Gynecomastia or hypertrophy of the male breast refers to the development of male breast tissue that resembles normal female breast tissue histologically. It can be seen at almost any age.
(I), basic classification
Idiopathic gynecomastia is the most common clinical condition. It has two peak ages of onset, puberty and menopause, called adolescent hypertrophy and old age hypertrophy, respectively. Idiopathic means that there are no obvious clinical problems to investigate, that is, no genital development abnormalities, and no other organic lesions. The secretion of sex hormones is obviously high during puberty. Anterior pituitary gonadotropins stimulate the release of estrogen and testosterone from the interstitial cells of the testes. In some cases estrogen may predominate. In male children, there is a transient proliferation of mammary glands. The adrenal glands also secrete a few androgens, but they are mostly inactivated by the liver. Androgens in the body can also be “aromatized” by peripheral fat cells and become estrogens. In cases of familial gynecomastia, breast tissue aromatase levels are increased. In older patients, this may be associated with excessive conversion of adrenal and testicular androgens to estrogen, or it may be associated with physical obesity.
Those with secondary gynecomastia have an obvious etiology, such as certain drugs such as testosterone, thyroxine, reserpine, trichothecenes, isocoumarins, phenothiazines, vitamin D, etc. Certain tumors such as testicular teratoma, testicular chorioepithelial carcinoma, adrenal gland tumors, bronchopulmonary carcinoma, liver tumors, etc. Certain diseases such as diffuse liver disease, etc. Certain congenital malformations or dysplastic diseases are often accompanied by breast enlargement, such as cryptorchidism, Klinefelter syndrome (spermatogenesis deficiency – gynecomastia syndrome), Reifenstein syndrome (male female-type breast – hypospadias syndrome), etc.
(b), clinical inquiries are needed to identify the following triggers for the onset of the disease
1. Drugs: Many drugs can cause this syndrome, and estrogen treatment for prostate cancer is a common case of breast enlargement. Estrogen can also be absorbed through the skin through industrial production and vaginal contraceptives during sexual intercourse. Other drugs such as digitalis also have estrogenic effects, and cimetidine has anti-androgenic effects that can cause breast enlargement in men, only at high doses. The mechanism by which most drugs cause breast enlargement is not known, such as ambrisentin, methyldopa mercaptoproline, and channel blockers. Others, such as the antifungal ketoconazole, tricyclic antidepressants and Valium, can also cause gynecomastia in men. Inhalation of marijuana, heroin, etc. is also one of the causes.
2, tumors: benign testicular mesenchymal cell tumors produce too much estrogen can cause male breast enlargement, but very rare. The tumors that cause breast enlargement are related to chorionic gonadotropin (HCG), which stimulates the production of testosterone and estrogen in the mesenchymal cells. The most common tumors are choriocarcinoma, embryonal tumors, and seminoma. The most common of the other tumors is bronchopulmonary carcinoma and occasionally malignant tumors of the stomach and pancreas. Adrenal tumors can also cause breast enlargement due to excessive production of androgens that are later converted to estrogens. The mechanism of breast enlargement caused by liver tumor is related to the increase of aromatase activity of the tumor itself.
3, hepatic sclerosis: one of the important causes of male breast enlargement. Due to the decrease of liver inactivation of adrenal androgens, more androgens are converted into estrogens in the surrounding tissues.
4, hyperthyroidism: 10% to 40% of male patients with hyperthyroidism can be accompanied by this disease. It may be caused by excessive production of androgens in the adrenal glands and the massive aromatization of androgens into estrogens in the surrounding tissues.
5, renal failure: testicular function is suppressed in renal failure, about 30% of patients develop gynecomastia 4 weeks to a few months after treatment, and symptoms often disappear within a year.
6, sexual function decline: primary testicular insufficiency can not produce a sufficient amount of testosterone, which leads to increased levels of pituitary gonadotropin, the latter stimulates the testes to secrete more estrogen causing breast enlargement. Cryptorchidism, trauma or viral infection (such as mumps) are also common causes.
7, other: in addition to bronchial lung cancer, other chronic lung diseases with proliferative osteoarthropathy, such as tuberculosis, cystic pulmonary fibrosis can also cause male breast enlargement, the mechanism is not well understood.
In conclusion, factors that can affect hormonal imbalances such as sex hormones (estrogen, progesterone, androgen), growth hormone, and oxytocin can all cause gynecomastia. Mammary gland development is caused by hormonal stimulation, and hormonal stimulation is equal for both mammary glands, but male mammary gland development is mostly unilateral, and the mechanism is not yet understood.
(c) Clinical manifestations and diagnostic points
Mammary gland development resembles that of adolescent girls, with well-developed nipples and areolas. The clinical manifestation is the enlargement of one or both breasts, mostly whole breast enlargement, and a few only enlargement of the outer upper quadrant of the breast. The enlarged breast is well-defined, with smooth edges and a rubbery texture, and is often associated with nodularity. Most advocate that the lump should be more than 2 cm in diameter, while some consider a lump of 0.5 cm or more to be diagnostic.
When diagnosing gynecomastia, the first step should be to look for possible causes. Patients with unknown causes should be questioned about their medication history and the testes should be carefully examined to detect tumors or atrophy. Liver and thyroid function and related hormones (serum HCG, LH, estrogen and testosterone, etc.) should be measured. Local examination of the breast is performed in the same way as that of female breast tumors, and cytology and histology should be performed if necessary.
Clinically, male breast cancer should be excluded first, especially unilateral gynecomastia should be differentiated from male breast cancer. Breast cancer lumps are often deviated from the areola, with unclear and hard borders, and may be fixed in deep fascia or skin, and mostly have depressed or deviated nipples.
It is worth noting that some clinical breast lumps with significant fat accumulation (over-obese) may cause “pseudogynecomastia” with soft tissues and indistinct borders when examined.
(iv) Treatment
Idiopathic gynecomastia does not require special treatment, but should be closely followed up. Idiopathic gynecomastia is mostly self-healing. Some proprietary Chinese medicines can relieve clinical pain and other symptoms.
Secondary gynecomastia should be treated for its etiology. There is no need to rush into local treatment until the cause is treated.
Related hormone therapy should be applied with caution. Among the anti-estrogens, clomiphene is ineffective and has side effects; TAM is effective in adolescents and in 70% of middle-aged and elderly patients. Non-aromatized androgens (e.g., dihydrotestosterone) can inhibit the aromatization of androgens in the body, thereby reducing androgen production, and can be used under medical supervision.
To avoid misdiagnosis with breast cancer or to relieve patients from excessive psychological stress, subcutaneous mastectomy can be considered if necessary.