Distribution and ultrastructural characterization of the stroma in scirrhous 'infiltrating' carcinoma of the human breast.

A combination of light microscopic, histochemical, immunohistochemical and transmission electron microscopic techniques were used to study the distribution and ultrastructural characterization of the stroma of Scirrhous 'infiltrating' carcinoma of the human breast. Both the light and electron microscopic techniques emphasized the presence of regional variations in the distribution of fibrous tissue in this type of tumour. Whilst fibronectin and collagen type III appeared relatively rich in both periductal and diffused regions, there was a clear contrast in the distribution of collagen type I and elastic tissue between the two regions. Collagen type I was more numerous in the diffused regions whereas elastic tissue was more produced in the periductal regions. The present study confirmed the views that Scirrhous carcinoma cells secrete inappropriately the majority of collagen, elastic and possibly other fibrillar elements of the connective tissue stroma. Fibroblasts, myofibroblasts and myoepithelial cells are believed to contribute in a minor way to the production of the various connective tissue elements. Finally, our findings have been discussed in relation to the mechanism of invasiveness of the tumour cells.