Estrogen and progesterone receptors in benign breast tumors and lesions: Relationship with histological and cytological features

The pattern of estrogen (ER) and progesterone receptors (PR) and their relationship to histo‐ and cytopathological parameters has been studied in 97 cases of benign breast disease and benign phyllode tumors (95 women, of whom 76 were premenopausal, and 2 men). Total (cytosolic + nuclear) ER and PR were assayed by a single‐saturating dose method using a tris‐KCI buffer. The cut‐off between positive and negative ER and PR assay was 100 femtomoles/g tissue. All specimens were processed for histological examination: epithelial and fibroblastic proliferation, epithelial/stromal ratio and presence of focal or diffuse hyalinosis. In 33% of the 46 cases of fibrocystic disease one receptor at least was present (13% ER+, 31% PR+). All the 8 cases in which infiltrating epitheliosis was present were PR+ and 4 of them were also ER+. In 72% of the 31 fibroadenomas one receptor at least was present (19% ER+, 71% PR+). In all these cases levels of receptors were lower than in malignant tumors. An inverse correlation between PR + prevalence and fibrohyalinosis was observed; on the other hand a positive relationship between PR + and fibroblastic (p