Definition Juvenile gynecomastia is any visible or palpable one- or two-sided increase in the mammary gland in boys and in young males.
Synonym: pubertal gynecomastia, transient gynecomastia.
Spread. 75% of adolescent boys have transient gynecomastia. The frequency of juvenile gynecomastia during the entire puberty reaches 15-50%. Most often it is observed at the age of 13-14 years.
Etiology. In girls, a rapid growth of the mammary glands can be observed in the pubertal period. No hormonal disorders can be detected. Sometimes a giant increase in the mammary glands requires surgery. In one case, in 1.5 years the mammary glands reached colossal sizes, the total mass of the removed mammary glands reached 20 kg.
Juvenile gynecomastia in boys and adolescents develops as a result of hyperplasia of the epithelium and connective tissue of the mammary glandular passages.
In adolescents, the size of gynecomastia can vary from a small lump, which can only be determined by palpation, to the gland of an adult woman.
True adolescent gynecomastia is an increase in the mammary gland in adolescents associated with puberty. Juvenile gynecomastia in typical cases occurs in the stages I-III of Tanner puberty.
In general, it is considered as a physiological phenomenon that does not require medical intervention.
At the same time, an increase may be accompanied by loading and soreness. As a rule, it is bilateral, but not necessarily an enlargement of both glands occurs simultaneously.
Gynecomastia may occur after fasting, after chronic hemodialysis. Occasionally, this may be a manifestation of a systemic blood disease — unilateral pseudogynecomastia (see below) may be with lymphocytic leukemia (extramedullary center of blood bleeding), with a primary tumor.
Gynecomastia may occur due to injury or mechanical irritation of the gland, as well as as a result of treatment with estrogens, gonadotropins, and choriogonin.
Tumors of the liver, lungs, mediastinum may produce paraneoplastic gynecomastia. Often there is a false gynecomastia with hypothalamic puberty syndrome.
Family gynecomastia — with the development of the male line over several generations — is inherited as a dominant trait, appearing early, even in childhood.
Symptomatic gynecomastia often occurs in a number of endocrine and somatic diseases (in chronic hepatitis and cirrhosis of the liver, in case of tuberculosis), in genetic abnormalities (Kleinfelter syndrome, Prader-Willi syndrome), hyperprolactinemia, hyperthyroidism in adolescents, femae lowering testicular tumor in Cushing’s syndrome. Gynecomastia in hyperprolactinemia in adolescents — late manifestation of prolactinoma.
Gynecomastia is observed in Reifenstein syndrome (see above), which is characterized by a testosterone biosynthesis defect. This is a family disease with a male karyotype, when there is virilization of the genital organs, evident from birth, but accompanied by hypospadias with a relatively small penis, often cryptorchism, and by the period of puberty, pronounced gynecomastia appears with poor body incontinence.
With feminizing tumors of the adrenal cortex and testicles, with various forms of intersexuality, with true hermaphroditism, gynecomastia is also noted.
Gynecomastia may be in the treatment of premature puberty. Often this is a familial manifestation of pronounced pubertal gynecomastia.
Abroad, gynecomastia is often detected by eating milk from cows that receive
estrogens, as well as poultry meat that received feed from poultry factories with the addition of anabolic steroids for effective weight gain.
In girls, isolated thelarche is a heterogeneous group in terms of clinical and laboratory parameters. Prognostically favorable when telarh are normal indicators of prolactin.
Gynecomastias of unknown etiology are possible. When the cause is unclear, they talk about idiopathic gynecomastia.
Gynecomastia remains a mysterious syndrome in terms of pathophysiology. Its pathogenesis has not yet been studied in detail. To date, only some hormonal factors of breast growth regulation (epidermal growth factor, IGF-1, progestins and estrogens) are known. There is no increased production of estrogen in adolescent gynecomastia.
Apparently, this is a local endocrinopathy with an increased sensitivity of target organ cells (mammary glands) to growth factors — cytokines.
It is believed that the cause is an androgen-estrogenic imbalance shifted towards estrogen. The gonadotropic hormones of the pituitary play a role, since follitropinemia is often found in gynecomastia.
According to current concepts, hyperprolactinemia plays a role in the pathogenesis of true pubertal gynecomastia.
Sexual dimorphism in the development of the mammary gland embryo does not directly depend on the set of sex chromosomes in the gland cells, it is a result of different sensitivity to hormonal influences.
Two different histological forms of gynecomastia are distinguished: proliferation of the milk ducts with the formation of lobules (parenchymal transformation) and proliferation of interlobular and paradctal tissue with proliferation of connective tissue and fat deposition (interstitial transformation). Apparently, the first is a consequence of the effects of estrogen, as well as testosterone and progesterone. Prolactin plays only a permissive role. Interstitial transformation, in contrast, is associated with excessive exposure to prolactin, as well as observed in gynecomastia of unknown origin.
Clinic. For young men, gynecomastia is a source of anxiety and a great trauma: instead of maturity, it is feminized. The asymmetry of the increase can be very cosmetically sharp. In addition, the rudiments of the breast glands sometimes become quite painful. Teens hide gynecomastia in all ways, shy away from playing sports, swimming, do not play with their peers. Since this is a transient phenomenon, it is often possible to hide it from others.
The skin in the area of the mammary glands is usually normal. The nipple is almost always enlarged, the areola is pigmented and enlarged. There may be a slight nipple retraction. Breast weight can reach 160 g
The epithelium of the ducts is in a state of hyperplasia. A large amount of smooth muscle fibers is found in the nipple.
Other signs of feminization may be observed in young men: hermaphroditism, gonadal hypoplasia, cryptochism, hypospadias, testicular atrophy.
Classification. Gynecomastia can be physiological and pathological. Etiologically, there is a difference between true adolescent, idiopathic, medicinal, familial, symptomatic and false gynecomastia. False or pseudo-gynecomastia refers to an increase in the mammary glands due to the growth of fatty tissue in them or due to a tumor.
There are also bilateral (symmetrical or asymmetrical) and unilateral gynecomastia.