The precise causes of fibroadenomas are not fully understood. However, their development and behavior are strongly linked to hormonal changes. These benign breast lumps often emerge during periods of significant hormonal activity such as adolescence and pregnancy, and they tend to shrink after menopause. Furthermore, fibroadenomas have been observed to increase in size in women undergoing hormone therapy. These observations collectively suggest that fluctuating hormone levels, particularly estrogen, play a significant role in the formation and growth of fibroadenomas.