Apocrine carcinoma of the breast is characterized by a >90% proportion of tumour cells with cytological and immunohistochemical features of apocrine cells. There are usually two types of tumour cells which are variously intermingled. Type A cells have abundant granular, intensely eosinophilic cytoplasm. The cytoplasm of type B cells contains fine, empty vacuoles, resulting in a foamy appearance. The nuclei of both cell types vary from globoid with prominent nucleoli to hyperchromatic.
Clinical and mammographic features, size and site of apocrine carcinomas correspond to other, non-apocrine lesions. Bilaterality is rare.
Apocrine carcinomas of the breast are uncommon and account for maximally 4% of invasive carcinomas (but focally, apocrine cells are found in at least 30% of invasive carcinomas). The prognosis for apocrine duct carcinoma is the same as for non-apocrine duct carcinoma
Abati AD, Kimmel M, Rosen PP (1990)
Apocrine mammary carcinoma. A clinicopathologic study of 72 cases.
Am J Clin Pathol 94: 371-7
Tavassoli FA, Devilee P (Eds.)
World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of the Breast and Female Genital Organs.
IARC Press: Lyon 2003