Causes of Accessory Breasts and Tips for Removing Them

What is Accessory Breast?

Accessory breast (supernumerary or accessory breast; polymastia) refers to the presence of normal breast tissue in areas other than the breast. The roots of the mammary glands, called milk lines or mammary ridges, are formed around the fourth week of pregnancy while the fetus is still in the womb. The roots of the mammary glands except for the chest area disappear as the fetus grows, so the fetus is born with breasts only in the chest area (The Internet Journal of Surgery, 2007). However, in about 3-6% of the population, the roots of the mammary glands do not degenerate and remain. Since the location of the accessory breasts is the same as that of other mammals, it can be explained by atavism (seeing the presence of two pairs of breasts as a trait of mammals, the ancestors of humans).

Milk lines (blue lines in the left picture) that form in two bands around day 28 in mammalian embryos, and the location where floating breasts usually develop in humans (right picture)

How to distinguish between armpit fat and Accessory breast

Accessory breasts are a type of congenital malformation that occurs from the embryonic stage, so they can occur in both men and women, and can grow larger when estrogen levels increase due to secondary sexual characteristics, pregnancy, childbirth, or hormonal imbalances. The most common area is the armpit. If there is fat protruding near the armpit, or if pain increases with the menstrual cycle, swelling, or lumps can be felt, it is likely accessory breasts. In rare cases, there may be nipples or discharge (breast milk) during pregnancy and childbirth. You can easily distinguish between accessory breasts and armpit fat by visiting a hospital and undergoing an ultrasound examination to determine whether there is mammary tissue.

Armpit accessory breasts

Do you and I have floating breasts?

As explained above, accessory breasts are a rare congenital deformity that occurs in about 5% of the population. But why are there so many people with accessory breasts these days?

If they didn't exist before but suddenly appeared as you got older, or if you don't feel any pain or lumps during your period, it's almost 99% likely due to breast deformation (armpit fat) caused by wearing the wrong underwear. The human body is an organism, so it can be deformed by pressure. The corsets and foot bindings of the past are typical examples.

Body deformed by corset (left) and foot binding (right)

Korea has the highest breast cancer rate among OECD countries, and it is reported that the biggest reason is wearing the wrong bra from childhood. Korean women often do not know the exact size of their breasts (chest circumference based on the underbust circumference and BP point; cup size) and usually wear one or two sizes smaller (The Research J Costume Culture, 2014). In addition, breasts constantly change size depending on menstrual cycle, diet, weight gain, pregnancy, and childbirth, but most people just wear one size. These days, many people wear thick volume pads, but pads, wires, and underwear that are smaller than your body size can compress your body, shift fat, and distort the shape of your breasts. If you think that the fat that bulges out under your armpits is not a symptom of accessory breasts, take a close look. Does the bulging part fit perfectly with the shape of the bra's side belt?

Choosing underwear that doesn't fit you properly can deform your body.

If a bra presses on your chest, it can cause lymphatic circulation problems, which can lead to benign breast tumors, breast cancer, digestive problems, and other secondary diseases. The best thing is to go braless, but it seems that this is still difficult to do in Korea. There are many no-wire bras and bralettes, which are single-layer bras without wires or pads, but the most important thing is to wear underwear that does not press on your chest according to your chest size. Surprisingly, many people wear bras even when they sleep, but please, just take off your bra at home! Your accessory breasts will probably improve within a few months just by changing your underwear.

 

Insurance Coverage for Floating Breast Removal Surgery

If it is confirmed through ultrasound and tissue examination that there is floating breast tissue distributed, there is no other way than to remove the breast tissue and fat through surgery. However, liposuction for cosmetic purposes is not covered by insurance (Korean Ministry of Health and Welfare Notice No. 2017-152), and in the case of removing breast tissue for therapeutic purposes, national health insurance or actual expenses may be applied.