Cysts are a common type of benign breast lump. These lumps are fluid-filled sacs that develop in the breast. Cysts most often occur in women between the ages of 35 and 50, but can develop at any age. These benign lumps are usually found in both breasts. They often enlarge and become tender and painful just before the menstrual period and may seem to appear overnight.

Cysts can feel either soft or hard. A round, moveable lump, especially one that is tender to touch, suggests a cyst. When close to the surface of the breast, cysts can feel like a large blister, smooth on the outside, but fluid-filled on the inside. However, when they are deeply imbedded in breast tissue, cysts will feel like hard lumps because they are covered with tissue.

Care: Your healthcare provider may identify a lump as a cyst by physical examination, but many providers confirm the diagnosis by ultrasound. A physician may perform a needle aspiration (drawing fluid out), which will both confirm the diagnosis and serve as a treatment by collapsing the cyst. Cysts may return, in which case they are simply drained (aspirated) again.