Condition by which males develop breast tissue due to an imbalanced ratio of oestrogen and androgen activity
Aetiology
Usually a benign disease but breast cancer can develop in about 1% of cases
Physiological
Physiological gynaecomastia most commonly occurs in adolescence, resulting from the delayed testosterone surge relative to oestrogen at puberty
Less commonly it occurs in the older population, secondary to decreasing testosterone levels with increasing age
Pathological
Lack of testosterone - causes include Klinefelter’s syndrome, androgen insensitivity, testicular atrophy, or renal disease
Increased oestrogen - causes include liver disease, hyperthyroidism, obesity, adrenal tumours, or certain testicular tumours (e.g. Leydig’s cell tumours)
Medication - causative agents include digoxin, metronidazole, spironolactone, chemotherapy, goserelin, antipsychotics, or anabolic steroids
Idiopathic
Pathophysiology
There is ductal growth without lobular development
Clinical features
Often insidious onset
On examination, gynaecomastia will present as a rubbery or firm mass (typically >2cm diameter) that starts from underneath the nipple and spreads outwards over the breast region
Investigations
Tests are only necessary if the cause for gynaecomastia is unknown (especially if physiological or iatrogenic)
In cases where malignancy is suspected, patients will require the triple assessment
