There are several pathological typing methods for breast cancer, and the following pathological types are mostly used in China: 1. Non-invasive carcinoma: including intraductal carcinoma (cancer cells do not break through the basement membrane of duct wall), lobular carcinoma in situ (cancer cells do not break through the basement membrane of terminal milk duct or alveoli) and nipple eczema-like breast cancer (those with invasive carcinoma are not included in this list). This type belongs to early stage cancer and has better prognosis. 2.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 lobular area). This stage is still early and has a better prognosis. 3.Infiltrative special carcinoma: including papillary carcinoma, medullary carcinoma (with large number of lymphocyte infiltration), tubular carcinoma (highly differentiated carcinoma), adenoid cystic carcinoma, mucinous adenocarcinoma, sweat gland-like carcinoma, squamous cell carcinoma, etc. This type is generally more differentiated and has a good prognosis. 4.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. 5. 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 first 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 nipple, later roughness and eczema-like erosion on the skin of the nipple and areola, and then ulceration, sometimes covered with yellowish-brown scaly crust. In some cases, a lump can be found in the areola area.