If they remove my breast tumor will it disfigure my breast?

Hopefully not: Benign breast tumors (i.e. Fibroadenomas) can be addressed percutaneously via vacuum assisted excision or cryoablation with min. Scar and little or no cosmetic effect. Cancer treatment will leave a scar. A secondary goal of breast conservation (after appropriate treatment of the cancer) is to preserve a cosmetically appropriate breast. Oncoplastic techniques may assist in this regard.

Depends: Depending on the size of the tumor and the size of the breast, the deformity that may occur varies greatly. If the tumor is large and the breast is small, the change of a disfiguring change is high. The larger the breast, the less likely the surgery will disfigure the breast. Discuss this with your surgeon.

Generally yes: There are many considerations when answering this question. If the cancer is confined to the breast without having spread to any distant organs, then surgery is an important part of the cancer therapy, even if it disfigures the breast. Ask to talk to a plastic surgeon to see what breast reconstruction may be an option for you.

Second opinion: There are many options availabe for removing tumors and preventing disfiguring the breast. If this is a cancer, then you may consider chemotherapy or hormonal therapy before surgery to shrink the tumor. If this is a benign tumor then an "oncoplastic" procedure can be performed. Usually a breast surgeon and plastic surgeon will work together to get the tumor out and leave you with good cosmesis.