Differential diagnosis of breast adenosmooth muscle tumor: 1, fibroma: rich in collagenous matrix, its spindle-shaped cells were arranged in bundles, the nucleus was pointed at both ends, immunohistochemical staining vimentin (+), actin (-); 2, nerve sheath tumor: tumor cells were arranged in a fenestrated shape, the nucleus of the cells was elongated and curved, immunohistochemical staining synaptophysin (+); 3, fibrous histiocytoma: common petal-like arrangement, immunohistochemical staining vimetin (+), macrophage antigen (CDC); 3, fibrous histiocytoma: commonly arranged in a petal-like shape, immunohistochemical staining vimetin (+), macrophage antigen (CDC). Fibrous histiocytoma: common petal-like arrangement, immunohistochemical staining vimetin (+), macrophage antigen (CD68) (+); 4, breast myofibroblastoma: the swelling compresses the surrounding breast tissue to form a pseudo-peritoneum, there is no breast parenchymal structure, characterized by bipolar spindle cells often arranged in short bundles. Breast adenomyoepithelioma: the glandular ducts are single-layered columnar or cubic epithelium, surrounded by obviously proliferated spindle-shaped and polygonal myoepithelial cells, immunohistochemical staining of actin(+), desmin(-); 6. Breast adenosquamous tumors: the ducts are composed of adenoepithelium and myoepithelium, and the boundaries between the myoepithelium and the surrounding spindle-shaped smooth muscle cells are clear, without transition or migration, immunohistochemistry staining actin(+), desmin(-). Transition or migration, immunohistochemical staining actin (+), desmin (+); Masoon staining, blue smooth muscle tissue. Breast adenosmooth muscle tumor is a benign tumor, which can be cured after complete excision of the mass. Mammary gland adenosmooth muscle tumor Mammary gland adenosmooth muscle tumor is a rare benign tumor, which can occur in women aged 25-57 years old. The tumor is usually located in the nipple and areola area, but it can also occur in the breast parenchyma occasionally. Pathological visualization: gray-red unplastic tissue, nodular, with partial envelope and tough texture. Pathological microscopy: the tumor cells are spindle-shaped, with abundant eosinophilic cytoplasm, clear boundary, rod-shaped nuclei, bluntly rounded ends, located in the center of the cells, no nuclear schizophrenia, the tumor cells are arranged in bundles or fenestrations, and there are a small number of mammary tubules composed of columnar or cuboidal epithelium and myoepithelium in between the tumor cells. Immunohistochemistry and special staining: actin (+), desmin (+); Masoon’s trichrome stain, smooth muscle tissue blue. Types: superficial smooth muscle tumor originating from the skin smooth muscle of the areola; angiomyosarcoma originating from the vascular smooth muscle of the mammary gland itself; adenosarcoma originating from the vascular smooth muscle of the mammary gland itself and the glandular epithelium together.