Adenomyoepithelioma of the Breast: A Report of 3 Cases

Abstract

BACKGROUND Breast adenomyoepithelioma is a rare benign breast tumor characterized by a biphasic proliferation of epithelial and myoepithelial cells with variable clinical and diagnostic features. Establishing the diagnosis, determining optimal therapy, and predicting outcome are problematic because of the rarity of this entity. There have been only 2 large series of adenomyoepitheliomas of the breast, reported by Tavassoli and Rosen, which included 27 and 18 patients, respectively. In this report, we present 3 cases of breast adenomyoepithelioma. CASE REPORT Herein, we report 3 cases of breast adenomyoepithelioma. The first case is of a 64-year-old woman who was found to have right breast microcalcification on a screening mammogram. The second case is of a 74-year-old woman who had a right breast mass. These 2 patients were managed by wide local excision. Postoperative microscopic examination revealed adenomyoepithelioma. The third case is of a 49-year-old woman with bilateral saline breast implants who presented with a left breast mass. A core needle biopsy was done and revealed adenomyoepithelioma associated with usual ductal hyperplasia and ductal carcinoma in situ. CONCLUSIONS Breast adenomyoepithelioma is a rare condition that can pose diagnostic challenges due to variable imaging presentations, necessitating percutaneous core biopsy for initial diagnosis. Correct diagnosis is usually possible only on excisional biopsy and confirmed by demonstrating the biphasic nature of the tumor by IHC. Clinical suspicion coupled with utilizing both radiological and histopathological facilities can aid in the accurate diagnosis and management. For the most part, they are considered to be benign, but they can locally recur.

Figure 1.

(A) Mammogram with mediolateral oblique view (MLO) that shows the partially obscured breast mass, denoted by the arrow. (B) Ultrasound confirms the findings of the mammogram in Figure 1A.

Figure 2.

(A) Mammogram with craniocaudal (CC) view demonstrates the poorly defined mass on a background of fatty breast tissue (large arrow) and vascular calcification (small arrow). (B) Ultrasound confirms the findings of the mammogram in Figure 2A.

Figure 3.

(A) H&E ×10; (B) H&E ×20; (C) H&E ×40, showing a biphasic tumor composed mainly of myoepithelial cells surrounding epithelial-lined spaces.

Figure 4.

(A) Demonstrates CK7 in glandular components; (B) CD10 highlights the myoepithelial cells.

Figure 5.

MRI shows a well-defined mass with a concomitant diffuse lesion on the surface of the intact implant on the left breast, denoted by the arrow.