Breast cancer can be categorized in various ways, and the clinical classification commonly used in China is mainly divided into the following four types. The first type is non-invasive carcinoma, including intraductal carcinoma, lobular carcinoma in situ and nipple eczema-like breast cancer, which belongs to the early stage and generally has a better prognosis. The second type is early invasive carcinoma, including early invasive ductal carcinoma and early invasive lobular carcinoma, which belongs to the early stage and has a better prognosis. The third type is invasive specialized carcinoma, including papillary carcinoma, tubular carcinoma, adenoid cystic carcinoma, mucinous adenocarcinoma, sweat gland-like carcinoma, squamous cell carcinoma, and also a kind of medullary carcinoma, but this kind of medullary carcinoma is more special, which is medullary carcinoma accompanied by a large number of lymphocyte infiltration. The fourth type is invasive non-specific carcinoma, including invasive lobular carcinoma, invasive ductal carcinoma, sclerocarcinoma, simple carcinoma, adenocarcinoma, and a medullary carcinoma, but this medullary carcinoma is a medullary carcinoma without a large number of lymphocyte infiltration. In addition, this type is the most common type of breast cancer, which usually accounts for about 80% of the cases, but the prognosis needs to be determined by combining the stage and grading of the disease, as well as the pathological results and immunohistochemical results. The fifth type is other rare cancers, which are relatively uncommon, so they are generally not emphasized as a priority.