正常的乳腺导管系统由内衬的上皮细胞层和环绕其周围的不连续的肌上皮细胞层构成管腔样结构,任何一种成分的增多或减少都是一种病理性改变。导管周围肌上皮细胞保存完整常被认为是大多数乳腺良性病变和非浸润性上皮 The normal mammary ductal system consists of a lining of the epithelial cell layer and around it around the discontinuous layer of myoepithelial cells constitute the lumen-like structure, any increase or decrease in composition is a pathological change. Peripheral ductal myoepithelial cells are often considered intact as the majority of benign breast lesions and non-invasive epithelium