The incidence of breast cancer in men was reported to be 0.5/100,000 in 1990 in Shanghai, and the ratio of male to female breast cancer was 1:62. The main factors associated with the development of male breast cancer are the increase in the absolute or relative value of estrogen level and testicular damage. This disease mostly occurs in older men. After the age of 50, the peripheral blood testosterone level starts to decline, coupled with the weakened metabolism of liver function in old age, which increases the estrogen level in the body, thus leading to an imbalance in the ratio of estrogen to androgen, which may be one of the important factors for the occurrence of male breast cancer. Compared with female breast cancer, male breast cancer is characterized by older age of onset, longer medical history, late diagnosis, early metastasis, and relatively poor treatment effect. Clinical manifestations: It is often a painless lump under or around the areola on one or both sides, hard and poorly defined, with common nipple retraction or fixation. Enlarged axillary lymph nodes and supraclavicular lymph nodes are also more common. Male breast cancer should be differentiated from benign breast tumors, especially from male breast enlargement. Many studies have shown that the prognosis of male breast cancer is generally worse than that of female breast cancer. Male breast cancer has more and earlier axillary lymph node metastasis, and distant metastasis is also common. Therefore, to enhance the understanding of male breast cancer, early detection, early diagnosis and early treatment is the key to improve the prognosis of male breast cancer. Male breast cancer, like female breast cancer, has a tendency to run in families or be hereditary. Men should pay attention if they have hard nodes or other abnormalities in their breasts. Please make sure you go to a regular hospital and doctor to avoid delaying the disease and the negative consequences. Since male breast cancer is relatively rare, early diagnosis and treatment is more difficult. Our breast surgery department provides consultation and treatment for male breast disease patients.