Benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins

This study emphasizes the clinico-pathologic features of 5 cases of mammary benign fibro(stromo)-epithelial lesions sharing as a common morphologic theme the presence of minimally infiltrative margins due to the overgrowth of the stromal component into the surrounding fibro-fatty tissue. Notably the radiological features were suspicious for malignancy in 3 out of 5 cases. The following histologic features were seen in all cases: i) an epithelial component of benign glandular structures exhibiting the morphological spectrum of fibro-cystic disease; ii) a stromal component of bland-looking spindle cell myofibroblasts (vimentin + and α-smooth muscle actin +) set in a variably fibro-myxoid stroma. The present paper contributes to widen the morphological spectrum of the benign fibro-epithelial lesions of the breast, emphasizing the possibility that some cases, exhibiting a predominant myofibroblastic stromal component and minimally infiltrative margins, may be confused with other primary spindle cell mimickers of the breast. Accordingly, we propose the descriptive term "benign myofibroblastic/epithelial lesions of the breast with minimally infiltrative margins" for these previously underrecognized lesions.PMID:34455362 | DOI:10.1016/j.prp.2021.153577
Source: Pathology, Research and Practice - Category: Pathology Authors: Source Type: research