Fibroadenoma of the breast is a common disease in young women. The cause of its development may be related to the imbalance of the ratio of estradiol to progesterone in the patient’s blood. During pregnancy and lactation, ducts can proliferate and form vesicles both inside and outside the tumor as hormone levels change, leading to rapid growth and even milk production. Conversely, postmenopausal fibroadenomas can degenerate and shrink like the surrounding glands. Fibroadenomas are the leading cause of breast swelling in women under the age of 25. Most fibroadenomas are uncomfortable, and a few are mildly painful. Fibroadenomas can be multiple or solitary, with solitary being more common. Most fibroadenomas are smooth lumps with good mobility. Some fibroadenomas are not clearly demarcated from the surrounding tissue and have limited mobility. More than half of the fibroadenomas will remain the same size or increase in size, and some may disappear or shrink on their own in about two years. The percentage of breast cancer in fibroadenoma is about 0.1%, usually microscopic cancer or microscopic cancer, half of them are lobular carcinoma in situ, and ductal carcinoma in situ and infiltrating carcinoma each account for 1/4. However, diagnosis by physical examination alone is not absolutely reliable. The preferred auxiliary examination is ultrasonography, and mammogram can show high-density shadow with clear boundary, uniform texture and regularity, a few of them have calcification or even ossification, but this calcification shadow is coarse and high density. In principle, the treatment of breast fibroadenoma should be surgical, but due to various reasons, a comprehensive consideration should be made when choosing surgical treatment. For multiple breast fibroadenomas that are scattered and distributed, it is obviously unacceptable to remove them all and cover the breast with incisions. The larger adenomas or suspected masses should be selected for removal, while those typical fibroadenoma masses should be observed. During observation, lesions that are found to be enlarged, or that cannot be excluded from malignancy, or that do not subside after more than two years of observation, may be treated by elective surgery. This kind of adenoma is usually called giant fibroadenoma, which is not different from general fibroadenoma in nature, but is also called multicellular fibroadenoma because of its large number of cells. Rapidly growing fibroadenoma of the breast that develops around the first menstrual period is also called adolescent fibroadenoma. The tumor can reach more than 20 cm and cause changes in the appearance of the breast, but the tumor remains well-defined and does not adhere to the surrounding area. Giant fibroadenoma needs to be differentiated from breast sarcoma in diagnosis. Surgical treatment should be chosen for giant fibroadenoma. Surgery emphasizes complete excision, and the design of the incision, how to remove the tumor completely and maintain the aesthetic appearance of the incision and the normal shape of the breast, is an issue that needs to be carefully considered. Since most patients with breast fibroadenoma are young women, the timing of surgical treatment should be treated separately according to the patient’s specific situation. For patients who are about to get married, it is better to choose the timing of surgery after the wedding period. For patients who wish to have a baby, it is wise to remove the breast mass before pregnancy and avoid surgery during pregnancy or lactation.