The Who, What, Where, When and Sometimes, Why.

Surgical Breast Biopsy Procedures

A core needle biopsy is the standard and preferred way to diagnose breast cancer. In rare cases, a surgical breast biopsy may be needed for diagnosis.

The tissue removed during a surgical biopsy is studied under a microscope to see if breast cancer is present. If breast cancer is found, other tests are done on the tissue to help plan your treatment.

Most surgical biopsies are excisional biopsies. With an excisional biopsy, the whole abnormal area (plus some of the surrounding normal tissue) is removed.

Today, few people have an incisional biopsy. An incisional biopsy only removes part of the tumor.

Learn more about types of breast biopsies.

Learn about factors related to prognosis (chances for survival) and treatment.

Excisional biopsy

The procedure

An excisional biopsy is done by a surgeon in an operating room.

The surgeon will use local anesthetic to numb the area that will be biopsied. You’ll get a drug to help you sleep (sedative), rather than general anesthesia. The sedative will be given by vein (through an IV).

Most people don’t need to stay overnight in the hospital.

Before surgery, a localization procedure may be done. A radiologist uses a mammogram or breast ultrasound image to guide a very thin wire, radioactive seed or other marker into the suspicious area of the breast. This is usually done if the abnormal area in the breast was first detected on an imaging test (such as a mammogram) and cannot be felt.

The surgeon makes a cut in the skin to remove the abnormal tissue.

During the procedure, the surgeon uses the wire, seed or other marker to find the area during surgery. The marker will be removed during the surgery.

The breast tissue that’s removed is usually X-rayed. This lets the surgeon and radiologist match the suspicious areas on the mammogram with those in the biopsy tissue.

If the areas match, the correct tissue was removed. If the areas don’t match, the surgeon may try again to make sure the suspicious area is removed, or they may wait and do another biopsy.

Learn how biopsy tissue is preserved for a pathologist’s exam.

When is excisional biopsy the only surgery needed?

Although the goal of an excisional biopsy is to diagnose breast cancer, sometimes the surgeon can fully remove the cancer. In these cases, excisional biopsy may be the only breast surgery needed to treat the cancer.

Some people diagnosed with breast cancer may need to have lymph nodes removed in a second surgery at a later date.

Learn more about breast cancer treatment.  

Assessing margins

If the biopsy shows breast cancer, a pathologist will study the tissue removed during surgery to check if there’s a wide enough rim of normal tissue surrounding the tumor.

This rim is called a margin. It helps show whether or not all of the tumor was removed.

Learn more about tumor margins.

Pathology exam

A pathologist’s exam of the breast biopsy tissue gives information that helps plan treatment, including:

Learn more about these factors.

Drawbacks of excisional biopsy

Compared to a needle biopsy, a surgical breast biopsy:

  • Is more invasive
  • Has a longer, more uncomfortable recovery time
  • Has a higher risk of infection and bruising
  • If invasive breast cancer is found, lymph nodes will need to be checked in a separate surgery

The amount of tissue removed during an excisional biopsy can also change the look and feel (sensation) of the breast.

If the excisional biopsy results are benign (not cancer), more surgery may have been done than was needed.

Updated 12/20/22


Fact Sheet

Fact Sheet