CausesBy Mayo Clinic Staff
Each of your breasts contains lobes of glandular tissue, arranged like petals of a daisy. The lobes are divided into smaller lobules that produce milk during pregnancy and breast-feeding. The supporting tissue that gives the breast its shape is made up of fatty tissue and fibrous connective tissue. Breast cysts develop as a result of fluid accumulation inside the glands in the breasts.
Breast cysts may be defined by their size:
- Microcysts are too small to feel, but may be seen during imaging tests, such as mammography or ultrasound.
- Macrocysts are large enough to be felt and can grow to about 1 to 2 inches (2.5 to 5 centimeters) in diameter. Large breast cysts can put pressure on nearby breast tissue, causing breast pain or discomfort.
Experts don't know what causes breast cysts. They may develop as a result of hormonal changes from monthly menstruation. Some evidence suggests that excess estrogen in your body, which can stimulate the breast tissue, may contribute to breast cysts.
Oct. 08, 2015
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