Non-invasive carcinoma: including intraductal carcinoma (cancer cells do not break through the basement membrane of the duct wall), lobular carcinoma in situ (cancer cells do not break through the basement membrane of the terminal milk duct or alveoli) and eczema-like breast cancer of the nipple (those with invasive carcinoma are not included). This type belongs to early stage cancer and has better prognosis. 1.Early invasive carcinoma: including early invasive ductal carcinoma (cancer cells break through the basement membrane of duct wall and infiltrate into the interstitium) and early invasive lobular carcinoma (cancer cells break through the basement membrane of terminal milk ducts or alveoli and infiltrate into the interstitium, but not beyond the range of lobules). This stage is still early and has a better prognosis. 2.Infiltrative special carcinoma: including papillary carcinoma, medullary carcinoma (with large number of lymphocyte infiltration), ductal carcinoma (highly differentiated carcinoma), adenoid cystic carcinoma, mucinous adenocarcinoma, sweat gland-like carcinoma, squamous cell carcinoma and so on. This type generally has higher differentiation and good prognosis. 3.Invasive non-specific carcinoma: including invasive lobular carcinoma, invasive ductal carcinoma, sclerosing carcinoma, medullary carcinoma (without large number of lymphocyte infiltration), simple carcinoma, adenocarcinoma, etc. This type is generally less differentiated and has a worse prognosis than the above types. However, this type is the most common type of breast cancer, accounting for about 70-80% of the cases. 4. Other rare cancers or special types of breast cancer: such as inflammatory breast cancer, which is very rare, develops rapidly and has the worst prognosis. Localized inflammatory skin manifestation is seen, which is limited at the beginning and soon extends to most of the skin of the breast, showing redness, edema, thickening, roughness and increased surface temperature. Another type of eczema-like breast cancer of the nipple is also rare, with low malignancy and slow progression. Itching and burning sensation on the nipples, and later rough, eczema-like skin around the nipples and areola, and then ulcers, sometimes covered with yellowish-brown scaly crust. In some cases, a lump can be found in the areola area.