Overview — Anatomy of the Breast & Axilla

The breast is composed of breast tissue and a variable amount of fat. Breast tissue is made up of 10-12 ducts, which divide into trees of smaller ducts and end blindly as lobules.

The lobules are composed of secretory cells. During most of a woman’s life, the secretory cells are inactive and the lobules are small. However, in late pregnancy and after a baby is born, the lobules enlarge and the secretory cells begin to produce milk.

Breast cancer can develop from the cells of the ducts (86%) or the cells of the lobules (12%) ref. Few breast cancers develop from cells surrounding the breast tissue such as inflammatory breast cancer and medullary breast cancer,

Click on any of the buttons in interactive module at left to gain an overview of breast anatomy. Requires Flash.