“Breast cancers can start from different parts of the breast.
Most breast cancers begin in the ducts that carry milk to the nipple (ductal cancers). Some start in the glands that make breast milk (lobular cancers). There are also other types of breast cancer that are less common like phyllodes tumor and angio-sarcoma. A small number of cancers start in other tissues in the breast. These cancers are called sarcomas and lymphomas and are not really thought of as breast cancers. Breast cancer can spread when the cancer cells get into the blood or lymph system and are carried to other parts of the body.”
American Cancer Society