has part has part has_part characteristic of part of has modifier abnormal mammary gland epithelium morphology abnormal mammary gland myoepithelium morphology abnormal mammary myoepithelium morphology abnormal mammary MEC morphology abnormal mammary myoepithelial cell morphology any structural anomaly of the outer cell layer of the mammary gland epithelium bilayer which is located basal to the luminal (secretory) cells and adjacent to the basement membrane; basal cells (aka myoepithelial cells) are specialized epithelial cells that express smooth muscle-specific contractile and cytoskeletal properties; in lactating females, milk is produced by luminal cells, secreted into the alveolar lumen and collected in the ducts for expulsion out of the body through the nipple, due to the contractile activity of the basal myoepithelial cells abnormal mammary epithelium basal cell morphology abnormal mammary epithelium basal cell layer morphology MP:0013778 morphology abnormal mammary gland myoepithelium