If this is truly a milk cyst, it should be left alone.  There is no need
to do anything, and doing something may just lead to complications.

However, I don't dread a needle biopsy the way this surgeon does.  I've
put needles into many breasts, and never caused a fistula.  The risk of
a fistula with a needle biopsy is virtually zilch.  If he is not willing
to do this, I would search out another surgeon.

Most of the time, even an open biopsy causes no problems, but there is a
risk of fistula, particularly if the incision is done across skin lines.
Nevertheless, if there is a real concern (and it doesn't seem as if
there should be), I would wait a few more months, and if the surgery
still seems necessary, and there is no other surgeon who will do the
surgery, the mother *can* dry up on just one side, you know.  I know you
all out there know that, but somehow surgeons don't know that.

Jack Newman, MD, FRCPC