Intraductal breast cancer is a tumor inside the breast ducts, which mainly manifests as a lump in the areola below the nipple and overflow from the nipple, etc. Metastasis may occur after a long time, such as lymph node metastasis and hematogenous metastasis. Lymph node metastasis usually includes metastasis in the internal lymph nodes of the breast, metastasis in the axillary lymph nodes, metastasis in the subclavian lymph nodes, and even metastasis in the supraclavicular lymph nodes. Hematogenous metastases include lung metastases, bone metastases, and possibly liver metastases, but not only in advanced breast cancer.