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

Surgical Biopsies

Although core needle biopsy is the standard way to diagnose breast cancer, some people need a surgical biopsy [6].

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.

Learn more about these tests.

Types of surgical biopsies

Most surgical biopsies are excisional biopsies.

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

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

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 wire-localization or marker/radioactive seed-localization procedure may be done. 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.

During the procedure, a radiologist uses a mammogram or breast ultrasound image to guide a very thin wire or radioactive seed into the suspicious area of the breast.

The surgeon uses this wire or seed to find the area during surgery. (The wire or seed 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 ensure the suspicious area is removed or 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 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 cancer, a pathologist will study the tissue removed during surgery to determine whether there’s a wide enough rim of normal tissue around 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.

Advantages of excisional biopsy

Excisional biopsy is accurate and gives few false negative results.

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

Learn more about these factors.

In some cases, excisional biopsy is the only surgery needed to remove the tumor.

Drawbacks of excisional biopsy

Compared to a needle biopsy, a surgical biopsy:

  • Is more invasive
  • Has a longer, more uncomfortable recovery time
  • Has a higher risk of infection and bruising

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

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

Updated 12/11/20


Fact Sheet

Fact Sheet