Associate breasts, also known as multiple breasts, paronychia, and polydactyly, are not uncommon in clinical practice and refer to one or more breasts other than the normal pair of breasts, also known as excess breasts. Paramastia most often occurs on the upper outer side of the normal breast, i.e., the axillary paramastia, or on the lower inner side of the normal breast, i.e., between the normal breast and the umbilicus. Depending on the degree of development of the paratesticular breasts, they can be categorized into fully developed and incompletely developed types. Fully developed paratesticular breasts are extra breast tissue that is fully developed and affected by estrogen. They are swollen and even slightly painful with the menstrual cycle, and disappear after the menstrual cycle. During pregnancy, the paratesticular breast also swells with breast development; during breastfeeding, milk can be discharged from the paratesticular nipple; after weaning, it can become soft and the mammary gland shrinks. Incompletely developed paratesticular breasts can be characterized by incompletely developed breast tissue without nipple and areola, or only pigmented areola with localized skin thickening as nipple. There are also nipples that exist only in an infantile state without areola, or areolas that are pigmented only without nipple and breast. Those with underdeveloped breast tissue may also experience swelling and pain with menstruation. Those with only areola or only nipple do not. In a few breasts, the paratesticular glands are connected to the normal mammary glands and empty their secretions into the normal mammary glands, but most of the paratesticular glands are not connected. What are the dangers of paratesticular breasts? Not only does the paratesticular breast affect the patient physically and psychologically, but it can also plant a time bomb in the body. On the one hand, paratesticular breasts will affect normal breastfeeding, causing a drop in prolactin in the breasts and affecting the normal secretion of milk; on the other hand, paratesticular breasts, like normal breast tissues, have the risk of developing breast cancer. Associate breasts have the same tissue structure, physiological characteristics and pathological changes as normal breasts, and are also affected by female hormones, presenting swelling and pain during the menstrual cycle, pregnancy or breastfeeding, and a small amount of milk secretion during breastfeeding; some associate breasts do not have nipples, and the secreted milk accumulates due to the impossibility of emptying, and it is easy to be swollen and painful and inflammatory, so as to pus the disorders that the normal breasts might be facing, such as mastitis, lobular hyperplasia of the mammary glands, Breast fibroma, breast cancer, etc., may also occur in the paratits, and the degree of harm is higher than the normal breast. In addition, paratesticular breasts often wear a variety of confusing “garments”, which can easily lead to misdiagnosis. For example, inflammation of the paratesticular breast is mistaken for inflammation of the lymph nodes, or lobular hyperplasia of the paratesticular breast is misdiagnosed as lipoma. Since the former is an inflammation, the treatment principle is more or less the same as that of common inflammation, which is treated with antibiotics; while the latter is mostly a benign lesion, which is not life-threatening. However, if cancer of the paratesticular breast is recognized as an ordinary inflammation, it can lead to serious consequences. Which cases should be treated aggressively? 1.Fully developed paratesticular breasts and incomplete paratesticular breasts: when periodic pain or irregular pain occurs during menstruation, pregnancy or breastfeeding, which obviously affects the health of human body, surgical excision can be considered. 2, large size of the paratesticular breast: if the large size of the paratesticular breast affects the activity and appearance of the upper arm, surgical excision can be performed; if malignant changes are suspected and cannot be differentiated from tuberculosis and other lesions, excision is preferred. 3. Tumor of the secondary breast: all tumors of the secondary breast should be excised, and the normal breast should be excluded from the cancer of the secondary breast; the operation mode is radical mastectomy with excision of the affected secondary breast and excision of the normal ipsilateral breast, and the lymph nodes of the ipsilateral armpit should be dissected routinely. According to the different positions of the secondary breasts, routine postoperative radiotherapy and chemotherapy and regular close observation of the opposite breast. 4.Submilk with nipple and areola only and no gland: because of the rare occurrence of malignant changes, although the patient has symptoms during the breastfeeding period, but the symptoms disappear after the breastfeeding period, it can not be treated by surgery.