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Biopsies and Other Image-Guided Interventions

If diagnostic imaging cannot resolve a suspicious area of the breast, your doctor may recommend a breast biopsy.

A biopsy involves removing a small amount of tissue or fluid from the suspicious area and examining the cells under a microscope. Biopsy is the only way to definitively determine that a suspicious area is cancerous or benign.

The good news is that approximately 70 percent of women who have a breast biopsy do not have breast cancer. 

Types of Biopsies: What to Expect

The type of biopsy recommended for you will depend on the abnormality being evaluated. For example:

  • Stereotactic-guided biopsy is used to target calcifications or masses seen only on a mammogram. For the procedure, you will be asked to lie face down on a special table with an area for your breast. The breast is then compressed like a mammogram, and a sequence of images are obtained to localize the finding. Local anesthetic is then injected into your skin and breast, and additional images are obtained to guide the biopsy. The procedure usually takes 45 minutes.
  • Ultrasound-guided biopsy is used to target masses, cysts or abnormal appearing axillary lymph nodes seen on ultrasound. For the procedure, you will be asked to lie on your back on a table, like you did for the diagnostic ultrasound exam. Your radiologist will then inject local anesthetic into your skin and breast and use the ultrasound images to guide the biopsy or cyst aspiration. The procedure usually takes 15 to 30 minutes.
  • MRI-guided biopsy is used to target masses seen only on a MRI. For the procedure, you will be asked to lie on a table face down, like you did for the diagnostic breast MRI scan, and have contrast infused through an IV into your arm. A shorter version of the MRI scan will be performed. Your radiologist will then inject local anesthetic into your skin and breast, and MRI images will be repeated to guide the biopsy. The procedure usually takes 45 to 60 minutes.
  • Fine needle aspiration and lymph node biopsy are used to target suspected fluid-filled cysts or lymph nodes. During the procedure, a thin needle and syringe are used to aspirate fluid from a lump or lymph node. If the lump collapses when the fluid is removed, the lump is likely a non-cancerous cyst. If the lump persists after the fluid is removed, cells from the lump will be removed for examination. Lymph node biopsies are used to document metastasis (spread of cancer).

Your biopsy tissue or fluid will be sent to our pathology lab, where pathologists trained along sub-specialty lines will examine the sample. The pathologist's report will be sent to your physician and shared with you as soon as it is available.

Image-Guided Needle Localizations

If breast surgery is required as a result of the biopsy, our radiologists can help the surgeon locate the lesion, to ensure accurate removal of the tumor. Needle localizations can minimize the degree of cosmetic disfigurement and improve patient outcomes. 

During the procedure:

  • On the morning of your scheduled surgery, you will be asked to go to the Breast Imaging Center at Moores Cancer Center
  • Using mammography, ultrasound, or MRI as indicated, your radiologist will place a thin needle and wire into the lesion or biopsy clip
  • A small amount of local anesthetic is infused into the area
  • The localization device is then secured to the skin with tape, and you are escorted to the surgical area
  • When your surgery is performed, additional X-rays are made of the removed tissue and reviewed by the radiologist

Wireless Breast Localizations

In certain patients, the localization can be done without a needle. Instead, a small reflector is injected in the breast up to 30 days before surgery to help the surgeon perform a more precise surgical excision. UC San Diego Health is the first health care provider to offer "wireless" breast localization.


Women with unexplained clear or bloody spontaneous nipple discharge may be referred for a ductogram, which is a technique used to visualize and hence better understand what is going on inside your breast.

During the procedure:

  • You will be asked to lie on your back while we try to express nipple discharge
  • A small cannula (needle) is placed into the duct with discharge 
  • A small amount of contrast medium is injected 
  • The breast is imaged 
The reason for discharge is found to be benign in more than 85 percent of women tested.

Appointments & Referrals


Clinic Location

La Jolla

Logo for the Athena breast health study 

Athena Breast Health Network is a partnership between all five University of California medical centers, dedicated to saving lives by transforming how breast cancer screening, prevention and treatment is delivered.

Better breast health begins with completing Athena's questionnaire prior to your annual screening mammogram. By telling us your personal story, we can provide a personal roadmap to guide your breast cancer prevention, screening or treatment plan.