When breast cancer cells reach the axillary lymph nodes, they can continue to grow, often causing swelling of the lymph nodes in the underarm area. If breast cancer cells have grown in the axillary lymph nodes, they are more likely to have spread to other organs of the body as well. This is why finding out whether breast cancer has spread to axillary lymph nodes is important in selecting the best mode of treatment. Most breast lumps are benign, that is, not cancerous. Most lumps are caused by fibrocystic changes.
Cysts are fluid-filled sacs, and fibrosis refers to connective tissue or scar tissue formation.
Breast swelling and pain can be associated with fibrocystic changes. The breasts may feel nodular, or lumpy, and, sometimes, a clear or slightly cloudy nipple discharge is present. They are not life-threatening. This is a general type of carcinoma that starts in glandular tissues anywhere in the body. There are several subtypes of adenocarcinoma which account for nearly all breast cancers.