Microglandular adenosis of the breast: A case report and a highlight on main diagnosis and management aspects

Abstract

Microglandular adenosis (MA) is a basically benign–recently borderline-breast disease which mimics well differentiated breast carcinoma clinically and pathologically. The incidence of carcinoma associated with MA reaches up to 27%. In this manuscript, we present a 64-year-old female patient presented with a right breast swelling. Sonomammogram revealed a breast imaging, radiology, and data system IVa right breast architectural distortion. Breast magnetic resonance imaging showed a heterogeneous segmental non mass enhancement in the upper outer quadrant with less extension to lower outer quadrant. Core needle biopsy revealed small uniform glandular structures lined by single layer cuboidal cells with luminal eosinophilic secretions. The cells showed positivity for cytokeratin (CK) and S-100 while P63, smooth muscle actin and CK5/6 were negative. Wide local excision of the mass was done. Microscopic examination revealed proliferation of small glands surrounded by collagenous stroma, some of them infiltrated into the adipose tissue, these glands were lined by a single layer of epithelial cells that lacks a myoepithelial cell layer. They showed positive reaction for S100 and were negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. This led to the diagnosis of breast MA. MA should be considered as a precursor for malignancy rather than an innocent lesion. Adequate surgical excision is recommended.