Lymphatic ulceration of breast cancer may be caused by local trauma, local infection, tumor necrosis and ulceration. 1. Local trauma: lymphatic ulceration of breast cancer may be caused by local trauma, such as extrusion injury or impact injury, etc., which may be accompanied by the symptoms of bruising of the surrounding skin. 2. Local infection: Breast cancer tumor will be easily affected by external factors, which will lead to local infection, and may cause purulent inflammation, which will lead to lymphatic ulceration of breast cancer, and may be accompanied by purulent secretion, and accompanied by the symptom of bad smell. 3. Tumor necrosis: lymphatic ulceration of breast cancer may be caused by more serious condition, resulting in tumor necrosis in the breast area, and there may be bleeding symptoms, which is usually related to the invasion of tumor cells into lymphatic tissues. After the symptoms of lymphatic ulceration of breast cancer appear, it is recommended to take good care of hygiene to avoid cross-infection and aggravation of the disease, and then actively cooperate with the doctor to carry out regular treatment.