Making The Diagnosis

When a concerning breast lump has been identified by a health care provider or an abnormality is noted on mammogram or breast ultrasound - a biopsy may be necessary to rule out or confirm a cancer. There are two goals of breast biopsy that are equally important. The first is to learn whether or not the abnormality represents a cancer. The second is to prove that the original area of concern has been targeted or sampled satisfactorily. Two types of breast biopsies are available as office procedures at the Breast Care Center: the ultrasound guided biopsy (also known as vacuum assisted mammotome biopsy) of an abnormality that can be seen on ultrasound and the core biopsy of a lump that can be felt by hand. If the biopsy returns benign (not cancer), in most cases a follow-up mammogram and/or ultrasound will be done in about 2 months to confirm the abnormality is removed or shows adequate evidence of having been biopsied.

There are several other types of breast biopsies which require additional technical equipment and support and therefore are performed on an outpatient basis at a local hospital or surgery center.

Stereotactic Biopsy

This is performed for an abnormality seen on mammogram, but not on ultrasound. The patient is lying face-down on a padded table and the breast is placed in an opening directly into a small mammogram unit that is beneath the table. Breast images are taken and the abnormality is identified with coordinates that direct the surgeon to the correct area. Local anesthetic is used to numb the breast and a small incision is made through which the biopsy device is passed. Several small samples of tissue are taken and also additional pictures to show the abnormality has been sampled. A small titanium tissue marker is inserted exactly where the tissue was removed. This process takes about 20-30 minutes. Pressure and ice are applied. No sutures (stitches) are needed and results are available in 48-72 hours. There is an approximate 350 pound weight limit for the table. Most patients return to work the next day.

MRI Guided Biopsy

This is performed for an abnormality seen only on breast MRI, and not on any other breast imaging (mammogram or ultrasound). The procedure is similar to stereotactic biopsy, but the method of guidance is Breast MRI. This is typically performed by a specially-trained radiologist, or surgeon. This process takes about one hour and the results are available in 48-72 hours. No sutures (stitches) are needed and you are awake throughout the procedure.

Open or Excisional Biopsy With or Without Wire Localization (Guidance)

This type of biopsy is done in the hospital as an outpatient for the following reasons:

  • When a previous core biopsy identifies atypical cells (abnormal but benign) and a larger sample of tissue is needed to check a wider area in the location the atypical cells were found.
  • When the abnormality is too close to the skin surface of the breast for a stereotactic biopsy to be safely performed.
  • When a previous core biopsy of a worrisome abnormality returns nondiagnostic (without enough abnormal tissue to make a diagnosis) or with a result that does not satisfactorily explain the abnormality and a larger area of tissue is needed to answer these questions.
  • If the abnormality cannot be felt-which is often the case, a “guide wire” is placed in the breast by the radiologist prior to the biopsy. This wire is guided to the abnormality by a mammogram and the patient is awake for this part of the procedure, performed in the radiology suite.