[Biologic bases of the treatment of diffuse benign breast diseases].

An analysis is made of the contributions that animal experiments have made to the understanding of diffuse benign mastopathies. By the use of epidemiological studies and the examination of biopsy material, from women using hormones, in a histo-pathological way conclusions could be drawn as to the effect of these steroids on the human mammary gland. Consideration has been given to the action of oestrogens and progestogens used alone or in combination.