When 68-year-old Grandma Ma took a bath, she suddenly found many small dots of depressions on the skin of her left breast, which looked like an orange peel from a distance, and when she felt it carefully, an egg-sized lump could be touched under the areola of her left breast. The next day, Grandma Ma came to the hospital accompanied by her daughter, and after careful examination, she was clinically diagnosed with left breast cancer. So, how did the “orange peel sign” appear? What does this skin change mean? When the lymphatic ducts under the skin of the breast are blocked by cancer cells, or the tumor in the central area of the breast is infiltrated and causes the obstruction of lymphatic fluid return to the breast, the dermis of the skin will become edematous, and because the skin is closely connected with the subcutaneous tissue at the hair follicle, multiple punctate depressions will appear at the hair follicle and the pores will be clear, making the skin of the breast appear orange peel-like appearance, that is, the “orange peel sign”. “The orange peel sign. Once the “orange peel sign” is formed by lymphedema of the breast skin, it is a typical sign of advanced breast cancer, which means that the cancerous tissues of the breast are already infiltrating. In general, the breast lump is already very large and the lymph nodes in the armpit are probably also enlarged, so you need to be admitted to the hospital immediately for better examination and treatment. The examination includes breast ultrasound, mammogram, breast MRI, serum tumor markers, chest X-ray, abdominal ultrasound, whole body bone imaging and hollow needle aspiration biopsy. If the diagnosis of breast cancer is confirmed by hollow needle aspiration biopsy, preoperative chemotherapy or preoperative endocrine therapy can be given first, and then surgery can be performed after the tumor is reduced.