5 cm is a size when many doctors start to recommend surgery. After menopause
, even more so. With a family history of breast
cancer (which could have some link to ovarian cancer) then waiting is even less advisable. Most cysts are benign, but the more risk factors a person has , the more it makes sense to opt for surgery...and if you really want to remove the fear of ovarian cancer from your life, then have both ovaries removed , too.