Physiological

Breast enlargement in a male may be a natural phenomenon at three different times of life:

• newborns -
  • due to transfer of maternal and placental oestrogen and progesterone, and persists up to several months (1,2)
• adolescence or puberty associated -
  • seen in 38% of boys aged 10-16 years; reaching a peak of 65% in 14-year-olds (1)
  • 25% or more of pubertal gynaecomastia are unilateral, and where bilateral, are normally of different degrees - this finding is suggestive of a variation in local factors, possibly related to hormone receptors or local hormone conversion
  • most cases resolve spontaneously in late puberty but a few may persist into adulthood for which the term, pubertal macromastia may be applied
  • for more details see linked item
• elderly -
• 40-70% of men may be affected. Frequently, it is a reflection of underlying pathology such as cardiovascular and liver dysfunctions, or current medication.
• in other cases, it may be due to changes in oestrogen and androgen metabolism with a relative oestrogen excess.
• elevation of plasma testosterone binding globulin, increased rate of peripheral conversion of androgen to oestrogen, increased plasma LH and FSH, and loss of circadian rhythmicity of plasma testosterone levels have all been noted

Physiological gynaecomastia requires no treatment unless it is accompanied by pain or is a reason of significant embarrassment to that person (2).

Reference:

• (1) Gately CA. Male breast disease.The Breast (1998) 7, 121-127.
• (2) Niewoehner CB, Schorer AE. Gynaecomastia and breast cancer in men. BMJ. 2008 Mar 29;336(7646):709-13.