It originated from the Greek words for “women-like breasts.” It affects an estimated 40% – 50% of the male population. It is the abnormal development of breast tissue in males.
Enlargement of male breast tissue is associated with proliferation of glandular tissue. Enlargement is concentric around the areola, with a definite disc of tissue palpable. Usually bilateral, may be tender, but not usually painful. Diagnosis of gynecomastia is made by palpating the breast tissue.
Gynecomastia results from an imbalance in hormone levels in which levels of estrogen (female hormones) are increased relative to levels of androgens (male hormones). Gynecomastia that occurs in normally-growing infant and pubertal boys that resolves on its own with time is known as physiologic gynecomastia.
All individuals, whether male or female, possess both female hormones (estrogens) and male hormones (androgens). During puberty, levels of these hormones may fluctuate and rise at different levels, resulting in a temporary state in which estrogen concentration is relatively high. Gynecomastia caused by transient changes in hormone levels with growth usually disappears on its own within six months to two years. Occasionally, gynecomastia that develops in puberty persists beyond two years and is referred to as persistent pubertal gynecomastia.
A number of medical conditions may also result in gynecomastia.
- Malnutrition and re-feeding (recovery from malnutrition) have both been shown to create a hormonal environment that may lead to gynecomastia. Similarly, cirrhosis of the liver alters normal hormone metabolism and may lead to gynecomastia.
- Disorders of the male sex organs (testes) can result in decreased testosterone production and relatively high estrogen levels, leading to gynecomastia. These disorders may be genetic or acquired due to trauma, infection, reduced blood flow, or aging. Testicular cancers may also secrete hormones that cause gynecomastia.
- Other conditions that are associated with an altered hormonal environment in the body and may be associated with gynecomastia are chronic renal failure and hyperthyroidism. Rarely, cancers other than testicular tumors may produce hormones that can cause gynecomastia.
Gynecomastia can also be a side effect of a number of medications. Examples of drugs that can be associated with gynecomastia are listed below.
- Spironolactone (Aldactone), a diuretic that has anti-androgenic activity.
- Calcium channel blockers used to treat hypertension, such as nifedipine, Procardia, etc.
- ACE inhibitor drugs for hypertension (captopril, enalapril or Vasotec)
- Some antibiotics (for example, isoniazid, ketoconazole, Extina, Xolegel, metronidazole, etc.
- Anti-ulcer drugs such as ranitidine, cimetidine, andomeprazole.
- Anti-androgen or estrogen therapies for prostate cancer.
- Methyldopa (Aldomet).
- Highly active anti-retroviral therapy (HAART) for HIV disease, which may cause fat redistribution leading to pseudo-gynecomastia or, in some cases, true gynecomastia.
- Diazepam (Valium).
- Drugs of abuse (for example, alcohol, marijuana, heroin).
- Lavender oil and tea tree oil, when used in skin-care products, have been associated with gynecomastia.
Risk Factors for Gynecomastia
Normally-developing pubertal males may be at risk for gynecomastia that is part of the normal developmental process. Normal male infants also may have gynecomastia. Other risk factors include aging, since aging may promote decreases in testosterone production that can cause gynecomastia. The risk factors for developing gynecomastia related to specific diseases and conditions (such as cirrhosis of the liver) are the same risk factors that predispose to those conditions. Taking certain medications (see above) may increase the risk of developing gynecomastia.
As mentioned before, gynecomastia is the enlargement of glandular tissue rather than fatty tissue. It is typically symmetrical in location with regard to the nipple and may have a rubbery or firm feel. Gynecomastia usually occurs on both sides but can be unilateral in some cases. The enlargement may be greater on one side even if both sides are involved. Tenderness and sensitivity may be present, although there is typically no severe pain.
The most important distinction with gynecomastia is differentiation from male breast cancer. Cancer is usually confined to one side, is not necessarily centered around the nipple, feels hard or firm, and can be associated with dimpling of the skin, retraction of the nipple, nipple discharge, and enlargement of the underarm lymph nodes.
How is Gynecomastia Diagnosed?
The definition of gynecomastia is the presence of breast tissue greater than 0.5 cm in diameter in a male. In most cases, gynecomastia can be diagnosed by a physical examination. A careful medical history is also important, including medication and drug use. If there is a suspicion of cancer, a mammogram may be ordered by a health care practitioner. Further tests may be recommended to help establish the cause of gynecomastia in certain cases. These can include blood tests to examine liver, kidney, and thyroid function. Measurement of hormone levels in the bloodstream may also be recommended in some cases.
Gynecomastia, especially in pubertal males, often goes away on its own within about six months, so observation is preferred over specific treatment in many cases. Stopping any offending medications and treatment of underlying medical conditions that cause gynecomastia are also mainstays of treatment.
Treatments are also available to specifically address the problem of gynecomastia, but data on their effectiveness are limited, and no drugs have yet been approved by the U.S. Food and Drug Administration (FDA) for treatment of gynecomastia. Medications are more effective in reducing gynecomastia in the early stages, since scarring often occurs after about 12 months. After the tissue has become scarred, medications are not likely to be effective, and surgical removal is the only possible treatment.
Medications that have been used to treat gynecomastia include:
- Testosterone replacement has been effective in older men with low levels of testosterone, but it is not effective for me who have normal levels of the male hormone.
- Clomiphene, an anti-estrogen medication has been used to treat gynecomastia. It can be taken for up to 6 months.
- The selective estrogen receptor modulator (SERM) tamoxifen (Nolvadex) has been shown to reduce breast volume in gynecomastia.
- Danazol is a synthetic derivative of testosterone that decreases estrogen synthesis by the testes. It works by inhibition of pituitary secretion of LH and follicle-stimulating hormone (FSH), substances that direct the sex organs to produce hormones. It is less commonly used to treat gynecomastia than other medications.
Gynecomastia that occurs because of hormonal fluctuations with growth or aging cannot be prevented. Gynecomastia related to medical conditions can only be prevented to the extent that the underlying or responsible condition can be prevented. Gynecomastia is potentially reversible if present for less than one year, but changes may be irreversible after one year.