Polymastia: Definition, Types, Causes, Symptoms, Diagnosis, Treatment and Complications

The extra breast tissue is usually in the torso, although this is not always the case.

Polymastia is a condition in which a person has more than two mammary glands, called accessory breasts, third nipple, or supernumerary breasts.

It is also sometimes called polymastia . The shape of the additional mammary glands can vary, ranging from relatively underdeveloped breast tissue under the skin that may not even be visible externally to an additional fully functional breast or breasts.

This condition is related to but not identical to the more common condition called polythelia, in which a person has supernumerary nipples.

The supernumerary breast of a person with polymastia may or may not have a nipple, while polythelia more commonly refers to additional nipples that are not connected to the tissue of the mammary gland.

The medical condition of polymastia should not be confused with the sponge genus of the same name, which was called polymastia because the numerous structures protruding from its surface were thought to resemble nipples and have no bearing on the human medical condition.

Polymastia is also sometimes called hypermastia , although hypermastia generally refers to a condition in which the breasts grow to an abnormally large size.

Supernumerary third nipples may be smaller compared to normal nipples.

The condition is more prevalent in men than women. In most cases, the additional nipples are smaller and less developed than normal nipples.

When a woman has given birth and her milk “comes in,” her third nipple may be breastfed.

The supernumerary breasts that develop as a result of polymastia appear most often in a region called milk lines, structures present in all mammals of both sexes.

In humans, they are normally invisible and run down both sides of the torso from the armpits to the groin.

This structure is where the nipples and mammary glands of an organism begin to form while it is still a developing embryo and is therefore the most common source of supernumerary breasts produced during embryo formation, although they can occur virtually anywhere. place.

There are cases of people with supernumerary breasts in areas of the torso away from the milk lines, such as the back, but they can also appear on the extremities of a person or in places such as the buttocks, hips or neck.

The extent to which the supernumerary sinus develops or is seen varies, both between different individuals and in the same individual under different conditions.

In some cases of polymastia, the supernumerary breast is fully developed, fully visible, and can even breastfeed like a normal breast.

More commonly, it is not developed to that extent and may appear only as a lump under the skin, in which case it is often mistaken for a tumor.

In many cases, supernumerary breast tissue goes completely unnoticed until a physiological change that affects the breasts, such as the hormonal changes that women undergo during pregnancy and lactation, causes it to swell in size or become inflamed.

Polymastia is more common in women than in men, but it can occur in both genders. It is not dangerous in and of itself, although many people with supernumerary breasts choose to have it surgically removed for appearance or self-esteem reasons.

It is also possible for supernumerary breasts to develop breast cancer in the same way as a normal breast.

Symptoms of polymastia

How is it recognized?

A third or supernumerary nipple is not always easily recognized. They are generally smaller and less developed than normal nipples. As a result, it is easy for a person to think that it could be something else, like a mole.

Some additional nipples are so small that they cannot be recognized as a nipple, although others may look like one.

What does it look like?

It is common for a third or supernumerary nipple to appear on the front of the body between the area that begins in the armpit and passes through the nipples to the genitals. This is known as a person’s “milk line.”

However, third nipples can appear anywhere on the body, including the hands and feet (this is medically known as ectopic supernumerary nipples).

People can often dismiss their third nipple as a mole or birthmark. However, it is possible to tell the difference, as moles or birthmarks tend to be flat and are unlikely to have any bumps or ridges.

The types of polymathy

A category one nipple, or polymastia, may have an areola around it.

There are different types of supernumerary nipples, and these are classified based on specific characteristics such as shape and size and tissue composition.

The different categories are as follows:

Category one (polymast)

An additional category one nipple will have an areola around the outside. An areola is a ring of smooth circular tissue. In this category, the underlying tissue is regular breast tissue; this indicates that a full breast has also developed.

Category of

An additional category two nipple will not have an areola around it, although the presence of breast tissue underneath is still evident.

Category three

An additional category three nipple is where the area has breast tissue present, but no actual nipple has formed.

Category four

One category for extra nipple is where breast tissue has formed underneath, but there is no nipple or areola.

Category five (pseudomamma)

An additional category five nipple has an areola around the nipple area, but instead of breast tissue underneath, there is fatty tissue in its place.

Category six (politelia)

An additional category six nipple is where the nipple appears on its own and there is no areola or breast tissue underneath.

Some third nipples are so small that they look like a birthmark, many of them are also harmless. Learn more about the most common here.


Polymastia develops in the uterus. When an expectant mother is 4 weeks pregnant, the two milk lines of the developing embryo begin to thicken.

Milk lines are made of striated ectoderm tissue and will eventually become part of the baby’s skin.

Two strips of tissue that cross the thorax known as “mammary ridges” recede into the uterus, and in doing so form two regular nipples. However, there are cases where they do not fully recede, which can result in the creation of additional nipples.

Diagnosis of polymastia

Many people can diagnose the condition on their own, as the nipple will look similar to regular nipples and will appear in the milk line. In the case of women, women feel pain in the area with the hormonal changes of menstruation.

However, if a person is unsure, they can make an appointment with their doctor, who can tell if it is a third nipple or something else.

It is also important to see a doctor if the extra nipple causes any discomfort (this may be due to breastfeeding or general pain). If the nipple becomes hard, additional lumps form, or a rash appears in the area, it is important to seek medical attention as soon as possible.

If a person has a third or supernumerary nipple, it is advisable to make regular appointments with their doctor, who will check for signs of abnormal or unusual growths, related to activity in or around the nipple tissue.


They are rarely an indication of an underlying problem, so removing them is usually for cosmetic reasons and not related to health.

However, there are some cases where a third nipple may have an underlying problem that requires medical attention, in which case a doctor may recommend that the nipple be surgically removed and also prescribe other medications to treat the underlying cause.

Removal of a supernumerary nipple generally involves non-invasive outpatient surgery. The surgery is generally quick and causes minimal pain.


Doctor explaining the diagnosis and treatment options to the patient.

In most cases, a third nipple will not cause any health risks, however there are some complications to be aware of.

While rare, there are some cases where an extra nipple can be a sign of a congenital breast defect or a malignant growth or tumor.

The Scaramanga gene is one that can cause an extra nipple to form and can also cause the extra nipple to have breast cancer.

Certain additional types of nipples, such as polythelia (category six), have been linked to various kidney conditions, such as end-stage kidney disease, and may also be associated with kidney cell cancer.

This is why it is important to note any changes or discomfort that a third nipple may cause and to make an appointment with a doctor if there are any concerns.