Sometimes the skin of the breast will have a small depression, like a dimple, which we call the “dimple sign”. Sometimes the skin of the breast also has many small dots like orange peel, which is called the “orange peel sign”. How do the “dimple sign” and the “orange peel sign” appear? What does this skin change mean? As we have already mentioned, the mammary glands are located between the superficial and deep layers of the superficial subcutaneous fascia. The superficial fascia extends into the breast tissue to form cords of lobular septa, one end of which is attached to the pectoralis muscle fascia and the other to the skin, anchoring the mammary glands in the subcutaneous tissue of the chest. These fibrous connective tissues that support and hold the breast in place are called the suspensory ligaments of the breast or Cooper’s ligaments. When breast cancer invades the Cooper’s ligament, the ligament shortens and pulls on the skin, causing the skin to sink and the “dimple sign” to appear. Although the “dimple sign” is also the result of tumor invading the skin, it is not always the manifestation of advanced breast cancer. For example, breast cancer occurring in the terminal ducts and glandular epithelium, which is closer to the skin, is more likely to appear this phenomenon, which can be one of the earlier clinical manifestations of breast cancer. When the tumor is small, it causes very mild skin adhesion, which is often neglected because it is very slight. At this time, under good light, gently lift the whole breast with hands, so that the tension of breast skin increases, and gently move the breast lump, and you can see slight skin wrinkling and tiny indentation caused by pulling on the top of the lesion. This early appearance of slight skin adhesions in the breast is often one of the most important bases for identifying benign and malignant breast lumps. When the lymphatic vessels under the skin of the breast are blocked by cancer cells, or when the infiltration of the tumor located in the central area of the breast causes obstruction of the superficial lymphatic return of the breast, the dermis of the skin will be edematous, and due to the close connection between the skin at the hair follicle and the subcutaneous tissues, there will be multiple punctate depressions at the hair follicle, and the pores are clearly defined, which will make the skin have an orange-peel-like appearance, i.e., the “orange-peel sign”. “. The “orange peel sign” formed by skin lymphedema in the breast is a typical manifestation of advanced breast cancer, which indicates that the cancerous tissues of breast cancer have already shown infiltrative growth. Generally speaking, the lump is already very large and the “orange peel sign” is very obvious, so it is not difficult to make a diagnosis based on this.