The breast is made up of fatty tissue, connective tissue, and glands. These glands—also called lobes—are where breast milk is made. Milk exits the body through the nipple through ducts called milk ducts.
The size and shape of the breast varies from one woman to another depending on time of the menstrual cycle; for example, before a woman has her period, it is normal for breasts to feel more swollen than normal.
THE LYMPHATIC SYSTEM
The lymphatic system protects us and helps the body fight off infection and disease. This system is made up of a number of ducts called lymphatic vessels, which connect lymph nodes to one another. Circulating within these ducts we can find lymph, which transports the cells whose job it is to destroy the substances that can damage our organism to the lymph nodes.
Often, cancer cells can spread outside the breast and end up invading the lymphatic system. The most common place for these cancer cells to go is the lymph nodes located in the underarm (axillary lymph nodes). Axillary lymph nodes are analyzed to see if there are any cancer cells.
In addition to invading axillary lymph nodes, cancer cells can reach the chain of lymph nodes found in the neck and the middle part of the torso.