Breast cancer itself is malignant, breast malignant tumors are divided into two kinds: 1, breast cancer; 2, breast sarcoma. Breast tumors are divided into benign tumors and malignant tumors, in order to answer the benign tumors of the breast, malignant tumors, the difference between the two aspects to illustrate, the clinical manifestations as well as signs, benign tumors of the breast generally grow more slowly, the tumor from the beginning of the discovery of the 1cm, 2cm, to the 2-3 years when it may also maintain this level, or have a slow growth. Malignant tumors of the breast, breast cancer generally grows more rapidly, more quickly, may be 2-3 months between the volume can reach a doubling of the change, if in the clinical often encountered in a short period of time the rapid growth of the mass, this often suggests that the tumor is a bad nature, may be cancerous or cancerous characteristics of the tumor changes, invasive ability to enhance. Benign tumors generally have clear boundaries, smooth and regular morphology, like oval or round shape, while malignant tumors like breast cancer generally have unclear boundaries, like starfish or octopus, sticking out a lot of pseudopods to erode the normal surrounding glands, with less clear boundaries and very hard texture, which is the most important feature of malignant tumors in physical signs, and the difference between benign tumors and malignant tumors in pathomorphology. The difference between benign tumors and malignant tumors in pathomorphology is that benign tumors have more regular cells, more uniform and consistent nuclei, and the morphology has the corresponding polar arrangement of the cells, while breast cancer has inconsistent cell size, larger nuclei, denser chromatin, darker cytoplasmic staining, and the surrounding mesenchymal reaction and destruction of the basement membrane, which are the pathological features of the malignant breast cancer.