Adenofibroma of the breast is also known as fibroadenoma. The incidence of adenofibroma in the general population has not yet been reported exactly. The age of onset of this disease is 9 to 68 years old, mostly young women around 20 years old. 60% of patients are less than 30 years old. The cause of adenofibroma is unknown. Estrogen may accelerate the growth of adenofibroma in pregnant women and may induce the development of adenofibroma in animals. The significantly higher levels of estrone and estradiol in adenofibroma suggest that the high level of estrogen or the over-sensitivity of the local weaving of the breast to the action of estrogen may be closely related to the development of adenofibroma. Very few adenofibromas of the breast can become malignant, and the fibrous component can become sarcoma, while the glandular epithelial component can become cancer. Clinical manifestations Commonly found in young women. Breast lumps are found unintentionally, mostly without pain, pressure pain and abnormal nipple secretion. The lump is mostly round, oval or flat. The boundary is clear, the surface is smooth, the texture is solid and tough, the mobility is large, and there is no adhesion to the epidermis or pectoral muscle. The size of the swelling can be 0.3-24 cm.2/3 is less than 3 cm. It can be located in all parts of the breast, but mostly in the upper quadrant. Most of them are solitary, but about 10-25% are multiple in one or both mammary glands. It can be multiple at the same time or multiple at different times. The growth rate of the tumor is very slow, with no change for several years or more than 10 years. The menstrual cycle has little effect on the growth of tumor. Some of them have slight swelling and pain during menstruation and slightly increase during pregnancy and lactation. Some of them have slight swelling and pain during menstruation, and slightly increase during pregnancy and lactation. A few of them increase rapidly and are called giant fibroadenoma. Generally, the axillary lymph nodes are not enlarged. If the tumor suddenly increases rapidly after many years of quiescence, with pain and enlargement of axillary lymph nodes, it is highly suspected that malignant transformation has occurred. Individual adenofibromas that occur before menarche can rapidly increase in size a few months or 1-2 years after menarche, mostly >5cm, up to 20cm, and occupy the whole breast, with tense and shiny breast skin, redness, and enlarged varicose veins, resembling malignant tumors. However, it does not adhere to the epidermis and can be pushed without pain, and the axillary lymph nodes are not enlarged. The diagnosis of adenofibroma with the above typical symptoms and signs is not difficult. In a few cases, mammography, B-ultrasound, infrared fluoroscopy, fine needle aspiration cytology can be helpful for diagnosis. Treatment Although breast adenofibroma is a benign tumor, very few of them have the possibility of malignant transformation, and the risk of such malignant transformation is cumulative. Therefore, most authors advocate that once diagnosed, surgical resection should be performed in principle. The results of various drug treatments are not reliable. When the endocrine environment changes rapidly during pregnancy and lactation, some adenofibromas may accelerate their growth, so patients with this disease should have their tumors removed before marriage or at least before pregnancy. If the tumor is found after pregnancy, it can be removed in the third or fourth month of pregnancy. All breast tumor specimens should be routinely sent to pathology department for histological examination to clarify the pathological diagnosis. Adenofibroma can be cured if it is completely removed. Due to the persistence of the endocrine environment that causes the disease, about 10-25% of patients can have multiple occurrences at the same time or successively, and this tendency of multiple occurrences should not be regarded as recurrence.