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

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.

Triple-Negative Breast Cancer Histological Subtypes with a Favourable Prognosis

“…Acinic cell carcinoma (ACC) of the breast is a subtype of TNBC, morphologically similar to ACC of the salivary glands ( Figure 1 A). It mainly affects adult women, presenting as a nodule/mass ranging in size from 10 to 52 mm (average 28 mm; summary in Supplementary Table S1 ) [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ].…”

“…ACC was originally described in 1996 [ 16 ], with a limited number of reported cases in the English literature. Foschini et al [ 41 ] listed 45 ACCs with a further 2 cases since reported [ 36 , 37 ]. Some studies include very limited or no follow-up data.…”

Acinic cell carcinoma of the breast: A comprehensive review

“… 0/2 49 Peritoneal metastases/DOD 2 Yu et al 3 (2022) [ 11 ] F/49 F/42 L uiq R uoq 35 30 Solid and microglandular Solid, microglandular and pseudolobular Mammography: Occult cancer. Mammography: Detected during screening 0/3 0/3 4 Waever et al (2021) [ 12 ] F/42 L 60 Solid, microlobular and pseudolobular Ultrasonography: Well-defined, lobulated, solid lesion with characteristics of a fibroadenoma 48 NED 5 Sen et al (2018) [ 13 ] F/41 R uoq 25 Acinar and solid Ultrasonography and mammography: No abnormalities. 0 12 NED 6 Li et al (2017) [ 14 ] F/52 L luq 15 Cystic and cribriform 0/1 3 AW 7 Kim et al 8 (2017) [ 15 ] 9 F/38 F/47 F/60 L L L 0 1a 0 NED NED NED 10 Kawai et al (2016) [ 16 ] F/49 R 35 Solid-trabecular and acinar Mammography: Lobulated mass...…”

Acinic Cell Carcinoma of the Breast: A Case Report and Review of Literature

“…Mammography revealed varieties of interpretations ranging from no abnormalities detected [ 11 ], occult carcinoma [ 15 ], a small oval radiopaque mass [ 16 ], a thickening with microcalcifications [ 17 ], a firm nodular lesion, a well-demarcated mass without microcalcifications to lobulated mass with poorly defined margins, without microcalcification, to a mass with well-defined margins with scattered granular calcifications [ 8 ]. Ultrasonography ranged from no abnormalities detected to a hypoechoic nodule with a smooth surface.…”