RESUMO
Estrogen receptors (ER) were investigated using immunohistochemical techniques in 54 cases and biochemical techniques in 38 cases on a series of biopsy specimens of normal, hyperplasic and malignant mammary tissue (intraductal carcinoma). Immunohistochemical data were submitted to quantitative and semi-quantitative analysis (SAMBA 200, TITN). On normal tissue, immunostaining is bright and evenly distributed in galactophores and ductulo-lobular junctions; it is unevenly distributed but consistently present in lobules and increasing after menopause. On hyperplasic tissue, immunostaining of papillary cystadenomas and epitheliosis and fibroadenosis zones was similar to normal tissue with respect to the intensity and heterogeneity. Conversely, their immunohistochemical features are close to blunt duct adenosis and atypical lobular hyperplasia of ductulo-lobular junctions. On malignant tissue, immunostaining is unpredictable, it can be evenly distributed, unevenly distributed in patches or gradients, or totally absent. Immunohistochemical techniques can only be used to assess the intensity and distribution of ER in function of cell type in normal tissue and during a cancerous process. Thus strong receptivity of ductulo-lobular junctions may reinforce the claim that these structures are the targets for estrogen co-carcinogenic substances. The heterogeneity of ER at the onset of carcinoma suggests the possibility of several pathway of development. The fact that myoepithelial cell never seem to display estrogen type receptivity makes it logical to seek a special sensitivity for them.