Primary acinic cell carcinoma of the breast: A case report with a clinicopathological and immunohistochemical study of a rare breast cancer subtype.

Rajeev Sen,Jashanpreet Kamboj,Sakshi Dahiya,Namita Bhutani

doi:10.1016/j.amsu.2018.09.030

Abstract

Acinic cell carcinoma (ACC) of the breast is extremely rare subtype of triple-negative breast carcinoma and demonstrates extensive morphologic overlap with acinic cell carcinoma of the salivary gland. Herein, we report a case of acinic cell carcinoma of the breast in a 41-year old female presenting with a palpable breast mass along with significant morphological and immunohistochemical findings. Histologically, ACC showed a diffuse glandular infiltrative pattern, with small acinar or glandular structures mixed with solid nests. Both glandular and solid tumor cell populations were strongly positive for lysozyme. The immunohistochemical profile of the tumor was also similar to that of salivary gland acinic cell carcinoma. She received postoperative chemoradiation therapy and has been doing well. As studies on large series are lacking, further studies are needed to elucidate the biological characteristics of acinic cell carcinoma of the breast. In this study, we perform a detailed morphologic and immunohistochemical description of cases of this rare entity and undertake a comprehensive review of all reported cases of breast acinic cell carcinoma in the English language literature to date.

Highlights

Acinic cell carcinoma (AcCC) of breast was first described by Roncaroli et al [1] in 1996 and is recognized as a subtype of triplenegative breast carcinoma (TNBC) in the current World Health Organization classification [2]
The term secretory carcinoma is currently used exclusively to describe breast carcinomas associated with the presence of the ETV6- NTRK3 translocation, it may be said that there is a larger subcategory of breast carcinomas, including rare entities such as AcCC and cystic hypersecretory carcinoma, which recapitulate the prosecretory phenotype of the lactating breast
We report a recent case of breast AcCC diagnosed at our institution, and we review what is currently known about this rare entity in terms of morphology, immunohistochemistry, and molecular pathology

Summary

Introduction

Acinic cell carcinoma (AcCC) of breast was first described by Roncaroli et al [1] in 1996 and is recognized as a subtype of triplenegative breast carcinoma (TNBC) in the current World Health Organization classification [2]. It is one of several rare subtypes of breast carcinoma that demonstrate morphologic overlap with the repertoire of tumors seen in the salivary glands [3]. We report a recent case of breast AcCC diagnosed at our institution, and we review what is currently known about this rare entity in terms of morphology, immunohistochemistry, and molecular pathology. We state that the work has been reported in line with the SCARE criteria [6]

Case report

Discussion

Conclusion