Pure acinic cell carcinoma of the breast in an 80‐year‐old Japanese woman

Abstract

Acinic cell carcinoma of the breast is an uncommon neoplasm. Since the first case of this rare variant of breast carcinoma was reported in 1996, only 10 cases have been reported in the English-language literature. Reported herein is the first case of primary acinic cell carcinoma of the breast in a Japanese woman. To the naked eye, the tumor appeared well circumscribed and the cut surface was grayish-pink and hemorrhaging. Microscopically, the tumor was predominantly made up of a monotonous proliferation of cells with a finely granular cytoplasm, resembling acinic cells of the parotid gland. Some neoplastic cells had a clear cytoplasm. In spite of extensive sampling, no common histological patterns of breast carcinoma such as in situ and invasive ductal carcinoma were recognized in the present case, indicating that the present case was pure acinic cell carcinoma. In addition, the immunohistochemical profile of this tumor was identical to that of the acinic cell carcinoma of the salivary gland: estrogen receptor, progesterone receptor, HER2 and cytokeratin (CK)20 were negative and amylase and CK7 were positive. The patient has been well for 22 months since the wide local excision of the tumor and no signs of salivary neoplasm are evident to date.

Primary Acinic Cell Carcinoma of the Breast: A Case Report with an Immunohistochemical and Ultrastructural Studies

“…Matoso et al [2] emphasized that breast tumors with salivary gland differentiation originate from a malignant transformation of terminal duct-lobular units with metaplastic changes. Furthermore, the immunohistochemical profile of the tumor reported herein was identical to that of salivary ACC [3,4]. The significance of acinar cell differentiation in breast carcinomas is not clear.…”

Breast carcinoma—rare types: review of the literature

“…A well-defined mass creates a differential diagnosis with MC, intracystic carcinoma and metaplastic carcinoma [48].…”

Primary Acinic Cell Carcinoma of the Breast: A Clinicopathological and Immunohistochemical Study

“…It generally presents as a palpable nodule ranging from 2 to 6 cm in size although 1 case involved a nonpalpable mass that was only discovered by mammography [3]. Several studies have discussed the usefulness of diagnostic imagings for ACC, although their findings have sometimes differed [1, 2, 8–10]. For example, mammography showed a well-defined mass in some cases [1, 8, 10] but no abnormal findings in another [9].…”

“…Several studies have discussed the usefulness of diagnostic imagings for ACC, although their findings have sometimes differed [1, 2, 8–10]. For example, mammography showed a well-defined mass in some cases [1, 8, 10] but no abnormal findings in another [9]. Ultrasonography revealed an intracystic tumor in only male patient yet described [2].…”