HI Thank for asking to HCM I really appreciate your concern, this could be physiological condition, in my opinion no need to go for any medical therapy because there you would be given hormone therapy and that would be more harmful, at the most you can just go to find out any systemic reason of this but of course this is very uncommon, just take care in your diet, do some aerobic exercise, low down your stress level, and stop worrying about this, chances of increasing the mass of mammary gland is likely hope this information helps you have good day.