Gynaecomastia

Gynaecomastia is the benign proliferation of glandular tissue of the male breast. Most patients with gynaecomastia are asymptomatic. Symptomatic patients may present with breast or nipple pain or tenderness, breast enlargement, or a breast lump
Physiological causes
- Infancy – 60–90% of infants have transient gynaecomastia due to oestrogenic stimulation from the mother and placenta (resolves neonatally)
- Puberty – 30–60% of boys develop transient gynaecomastia (usually develops after the age of 10 years and resolves by age 17 years)
- Aging – gynaecomastia is seen in an increasing number of normal adult men with increasing age (65% at age 80 years)
Pathological causes
- Drug induced (therapeutic drugs)
  - Androgens
  - anabolic steroids
  - oestrogens and oestrogen agonists
  - cyproterone
  - cimetidine
  - digoxin
  - spironolactone
- Drug induced (drugs of abuse)
  - Alcohol
  - Amphetamines
  - Heroin
  - marijuana
- Liver cirrhosis
- Malnutrition
- Primary or secondary hypogonadism
- Testicular tumours
- Hyperthyroidism
- Renal disease
- Idiopathic – in 25% of cases of gynaecomastia, no specific cause is identified