Fine Needle Aspiration Cytology Biopsy (FNAC) :
Fine Needle Aspiration Cytology is the commonly used form of initial diagnostic biopsy method for breast lumps.
FNAC is done by cleaning the breast lump area, followed by insertion through the skin a 22 gauge fine needle and syringe through the skin.
If the lump is non-palpable (cannot be felt), the procedure should be done under image-guidance (Stereotactic mammography or Ultrasound).
Stereotactic mammography involves using computers to pinpoint the exact location of a breast mass based on mammograms (x-rays) taken from two different angles. The computer will help the physician to guide the needle to the correct area in the breast.
With ultrasound, the radiologist or surgeon will view the needle on the ultrasound monitor to help guide it to the area of biopsy. FNAC is usually performed under ultrasound image guidance.
Fluid aspirated from the breast lump may be clear, straw-colored, green or brown tinged, white, yellow, or more rarely, bloody. In most cases, these fluids are benign (non-cancerous).
If the fluid is not bloody, it is usually simply discarded because there is not typically any benefit gained from microscopic examination by a pathologist.
The bloody fluid may indicate cancer and is usually sent to the laboratory for analysis.
The samples are then smeared on a microscope slide and are:
Allowed drying in air.
Fixed by spraying, or immersed in a liquid.
The fixed smears are then stained and examined by a pathologist under the microscope.
FNAC does not require stitches and can usually be performed as an outpatient procedure. A small bandage or a sticky skin tape is placed over the area after the procedure. Many patients resume their routine work the same day after the FNAC procedure.
What is Core Needle Biopsy ?
A core needle biopsy is a percutaneous ("through the skin") procedure that involves removing small samples of breast tissue using a hollow "core" needle.
The needle used in core needle biopsy (16 gauge) is larger than the one used in FNAC. The needle has a special cutting edge. The breast area is applied with local anesthesia after localizing the lump and by fixing the lesion with one hand and performing a freehand needle biopsy with the other.
In the case of non-palpable lesions (those unable to be felt), stereotactic mammography or ultrasound image guidance is used.
The core needle biopsy procedure takes only a few minutes, and most patients are able to resume normal activity almost immediately afterwards. Core needle biopsy usually allows for a more accurate assessment of a breast mass than fine needle aspiration (if the sample is found to be solid or cloudy, suspicious-looking fluid) because the larger core needle usually removes enough tissue for the pathologist to evaluate abnormal cells in relation to the surrounding small sample of breast tissue taken in the specimen.
Core needle biopsy, like fine needle aspiration, only removes samples of a mass and not the entire area of concern. Therefore, it is possible that a more serious diagnosis may be missed by limiting the sampling of a lesion (abnormality).
Vacuum-assisted Biopsy :
Vacuum-assisted Biopsy procedures uses stereotactic mammography or ultrasound Imaging. VA biopsy method is a minimally invasive procedure that allows for the removal of multiple tissue samples.
The special biopsy probe used is inserted and properly positioned, by which a vacuum draws the breast tissue through the aperture of the probe into the sampling chamber of the device. The tissue inside the sampling chamber is collected by the rotating cutting device. Once the tissue sample is captured in the probe the surgeon rotates the thumbwheel of the probe, moving the sampling chamber approximately 30 degrees.
When sufficient number of tissue samples has been collected the surgeon removes the probe and applies pressure to the biopsy site. An adhesive bandage is applied to the skin nick.
This method is becoming more common as it is minimally invasive with appearance of no significant scaring. The test procedure can be performed under local anesthesia with the procedure taking less than one hour.
Large Core Biopsy :
Large core breast biopsy (ABBI - Advanced Breast Biopsy Instrumentation) is a surgical technique to remove the small suspicious tissue from the breast fully that involves removing an entire intact breast lesion (abnormality) under Stereotactic Mammography Imaging guidance. ABBI can remove 5 to 20 millimeters (mm) of breast tissue.
Before the biopsy test, the breast is cleaned and local anesthesia is injected to anaesthetize the area and a Narrow Core needle with a cutting device is inserted into the breast. The breast tissue is removed with the looped wire and taken to pathology laboratory for diagnosis.
X-ray Guided Breast Biopsy :
A computerized mammography machine uses intersecting coordinates to pinpoint the area of tissue change. This method is called stereotactic biopsy or x-ray guided biopsy.
X-ray guided breast biopsy is done when mammogram shows a suspicious mass that cannot be felt on breast examination, or having a suspicious cluster of small calcium deposits, when the structure of breast tissue is distorted
When do you need a X-ray guided breast biopsy ?
X-ray guided breast biopsy is done when
Mammogram showing a suspicious solid mass that cannot be felt on breast examination.
Mammogram showing a suspicious cluster of small calcium deposits.
The structure of breast tissue is damaged.
Presence of a new mass or calcium deposits presents at a previous site of surgery.
How is X-ray guided breast biopsy done ?
Stop taking aspirin or blood thinning drugs 3 days in advance of the biopsy procedure.
The patient is made to lying face-down, with her breast projecting through a hole in the table. The actual biopsy is done below the table after raising it to gain access to her breast. The procedure can also be done with the patient upright in a chair, the images are obtained by using computerized or digital imaging which reduces x-ray exposure to the breast, and also permits the images to be viewed on a computer monitor seconds after exposure.
The principle of Stereotactic biopsy is that a lesion can be located precisely in three dimensions by calculating its apparent change in position on angled x-ray images.
The first x-ray locates the abnormality in the breast, after which two stereo views are obtained; each angled 15 degrees to either side of the initial image.
Physician then marks the lesion electronically on the stereo images. The computer calculates how much the lesion's position appears to have changed on each of the stereo views, and in this way it is able to determine its exact site in three-dimensional space.
The first step in tissue isolation is to clean the skin and inject a local anesthesia.
A small nick is made in the skin and the tip of the biopsy needle is advanced to the calculated site of the lesion. At this point stereo images are again obtained to confirm that the needle tip actually is within the lesion.
Usually 5 to 10 samples are collected when doing a core biopsy, and at least 12 when using the Vacuum Assisted Device (VAD). Then a final set of images is obtained. If they show that the lesion has been mostly or completely removed, a small clip is left at the biopsy site so that it can be easily located if the lesion proves to be cancer.
The skin opening is covered with a dressing.
Avoid strenuous activity for 24 hours after returning home.
What is the Biopsy instruments used in this Procedure ?
The two instruments used in Biopsy procedure are
Core Needle Biopsy Device :
The equipment consists of an inner needle with a trough extending from it at one end and an overlying sheath attached to a spring-loaded mechanism that, when fired, shoots forward, filling the trough with tissue.
The outer sheath instantly moves forward to cut the tissue and keep it in the trough.
Each sample is obtained in a fraction of a second. It is necessary to withdraw the needle after each sample is taken to collect the tissue.
Vacuum Assisted Device (VAD) :
This equipment uses vacuum pressure to pull the inner breast tissue into a needle and remove it without having to withdraw the needle after each sampling.
The advantage of this device is that biopsies are obtained in an orderly manner by rotating the probe, assuring that the entire region of interest will be sampled. Using the automated core biopsy needle, sampling is more random and quicker.
