Suggest Treatment For Cyst On The Breast With Fluid Discharge

i have had a cyst in my breast for 2yrs. the drs have done repeat mamos and ultra sounds to watch it. It is tender but more so during my menstral. I have noticed i seem to be leaking a clear fluid too. i am one that stays away from the knife until absalute necessary but i am starting to think this could ne caused by pre menapause. should i think about letting them do a sirenge biopsy or what