NCCN Guidelines for Patients
Breast Cancer – Metastatic (STAGE IV), Version 2.2017
You’ve learned that you have breast
cancer. It’s common to feel shocked and
confused. Part 1 reviews some basics that
may help you learn about breast cancer.
Before learning about breast cancer, it is helpful to
know about breasts. The ring of darker skin on the
outside of the breast is called the areola. The raised
tip in the middle of the areola is called the nipple. In
young girls, there are small ducts under the nipple
that branch into fatty tissue called stroma.
Increases in female hormones during puberty among
girls cause their breasts to change. The stroma
increases, the ducts grow and branch out like tree
limbs, and lobules form at the end of the ducts.
Lobules are small sacs that make breast milk after a
baby is born. Breast milk drains from the millions of
lobules into the ducts that connect to the nipple. See
for a look inside women’s breasts.
Lymph is a clear fluid that gives cells water and
food. It also helps to fight germs. Lymph drains from
breast tissue into lymph vessels within the stroma.
See Figure 2.
Then, it travels to the breast’s lymph
nodes, most of which are in your armpit. Lymph
nodes are small structures that filter and remove
germs from lymph. Nodes near the armpit are called
axillary lymph nodes.
Breast cancer basics