Humans evolved from animals, and most animals are multi-breasted. In humans, during fetal life, there are 6-8 pairs of mammary gland primordia along two lines from the axillae on both sides all the way to the groin, and by birth, all but one of the external ones on the front of the chest are degenerated. In a small number of women, the extra breasts do not degenerate or degenerate incompletely (most commonly the axillary or anterior axillary pair, occurring in the abdominal wall, groin, and vulva. It is rare to occur on the face, cheeks, ears, neck, back, arms, and outer thighs), which is called polymastia, vagal breast, extra breast, and is generally referred to as paramecium. It has no normal effect on the organism (it is a wasted organ), with an incidence of about 1% to 6%, and often has a tendency to have a family history. This disease is more common in clinical practice, mostly in adolescent and fertile females, and can also occur in males. Because the parametrial breast is a remnant of incomplete embryonic degeneration, it is not only much smaller than the normal breast, but also mostly underdeveloped. The paramammary gland is also affected by endocrine secretion like the normal breast, and can develop the same diseases as the normal breast, such as inflammation, hyperplasia, cumulus cysts, and benign and malignant tumors. Because of its hidden location, it is easy to be misdiagnosed and mistreated clinically, so it should be taken seriously. What are the symptoms of parametrial gland? 1. Periodic axillary swelling and pain: Most patients feel painful axillary swelling before menstruation, during pregnancy or lactation, and the pain is aggravated when touched, but usually it is not obvious. 2.Local lumps: varying in size, mostly flattened, soft to the touch, with a sense of striae or nodules. Some patients have small nipples and nipple overflow in the axilla or chest, with or without the development of parametrial glands. What kind of parametrial glands need surgery? Depending on the type of parametrial glands, different treatment methods may be used. For the nipple and areola type of parametrium, since there is no glandular tissue, there is no secondary disease or cancer, there are no symptoms, and it does not affect physical activity or aesthetics, it can be observed and does not require treatment. For glandular or complete parametrium, if there is swelling and pain in the armpit with the menstrual cycle, or if there is an increase in the nature of the local lump to be investigated, surgical excision should be considered to avoid secondary lesions and cancer. The anatomy of the paramammary gland is not as clear as that of the normal breast, so there is often a possibility of recurrence after paramastectomy, so the scope of surgery should be designed before surgery so that the excision is sufficient to achieve complete removal. In conclusion, the indications for surgery of the parammary gland are as follows: if the parammary gland is large and affects the appearance and posture, and has a negative psychological impact; if there is hyperplasia or suspected cancer, surgery should be considered for removal. Considering the importance of female breast appearance, the surgical incision should be as small as possible to reduce the damage to normal tissues under the premise of ensuring safety and effectiveness. Asymptomatic and small parametrial breasts can be left untreated. Paramastectomy can be performed on an outpatient or inpatient basis.