Excessive breast development in boys or men is called ‘gynecomastia’ in medical jargon. By disturbing the balance between the female hormone estrogen and the male hormone testosterone, breast gland tissue will grow on one or both sides. The cause differs per age group. In newborns, adolescents and men over 50 years of age, it is usually a natural phenomenon:
– at birth, all babies (both boys and girls) have mammary gland tissue. In the womb, the baby receives estrogen through the placenta and the mother herself. That mammary gland tissue usually disappears spontaneously after the first weeks of life and for the first year of life;
– during (pre) puberty, where the hormones temporarily play, the ratio between estrogens and androgens fluctuates. This can cause breast growth. That is often asymmetric and temporary. At 92%, that mammary gland tissue disappears within 2 years;
– older men make fewer and fewer male hormones and just more estrogens, resulting in breast growth.
In some cases, the swelling of the breast in men has a different cause:
– medication: hormones, certain diuretics, antidepressants, heart medication, stomach medication, hormones for cancer;
– certain diseases (rare): overweight (adipose tissue is converted into estrogens), hormonal disorders (testicular, adrenal, pituitary problems), genetic abnormalities (eg Klinefelter syndrome), liver , kidney and thyroid diseases;
– use of drugs (cannabis and amphetamines);
– use of anabolic steroids ;
– dietary supplements can contain a type of estrogens.
Gynecomastia does not increase the risk of breast cancer.
How often does it occur?
The natural and innocent variant of breast growth in boys and men is common. Between 10 and 15 years old, about 50% of the boys have breast swelling; in the 50-69 age group this is even 72%. Men who receive hormone therapy for cancer have breast formation in more than half of the cases.
How can you recognize it?
Mammary tissue can be recognized by the swelling of one or both breasts. It usually feels like a flat round swelling behind the nipple that is elastic. The swelling can be sensitive or painful. Sometimes you lose fluid from the nipple.
How does your doctor diagnose the condition?
Your doctor examines the breasts : he sees if the swelling is behind the nipple, whether it is soft, hard or elastic, and whether it is on two sides. For example, he can see the difference between gynecomastia, pseudogynaecomastia (growth of adipose tissue) and breast cancer. He checks whether there is fluid coming out of the nipple, whether you have signs of a liver, kidney or thyroid disease, and whether there are hormonal changes or disorders such as changed hair growth, testicles … He asks if there are symptoms such as impotence or a reduced libido. He also checks which medicines, nutritional supplements and drugs you use. If necessary, he can do a blood test to know your hormone status. In some cases a genetic examination is done, usually in a specialized center.