Hypothalamic-pituitary-gonadotropic function in girls with premature thelarche

Premature Thelarche: An Updated Review

BACKGROUND

Premature thelarche is the most common pubertal disorder in girls. The condition should be differentiated from central precocious puberty which may result in early epiphyseal fusion and reduced adult height, necessitating treatment.

OBJECTIVES

The purpose of this article is to familiarize physicians with the clinical manifestations of premature thelarche and laboratory tests that may help distinguish premature thelarche from central precocious puberty.

METHODS

A search was conducted in September 2022 in PubMed Clinical Queries using the key term "Premature thelarche". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used to compile the present article.

RESULTS

Premature thelarche denotes isolated breast development before the age of 8 years in girls who do not manifest other signs of pubertal development. The condition is especially prevalent during the first two years of life. The majority of cases of premature thelarche are idiopathic. The condition may result from an unsuppressed hypothalamic-pituitary-gonadal axis in the early years of life, an "overactivation" of the hypothalamic-pituitary axis in early childhood secondary to altered sensitivity to steroids of the hypothalamic receptors controlling sexual maturation, increased circulating free estradiol, increased sensitivity of breast tissue to estrogens, and exposure to exogenous estrogens. The cardinal feature of premature thelarche is breast development which occurs without additional signs of pubertal development in girls under 8 years of age. The enlargement may involve only one breast, both breasts asymmetrically, or both breasts symmetrically. The breast size may fluctuate cyclically. The enlarged breast tissue may be transiently tender. There should be no significant changes in the nipples or areolae and no pubic or axillary hair. The vulva, labia majora, labia minora, and vagina remain prepubertal. Affected girls have a childlike body habitus and do not have mature contours. They are of average height and weight. Growth and osseous maturation, the onset of puberty and menarche, and the pattern of adolescent sexual development remain normal. Most cases of premature thelarche can be diagnosed on clinical grounds. Laboratory tests are seldom indicated. No single test can reliably differentiate premature thelarche from precocious puberty.

CONCLUSION

Premature thelarche is benign, and no therapy is necessary apart from parental reassurance. As enlargement of breasts may be the first sign of central precocious puberty, a prolonged follow- up period every 3 to 6 months with close monitoring of other pubertal events and linear growth is indicated in all instances.

Leptin, ghrelin, nesfatin-1, and orexin-A plasma levels in girls with premature thelarche

PURPOSE

Reducing the mean age of puberty onset in recent years has crucial public health, clinical, and social implications. This study aimed to evaluate the serum levels of appetite-related peptides (leptin, ghrelin, nesfatin-1, and orexin-A) and anthropometric data in girls with premature thelarche (PT).

METHODS

We enrolled 44 girls aged 4-8 years diagnosed with PT and 33 age-matched healthy girls as controls. The demographic data of the girls were obtained using a questionnaire. Anthropometric data were measured and fasting blood samples were collected.

RESULTS

Body weight, height, body mass index (BMI), body fat mass, and basal metabolic rate (BMR) were higher in the PT group than in the control group (p < 0.05). Serum leptin (p < 0.001), nesfatin-1 (p = 0.001), and orxein-A (p < 0.001) levels were significantly higher in the PT group than in healthy controls. However, there were no significant differences in the serum ghrelin levels between the groups (p > 0.05). The results of multivariate logistic regression revealed that serum leptin level (OR (95% CI): 42.0 (10.91, 173.06), p < 0.001), orexin-A (OR (95% CI): 1.14 (1.04, 1.24), p = 0.006), and BMI for age z-score (OR (95% CI): 6.97 (1.47, 33.4), p = 0.014) elevated the risk of incidence of PT at 4-8 girls.

CONCLUSION

These results suggest that in addition to serum leptin levels, serum orexin-A and nesaftin-1 can take part in the initiation of PT. Few studies have investigated the relationship between nesfatin-1 and orexin-A levels and age at onset of puberty; hence, it should be a subject for future studies.

Etiological, Clinical and Biochemical Characteristics of 367 Children with Early Pubertal Development from Thrace Region of Turkey

Background: Appearance of menarche before nine years of age, secondary sex characteristics before 8 in girls and 9 in boys is defined as Precocious Puberty (PP). Objective: The aim of this study was to describe etiologies, clinical findings, and compare anthropometric properties and biochemical characteristics of children with PP. Methods: In this single-centre study, 367 patients of whom medical records were reviewed diagnosed as premature thelarche (PT), premature adrenarche (PA), Central PP (CPP), and peripheral PP (PPP). The diagnosis was based on clinical, laboratory, and radiologic investigations and their follow-up. Results: During six years, 349 girls (%95,1) and 18 boys (%4,9) diagnosed as PP. The most common etiologies were CPP;127 (%34,6), PT;117 (%31,9), PA;112(%30,5) and PPP 11(%3), respectively. CPP group had significantly higher levels of height, weight, body mass index (BMI) and obesity/overweight incidence, estradiol (E2), basal luteinizing hormone (LH), peak LH, and peak LH/ follicle-stimulating hormone (FSH) ratio and higher uterine dimensions compared to the PT group while the PT group had significantly higher levels of peak FSH compared to the CPP group (p

Differential analysis of nutrient intake, insulin resistance and lipid profiles between healthy and premature thelarche Chinese girls

Background

Premature thelarche (PT) is a benevolent ailment affecting young girls. Multiple factors are reported to correlate with this condition, but the mechanisms responsible for the onset of PT have not yet been fully investigated. This study aimed to evaluate the relationship of nutrient intake, insulin resistance and lipid profile with PT.

Methods

Two hundred sixty-three girls with PT, and 222 healthy girls of similar age were enrolled into this study. Their demographics, Tanner stage of breast development, nutrient intake, insulin resistance and lipid profiles were compared.

Results

Daily protein and fat intakes, insulin resistance parameters including serum insulin-like growth factor 1, fasting glucose to insulin ratio, quantitative insulin check index and homeostasis model of assessment of insulin resistance, as well as serum levels of triacylglycerol, total cholesterol and low-density lipoprotein, were all significantly altered in PT patients. Daily intake of energy and carbohydrate, and serum level of high-density lipoprotein protein were statistically indistinguishable between PT patients and healthy controls.

Conclusion

Chinese girls with PT are potentially insulin resistant, which warrants more clinical attention and further investigation to address the underlying etiology.

Premature Thelarche

Premature thelarche is a benign condition that affects young girls and may be interpreted as a sign of central precocious puberty (CPP). Parental concern is common when breast development is noted in a young girl. It is important to differentiate premature thelarche from CPP, as the latter is a more serious disorder that may affect final adult height and menarcheal age, and may have psychological implications as well. Distinguishing between the two conditions clinically may help the patients avoid unnecessary testing. Pediatricians can play a pivotal role by providing reassurance to families and helping alleviate parental anxiety. This article reviews the clinical presentation of premature thelarche, its usual course, and implications. [Pediatr Ann. 2018;47(1):e12-e15.].

No association between estrogen receptor gene polymorphisms and premature thelarche in girls

OBJECTIVE

Premature thelarche (PT) is a benign, nonprogressive condition defined as isolated breast development. While the pathophysiology of PT remains unclear, increased sensitivity to estrogen may cause PT. The aim of this study was to investigate the association between polymorphisms in the estrogen receptor alpha (ERα) gene and PT in girls.

METHODS

In this case-control study, we examined 96 girls referred for early breast development (before the age of 8 years). The control group included healthy Korean females with normal pubertal progression. Anthropometric and hormonal parameters were measured and PvuII and XbaI ERα gene polymorphisms were evaluated by PCR. Out of the 96 girls, all coding exon and exon-intron boundaries of ERα were sequenced from the DNA of 46 girls.

RESULTS

There was no significant difference in the distribution of PvuII and XbaI polymorphisms between patients and controls. However, the carriers of XbaI polymorphisms had more advanced Tanner stage than did the non-carriers. Also, four ERα gene polymorphisms were previously identified, but these polymorphisms had no clinical significance.

CONCLUSION

No association was found between the ERα gene polymorphisms and PT in girls. However, XbaI polymorphisms may contribute to early breast budding.

Serum nesfatin-1 and leptin levels in non-obese girls with premature thelarche

AIM

We aimed to investigate serum nesfatin-1 level in girls with premature thelarche (PT) and its relationship with anthropometric parameters and leptin, which are involved in the initiation of pubertal process.

SUBJECTS-METHODS

Non-obese girls who presented with the complaint of early (2-8 years) and isolated breast development were included in the study. The control group consisted of age-matched healthy prepubertal girls. Auxological measurements were performed in all subjects. Gonadotropin-releasing hormone (GnRH) stimulation test and bone age assessment were conducted in subjects with early breast development. Girls with a bone age/chronologic age ratio <1.2 and a peak luteinizing hormone (LH) response to GnRH stimulation <5 mIU/L were included in the PT group.

RESULTS

The study included 22 non-obese girls with PT and 24 healthy prepubertal controls. Body mass index (BMI), BMI-standard deviation score (SDS) and height SDS were similar between the groups (p > 0.05). Serum leptin and nesfatin-1 levels were found significantly higher in the PT group compared to controls (p < 0.05). No correlation was detected between nesfatin-1 and basal LH, basal follicle stimulating hormone (FSH), stimulated peak LH, peak FSH, leptin levels and anthropometric parameters in the PT group (p > 0.05).

CONCLUSION

Results of the present study showed that serum nesfatin-1 and leptin levels are significantly higher in girls with PT than in prepubertal controls. This finding suggests that similar to leptin, nesfatin-1 may also have a central or peripheral role in the initiation of pubertal process and may be related to PT pathogenesis.

Is premature thelarche in the first two years of life transient?

OBJECTIVE

Premature thelarche (PT) refers to isolated onset of thelarche in girls younger than 8 years of age. Most cases have an onset under 2 years of age. We aimed to establish whether the onset of thelarche under 2 years of age certifies a transient clinical course, as suggested by several authors.

METHODS

Sixty-seven girls with an onset of PT under 2 years of age were classified as having early puberty (EP) or classical PT after one year of follow-up. Progression of pubertal findings or absolute growth velocity (GV) standard deviation score (SDS) above 1 SDS constituted the criteria for a diagnosis of EP.

RESULTS

Twenty (29.1%) girls were classified as having EP and 47 (70.1%) girls as having classical PT. Basal serum luteinizing hormone (LH; ICMA) values at a cut-off level of 0.3 IU/L were found to be a significant risk factor for having an atypical course [OR=7.8; CI (95%): 2.04-30.4, p=0.003].

CONCLUSIONS

Onset of thelarche under 2 years of age does not assure a transient course in a remarkable proportion of girls with PT. An absolute GV value of >1 SDS or a basal LH level ≥0.3 IU/L are suggested as indicators for close follow-up.

Premature thelarche in Taiwanese girls

This study was conducted to understand the clinical features and natural course of Taiwanese girls with premature thelarche (PT). The medical records of 91 Taiwanese girls with PT who were diagnosed younger than six and have been regularly followed up for more than two years were reviewed. For comparison, GnRH test was also done in 25 girls with central precocious puberty (CPP) and 10 normal prepubertal girls. The age of onset of these patients was 1.5 +/- 1.6 years and 79% of them developed PT before the age of two. Girls with PT had intermediate degree of hypothalamic-pituitary-ovarian activity between prepuberty and CPP with FSH-predominant response to GnRH stimulation. 87% of patients have complete regression of breast development during 3.8 +/- 2.5 years' follow-up but 19% of them have progressed to CPP during follow-up. We conclude that Taiwanese girls with PT more often developed within the first two years of life. Activation of hypothalamic-pituitary-gonadal axis with predominant FSH activity during infancy may contribute to its development. In addition, PT is not always a benign self-limited condition, and clinicians should be cautious about pubertal development of these patients.

Premature thelarche: clinical and laboratorial assessment by immunochemiluminescent assay

In order to establish cut-off limits and to distinguish isolated premature thelarche (IPT) from precocious puberty (PP), we evaluated data from 79 girls with premature thelarche, comparing basal and stimulated LH and FSH serum concentrations with those from 91 healthy girls. A GnRH stimulation test was performed in 10 normal girls and in 42 with premature thelarche. Comparison among groups was performed by Kruskal-Wallis and Dunns tests. LH values were significantly greater in girls with IPT than in control groups. Basal gonadotropin concentrations were higher in patients with PP than in controls, but not different from patients with IPT. Peak LH levels after GnRH stimulation distinguished those two groups, with a cut-off value of 4.0 IU/L, but still with minimal overlap. In conclusion, a girl with premature thelarche and LH peak value above 4.5 IU/L has, indeed, PP, but values between 3.5 and 4.5 IU/L point to careful follow-up.

[High intake of phytoestrogens and precocious thelarche: case report with a possible correlation]

Precocious thelarche is the breast development before 8 years of age with two peaks of incidence during the first two years of life and after 6 years of age. A 4.75-year-old girl presented with thelarche associated to an excessive intake of phytoestrogens (phye). Tanner development B2P1-2, hormonal levels and pelvic US were compatible with peripheral precocious puberty. During follow-up, a daily intake of soy-based foods was observed (> 40 mg phye/day). Soy is rich in phytoestrogens, mainly genistein and daidzein. Although phye are less strong than estradiol, its concentration could be from 13,000 to 22,000 times stronger in children fed only by soy-based formulas. Parents were advised and soy intake was reduced to once a week. Progression of pubertal development ceased at B2-3P1. The patient, now 8.66 years old, keeps growing with similar bone and chronological ages. Some questions related to industrial food security, mainly the soy-based food, remain without precise answer. Although it is well known the entity of non-progressive precocious puberty and premature thelarche, pubertal development in this case was strongly related to excessive daily intake of soy and other phye-rich food that could trigger puberty as endocrine disruptor.

Evidence for increased ovarian follicular activity in girls with premature thelarche

OBJECTIVE

Inhibin B is produced by granulosa cells in small antral follicles, under the influence of FSH, and has a paracrine role in oestradiol synthesis. To test the hypothesis that premature thelarche is associated with increased FSH-driven follicular development, we measured inhibin B and FSH in girls with premature thelarche, girls with central precocious puberty (CPP) and controls matched either for age or breast stage.

PATIENTS

Blood samples were collected from 11 girls with premature thelarche (breast stage 2, aged 0.4-5.6 years), 11 prepubertal controls age-matched to the thelarche girls (0.5-5.4 years), 13 girls with CPP (breast stage 2, 3.9-8.2 years) and nine normal pubertal controls (breast stage 2, 9.0-13.2 years).

MEASUREMENTS

Dimeric inhibin B was measured in plasma by double-antibody enzyme-linked immunoassay and FSH by immunoradiometric assay. Pelvic ultrasonography was performed on all girls with CPP and 10/11 girls with premature thelarche.

RESULTS

Seven of the 13 girls with CPP and three of the eight girls with premature thelarche whose ovaries could be visualized had visibly nonhomogeneous ovarian structure on ultrasonography. Girls with premature thelarche had inhibin B and FSH concentrations higher than those in their age-matched controls (P < 0.01 and P < 0.05, respectively), and similar to those observed in girls with CPP and normal pubertal controls matched for breast stage. In thelarche girls, as in precocious puberty girls and normal pubertal controls, inhibin B and FSH were positively related (rs = 0.54-0.61).

CONCLUSIONS

This study provides further evidence that premature thelarche is associated with enhanced follicular development, similar to that which occurs in early puberty, probably under the influence of FSH.

Diagnostic utility of a low-dose gonadotropin-releasing hormone test in the context of puberty disorders

OBJECTIVES

The 10-microg gonadotropin-releasing hormone (GnRH) test assesses pituitary gonadotroph responsiveness, whereas the 100-microg dose assesses maximal secretory capacity. Our aims were to establish normative data for the low-dose test in children and to evaluate the test in diagnosing common pubertal disorders.

METHODS

We retrospectively classified 107 children who underwent 10-microg GnRH tests into normal prepubertal (20 boys, 10 girls), normal early pubertal (10 boys, 16 girls), constitutional delay of puberty (CDP, 13 prepubertal boys >12 years), hypogonadotropic hypogonadism (HH, 5 prepubertal boys >12 years), central precocious puberty (CPP, 19 girls) or premature thelarche/variant (13 girls).

RESULTS

Peak LH response was higher in prepubertal boys >12 years compared with younger boys (p < 0.01) but showed no further change in early puberty. CDP boys had LH responses similar to prepubertal boys >12 years. HH boys showed an absent LH response which diagnosed HH with 100% sensitivity and 96% specificity. Thelarche girls had LH:FSH peak ratios lower than normal prepubertal (p = 0.001), pubertal (p < 0.05) or CPP (p = 0.001) girls.

CONCLUSIONS

We have established normative values for the low-dose GnRH test in children. The test successfully differentiated HH from CDP in boys, and contributed to the differential diagnosis of CPP and premature thelarche in girls.

Estrogen levels in girls with premature thelarche compared with normal prepubertal girls as determined by an ultrasensitive recombinant cell bioassay

OBJECTIVE

Estradiol levels in girls with premature thelarche have not previously been well defined because of the lack of adequate sensitivity of previously available estradiol assays. The ultrasensitive recombinant cell bioassay for estradiol has made the study of estradiol levels in premature thelarche possible. We hypothesized that girls with premature thelarche have higher estradiol levels than normal prepubertal girls.

STUDY DESIGN

We used an ultrasensitive recombinant cell bioassay to study estradiol levels in 20 girls with premature thelarche and 15 normal prepubertal girls less than 3 years of age. The 2 groups were compared by Student t test.

RESULTS

Estradiol levels were significantly greater in the girls with premature thelarche (8.4 4. 5 pmol/L estradiol equivalents) than in the normal prepubertal girls (3.3 3.5 pmol/L estradiol equivalents; P <.01). The estradiol level was not significantly correlated with age, height, weight, body mass index, age at onset of thelarche, or the presence or absence of ovarian cysts.

CONCLUSION

Girls with premature thelarche have significantly higher estradiol levels than normal prepubertal girls. This is consistent with the hypothesis that the mechanism of premature thelarche involves increased estradiol levels rather than increased sensitivity of breast tissue to normal estradiol levels.

Cytologic findings from a nipple discharge in an infant with premature telarche

Premature telarche is a condition of isolated unilateral or bilateral breast development without additional signs of sexual maturation in girls primarily under 2 yr of age presumably occurring as a response to hormonal stimulation by estrogens. Prior reports concerning pathologic findings in premature telarche have been scarce. We report the cytologic findings from a nipple discharge in a 10-mo-old girl with unilateral breast enlargement due to premature telarche. The discharge showed an increased number of clusters of breast ductal epithelium, with a few in a papillary configuration. There was a moderate degree of nuclear irregularity in the epithelial cells, but no significant nuclear overlapping. No atypical single cells were present, and a rare myoepithelial cell was noted. These cytologic findings are in accord with a prior study describing the histology in three cases of premature telarche.

Precocious puberty

Puberty occurring before the age of 8 years in girls and 9 years in boys in considered precocious. The numerous causes of precocity can be classified as central or peripheral. Central or true precocious puberty (CPP) is due to premature activation of the hypothalamopituitary-gonadal axis and is isosexual. Peripheral or pseudoprecocious puberty (PPP) results from the production of sex steroids independent of the H-P-G axis and may be isosexual or heterosexual. CPP is the most common form of precocity involving more than 50% of children and is much more common in girls than boys. CPP is more common between 4 and 8 years. A peak serum LH levels > 10 iu/l following GnRH stimulation is the absolute evidence of CPP. Serum IGF-I levels are predictive of the outcome. Availability of CT and MRI has helped to determine the cause of CPP in most cases. Hypothalamic hamartoma is the most common tumour causing CPP especially in boys. Adrenal causes, particularly CAH, are the commonest cause of PPP in boys whereas ovarian causes are more likely in girls. Long acting GnRH analogues provide a safe and effective form of treatment of CPP.

A comparison of patients with premature thelarche and idiopathic true precocious puberty in the initial stage of illness

A comparative study of patients with premature thelarche and patients with idiopathic true precocious puberty was conducted. The age at the first visit tended to be lower for those with precocious puberty. In comparison with normative data for children, the frequency of low birthweight and small for date (SFD) status was greater in the 55 patients with premature thelarche, but SFD was also frequent in the 18 patients with precocious puberty. The height, weight and Kaup's index were all within the normal range for these two groups. The ratios for bone age/chronologic age and bone age/height age tended to be high in both groups. In the patients with premature thelarche, the blood luteinizing hormone (LH) level showed a normal response, and the blood follicle stimulating hormone (FSH) level a hyper-response, to stimulation with luteinizing hormone-releasing hormone (LH-RH). In contrast, both the blood LH and FSH levels showed a normal response to LH-RH stimulation in most of the patients with precocious puberty, and a hyper-response was rare among them. Although the blood estradiol (E2) level was higher in patients with precocious puberty than in those with premature thelarche, about 50% and 90% of the patients in the respective groups had normal levels. These results suggest that normal responses of blood LH and excessive responses of blood FSH to LH-RH loading may be useful in some patients for diagnosing premature thelarche at an early stage.

Premature thelarche: a long-term follow-up

The differentiation between premature thelarche and idiopathic central precocious puberty is essential for both long-term prognosis and therapeutic approach but, until now, there have been insufficient data to predict the future of the girls with premature thelarche. We studied 46 girls with premature thelarche longitudinally. The girls were subdivided into two groups according to the time of onset of thelarche: Group A consisted of 26 girls who presented thelarche before the second year of life (mean +/- SD 14.7 +/- 5.2 months) and Group B contained 20 girls who showed breast enlargement after the second year of life (5.7 +/- 3.1 years). The mean basal follicle-stimulating hormone (FSH) level of the patients as a whole was significantly higher than normal values (2.1 +/- 0.05 vs. 0.7 +/- 0.9 mIU/ml, p < 0.01) and the luteinizing hormone (LH) level was not significantly different from that in healthy control subjects (0.8 +/- 0.6 vs. 0.6 +/- 0.7 mIU/ml). After gonadotropin-releasing hormone test the FSH response was significantly higher than normal prepubertal values (12.9 +/- 2.1 vs. 3.9 +/- 2.9 mIU/ml, p < 0.001) whereas the LH response did not differ significantly (1.8 +/- 0.6 vs. 1.7 +/- 0.9 mIU/ml). After a follow-up time ranging from 5.1 to 7.8 years (mean +/- SD 5.9 +/- 1.9) we observed a greater percentage of disappearance in the girls in Group A than in those in Group B. The present data show that the percentage of girls who developed precocious puberty was significantly higher when they presented thelarche after the age of 2 years than before; the age of onset of thelarche can be useful to distinguish patients at risk of progressing towards precocious puberty.

Pelvic ultrasonography: early differentiation between isolated premature thelarche and central precocious puberty

We examined 55 girls with isolated premature thelarche between the ages of 0.3 and 7.4 years (group A), 20 children with central precocious puberty between 2.1 and 7.7 years of age and 101 age-matched controls. The children with precocious puberty were divided according to distribution of pubic hair into group B (Tanner stages PH1, B2-3; n = 11), representing an early stage of the disorder, and group C (stages PH2-3, B3-4; n = 9), representing an advanced stage. Uterine and ovarian volumes were measured sonographically, peak serum levels of luteinizing hormone and follicle-stimulating hormone were determined after intravenous administration of luteinizing hormone-releasing hormone. The mean uterine and ovarian volumes were significantly greater in children with precocious puberty than in controls (group B: uterine volume: 3.8 +/- 2.0 ml vs 0.9 +/- 0.3 ml for controls, P < 0.001; ovarian volume: 2.2 +/- 1.3 ml vs 0.6 +/- 0.2 ml for controls, P < 0.01; group C: uterine volume: 8.0 +/- 4.4 ml vs 1.0 +/- 0.3 ml for controls, P < 0.01; ovarian volume; 2.6 +/- 1.3 ml vs 0.4 +/- 0.1 ml, P < 0.01). No significant differences were found between children with premature thelarche and the control group. As a diagnostic method for the early detection of central precocious puberty, ultrasound measurement of uterine volume had a sensitivity and specificity of 100% (cut-off value, 1.8 ml), while ultrasound determination of ovarian volume had a sensitivity of 82% and a specificity of 95% (cut-off value, 1.2 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Progression of premature thelarche to central precocious puberty

To evaluate whether girls with premature thelarche progress to central precocious puberty (CPP) and to analyze their clinical and hormonal characteristics, we retrospectively examined 100 girls with premature thelarche who were followed for several years. Fourteen of the patients with characteristics diagnostic of premature thelarche (isolated breast development before age 8 years, bone age advancement within 2 SD of normal, normal growth velocity, follicle-stimulating hormone-predominant response to luteinizing hormone-releasing hormone) progressed during follow-up to precocious or early central puberty (progressive breast size increase, bone age acceleration, and significant decrease in predicted adult height). The chronologic age of this group of 14 girls was 5.1 +/- 2.0 years at the onset of premature thelarche and 7.8 +/- 0.6 years (mean +/- SD) after progression to central early or precocious puberty. Pelvic ultrasonography showed significant differences in measurements between the time of diagnosis of premature thelarche and progression to CPP. Nine of these patients required treatment, three with cyproterone acetate and six with luteinizing hormone-releasing hormone analogs, and all responded as expected for classic CPP. At baseline evaluation, no clinical or hormonal characteristics could be established that separated the 14 children who progressed to precocious or early puberty from the 86 girls who did not. We conclude that premature thelarche is not always a self-limited condition and may sometimes accelerate the timing of puberty.

High serum sex hormone-binding globulin (SHBG) in premature thelarche

OBJECTIVE

We determined serum sex hormone-binding globulin (SHBG), serum dehydroepiandrosterone sulphate, serum oestradiol and serum testosterone and its fractions in girls with premature thelarche.

DESIGN

Blood was drawn from girls with recently diagnosed (3-12 weeks) premature thelarche. Serum was kept frozen for at least one year before hormonal determination to exclude precocious puberty by clinical evaluation.

PATIENTS

Seventeen girls with premature thelarche aged 0.83-7.16 years were studied, and compared with a group of 22 normal prepubertal girls.

MEASUREMENTS

SHBG was measured by saturation analysis and serum dehydroepiandrosterone sulphate, serum total oestradiol and serum total testosterone were determined by radioimmunoassay. Non-SHBG-bound testosterone and free testosterone were calculated from an equation derived from the law of mass action.

RESULTS

Median serum SHBG in premature thelarche was 137 nmol/l (range 64-221), significantly higher than in normal controls, 93.7 (32-172) (P < 0.05) non-parametric test of medians. Serum SHBG decreased significantly with age in controls but not in premature thelarche. No difference was found in serum dehydroepiandrosterone sulphate. Median serum total testosterone (0.34 nmol/l, 0.17-0.97), median serum non-SHBG-bound testosterone (0.04 nmol/l, 0.02-0.10) and median free testosterone (2.2 pmol/l, 1.0-4.5) were significantly lower in premature thelarche than in control (P < 0.001).

CONCLUSIONS

Serum SHBG is high and bioavailable T is low in girls with premature thelarche. This might alter the oestrogen/androgen ratio in the breast.

Prognostic signs in the evolution of premature thelarche by discriminant analysis

Since premature thelarche (PT) can be a first sign of precocious puberty (PP), the aim of our study was to identify simple items in the course of the first 6 months of follow-up that could help predict if PT would evolve to PP. Thirty-two girls with PT were studied. First evaluation included bone age (BA), basal estradiol, FSH, LH and prolactin. GnRH was performed in 15 subjects and BA was checked at 6 month intervals in 30. Based on clinical outcome after a mean follow-up of 33.4 +/- 16.5 (SD) months, patients were divided into 2 groups: Group I (G-I) included subjects whose breast development either remained unchanged, increased or regressed; Group II (G-II) included subjects who progressed to PP. The multivariate combination of the items which was able to best discriminate between the two groups was chosen in predicting the evolution of PT. The items considered included four variables available at the time of diagnosis [chronological (CA) at onset less than 3 years, basal FSH, basal LH and BA/CA ratio] and two additional variables after a 6-month follow-up (delta BA/delta CA and growth velocity); 88% of G-I and 14% of G-II had CA less than 3 yr. Basal FSH levels were elevated in both G-I (7.6 +/- 3.0 mIU/ml) and G-II (12.1 +/- 4.1) with respect to controls (2.6 +/- 1.2); however, approximately 20% of G-I had low FSH levels. Basal LH levels were consistently higher in G-II (8.0 +/- 1.3 mIU/ml) than in G-I (2.9 +/- 1.5) or controls (2.8 +/- 1.2). Although initial BA was advanced (greater than 2SD) in 21% of G-I and in all of G-II, an acceleration of BA was seen only in G-II. The mean growth velocity of G-I (44.1 +/- 31.5%) was significantly less than G-II (92 +/- 32%; p less than 0.0025). With the help of the discriminant equations derived from data obtained at diagnosis and during the first 6 months of follow-up, all subjects with isolated premature thelarche could be sharply distinguished from those who subsequently progressed to precocious puberty.(ABSTRACT TRUNCATED AT 250 WORDS)

Massive breast enlargement in an infant girl with central nervous system dysfunction

A 6-month-old female is described who presented with severe idiopathic macromastia. The breast enlargement began at 2 months of age and progressed such that subtotal mastectomies were necessary at 23 months. Extensive hormonal evaluation prior to surgery revealed no evidence of estrogenization or precocious puberty. There was no galactorrhea. A breast biopsy showed immature mammary tissue. In vitro analysis of the patient's serum using a mouse mammary thymidine incorporation assay revealed similar mitogenic activity in the patient's serum compared to adult controls. Post surgical follow up of this patient, 3.5 years later, has revealed no breast enlargement, precocious sexual development, or growth acceleration. Of interest, however, she has manifested an idiopathic degenerative neurologic condition characterized by psychomotor delay, ataxia, and seizures. Remarkably, hormone studies at age 5.5 years showed an exaggerated gonadotrophin response to intravenous gonadotrophin releasing hormone and prepubertal estrogen levels. While this case may represent an extraordinary example of idiopathic premature thelarche, the severe nature of this infant's macromastia in association with neurologic dysfunction and increased gonadotrophins suggests that central nervous system factors were etiologic.

True precocious puberty in a girl with the fragile X syndrome

A 2.8-year-old girl was investigated for early breast development and delayed psychomotor development. Chromosome analysis showed a fragile site at Xq27. Skeletal maturation was advanced. Computerized tomography of the head was normal. Pelvic ultrasonography showed ovaries and uterus enlarged for age. Basal serum gonadotropins were within the normal prepubertal range, but serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels rose during sleep and following stimulation by gonadotropin-releasing hormone (GnRH), consistent with true precocious puberty. The occurrence of precocious puberty in this girl, and macro-orchidism in affected males may be a reflection of an underlying disturbance of hypothalamic-pituitary-gonadal function in fragile X patients.

Clinical and hormonal studies in precocious puberty

Data from 31 children, 23 females (74.2%) and eight males (25.8%) with precocious puberty were analysed. They included 19 cases with central precocious puberty, 5 with premature thelarche, 5 with premature adrenarche and 1 each with adrenal adenoma and virilizing hepatoblastoma. Their clinical and hormonal profile and the treatment outcome are briefly discussed.

Sex hormone-binding globulin and thyroxine-binding globulin levels in premature thelarche

Premature thelarche is defined as the isolated development of breast tissue in girls less than 8 years of age. Although breast development is an estrogen-dependent process, these girls do not have elevated serum estrogen levels, and the hormonal basis for their condition is unclear. We studied the levels of two estrogen-dependent transport proteins, sex hormone-binding globulin (SHBG) and thyroxine-binding globulin (TBG), in order to determine if there was evidence for a more subtle estrogen effect in girls with premature thelarche. SHBG levels in girls with premature thelarche were not significantly different from those of prepubertal girls of the same ages and were significantly lower than those in girls undergoing pubertal development at the appropriate age (P less than 0.05) and in normal women (P less than 0.001). There was no statistically significant difference in TBG levels between the girls with premature thelarche and prepubertal controls. There was also no significant difference in TBG levels between prepubertal girls and girls in early puberty. In contrast, women had TBG levels that were significantly lower than those in all girls studied. We conclude that the estrogen exposure (whether endogenous or exogenous) of girls with premature thelarche is less than that of girls in early true puberty and similar to that of other prepubertal girls. Further, changes in serum TBG are not as sensitive an indicator of estrogen effect as is breast development or changes in SHBG. This study also suggests that large amounts of exogenous estrogens are not an element in the development of premature thelarche.

Gonadotrophin, growth hormone and prolactin secretion in children with primary hypothyroidism

We have studied eight children with primary hypothyroidism (6F, 2M) aged 6.7 to 14.2 years. The girls were prepubertal and the boys had early normal pubertal development. Overnight secretion of LH, FSH, TSH, PRL and GH, and ovarian ultrasound morphology were assessed before and up to 9 months after commencing thyroxine treatment. Serum FSH concentrations in all the girls were increased above LH levels and severe hypothyroidism was associated with reduced GH secretion. These abnormalities reversed with thyroxine treatment. The boys had less severe hypothyroidism and did not demonstrate abnormal gonadotropin or GH secretion. We conclude that primary hypothyroidism in childhood is associated with widespread disturbance of pituitary function, including increased FSH secretion often without signs of early sexual maturation.

Pelvic ultrasonography in girls with precocious puberty, congenital adrenal hyperplasia, obesity, or hirsutism

Real-time ultrasonography of the pelvic organs was performed on 151 girls with various complete and incomplete forms of precocious puberty, 20 girls with congenital adrenal hyperplasia, 20 with hirsutism, 18 with obesity, and 133 age-matched normal girls. Uterine and ovarian volumes were calculated and the ovarian morphologic picture was classified as homogeneous, nonhomogeneous (less than three small cystic areas), microcystic (four or more small cystic areas less than 9 mm in diameter), follicular (at least one cystic area greater than 9 mm), and macrocystic (large cystic area greater than 20 mm). Ultrasound imaging allowed an easy distinction between true precocious puberty and premature thelarche or idiopathic premature adrenarche. It was also helpful in the diagnosis of transient sexual precocity, although in these cases the differential diagnosis of precocious puberty can be difficult. In postmenarcheal patients with congenital adrenal hyperplasia, ultrasound study showed a low uterine volume and, frequently, a macrocyst in the ovary. In hirsute girls and in a few obese patients, ovaries had an increased volume and a microcystic structure, similar to those in polycystic ovary syndrome. Pelvic ultrasonography can be useful not only in diagnosing disorders in sexual development but also for greater understanding of the pathogenesis of these and other disorders.

Studies of gonadotrophin pulsatility and pelvic ultrasound examinations distinguish between isolated premature thelarche and central precocious puberty

We have studied the pulsatile secretion of gonadotrophins at night and made ovarian ultrasound examinations in three girls with central precocious puberty and three with isolated premature thelarche. The three girls with precocious puberty had well-defined pulsatile secretion of LH and FSH with LH predominating, as would be expected in normal puberty. Pulsatile secretion of gonadotrophins was also seen in girls with premature thelarche but the pattern was reversed. In girls with precocious puberty, large "multicystic" ovaries and large uteri were seen on ultrasound examination, whereas girls with isolated premature thelarche had small uteri and ovaries with less than four "cysts" up to 15 mm in diameter. These data provide the key to understanding the aetiology of isolated premature thelarche.

Premature thelarche: a follow up study of 40 girls. Natural history and endocrine findings

Follow up of 40 girls with premature thelarche showed that where this disorder occurred before age 2 years it usually regressed completely, thus representing a transient and isolated phenomenon. Premature thelarche after age 2 years persisted more frequently, however, and represented the first sign of sexual development, generally leading to simple early puberty.

Premature thelarche--natural history and sex hormone secretion in 68 girls

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.

Pulsatile secretion of luteinizing hormone and sleep-related gonadotropin rhythms in girls with premature thelarche

The concentrations of LH, FSH and PRL were determined in serum samples obtained at night in 1-2 h intervals as well as at 15 min intervals during a 3 h period between 9 and 12 p.m. and 9 and 12 a.m. in three girls with premature thelarche, who had not developed further signs of precocious puberty for more than 18 months. A sleep-dependent LH and FSH increase was documented in all of them with a predominance of FSH secretion during sleep and after LHRH stimulation. In all three girls an episodic pattern of LH was found during sleep. In daytime minor fluctuations of LH secretion were found in two patients whereas in one patient an episodic LH pattern was demonstrable with minor peak values as during sleep. Normal PRL secretion during sleep as well as after TRH stimulation excludes a permissive role of this hormone in premature thelarche. We conclude that in girls with isolated premature thelarche a matured hypothalamo-pituitary gonadotropin axis is active comparable to normal pubertal children.