Such physiological gynaecomastia occurs in the neonatal and pubertal periods and also in old age. Neonatal gynaecomastia is due to the trans-placental passage of maternal oestrogen and may be associated with a nipple discharge known as 'witch's milk'. It usually resolves during the first few weeks of life. Pubertal gynaecomastia is the commonest male breast lesion. It can be either unilateral or bilateral.
Reassurance is often the only treatment that is required.
The lesion will generally settle spontaneously but may persist for months or years. Senile gynaecomastia can be difficult to differentiate from the pseudo- gynaecomastia due to general adiposity increasingly seen in old age. Only one third of patients with gynaecomastia will have a pathological cause. Acquired testicular failure - mumps, irradiation. Secondary testicular failure - hypopituitarism.