Annual or biennial mammograms are essential to a woman’s breast health because they detect early signs of cancer or abnormalities. A common abnormality seen on mammogram results is breast asymmetry.

Males and females are both born with breast tissue and mammary glands. Development of those glands — which don’t function in males — and of breast tissue itself usually stops when boys hit puberty.

The breasts lie on top of the chest wall and over the pectoral muscles. They contain glands, lobules, fatty tissue, and other structures. Milk ducts lead to the nipples, which are surrounded by a ...