Fibroadenoma is a common breast tumor in young women, with a peak incidence between the ages of 20 and 30. It is believed to be caused by an abnormal increased sensitivity of the fibrous cells within the lobules to estrogen, possibly related to the quantity or quality of estrogen receptors in these cells. About 75% of fibroadenomas are single, while a minority are multiple. In addition to a lump, patients often have no symptoms. The lump grows slowly and feels like a hard rubber ball with a smooth surface that is easy to move. The size of the lump is not significantly impacted by the menstrual cycle. Surgical removal is currently the only effective treatment for fibroadenoma, and the tumor should be removed intact with its capsule, including a small amount of normal breast tissue around it. Pathological examination should be routinely performed on the lump.