Surgical biopsies can be either excisional or incisional.
An excisional biopsy removes the lump or the suspicious area in its entirety. Excision is currently the standard procedure for biopsying lumps that are smaller than an inch or so in diameter. In effect it is similar to a "lumpectomy," surgery to remove the lump and a margin of surrounding tissue, which is often used (in combination with radiotherapy) as the basic treatment for early breast cancer.
An excisional biopsy is typically performed in the outpatient department of a hospital. A local anesthetic is injected into the woman's breast, and perhaps she is given a tranquilizer. The surgeon makes an incision along the contour of the breast and removes the lump along with a small margin of normal tissue. Because no skin is removed, the biopsy scar is usually small. The procedure typically takes less than an hour. After spending an hour or two in the recovery room, the woman goes home the same day.
An incisional biopsy removes only a portion of the tumor (by slicing into or incising it) for the pathologist to examine. Incisional biopsies are generally reserved for tumors that are larger. They too are usually performed under local anesthesia, with the woman going home the same day.
Whether or not a surgical biopsy will change the shape of your breast depends partly on the size of the lump and where it is located in the breast as well as how much of a "margin" of healthy tissue the surgeon feels it is wise to remove. You should talk with your doctor beforehand so you understand just how extensive the surgery will be and what the result is going to look like.