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Abnormal Breast Growth in Boys & Girls

Both boys and girls have breast tissue. Normal breast development first appears shortly after birth, and then again at the beginning of puberty. The timing of breast development varies greatly from one person to another and in some girls may not occur until well into the teenage years.

Here's an overview of some of the main breast abnormalities that can occur in children. 

Even Infants Have Breast Tissue!

Baby girls and boys will have a small breast bud that can be felt for a few weeks after they are born. These buds of tissue will become the breast tissue in the adult. In early infancy, they can be prominent because of the effects of the mother's estrogen. As the estrogen levels decrease, so does the prominence.

Nipple discharge in infants

Some babies will have discharge from and redness and swelling around the nipples and most times this will resolve spontaneously. Nipple discharge in an infant is not a reason to stop breastfeeding. Bring up any concerns with your child's doctor.

Extra Nipples

One of the most common breast abnormalities is extra nipples (also called supernumerary nipples) commonly found in the armpits or on the abdomen in both boys and girls. This extra tissue is called polythelia. If it is bothersome, it can be removed – typically with numbing medicine in the doctor's office at an age when the child wants to have it done.

Enlarged Breasts in Boys

Gynecomastia is the presence of enough breast tissue in a male to appear like a breast mound is developing. Gynecomastia can range from prominent breast bud tissue that does not go away to a feminized breast with a mound and rounded nipple. Half of all teenage boys will have tender, prominent tissue in the nipple area during puberty. In most cases this tissue will go down in size over 2-3 years. If it does not, and the boy is otherwise healthy, consideration can be given to removing the tissue surgically.

It is important to note that some substance abuse, including marijuana use, can aggravate the condition. It is not uncommon for teen boys with this abnormality to become self-conscious or bullied. Although breast growth in boys is often hereditary, parents should seek medical attention to look for any hormonal or endocrine imbalance.

Unusually Large Breasts in Girls

Macromastia is the word to describe girls' breasts that are disproportionately large compared to the rest of their body. Large breasts can cause a teen girl not only emotional distress but also physical distress. For example, large breasts can be associated with upper back pain, tingling in the arms, and skin irritation. Socially they can be burdensome as teenagers, and they can restrict athletic participation. Initially, management is with physical therapy, skin care, proper bra fitting, and pain medicine as needed.

Breast reduction surgeries

When breast size causes other problems or interferes with activities, surgery can be considered. Typically, this is two to three years after a girl's menstrual cycles have begun and after shoe size stops changing. Reduction mammoplasty surgeries, as they are called, are typically done as outpatients under general anesthesia. Activities are limited for four to six weeks, but usually girls are back at school by the next week. Surgery of this type may or may not be covered by medical insurance, depending on symptoms, duration, response to physical therapy, body-mass index (BMI), and the amount of tissue that is removed to reduce the breast size.

Breast Asymmetry

Up to 25 percent of teens will have breasts growing in an asymmetrical fashion, and many women reach full maturity with one breast that is larger than the other. Sometimes, this is because they are shaped differently and grow differently. Other times, when a benign mass called a fibroadenoma is present in the breast, it is removed to allow the breast to return to its normal size.

Other cases of asymmetry require consideration about how to balance the breasts. Balancing can be a combination of enlarging one side, reducing one side, or working on both sides. While parents or teens who are concerned should seek a medical evaluation, padded bras can often provide camouflage.

Breast Masses in Children and Teens

Because of heightened awareness of breast cancer, any lump in a child often creates a great deal of anxiety. Breast cancer is extremely rare before the age of 20; less than 0.1% of all breast cancer occurs in children or teens. Ultrasound studies can help determine whether a lump is a cyst that can be drained or a fibroadenoma.

If your child has a breast mass, talk to your child's doctor. He or she can refer you to a pediatric specialist or pediatric plastic surgeon who specializes in caring for growth problems in breast tissue. Breast operations on young girls should be carefully undertaken because of the risk of adverse effects upon future breast development.

All girls should be taught breast self-examination once their breasts are developing and they are going through their menstrual cycles. This should be the beginning of a lifelong habit.

Absence of Breast Development

When a girl does not have breast tissue by the age of 13, her breast development is considered delayed. Although rare, the breast bud may be nonexistent due to a chest wall deformity or failure of the underlying pectoralis muscle to develop properly. Girls with chronic illnesses like Crohn's disease, Turner syndrome, or an eating disorder may also fail to grow buds by the age of 13. See Delayed Puberty in Girls: Information for Parents.

Additional Information:

Last Updated
Section on Plastic Surgery (Copyright © 2015 American Academy of Pediatrics)
The information contained on this Web site should not be used as a substitute for the medical care and advice of your pediatrician. There may be variations in treatment that your pediatrician may recommend based on individual facts and circumstances.
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