It sounds like you are being set up for an excisional biopsy, and I would not want to have that done without general anasthesia. I would think that if the area of concern is in any way palpable, they would want to do a fine needle biopsy, or a stereotactic biopsy first to find out what you are dealing with.
An excisional biopsy with you awake could be very uncomfortable, and could cause you to have to go back for an additional surgery should there be any cancer cells found. If you have the biopsy's first, the surgery can be well planned, done once, and treatment planned for right afterward.
I don't mean to scare you, but I believe knowledge is power and strength. Your most important appointment is with the breast surgeon.....I am sure he will direct you to what he believes it the most effective strategy to deal with this issue.
Please click on the link below.I hope the information given by our Community Leader and a poster who had the surgery you'll be having, will answer your questions.
Wishing you all the best and good luck!