[Apocrine carcinoma of the breast--a morphologic comparison of the apocrine sweat glands and the apocrine metaplastic epithelia in mastopathy].

An operatively removed apocrine carcinoma of the breast from a 62-year-old Japanese lady has been observed by the ABC method, using the monoclonal antibody 115D8. The cancer cells and metaplastic epithelia exhibited similar ultrastructural findings (an apical snout, apocrine granules, etc.) as the apocrine sweat gland cells, although no evidence of apocrine secretion could be detected. The immunohistochemical testing, using monoclonal antibody, 115D8, showed an apical, linear, dot-like, staining in the supranuclear regions on the apocrine sweat gland cells and on the apocrine metaplastic cells of the mammary gland. Similar stainability also was observed in the well-differentiated area of the apocrine carcinoma, while a heterogeneity in staining, such as unstained cells and diffuse cytoplasmic-stained cells were found in the poorly-differentiated areas. These abnormal staining patterns indicate the malignant changes of the apocrine cells.