Pediatric premature thelarche occurs when a girl develops breast tissue before the typical age 10-14 years old.
Premature thelarche is not associated with other signs of puberty such as pubic hair or periods. Most are diagnosed before the age of three, but in rare cases, the condition is diagnosed up to the age of six.
Typically, the breast tissue is small (1-inch or less across). It usually occurs on both sides (bilateral), but it can occur on only one side (unilateral). This disorder usually goes away on its own, but it can take a few years to fully disappear.
The main symptoms of premature thelarche is enlarged breast tissue anytime from birth to eight years old. It can be associated with premature puberty.
The cause of premature thelarche is often unknown. The condition may be from sensitivity to estrogen, or it can be a symptom of hormonal imbalances in the adrenal glands or ovaries.