Breast cancer can start in different parts of the breast:
- Lobules: These are the glands that make milk. Cancer starting here is called lobular cancer.
- Ducts: These are small tubes that carry milk to the nipple. Most breast cancers start in these ducts and are called ductal cancers.
- Nipple: Less common, but some cancers start in or around the nipple, such as Paget disease of the breast.
- Stroma: This is the fat and connective tissue around the ducts and lobules. Rare cancer called phyllodes tumor can start here.
- Blood and lymph vessels: Very rare cancers like angiosarcoma can start in these vessels.