Gynaecomastia

Background

• Enlargement of breast tissue in men
• Not uncommon (more common than reported)- may occur in up to 30% of men
• Incidence increases with age; but also very common feature in neonates due to placental transfer of maternal hormones
• Causes may be physiological or pathological

Causes

• Physiological
  • Trimodal age distribution
    • Neonatal
    • Adolescents (around 50% of males will experience gynaecomastia at 13/14 due to increase in oestrogen and testosterone hormones)
      • Often resolves spontaneously but can be psychologically distressing
    • Old age (decreasing free testosterone)
• Non-physiological
  • Persistent adolescent symptoms
  • Obesity (fat is a store for oestrogen and can cause gynaecomastia)
  • Medications
    • Anti-androgenic e.g. chemotherapy agents; isoniazid; ketoconazole; methotrexate; metronidazole; omeprazole; ranitidine; spironolactone; penicillamine, cimetidine
    • Oestrogenic properties e.g. Anabolic steroids; diazepam; digoxin; oestrogens; phenytoin
    • Increased metabolism of androgens e.g. Alcohol
    • Increased sex hormone binding globulin e.g. diazepam, phenytoin
    • Induces hyperprolactinaemia e.g. Haloperidol and antipsychotics; metoclopramide
    • Unknown e.g. amiodarone; amlodipine and other CCBs; ACEIs; antiretrovirals; atorvastatin; diltiazem; fluoxetine and other SSRIs/antidepressants; heroin/methadone
  • Pathology
    • Cirrhosis/Liver disease
    • Primary Hypogonadism
    • Tumours e.g. Leydig (oestrogen producing) testicular cancer; adrenal tumours
    • Hyperthyroidism
    • Chronic Kidney Disease
    • Cushing’s

History

• Onset, duration and timing
• Associated pain/tenderness
• Associated symptoms- particularly ask about sexual dysfunction/impotence; also ask about others and explore alternative diagnoses where appropriate
• Ask about PMHx and RHx; social Hx including alcohol, illicit drug use and smoking

Examination

• Examine the tissue- is it true breast tissue or adipose (fat- pseudogynaecomastia)
  • True gynaecomastia can be felt as a separate tissue mass under the skin
  • Size/symmetry
• Look for any evidence of chronic liver disease or kidney disease
• Look also for any signs of hyperthyroidism or Cushing’s
• Look at the testes for any signs of atrophy, tumour or cryptorchidism

Investigations

• USS may help differentiate adipose and breast tissue if uncertain
• If an underlying medication or other cause is not found (e.g. liver failure, kidney failure, hyperthyroidism etc), then
  • Testosterone
  • LH, FSH, oestrodiol, prolactin and hCG (tumour marker)
    • If LH high and testosterone low- may indicate testicular failure
    • If LH and testosterone both low- usually due to increase in oestrogens
    • If LH and testosterone both high- androgen resistance or neoplasm secreting gonadotrophin

NB An underlying cause is often not found