Parametrium, as the name suggests, is a secondary “breast” outside of the two normal breasts; it is usually located in the anterior axillary area or underarm, and rarely in the chest wall, abdomen, groin, and vulva. It is the beginning of the mammary gland during embryonic development, not degenerated or degenerated incompletely. There are three types of parametrium: 1. with breast tissue and no nipple. 2. 2. There are nipples. No mammary tissue. 3. With nipple and mammary tissue. Parametrial breasts with glandular tissue are affected by the same sex hormones as normal breasts and undergo cyclical changes, resulting in premenstrual swelling and pain, as well as the same common diseases as normal breasts, such as hyperplasia, cysts, fibroadenoma, and parametrial cancer. Of course, if the parametrium is not combined with other diseases, it can be removed. The claim that parametrium is more prone to cancer than normal breast is unfounded. The existence of parametrial breast only increases the site of breast tumor. Clinically, the following cases can be surgically removed: 1. parametrium with benign or malignant tumor; 2. parametrium with severe pain and discomfort; 3. parametrium that affects aesthetics; 4. parametrium that the patient strongly requests to be removed.