bubble_chart Overview

Sexual precocity refers to the occurrence of sexual maturity that is 2.8 standard deviations (SD) earlier than that of normal children. Currently, it is considered that the appearance of any secondary sexual characteristics before the age of 9 is indicative of sexual precocity. Generally, breast development and pubic hair growth precede the onset of menstruation by several months. In some children, the only sign of sexual precocity is breast development (premature thelarche) or early appearance of pubic hair during puberty (premature pubarche), but most cases involve accelerated physical development. True precocious puberty refers to the differentiation of sexual development caused by the hypothalamic-hypophyseal-ovarian axis, which occurs at an abnormally early age, from pseudoprecocious puberty caused by ovarian or adrenal tumors or the effects of exogenous ovarian hormones. True precocious puberty not only includes associated hypothyroidism and central nervous system disorders but also McCune-Albright syndrome (polyostotic fibrous dysplasia) and approximately 80-90% of cases of sexual precocity with unknown causes.

bubble_chart Etiology

1. Sexual precocity of intracranial origin: The premature development or function of the reproductive tract caused by hypothalamic or pituitary lesions, apart from the early maturation and ovulation of ovarian follicles, is similar to the development seen in normal children. Most cases of sexual precocity of intracranial origin are due to lesions or tumors at the base of the third ventricle, often involving the posterior hypothalamus, especially the tuber cinereum, mammillary bodies, and optic chiasm. Congenital brain defects or encephalitis can also be accompanied by signs of premature sexual maturation. Neurological examinations can often confirm the diagnosis. The early sexual development in McCune-Albright syndrome, accompanied by polyostotic fibrous dysplasia, skin pigmentation, and other endocrine disorders, is due to a congenital defect in the hypothalamus.

Some children may initially show no neurological symptoms despite having sexual activity related to intracranial diseases. It is crucial to identify the location and characteristics of the disorder in many types of sexual precocity originating from intracranial lesions.

Sexual precocity caused by intracranial diseases can be explained by the posterior hypothalamus's ability to inhibit the production and release of gonadotropins from the anterior pituitary. Therefore, lesions in the posterior hypothalamus can disrupt or inhibit mechanisms that normally regulate the intensity of stimuli to the posterior pituitary gland, releasing the hypothalamus's control over the pituitary and increasing the production of gonadotropic substances, leading to gonadal activity and sexual maturation. In other cases, it may be due to direct stimulation of the pituitary.

2. Cryptogenic sexual precocity: About 80-90% of constitutional sexual precocity has no apparent cause. Classified by disease cause, it is often attributed to central nervous system origins, as patients may have small, unconfirmed hypothalamic lesions. Some patients have a family history of sexual precocity. It is appropriate to call this condition cryptogenic because little is known about the origin of this type of sexual precocity.

3. Ovarian tumors causing sexual precocity: Ovarian tumors as a cause of sexual precocity are worth emphasizing, but feminizing tumors are actually more common in childhood.

Most feminizing mesenchymal tumors in childhood develop alongside rapid growth in body development and bone age, along with pubertal feminization, genital maturation, and breast enlargement. Pubic hair appears but is less common than in true isosexual precocious puberty. Pelvic tumors are often not palpable. Vaginal secretions increase, and vaginal smears show enhanced estrogen effects, with irregular vaginal bleeding. The incidence of sexual precocity caused by estrogen-producing tumors is higher than that of cryptogenic cases. Urinary estrogen and 17-ketosteroid levels may be higher than in normal children of the same age. However, these cases generally do not ovulate and cannot achieve pregnancy. Occasionally, follicular non-neoplastic ovarian cysts can lead to sexual precocity. Removal of the cyst (which contains large amounts of estrogen) can alleviate the development of sexual precocity, but if gonadal remnants remain, small cysts can still grow, and sexual precocity may continue.

IV. Other Causes of Precocious Puberty Adrenal tumors that produce hormones can cause heterosexual precocity or a mixed type of sexual maturation. Exogenous estrogens are often due to improper medication or other sources. Young girls accidentally ingesting their mother's contraceptive pills may occasionally lead to precocious puberty; children with hypothyroidism may also occasionally experience precocious puberty. The latter is caused by excessive secretion of gonadotropins by the pituitary gland due to the cross-feedback effect between thyroid hormones and gonadotropins.

V. Transitory Sexual Precocity It is rare but not uncommon. Affected children often exhibit accelerated development of one or more secondary sexual characteristics. The majority of these children show physical development and breast development (about 50%). Vaginal bleeding occurs in up to 45% of cases. Vaginal vault smears show a significant estrogen effect in epithelial cells. This phenomenon of precocious sexual development can return to normal development after several months, and normal puberty is entered at the usual age.

Occasionally, the uterine membrane is particularly sensitive to estrogen, which can lead to uterine bleeding without other signs of precocious puberty. Gynecological examinations cannot determine the true cause of uterine bleeding, and hormone measurements are also normal. Uterine bleeding naturally stops after several months of recovery cycles.

Children with transitory sexual precocity or premature endometrial response should be closely followed up for several years until other special causes (including uterine bleeding) are ruled out.

bubble_chart Clinical Manifestations

A small number of children with constitutional precocious puberty may begin to show signs of precocious puberty shortly after birth; however, most experience menarche around the ages of 7 to 8. The earlier the sexual development, the earlier the menarche. Generally, before the appearance of secondary sexual characteristics, the patient's height, weight, and bone age have already developed rapidly.

Although girls with early precocious puberty are often significantly taller than their peers, early epiphyseal closure occurs. Clinical examinations include the growth of height and weight, breast development, pubic hair growth, genital development, abdominal examination, and abdominal palpation to check for any masses, as well as a detailed neurological examination, including fundoscopy, visual field testing, and electroencephalography.

bubble_chart Diagnosis

The primary objective of the diagnostic steps for female homosexual precocious puberty is to clarify the disease cause leading to accelerated sexual maturation. Approximately 90% of cases are of the constitutional type (especially those of unknown or idiopathic cause). However, before making such an interpretation for any case, other disease causes must be excluded.

A wrist anteroposterior X-ray can assess bone age and understand the progress of the developmental process. A sella turcica anteroposterior and lateral X-ray can determine whether there are any pituitary lesions. If suspicious, further moving qi encephalography (pneumoencephalography), ventriculography, CT, or/and MRI can be performed to clarify the diagnosis.

Laboratory tests include: hormone measurements, such as serum FSH, LH, E₂, and 24-hour urinary 17-ketosteroids, which help differentiate between true and pseudo-precocious puberty.

Laparoscopy, which should be performed by an experienced physician, can replace exploratory laparotomy if only a tumor is suspected.

There is no evidence that precocious puberty can cause premature heterosexual activity or adverse effects on reproductive function, delayed intellectual development, etc. Physical and genital development are parallel to bone age.

bubble_chart Treatment Measures

Children with precocious puberty should be educated about menstruation knowledge and menstrual hygiene. Sexual education should begin early according to the child's comprehension. The ideal treatment for precocious puberty is disease cause treatment.

I. Drug Treatment For most girls with constitutional precocious puberty, medroxyprogesterone 100-200mg can be used to inhibit menstruation by intramuscular injection on the 14th day of the menstrual cycle, but it cannot prevent the acceleration of other maturation phenomena. In recent years, Europe has experimented with an anti-androgen preparation, cyproterone acetate, which inhibits hypothalamic activity and is effective in treating precocious puberty.

II. Surgical Treatment If a child with precocious puberty has palpable enlarged ovaries, exploratory laparotomy is necessary. If it is an ovarian cyst, enucleation should be performed. It is possible to preserve the ovary in cases of benign tumors. For unilateral, large, and completely encapsulated mobile ovarian tumors, unilateral salpingo-oophorectomy is preferred, and the contralateral ovary should be biopsied. If the contralateral ovary and uterus are tumor-free, they should be preserved. Ascites itself should not be an indication for malignancy or radical surgery, but routine ascites tests and cytological examinations should be performed. For completely encapsulated and mobile granulosa cell tumors, after removal of the tumor and adnexa on the affected side, the contralateral ovary can be preserved, and the aforementioned examinations should be performed. For malignant ovarian tumors, rapid frozen section diagnosis should be made, and radical surgery should be performed according to the staging.