Oestrogen receptors in mucinous carcinoma of the breast: an immunohistological study using paraffin wax sections.

An immunohistological method (Shintaku-Said method) for the demonstration of oestrogen receptors in routinely processed paraffin wax embedded tissue was applied to 19 cases of mucinous carcinoma of the breast. Seventeen (89%) tumours showed variable degrees of positivity and two were negative. In eight cases the receptors were also assayed biochemically using a dextran-coated charcoal method, and the results of the two methods showed good correlation. No difference in the distribution of positive and negative cases was noted between pure and mixed mucinous tumours, and in the latter group the pattern of staining of the mucinous elements was similar to that seen in the solid elements. It is concluded that the major advantage of this method is its ability to offer for study the distribution of the receptors in individual cells and specific histological structures. The results also indicate that most mucinous carcinomas of the breast are oestrogen receptor positive, irrespective of whether they are pure or mixed type.