Inside the breasts are glands that produce and release milk after a woman has a baby. The glands that make the milk are called lobules and the tubes that connect them to the nipple are called ducts. The breast itself is made up of lobules; ducts; and fatty, connective, and lymphatic tissue.
There are several types of breast tumors. Most are benign; that is, they are not cancer. These lumps are often caused by fibrocystic changes. Cysts are fluid-filled sacs, and fibrosis refers to connective tissue or scar tissue formation. Fibrocystic changes can cause breast swelling and pain. The breasts may feel lumpy and sometimes there is a clear or slightly cloudy nipple discharge. Benign breast tumors are abnormal growths, but they do not spread outside of the breast and they are not life-threatening.
How it spreads
When breast cancer spreads outside the breast, cancer cells often are found in the lymph nodes under the arm. Cancer cells may spread beyond the breast such as to other lymph nodes, the bones, liver, or lungs. (Although it is not common, some patients whose underarm lymph nodes are clear of breast cancer may still have cancer cells which have spread to other parts of the body.)
When breast cancer spreads, it is called metastatic breast cancer even though it is found in another part of the body. For example, breast cancer that has spread to the bones is called metastatic breast cancer, not bone cancer.
Inflammatory Breast Cancer
Inflammatory breast cancer is a rare, but very serious, aggressive type of breast cancer. The breast may look red and feel warm. You may see ridges, welts, or hives on your breast; or the skin may look wrinkled. It is sometimes misdiagnosed as a simple infection.
Recurrent Breast Cancer
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the breast, in the soft tissues of the chest (the chest wall), or in another part of the body.