The vast majority are benign breast tumor that may appear at any age,but they are more common in women in their twenties and thirties.These benign lumps,are not related to
breast cancer
and are known to increase in size
and tenderness in relation to the menstrual cycles due to hormonal changes.In many cases fibroadenomas could go away on their own within a few years.
The development of these tumors is probably related to reproductive hormones.