What is thelarch

What Is Thelarch?: Classification, Early Thelarche Regression, Treatment

The thelarche, popularly known as the mammary button , represents the unilateral or bilateral development of the mammary glands: it is a physiological condition when it occurs in girls between the ages of 10 and 11.

When the thelarca manifests itself during early childhood, we speak of premature thelarca : girls show a moderate enlargement of the breasts already at the age of two – three years, a phenomenon which, however, is not associated either with the development of the nipples , or with areola hyperpigmentation.
In any case, it has been demonstrated that almost half of the girls affected by early thelarca (about 45%) already have appreciable breast hypertrophy at birth.
The thelarche is usually not accompanied by any typical sign of precocious pubertal development , but could be a possible indicator of precocious puberty .

Early Thelarch

According to the studies of some authors, the early thelarca manifests itself in the period between 10 months (in which the placental estrogenic effect is exhausted) and 2 years; for other scholars, on the other hand, the precocious thelarch appears around 2 years of age. While on the one hand there is a lack of uniformity of thought on the exact period of onset of early thelarche, on the other hand there is considerable congruence on the characterization of the disorder. In fact, all the authors agree on the absence of pubic hair and on the lack of structural and volumetric alterations of the large vaginal lips . Furthermore, in the precocious thelarche, the mammary areolas are not hyperpigmented (typical characteristic of puberty). Still, the development of growthappears normal, as does the bone age , which is adequate for the child’s age. From the ultrasound of the ovary of girls affected by thelarca, small cysts often appear which, as we will see later, stimulate the production of hormones .


The thelarche is not a single, standardized form , but comes with many nuances that vary from child to child:

  • The term ” exaggerated premature telarca ” is defined as the telarca characterized not only by premature enlargement of the breast , but also by a slight increase in body growth, accompanied both by a marked response of the FSH hormone to the GnRh test, and by a modest advance in skeletal age (taken from Gynecology from the neonatal period to the developmental age, by Vincenzina Bruni, edited by Bruni-Dei, Metella Dei).
  • The ” isolated precocious thelarca ” outlines a benign condition involving an enlargement of the mammary glands favored by an increase in estrogen and not accompanied by any typical signs of precocious puberty. This type of thelarche provides for a considerable increase in the FSH hormone and the bone age practically coincides with the physiological age . Isolated early telarca tends to regress spontaneously in a few years, therefore it does not require any therapeutic strategies.
  • “ Thelarche variant ”: some authors attribute to this term the clinical picture between premature thelarche and true precocious puberty. Girls affected by Thelarche variant (mixed form of thelarche), show breast enlargement often associated with pseudo-menstrual bleeding: vaginal blood loss occurs independently of gonadotropin pulsatility, and the response to the GnRH test is negative. Mixed thelarche is also a benign form and, if there is no early pubertal development, no type of therapy is required.

Early Thelarche Regression

Statistics have recorded a tendency towards spontaneous regression of the early telarca within 2-3 years from the moment of manifestation; however, when the development of the breasts reaches 5 centimeters in diameter, the regression of the thelarch may slow down (we speak of slow regression).
In other cases studied, the telarca does not regress spontaneously and lasts until puberty: consequently, the telarca is a bright indicator of precocious pubertal development. It is no coincidence that it is estimated that about 10% of girls affected by early thelarca present a predisposition to precocious pubertal development (but once again there is no uniformity in the thinking of scholars).

Thelarche and hormonal variations

Endogenous hormonal hypersecretion seems to be the cause that most predisposes to the thelarche: the level of plasma gonadotropins increases markedly, as do testosterone , estradiol and the hormone FSH . FSH levels appear to be higher than in “healthy” girls of the same age. Precisely the overproduction of the FSH hormone favors the formation of ovarian microcysts that secrete estrogen. In the telarca there is no activation of the luteinizing hormone LH , since only in conjunction with the menarche (first menstruation), the plasma concentration of the LH hormone begins to fluctuate, thus allowing the periodicity of the menstrual cycle.


Although the premature telarca remains, in most cases, a benign condition, it is always essential to control some parameters:

  • Ultrasound of the ovaries : useful for verifying the presence of any cysts, responsible for the stimulation of the follicles (hormonal oscillations);
  • Speed ​​of development: must not be altered;
  • Determination of bone age: it should coincide with the physiological age;
  • Hormonal dosage: FSH hormone increases markedly in girls with thelarca.

Periodic control of these factors is essential, since the thelarche is the first alarm bell of precocious pubertal development.

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