Autoradiographic demonstration of 3H-estradiol incorporation in benign human mammary lesions.

This study reports the distribution of 3H-estradiol incorporation as assessed by thaw-mount autoradiography after in vitro incubation of fresh tissue obtained from a series of 17 benign human mammary lesions. In four out of nine cases of fibroadenoma examined, putative estrogen target cells were identified in ducts where the specific labeling was confined to some but not all epithelial cells. Elsewhere in these lesions, negative ducts could be found. Similarly, in three out of eight cases of fibrocystic disease specific labeling was seen over epithelial cells in some areas but not others. Histologically identifiable myoepithelial cells were negative as well as the vast majority of stromal cells.