Pubertal stage
Age (years)
Breast buds (B2)
10.1
Sparse pubic hair growth (P2)
11.2
Darker, coarser pubic hair growth (P3)
12.2
Growth spurt
12.2
Menarche
12.7
Adult pubic hair in type and quantity (P5)
14
Mature breast (B5)
14
The Tanner stages have been the reference for generations of pediatric endocrinologists. In an American study of a very large cohort of girls examined between the ages of 3 and 11 years, most of the girls appeared to enter puberty at a younger age (9.9 years for B2 and 10.5 years for P2). This drop in the age of puberty onset was most evident in black girls. The authors attributed their findings to the impact of environmental factors (chemical pollution). The findings that most of the girls entering puberty at the youngest ages (between 6 and 8 years) do not present with short adult height and that the duration of puberty (tempo) is inversely linked to the age of onset (timing) should be considered as relevant to clinical practice, especially to any decision about therapeutic management.
These works as a whole have done much to elucidate the development of secondary sexual characteristics and the normal course of puberty in girls.
The activation of the gonadotropic axis is marked by a peak in LH above 5 μUI/ml and an LH/FSH ratio above 1 during LHRH testing. Conversely, to the assertions of other groups, we do not accept the basal values of LH (whatever the standard used) as a marker of pubertal onset.
The measurement of plasma estradiol by radioimmunology is not a reliable method to evaluate the onset of puberty because of its low specificity and high fluctuations. Only the analysis of the biological activity of estrogens using ultrasensitive methods is able to provide useful information on pubertal onset [2].
Last, pelvic ultrasonography with measurement of the uterus should be systematically performed: onset of puberty shows an increase in ovarian volume (>1.5 cm3) and uterine size with length exceeding 3.5 cm. The finding of an increased diameter of the uterine fundus and a uterine vacuity line reflects significant estrogenization.
Clinical, biological, anthropometric, and radiographic evaluations are all helpful in distinguishing normal puberty from precocious puberty, which may have important clinical, psychological, and therapeutic implications.
4.2 Clinical Expression of Peripheral Precocious Puberty
Precocious puberty is eight times more frequent in girls than in boys [3]. Premature breast development, pubic hair, and growth acceleration should prompt several questions (Table 4.2), the answers to which will provide clues as to the best adapted treatment strategy.
Table 4.2
Clinical forms of peripheral precocious puberty
Peripheral precocious puberty: precocious pseudopuberty |
Ovarian autonomy |
McCune-Albright syndrome, ovarian cyst |
Granulosa cell tumor |
Adrenal tumor (feminizing) |
Environmental pollution (pesticides) |
- 1.
Did puberty clinically begin before 8 years?
- 2.
What has been the progression of the clinical symptoms?
- 3.
Are there biological or radiographic signs of exaggerated maturation?
- 4.
How is predicted adult height affected?
- 5.
What are the psychological consequences?
- 6.
Is the hormonal secretion gonadotropin-dependent or -independent?
- 7.
In the case of central gonadotropin activation, is it due to a tumor or is it idiopathic?
Premature thelarche is the most common clinical expression of PPP. Premature thelarche refers to isolated breast development in girls between 2 and 7 years, which differs from the genital crisis of the newborn whose breast development (associated with strong estrogenization and even milk production) may last for the first 18 months of life. This premature breast development is bilateral in half the cases, unilateral, or, less frequently, asymmetric. Volume varies: 60 % at B2, 30 % at B3, and 10 % at B4. The breast is often tender and palpation is sometimes painful. There is no discharge.
In persistent or marked forms of thelarche, the hormonal work-up should be limited to the LHRH test to confirm a predominant FSH response [4]. Bone maturation is rarely accelerated. The progression is characterized by fluctuations over time: spontaneous remission, persistence, and aggravation of breast volume, which should evoke the possibility of puberty onset. In this case, pelvic ultrasound can provide useful information.
When estrogen secretion is patent (simultaneous increase in uterine volume), contamination by products with estrogen-like activity should be considered and sought (soy-rich foods, environmental pesticides, etc.). In its usual form, premature thelarche requires no treatment.
Peripheral precocious or precocious pseudopuberty is not characterized by the premature activation of the gonadotropic axis: it is caused by an abnormally high production of estrogens and, more rarely, androgens because of a “tumor” on the ovary or adrenal glands. It is iso- or heterosexual depending on the whether the excess steroid hormone strengthens or transforms the child’s phenotype.
4.2.1 Peripheral Precocious Puberty Caused by Ovarian Autonomy
The considerable progress in determining the molecular mechanisms of hormone transduction signals has greatly contributed to our understanding of the physiopathology and clinical expression of peripheral precocious puberty caused by ovarian autonomy. This progress may one day culminate in a specific treatment for this rare but incapacitating disorder. Heterosexual precocious pseudopuberty secondary to a virilizing adrenal or ovarian tumor is much rarer.
4.2.1.1 McCune-Albright Syndrome
McCune-Albright syndrome (MAS) is a sporadic disorder characterized by the classic triad of precocious puberty, fibrous bone dysplasia, and café-au-lait spots [5]. Diverse endocrine abnormalities can also be associated: somatotrophic pituitary adenomas, hypothyroid goiter, and adrenal hyperplasia.
Precocious Puberty
MAS affects girls almost exclusively and is characterized by its extreme precociousness and the gravity of the immediate clinical picture: isolated menstruation as early as the first months or first years of life. The full clinical picture will develop later, with breast enlargement and pubic hair. The often voluminous ovarian cysts discovered by ultrasound are cyclic and are difficult to treat: cystectomy or ovariectomy is often necessary when all other treatments fail. The acceleration of growth velocity is considerable (+2, +3 SD) and constant, on the order of 9–10 cm per year. Bone maturation is also accelerated and will thus compromise the prognosis for final adult height.
The biological work-up will show very high plasma estradiol associated with dramatically low plasma gonadotropins and no response to GnRH stimulation. This indicates LH/FSH-independent precocious puberty and situates this type of precocious puberty within the context of the ovarian-autonomous syndromes.
Café-au-lait Spots
The café-au-lait spots of MAS are hyperpigmented, typically light brown or brown, with irregular borders (“coast of Maine”) that distinguish them from the smooth-bordered spots observed in neurofibromatosis. The spots are usually unilaterally distributed, on the same side as the bone lesions. When associated with precocious puberty, they are an essential diagnostic element.
Fibrous Bone Dysplasia
Fibrous bone dysplasia is the third element in the classic triad. This bone abnormality may remain silent for many years, only to be revealed by a spontaneous fracture or on the occasion of a slight injury. X-rays reveal pseudocysts of the bone cortex that rapidly invade the entire skeleton.
Related posts:
Central Precocious Puberty: From Diagnosis to Treatment
Amenorrhoea and Anorexia Nervosa in Adolescent Girls
Premature Ovarian Failure in Adolescence and Young Adults: From Diagnosis to Therapy and Follow-up for Fertility Preservation
Emergency Contraception
Delayed Puberty: Impact on Female Fertility
Adolescent Pregnancy and Contraception
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