What is premature thelarche?
Thelarche means "the beginning of breast development." Therefore,
if a girl begins to show breast enlargement at an early age (anywhere from
birth to six years), it is called "premature thelarche."
Technically, most cases of early breast enlargement are harmless,
and do not progress significantly. They are not the beginning of (continued)
breast development. They also are not usually associated with the development
of the other physical signs of puberty, e.g., acne, pubic hair, periods,
or rapid growth. Therefore, a better term for this condition is infantile,
or early, "gynecomastia," which only signifies that one or both breasts are
What causes premature thelarche?
Studies of girls with early breast enlargement have not shown elevated
blood levels of estrogen or any other abnormality. Occasionally, an ovarian
cyst (or cysts) may be seen on a pelvic ultrasound, but this condition also
may occur in girls without breast enlargement; therefore, it is not clear
if the cyst(s) are secreting enough estrogen to cause the breast enlargement.
Some physicians believe that the girls are just temporarily more sensitive
to their normal blood levels of estrogen.
Who gets premature thelarche?
There is not one identifiable group of girls who develops early breast
enlargement. However, it is a concern if a male infant or a young boy shows
How does premature thelarche cause disease?
Premature thelarche is not a disease; instead, it is a normal finding
in some young girls or female infants. If there are other signs of puberty,
then a physician should evaluate the child for the causes of early puberty.
What are the common findings?
The common finding is the enlargement of one or both breasts. In simple
premature thelarche, there are no other signs of pubertal development, and
the child is growing at a normal-not an increased-rate.
How is premature thelarche diagnosed?
Most commonly, premature thelarche is diagnosed in a female infant
or a girl up to three years of age. Occasionally, a girl from three to six
years of age will show an enlargement of one or both breasts. However, after
age six, the beginning of breast development is actually the beginning of
puberty; however, it is a very slow form of development. In addition, girls
with early breast development usually do not have early periods.
Typically, the girl has no other signs of puberty, and is growing
at a normal, pre-pubertal growth rate, i.e., about two inches a year. Laboratory
studies are not usually helpful, since they show low (pre-pubertal)
concentrations of estrogen or other hormones that stimulate pubertal development.
An x-ray of the hand shows a picture that is normal for the girl's age, and
not that of an older girl.
How is premature thelarche treated?
Treatment for early breast development is not necessary; however,
the physician and the parents may want to monitor any changes in the girl's
What are the complications?
Usually, there are no complications associated with early breast
development. Since there is a very small chance that the girl is actually
starting puberty, it is recommended that both the physician and the parents
How is premature thelarche prevented?
Premature Thelarche cannot be prevented. Parents should be sensitive
to their children's concerns and encourage communication so as to alleviate
anxiety or fears.