The incidence of female breast tumors is very high, benign tumors with fibroadenoma as the most, accounting for about 3/4 of benign tumors, followed by intramammary ductal papilloma, accounting for about 1/5 of benign tumors. the vast majority of malignant tumors are breast cancers, and sarcomas are very rare. The majority of malignant tumors are breast cancer, and sarcoma is rare. Male breast tumors are rare, and the incidence rate of male breast cancer is about 1% of female. I. Breast fibroadenoma Causes: The cause of this disease is the abnormal increase in the sensitivity of fibroblasts to estrogen within the lobules, which may be related to the quantity or quality of estrogen receptor contained in the fibroblasts. Estrogen is the stimulus for the development of this disease, so fibroadenoma occurs in the ovarian function stage. Clinical manifestations: This disease is a common breast tumor in women, and the high incidence age is 20-25 years old, followed by 15-20 years old and 25-30 years old. It occurs in the upper outer quadrant of the breast, and about 75% of the cases are solitary, while a few are multiple. Except for the lump, patients often have no obvious symptoms. The lumps increase slowly, and are elastic like a hard rubber ball, with a smooth surface that is easy to push. The menstrual cycle has no effect on the size of the lump. Treatment: Surgical excision is the only effective treatment for fibroadenoma. Since pregnancy can make fibroadenoma increase in size, fibroadenoma found before or after pregnancy should generally be surgically removed. The tumor should be excised together with its envelope as a whole, with a small amount of normal breast tissue wrapped around it as appropriate, and the mass must be routinely examined for pathology. Intramammary duct papilloma Intramammary duct papilloma is mostly seen in menstruating women aged 40-50 years old, 75% of the cases occur in the jugular abdomen near the nipple of the large milk ducts, the tumor body is very small, with the tip and villi, and there are a lot of thin-walled blood vessels, so it is easy to hemorrhage. The papillomas occurring in the small and medium-sized milk ducts are often located in the area around the breast. Clinical characteristics: generally no conscious symptoms, often due to nipple overflow pollution of underwear and attention, the overflow can be bloody, dark brown or yellow liquid. The tumor is small and often not palpable, and occasionally there is a larger lump. Large ductal papilloma, can be in the areola area buckle and the diameter of a few millimeters of small nodules, mostly round, soft, can be pushed, light pressure on this mass, often from the nipple can be spilled bloody fluid. Treatment: Surgery is the mainstay, and the diseased ductal system should be excised for solitary intramammary papilloma. Preoperative need to correctly locate, with finger pressure to determine the mouth of the overflowing milk duct, insert a blunt tip fine needle, can also be injected with methylene blue, along the needle or methylene blue coloring site for radial incision, excision of the milk ducts and the surrounding mammary tissue. Pathologic examination is routinely performed, and radical mastectomy should be performed if there is malignancy. Simple mastectomy is feasible for older patients with active or interstitial epithelial hyperplasia of the milk ducts. Intraductal papilloma is generally benign, and the malignant rate is 6-8%, especially for the papilloma originated from small ducts, we should be alert to the possibility of malignant transformation. Breast sarcoma is a rare malignant tumor, including mesenchymal sarcoma, fibrosarcoma, angiosarcoma and lymphosarcoma of mesodermal connective tissue origin. In addition, there is another kind of tumor different from general sarcoma, which is composed of benign epithelial component and cell-rich mesenchymal component, and it is called lobulated tumor because of the fissures that often appear in its individual specimen, and it can be classified into benign and malignant according to its mesenchymal component and the degree of cell differentiation. The benign ones are called lobular fibroadenomas; the malignant ones are called lobular cystosarcomas, whose epithelial component may show benign hyperplasia, while the mesenchymal component has obvious nuclear division and anomaly. Clinically, it is commonly seen in women over 50 years old, manifested as a breast mass, which may be large in size, but with obvious boundaries, and dilated veins can be seen on the skin surface. The mass is usually not adherent to the skin and can be pushed, except when it invades the pectoral muscle. Axillary lymph node metastasis is rare, and lung, mediastinal and bone metastases are predominant. Simple mastectomy is sufficient for treatment, but if there is pectoral muscle fascia invasion, it should be removed as well. The effect of radiotherapy or chemotherapy is still difficult to evaluate. Breast cancer is one of the most common malignant tumors in women. In China, it accounts for 7-10% of all malignant tumors in the whole body, showing a rising trend year by year. Some big cities report that breast cancer accounts for the first place of female malignant tumors. The etiology of breast cancer is still unclear. it is rare before the age of 20, but the incidence rate increases rapidly after the age of 20, and is higher at the age of 45-50. The incidence rate continues to increase after menopause, which may be related to the increase of estrone content in the elderly. Early age at menarche, late age at menopause, infertility, and age at first full-term delivery are all associated with the development of breast cancer. A history of breast cancer in a first-degree relative is associated with a risk of incidence two to three times that of the general population. The relationship between benign breast diseases and breast cancer is still debated, and most people believe that high epithelial hyperplasia or atypical hyperplasia in the lobules of the breast may be related to the development of breast cancer. In addition, over-nutrition, obesity, and fatty diets can enhance or prolong the stimulation of breast epithelial cells by estrogen, thus increasing the chance of development. The incidence rate of breast cancer in North America and Northern Europe is about 4 times higher than that in Asia, Africa and Latin America, and the incidence rate of breast cancer in the second and third generations of immigrants gradually increases after the residents of low incidence areas migrate to the high incidence areas, suggesting that there is a certain relationship between the environmental factors and lifestyles and the incidence of breast cancer. Clinical manifestations: Early manifestation is the appearance of a painless, solitary small lump in the affected breast, which is often the main symptom that the patient unintentionally discovers and seeks medical treatment. The lump is hard, the surface is not smooth, the boundary with the surrounding tissue is not very clear, and it is not easy to be pushed in the breast. As the tumor increases in size, it may cause localized breast elevation. If the Cooper’s ligament is involved, it can be shortened and cause the skin on the surface of the tumor to be concave, which is the so-called “dimple sign”. Cancer adjacent to the nipple or areola may shorten the milk ducts due to invasion, which may lead the nipple to the side of the cancer, and then the nipple may be flattened, retracted and sunken. If the cancer mass continues to enlarge, if the subcutaneous lymphatic vessels are blocked by cancer cells, it will cause lymphatic return obstruction, dermal edema will appear, and the skin will be “orange peel-like”. Prevention: The cause of breast cancer is still unknown, and it is difficult to propose a definite etiological prevention (primary prevention). However, emphasizing early detection of breast cancer (secondary prevention) and detecting cases through screening will improve the survival rate of breast cancer. However, breast cancer screening is a complex endeavor that requires careful design, implementation plan and follow-up in order to be effective. Currently, mammography is generally considered to be the most effective method of detection. Surgery is one of the main treatments for breast cancer, along with adjuvant chemotherapy, endocrine and radiation therapy, and biologic therapy.