Gynaecomastia describes an abnormal amount of breast tissue in males and is usually caused by an increased oestrogen:androgen ratio. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia

Gynaecomastia is the growth of glandular tissue in male breasts. It is a benign condition that accounts for more than 65% of male breast abnormalities.

Causes

• Idiopathic gynaecomastia accounts for 75% of cases.
  • Physiological gynaecomastia occurs primarily in newborns and adolescents at puberty and usually will resolve spontaneously.
• syndromes with androgen deficiency: Kallman's, Klinefelter's
• testicular failure: e.g. mumps
• liver disease
• testicular cancer e.g. seminoma secreting hCG
• ectopic tumour secretion e.g. adenocarcinoma of the lung
• hyperthyroidism
• haemodialysis
• drugs: see below

PC

• Patients present with an increase in breast tissue, which is unilateral in one-third of cases.
• Tenderness may also be noted in a third of patients.
• Enlargement is usually central and symmetric.
  • Idiopathic and drug related gynaecomastia is usually unilateral.
  • Pubertal and hormonal cases tend to present with bilateral changes.