What is a biopsy?
A biopsy is the removal of cells or tissue from a suspicious mass. The tissue
or cells are then examined under a microscope to detect cancer cells. A biopsy
may be performed when an abnormal breast change is found during a mammogram,
ultrasound, or physical examination. A biopsy is the only way to determine if
cancer or a benign breast condition is present.
There are many types of biopsy procedures. The type of biopsy recommended by
your physician will depend on how large the breast lump or abnormal area is;
where in the breast it is located; how many lumps or abnormal areas, such as
suspicious calcifications, are present; if you have any other medical problems;
and what your personal preferences are.
What are the different types of biopsies?
- Fine needle aspiration (FNA): This is a non-surgical form of breast
biopsy in which a small needle is used to withdraw a sample of cells from the
breast lump. If the lump is a cyst (fluid-filled sac), removal of the fluid
will cause the cyst to collapse. If the lump is solid, cells can be smeared
onto slides for examination in the laboratory.
- Core biopsy: This is similar to FNA, but a larger needle is used because
actual breast tissue, rather than a sampling of cells, is removed. A sample of
the lump is removed, but the whole lump is not removed. The types of core
biopsies include ultrasound-guided core biopsy and stereotactic biopsy.
- Ultrasound-guided core biopsy: This tissue sampling technique does not
require surgery. A biopsy needle is placed into the breast tissue. Ultrasound
helps confirm the needle placement using sound waves reflected off breast
tissue so the exact location of breast tissue is biopsied. The type of echo
varies with each type of tissue. Ultrasound can distinguish many benign
lesions, such as fluid-filled cysts, from solid lesions. Tissue samples are
then taken through the needle.
- Stereotactic biopsy: With this technique, the area to be biopsied is
centered in the window of a specially designed compression paddle. First,
mammogram films, called scout films, are taken so the radiologist can examine
the breast tissue to be biopsied. Using a local anesthetic, the radiologist
makes a small opening in the skin. A sterile biopsy needle is placed into the
breast tissue area to be biopsied. Computerized pictures help confirm the
exact needle placement using digital imaging. Tissue samples are taken through
the needle. It is common to take multiple tissue samples (about three to
five).
- Open excisional biopsy: This is the surgical removal of the entire mass.
The tissue is then studied under a microscope. If a rim of normal breast
tissue is taken all the way around a lump (lumpectomy), the biopsy can also
serve as part of breast cancer treatment.
- Sentinel node biopsy: This is a new biopsy method used to pinpoint the
first lymph node into which a tumor drains (called the sentinel node) and to
remove only the nodes most likely to contain cancer cells. To locate the
sentinel node, a radioactive tracer and/or blue dye is injected into the area
around the tumor before a mastectomy is performed. The tracer travels the same
path to the lymph nodes that the cancer cells would take, making it possible
for the surgeon to determine the one or two nodes most likely to test positive
for cancer. If the nodes are positive for cancer, then more lymph nodes are usually
removed. Performing his method varies among hospital, and determining the best way to identify the positive nodes is still being
tested.