Apocrine carcinoma of the breast: a comprehensive review.
Apocrine carcinoma of the breast is a rare, special type of breast carcinoma showing distinct morphologic, immunohistochemical and molecular genetic features. Apocrine epithelium has a characteristic steroid receptor profile that is estrogen receptor and progesterone receptor negative and androgen receptor positive. This combination of morphologic and immunohistochemical characteristics is essential for the proper recognition of the apocrine carcinomas. Strictly defined, apocrine carcinomas express either Her-2/neu or EGFR, which along with androgen receptor positivity make patients with the apocrine carcinoma eligible for targeted therapies.