Gynaecomastia is the benign enlargement of glandular breast tissue in males. This non-cancerous condition results from an altered balance between the body’s estrogen and testosterone levels. It is distinct from pseudogynecomastia, which involves only an increase in fatty tissue without glandular growth. Gynaecomastia is most frequently observed during periods of natural hormonal fluctuation, such as infancy, adolescence, and older adulthood. Although physically harmless, the condition can lead to significant psychological distress and self-consciousness.
Recognizing the Physical Signs
The most recognizable sign of gynaecomastia is a palpable mass that is firm or rubbery in texture, typically concentrated directly beneath the nipple and areola. This localized tissue growth helps distinguish it from the softer, diffuse feel of fatty tissue accumulation. The enlargement is most often observed in both breasts (bilateral involvement), though it can sometimes affect only one side, presenting as asymmetrical or unilateral swelling.
Patients often report associated tenderness or mild discomfort in the breast area, particularly during the early, active phase of tissue growth. This sensation can range from slight sensitivity when brushed by clothing to a pronounced ache upon direct pressure. The nipple may also appear puffy or swollen due to the underlying glandular tissue expansion. The presence of a firm, disc-like mound of tissue confirms the proliferation of glandular structures.
Identifying the Underlying Causes
The primary driver of gynaecomastia is an imbalance that shifts the ratio of estrogen to testosterone in favor of estrogen action. Estrogen stimulates the growth of glandular tissue, while testosterone inhibits this process. Any factor that increases circulating estrogen, decreases testosterone, or blocks androgen receptors can trigger the condition.
Gynaecomastia is categorized into three main etiologies: physiological, pathological, and iatrogenic/external factors.
Physiological Causes
Physiological gynaecomastia occurs during predictable life stages due to natural hormonal fluctuations. Neonatal gynaecomastia, affecting up to 90% of male infants, is caused by residual maternal estrogens and resolves spontaneously within a few weeks. The second peak occurs during puberty, where a temporary surge in estrogen relative to testosterone causes transient breast growth in up to 70% of adolescent boys. A third peak occurs in older men, typically after age 50, due to a natural decline in testosterone combined with increased conversion of androgens into estrogen in fat tissue.
Pathological Causes
Pathological causes stem from underlying medical conditions that disrupt hormonal balance. Conditions causing hypogonadism, such as Klinefelter syndrome or testicular trauma, result in low testosterone production, increasing the estrogen ratio. Chronic systemic diseases like liver cirrhosis or kidney failure impair hormone clearance and increase the peripheral conversion of androgens to estrogen. Hormonally active tumors, such as those in the testes, adrenal glands, or lungs, can also directly secrete estrogens or human chorionic gonadotropin (hCG), leading to glandular stimulation.
Iatrogenic and External Factors
Iatrogenic or external factors relate to the use of specific medications and substances. Certain prescribed drugs, including anti-androgens, heart medications like spironolactone, and specific antidepressants, can promote gynaecomastia. Recreational substances also play a role; the use of anabolic steroids, which aromatize into estrogen, or chronic heavy alcohol consumption can induce the condition. Even some herbal supplements containing phytoestrogens may contribute to glandular growth.
How Doctors Confirm the Condition
The diagnostic process begins with a detailed medical history and a thorough physical examination. The physician carefully palpates the chest to confirm the presence of a firm, concentric, subareolar mass, characteristic of glandular tissue. A review of the patient’s medication list is undertaken immediately, as drug-induced gynaecomastia is common and often reversible upon stopping the causative agent.
Blood tests are the next step for identifying an underlying pathological cause, especially when the enlargement is pronounced, recent, or unilateral. Laboratory investigations typically include measuring serum levels of testosterone, estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) to evaluate the hormonal axis. Additional blood work assesses liver and kidney function, as chronic disease in these organs can be a pathological trigger.
If the initial evaluation suggests a complex endocrine issue or a tumor, specialized tests may be ordered, such as measuring human chorionic gonadotropin (hCG) or conducting a karyotype for Klinefelter syndrome. Imaging studies, such as a breast ultrasound or mammogram, are used to confirm the presence of glandular tissue versus fat and to rule out male breast cancer, particularly if the lump is fixed or eccentric.
Options for Management and Resolution
The management strategy is tailored to the underlying cause, the duration of the condition, and the degree of distress experienced by the patient.
Observation and Lifestyle Changes
For physiological cases, especially pubertal gynaecomastia, a period of observation is often recommended. Up to 90% of these cases resolve spontaneously within six months to three years. This watchful waiting is appropriate unless the condition causes severe pain or significant emotional anxiety. If the cause is medication-related, the first line of management involves stopping the drug or switching to an alternative therapy, which can lead to resolution.
Medical Treatment
Pharmacological treatments are most effective when the gynaecomastia is acute (present for less than 12 months), before the glandular tissue becomes irreversibly fibrotic. Selective estrogen receptor modulators (SERMs), such as tamoxifen and raloxifene, are the most common drugs used. They work by blocking estrogen’s effect on the breast tissue. Tamoxifen has been shown to result in partial or complete regression in up to 80% of patients with recent-onset gynaecomastia. For cases caused by hormonal deficiency, such as hypogonadism, testosterone replacement therapy may be instituted to correct the estrogen ratio. This approach requires careful monitoring, as the body can convert exogenous testosterone into estrogen, potentially worsening the condition.
Surgical Intervention
For long-standing cases, those resistant to pharmacological treatment, or for cosmetic concerns, surgery remains the definitive method for resolution. The surgical approach is selected based on the composition of the breast tissue. Liposuction alone is used when the enlargement is predominantly fatty tissue. Subcutaneous mastectomy is employed for the direct excision of dense glandular tissue. A combination of liposuction and direct excision is frequently utilized to achieve an optimal chest contour.