Cytochemical detection of estrogen receptors in mammary tumours

The technical details of a cytochemical method for estrogen receptor identification in mammary tumours are presented and applied in 19 carcinomas and six adenofibromas. A fluorescent estradiol conjugate was used as receptor tracer. From the 19 mammary carcinomas, six were interpreted as estrogen receptor-negative (ER-), two were strongly receptor-positive (ER++) and eleven were moderately estrogen receptor-positive (ER+), having cells with a heterogeneous content of estrogen receptors. In fibroadenomas, the proliferating epithelia were moderately estrogen-receptor positive.