Apocrine Carcinoma of Breast: A Case Report with Review of the Literature

Apocrine carcinoma is a very rare form of breast malignancy with an incidence of <1% of female invasive breast carcinoma. We report a case of apocrine carcinoma in a 42-year female with marked adenosis showing apocrine metaplasia and discuss the criteria to diagnose apocrine carcinoma with the emerging concept of androgen receptor positivity with its implication on treatment and management of the patient. 1. Introduction Apocrine carcinoma (AC) is a very rare form of breast malignancy with an incidence of <1% of female invasive breast carcinoma [1], with sparse information available in the literature [2]. Microscopically, apocrine carcinoma demonstrates the same architectural growth pattern as invasive ductal carcinoma, not otherwise specified type (IDC-NOS), differing only in their cytological appearance. Cells are characterized by typical apocrine features, namely, abundant eosinophilic granular cytoplasm and prominent/multiple nucleoli [2]. According to emerging evidence, apocrine carcinomas tend to show estrogen and progesterone receptor negativity and androgen receptor positivity ( / / ); and expression of Gross cystic disease protein fluid-15 (GCDPF-15) [3, 4]. Apocrine carcinomas show a unique response to androgen (fluoxymesterone) administration as a part of treatment [4]. We report a case of invasive apocrine carcinoma of breast as it is a very rare morphological entity. 2. Case-Report A 42-year-old female presented to Surgical OPD of our hospital, with history of lump in the upper inner quadrant of her right breast, for which lumpectomy was done outside and sent for histopathological examination, one month back, histopathology report was given as Invasive ductal carcinoma. There was no history of any nipple retraction and discharge, no significant past history of tuberculosis, and so forth. The patient was afebrile with no abnormality detected on general physical examination. Local examination of the right breast showed a linear scar mark, medial to the nipple. The breast was tender to touch while no mass lesion was felt. Left breast was unremarkable with no axillary lymphadenopathy. In view of the histopathology report, right-sided modified radical mastectomy (MRM) was performed at our hospital and excised specimen was sent for histopathological examination. Right MRM specimen measuring ？cm and weighing 500？gms was grossed. Overlying skin showed a scar mark. Serial cut section revealed a cavity (postlumpectomy); however, no any residual tumor could be appreciated on gross examination, representative bits were processed, and H&E stained tissue