Fibroadenomas are noncancerous growths in the breast tissue. They occur most often in women under 30 and may develop in one or both breasts. Their cause is not fully understood, but they are thought to be linked to sensitivity of breast tissue to female sex hormones.
The lumps are painless, round, firm, and movable. They do not usually require treatment, although large lumps that cause discomfort may be removed by surgery. Medical advice should be sought to exclude the possibility of breast cancer