Editors

IlpoHuhtaniemi

Gynaecomastia

Differentiate physiological breast enlargement and "normal variant" from pathological conditions in order to avoid unnecessary investigations.
Refer patients with quickly developing or symptomatic gynaecomastia for further investigations or perform at least the initial investigations.

In the neonate, maternal or placental oestrogens make the breasts to grow. The phenomenon disappears during the first weeks of life but may sometimes last longer http://www.dynamed.com/condition/gynecomastia#PROGNOSIS.
In girls, puberty may already start at the age of 8 years, with breast enlargement as its first sign. In boys, respectively, puberty may start at the age of 9 years, and gynaecomastia may appear at any phase of puberty.
Independent thelarche, i.e. breast growth without progressive puberty is often seen especially in girls, usually at the age of 2 to 3 years but it may also occur at any other time during the years preceding puberty. In boys this phenomenon is more rare but possible especially during the first year of life.
Pubertal gynaecomastia in boys is not an indication for further investigations if the pubertal development of the child has otherwise been normal http://www.dynamed.com/condition/gynecomastia#PROGNOSIS.
In children with independent thelarche it should be ensured that the child does not have progressive puberty which would require further investigations and treatment. If there is an acceleration of growth and the breasts continue to enlarge, investigations for precocious puberty are warranted; see Pubertal Development and its Disturbances.
As many as every second elderly overweight man has gynaecomastia. This is probably caused by androgens metabolised into oestrogens in adipose tissue.

For gynaecomastia of puberty, see Pubertal Development and its Disturbances.
Hormonal breast growth is caused by oestrogen-androgen dysequilibrium in men.
Testosterone deficiency is caused by congenital or acquired hypogonadism Male Hypogonadism and Hormone Replacement. The causes for hypogonadism include
- gonadotrophin deficiency
- hyperprolactinaemia
- testicular disease
- hypersecretion of oestrogen
- Klinefelter's syndrome
- androgen resistance.
Increased oestrogen production is caused by
- adrenocortical, testicular and other tumours (pulmonary, gastrointestinal, renal) producing oestrogens and human chorionic gonadotrophin (hCG)
- cirrhosis of the liver
- hyperthyroidism
- many drugs: spironolactone, oestrogens, androgens, anabolic steroids, antiandrogens, digoxin, isoniazid, phenothiazines, tricyclic antidepressants, phenytoin, metoclopramide, diazepam, ketoconazole, penicillamine, anti-HIV drugs, cytotoxic drugs and herbal drugs as well as amphetamine and marijuana.
Local nonendocrine gynaecomastia may be caused by a primary tumour or a metastasis.

Clinical examination of the breast
- Is the condition in question gynaecomastia or pseudogynaecomastia (growth of subareolar adipose tissue but not of glandular tissue)?
- Differential diagnosis between gynaecomastia and breast cancer (gynaecomastic tissue is soft and elastic and is deposited right beneath the areola, bilateral in 50% of cases; cancer tissue is solid or hard, not beneath the areola, often unilateral)
Observe the following signs and history:
- sexual function (impotence, decreased libido)
- size of the testes (small testes indicate hypogonadism, asymmetry suggests a tumour)
- hair growth (masculine or feminine?)
- milk or other discharge when squeezing the breasts
- signs of liver disease
- drug history (spironolactone, treatment of prostate cancer, natural drugs)

For gynaecomastia of puberty, see Pubertal Development and its Disturbances.
Because gynaecomastia is often transient and the aetiology can be determined in only about half of all cases, not all patients need hormone assays. Investigations are indicated if the drugs used by the patient do not explain the gynaecomastia, and
- the breast is tender (a sign of rapid growth) or
- the diameter of the breast tissue is > 4 cm.
In other cases the need for investigations is decided individually. For example, gynaecomastia associated with signs of androgen deficiency should always be investigated.

If serum LH concentration is increased and serum testosterone concentration decreased the patient probably has testosterone deficiency caused by testicular dysfunction.
If serum testosterone concentration is decreased and serum LH is normal or decreased the patient probably has hypogonadotrophic hypogonadism or increased oestrogen production.
If both serum LH and free testosterone concentrations are increased the patient has androgen resistance or a rare gonadotrophin-secreting tumour of the pituitary gland.
Serum beta-hCG concentration is increased in testicular trophoblast tumours.
In problematic cases the following tests can be performed according to specialist advice:
- serum oestrone and prolactin
- liver function tests
- karyotype
- mammography or breast ultrasonography in order to determine breast structure or detect eventual tumours.

In transient gynaecomastia the breast usually decreases in size spontaneously after the underlying cause has been corrected.
Tamoxifen is the drug of choice http://www.dynamed.com/condition/gynecomastia#MEDICATIONS.
Cosmetic harm and malignant tumours are indications for surgery.