Stromal changes in early invasive breast carcinoma. An immunohistochemical, histoenzymological and ultrastructural study.

The purpose of this work was to detect in periductal connective tissue of breast carcinoma in situ changes induced by intraductal tumor cells before any dehiscence in basement membrane. Histological, electron microscopic, immunohistochemical and histoenzymological methods were used in 3 carcinomas in situ, 4 microinvasive carcinomas and 13 control invasive carcinomas. We could demonstrate a high functional activity of fibroblasts with secretion of mucopolysaccharides and type III collagen around intraductal carcinomas. These changes occurred simultaneously to those of the basement membrane which was either thinning or thickening. Any dehiscence in basement membrane secondarily induced in this periductal stroma the usual changes seen in invasive stroma, peculiarly numerous vascular pedicles, myofibroblasts, elastic material. These periductal stromal changes are interpreted according to recent concepts about the possible influence of tumor cells upon their environment: stimulation of mitotic and metabolic activity of fibroblasts: stimulation of angiogenesis by means of an angiogenic factor.