Premature Thelarche–Natural History and Sex Hormone Secretion in 68 Girls

Abstract

Data obtained during long-term follow-up of 68 girls with premature thelarche were analysed. In 85% onset was before the age of 2 years, in 30.8% being present at birth. In 44.1% there was a regression after 3 2/12 +/- 2 8/12 years (SD). Basal levels of plasma FSH and response to LH-RH were significantly higher than prepubertal controls (1.93 +/- 1.56 vs. 0.8 +/- 0.1 mU/ml and peaks 12.3 +/- 5.4 vs. 7.9 +/- 1.0 mU/ml respectively; p less than 0.001). Twenty-seven of 52 patients tested had increased plasma estradiol and in 27 of 40 patients tested, urocytograms or vaginal smear showed estrogenization. Basal levels of LH and response to LH-RH were prepubertal. The girls with premature thelarche were significantly taller than normal controls of the same age (p less than 0.001). These results suggest that premature thelarche is an incomplete form of precocious sexual development probably due to derangement in the maturation of the hypothalamo-pituitary-gonadal axis which results in a higher than normal secretion of FSH, as well as a defect in the peripheral sensitivity to the sex hormones.

Ultrasonographic and clinical parameters for early differentiation between precocious puberty and premature thelarche

“…The relatively low ratio between the sizes of the PT and PP groups in the present study can be explained by our exclusion of girls younger than 4 years. The increased incidence of PT after age 4 years, following the progressive decrease up to age 4 years, may reflect "intermediate" or "atypical" forms of premature sexual maturation (6,8,35). Unfortunately there is no one parameter that is accurate and sensitive enough to distinguish among the different presentations of premature sexual development.…”

Premature thelarche: identification of clinical and laboratory data for the diagnosis of precocious puberty

“…In the IPT group, the clinical manifestation of breast enlargement usually started before 2 years of age (90.5% of the cases) as has already been observed by others 4,5,7,8 . In the PP group, this age distribution was not seen.…”

“…The PP group had a mean estradiol level slightly higher than normal; however, this difference was not statistically significant in relation to that of the IPT group. This finding emphasizes the low sensitivity of most estradiol immunoassays used recently, and perhaps suggests that the utilization of a biological assay such as hormonal vaginal or urinary cytology, indicating the level of cell estrogenization, would be of greater diagnostic value 5,27 .…”

“…Theories about the cause have become polarized: one confirming the nonprogressive, benign process [2][3][4] and the other suggesting that premature thelarche is a consequence of a defect in the hypothalamic-pituitary-ovarian axis along with an exaggerated peripheral response to sexual hormones 5,6 .…”

Role of Kisspeptine in Regulation of Reproductive Function

“…Патофизиологию ПТ еще предстоит выяснить. Различные ме-ханизмы ответственны за возникновение ПТ, например: повышенная чувствительность тка-ни молочных желез к эстрогенам [105,106], транзиторная выработка эстрогенов фол-ликулярными кистами яичников [105], по-вышенная продукция эстрогенов из пред-шественников в надпочечниках, таких как дегидроэпиандростерона сульфат [107], воз-действие экзогенных эстрогенов [108], повы-шенная активность фермента ароматазы [109], относительное увеличение уровня эстроге-нов, обусловленное повышением содержа-ния глобулина [110], связывающего поло-вые стероиды, временная активация ГГя-оси [111].…”