Fibroadenoma Biopsy: Understanding the Procedure & Next Steps

Question
Hi! I am in my 30's, quite healthy woman with no significant cancer family
history or previous cancer.
My gyn found a suspicious mass in my right breast so I got a diagnostic
mammography and ultrasound.

The ultrasound indicated the presence of a solid mass probably representing
a fibroadenoma.  Since there is no previous studies for comparison and the
finding is solid, they suggested biopsy to further evaluate. Category 4,
suspicious abnormality was the rate.

I visited a surgeon today since my gyn recommended to do so to be sure it is
a fibroadenoma. Surgeon touched the mass in my breast and suggested to
get right a way a fine needle biopsy followed by a surgery to extirpate the
tumor. He also said the chances the mass is malignant is 1%.

My question is... do I need to get the surgery? is it safe to wait see if it grows
before moving into surgery?

Can I be 100% sure the mass is not malignant with a fine needle aspiration?
Or should I get the core biopsy to "have a nice sleep".

If I can confirm with a biopsy that the tumor is benign can skip surgery for
now on and wait until the tumor grows to get rid of it?

As you can see I am very conservative about the surgery, but at the same
time I do not want to put myself at risk of getting cancer.

What would you do if you where in my shoes?  

Answer
It is almost impossible to be sure of anything in medicine to a 100% level. My personal opinion is that a fine/thin needle aspiration biopsy would be enough here together with ultrasound & mammography findings. Especially as the needle may be ultrasound guided to your lesion. The diagnosis of such a biopsy is based on cytology only however but in my opinion that is enough in this situation. If you insist on a histopathological diagnosis then the only choice would be a core biopsy. The choice is yours but I do not regard a core biopsy as necessary here. If the result of your biopsy etc. is that this is a fibroadenoma any further surgery in my opinion is unnecessary. If surgery is done anyway pathology can be done on the whole lesion making any biopsy more if not completely unnecessary. In my opinion a negative biopsy here will/should relieve of further surgery. This is my opinion on this matter!