Overall, nearly half of men may experience the condition at some time in their lives, says Glenn D. Braunstein, MD, chairman of the department of medicine at Cedars-Sinai Medical Center in Los Angeles and the author of an article on the topic in the Sept. 20 issue of The New England Journal of Medicine.
Later in life, in middle age and older adulthood, the condition can also appear or reappear, says Braunstein, who wrote the article to inform doctors about how to diagnose and treat the condition.
During puberty, the condition is even more common, he tells WebMD. "Up to two-thirds of boys will develop gynecomastia during puberty," he says, although some cases will be so mild they go unnoticed.
The good news: Gynecomastia during puberty generally disappears on its own. Later in life, the problem can often be traced to medications or treatments for prostate cancer. Treatment options, including medication and surgery, are very effective.
What Causes Gynecomastia?
Underlying the condition is an imbalance of estrogen and testosterone. When estrogen levels get too high, the breasts can begin to grow. Some breast tissue is more sensitive to estrogen than others, Braunstein tells WebMD.
As the body mass index, a measure of height to weight, increases, so does the chance of gynecomastia, he says. So the heavier the teen or man, the more likely he may get the condition. But "gynecomastia occurs even in normal-weight kids," he says.
Gynecomastia in Puberty
When gynecomastia occurs during puberty, it usually appears at about age 13 or 14, Braunstein says.
And if the enlarged breasts are noticeable, already self-conscious preteens can become embarrassed. "The kids are often socially conscious," he says. "They don't want to take their shirts off. They fear they are becoming like girls."
Depending on how enlarged the breasts are, there can also be tenderness. "[The breasts] can hurt when they are physically active," Braunstein says.
Recently, doctors have found that use of products containing lavender oil or tea tree oil may trigger breast growth in preteen boys, says Braunstein, citing a study published earlier in 2007. The boys who developed the breast growth had been using a lavender oil skin balm, a hair gel with lavender and tea tree oils, or lavender-scented soap and skin lotions. When they stopped using the products, their breasts returned to normal within a few months.
After ruling out other conditions, a pediatrician typically suggests waiting to see if the gynecomastia disappears, Braunstein says, typically telling the patient to return in three months.
"About 95% of the time, this [condition during puberty] will disappear within three to six months," he says.
Another expert, Yong Bao, MD, assistant professor of pediatric endocrinology at the University of Miami Leonard M. Miller School of Medicine, agrees that "tincture of time" often works. The smaller the growth, the more likely it will go away, Bao says. "After the peak of puberty, it usually goes away," he says.
"Most teens do not need any therapy," Braunstein says. But if the breasts are very tender and the patient is bothered by a large degree of growth, doctors may suggest taking tamoxifen, used in breast cancer treatment, Braunstein says. It works by interfering with the activity of estrogen on the breast cells, thus stopping the growth. While tamoxifen is not officially approved for this purpose, it's used "off-label," which is legal. A course of three months of the drug is typical, he says.
About 60% of teens and adults who take tamoxifen have complete regression of the growth, Braunstein says, citing published studies, and about 80% have at least partial regression.
Gynecomastia Later in Life
In older men, an imbalance of hormones is also at the root of gynecomastia, Braunstein says. "In older men, testosterone is down, estrogen is up. There is often an increase in body fat [which makes the condition more likely]."
A doctor should rule out tumors, breast cancer, and other problems, just as in preteens and teens, he says. Certain drugs used for the treatment of prostate cancer, as well as other medications, can lead to excess breast growth in men.
If possible, doctors should switch the medication associated with the breast growth, Braunstein says.
Other options are tamoxifen or surgery such as breast reduction or liposuction to remove the excess tissue.
Treatment May Not Be Needed
"Gynecomastia is a very common problem," Braunstein says. "It's been around a long time." If the teen or man isn't bothered by the problem? There's no reason to treat it, he says, if other problems have been ruled out.
Even if a teen is bothered by the condition, immediate treatment isn't warranted, Bao says. "We always recommend to wait."
Braunstein reports getting consultation fees from companies including Abbott Diagnostics, Esoterix, M&P Pharma, and Novartis -- and research funds from Procter & Gamble and BioSante.