Image Description
The main diagnostic feature of apocrine carcinoma is the cytologic appearance of tumor cells. Architecturally, apocrine ductal carcinoma-in-situ (DCIS) is similar to non-apocrine DCIS and can display comedo, micropapillary (shown here), cribriform, solid, and papillary patterns. In this case, the tumor cells have abundant densely eosinophilic cytoplasm, enlarged nuclei, and one or more punctate nucleoli. The nuclear grade is intermediate. Apocrine snouts can be seen on the luminal aspect of many tumor cells.
About the Disease
Apocrine morphology may be focally present in a variety of breast carcinomas, including ductal, lobular, mucinous, tubular, medullary and others. The term "apocrine carcinoma" is reserved for breast carcinomas in which majority of the tumor cells have apocrine morphology - consisting of abundant densely eosinophilic cytoplasm that may show granularity or vacuoles, enlarged nuclei and prominent nucleoli. They make up about 1% of all breast carcinomas. There are no major differences in the clinical features, mammographic presentation, or prognosis between apocrine and non-apocrine ductal carcinomas.Most cases of invasive apocrine carcinomas are negative for estrogen receptors (ER) and progesterone receptors (PR) and express androgen receptors (AR). About 50% of cases of pure apocrine carcinomas are HER2-negative. Gross cystic disease fluid protein 15 (GCDFP-15) - a marker of apocrine differentiation is expressed in majority of the cases, but it is not required to make the morphologic diagnosis of apocrine carcinoma.