Gynecomastia is enlargement of the gland tissue of the male breast. During infancy, puberty, and in middle-aged to older men, gynecomastia can be common. Gynecomastia must be distinguished from pseudogynecomastia or lipomastia, which refers to the presence of fat deposits in the breast area of obese men. True gynecomastia results from growth of the glandular, or breast tissue, which is present in very small amounts in men. The condition is the most common reason for medical evaluation of the male breast.
What are the signs and symptoms of gynecomastia?
The primary symptom of gynecomastia is enlargement of the male breasts. 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, which accounts for about 1% of overall cases of 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 (axillary) lymph nodes.
Who gets 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 the problem.
- The risks for developing enlarged male breasts 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 may increase the risk of developing the problem.
What does gynecomastia look like?
Illustration of Enlarged Male Breasts (Gynecomastia)
What causes gynecomastia during puberty, and how long does it last?
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. Studies regarding the prevalence of gynecomastia in normal adolescents have yielded widely varying results, with prevalence estimates as low as 4% and as high as 69% of adolescent boys. These differences probably result from variations in what is perceived to be normal and the different ages of boys examined in the studies.
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.
What diseases and conditions cause 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, such as Klinefelter's syndrome, 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.