase study

Immunohistological localisation of elastin was achieved by means of the peroxidase-antiperoxidase method after preliminary trypsinisation of sections from 48 benign breast biopsies. The procedure allows retrospective examination of routinely formalin-fixed, paraffin-embedded breast tissue. In general the immunolocalisation of elastin showed a close microanatomical correlation with the fibres demonstrable in sections from the same blocks by standard elastic-fibre stains. Discrepancies between elastic-fibre stains and elastin immunoreactivity appear to relate to the enhanced avidity of the antibody for immature elastin. In this way sites of recent synthesis of elastin were demonstrated in the inner zone of the periductal elastica, sclerosing adenosis, and in the internal elastic lamina of breast arteries which displayed reduplication of the internal elastic lamina or intimal proliferation.