Gynecomastia
Benign enlargement of male breast tissue caused by an imbalance between estrogen and testosterone, often resolving on its own or treated by stopping offending medications.
Emergency Management: None.
Gynecomastia is the benign proliferation of glandular breast tissue in males, typically presenting as a palpable, concentric, rubbery mass extending symmetrically from the nipple. It is caused by an imbalance between estrogenic and androgenic action at the breast tissue level.
Detailed Overview
Gynecomastia is the most common breast disorder in males. It frequently occurs physiologically during three distinct life phases: infancy, puberty, and older adulthood, driven by transient natural hormonal fluctuations. Pathological gynecomastia can result from drugs, systemic diseases (like cirrhosis or chronic kidney disease), or endocrine tumors. It must be clinically distinguished from pseudogynecomastia (excess adipose tissue without glandular proliferation, common in obesity) and male breast cancer.
Epidemiology & Demographics
Extremely common. Physiologic pubertal gynecomastia affects up to 60% of boys (peaking around age 14) and usually resolves within 1-2 years. Senescent gynecomastia affects up to 65% of men over age 50.
Etiological Mechanism
The fundamental mechanism is an altered ratio of estrogen to testosterone. This can be absolute (increased estrogen production or exogenous exposure) or relative (decreased testosterone production or androgen receptor blockade).
Primary Causes
["Physiologic (Neonatal, Pubertal, Aging).", "Medications (Spironolactone, Ketoconazole, Cimetidine, Anti-androgens for prostate cancer).", "Cirrhosis (reduced hepatic degradation of estrogens and increased aromatization of androgens).", "Hypogonadism (Klinefelter syndrome)."]
The male breast contains receptors for both androgens (which inhibit glandular growth) and estrogens (which stimulate glandular growth). When estrogen levels rise relative to testosterone (due to increased peripheral aromatization, decreased testosterone synthesis, or receptor blockade), it stimulates ductal epithelial hyperplasia and periductal stromal proliferation, resulting in a palpable glandular mass.
Diagnostic Criteria & Guidelines
Clinical diagnosis based on palpation of >0.5 cm of firm, glandular tissue concentric to the nipple-areolar complex. Workup to identify pathological causes includes medication review and laboratory testing.
Observation and reassurance for physiologic pubertal gynecomastia, which resolves spontaneously in 90% of cases. Discontinuation of any offending medications. Treatment of underlying disorders (e.g., testosterone replacement for primary hypogonadism).
Second-Line & Adjunctive Therapy
In the early (florid) phase (<6-12 months) causing severe pain or psychological distress, selective estrogen receptor modulators (SERMs) such as Tamoxifen (10-20 mg PO daily) or Raloxifene, or aromatase inhibitors (Anastrozole), can be used off-label to regress glandular tissue.
Surgical & Procedural Management
Subcutaneous mastectomy (surgical excision of the glandular tissue, sometimes with liposuction) is indicated for patients in the late fibrotic phase, or those with severe aesthetic/psychological impairment who fail medical therapy.
Patient Counseling & Advice
Provide strong reassurance to adolescents that this is a normal part of puberty and will likely go away on its own. Advise against squeezing or frequently manipulating the breast, as this can stimulate further growth.
Follow-Up & Monitoring Schedule
Clinical re-evaluation every 3-6 months for resolving pubertal gynecomastia.
Preventive Strategies
Avoid known pharmacological triggers when alternatives are available (e.g., use Eplerenone instead of Spironolactone).
Excellent. Physiologic cases mostly resolve. Pathologic cases respond well to cause-removal or surgery. It does not significantly increase the risk of male breast cancer.