An ultrasound-guided breast biopsy is a minimally invasive procedure that utilizes sound waves to pinpoint a breast lump or abnormality and extract a tissue sample. This sample is then examined under a microscope for diagnosis. Compared to surgical biopsies, it offers benefits such as minimal scarring and avoids exposure to ionizing radiation.
If you have any recent illnesses or medical conditions, or if you have allergies, especially to anesthesia, inform your doctor. Discuss all medications you are taking, including herbal supplements and aspirin. You might need to discontinue aspirin or blood thinners a few days before the procedure. Refrain from wearing jewelry and opt for comfortable, loose-fitting clothing. You might be asked to change into a gown. If sedation is planned, ensure someone can drive you home afterward.
Understanding Ultrasound-Guided Breast Biopsy
Lumps or abnormalities in the breast are often detected through physical exams, mammography, or other imaging tests. However, these methods cannot definitively determine whether a growth is benign or cancerous.
A breast biopsy involves removing a small tissue sample from a suspicious area for laboratory analysis. While surgical biopsies are an option, radiologists often employ less invasive techniques using a hollow needle guided by imaging technology. This image-guided needle biopsy doesn’t remove the entire lesion but obtains a small sample for further examination.
Alt text: A radiologist using an ultrasound transducer on a patient’s breast to guide a biopsy needle.
Image-guided biopsy employs ultrasound, MRI, or mammography to guide the sampling of abnormalities. In an ultrasound-guided breast biopsy, ultrasound imaging helps guide the radiologist’s instruments to the precise location of the abnormal growth.
Common Uses of the Procedure
An ultrasound-guided breast biopsy is commonly performed when a breast ultrasound reveals abnormalities, including:
- A suspicious solid mass
- Distortion in the breast tissue structure
- An area exhibiting abnormal tissue changes
Even if a mass is palpable (can be felt), your doctor may still recommend ultrasound guidance for the biopsy to ensure accuracy and precision.
Ultrasound guidance is applied in four main biopsy procedures: fine-needle aspiration, core needle biopsy, vacuum-assisted biopsy, and surgical biopsy.
Preparing for the Procedure
Wear comfortable, loose-fitting clothing to your appointment. You may need to remove clothing and jewelry from the area being examined and change into a gown.
Before the needle biopsy, inform your doctor about all medications you are taking, including herbal supplements, and list any allergies, particularly to anesthesia. Your doctor may advise you to stop taking aspirin, blood thinners, or specific herbal supplements three to five days prior to the procedure to minimize bleeding risks.
Alt text: A patient in position for an ultrasound-guided breast biopsy procedure.
Additionally, inform your doctor about any recent illnesses or other medical conditions. Consider arranging for someone to drive you home, especially if you are receiving sedation.
What to Expect During the Procedure
During an ultrasound exam, a transducer sends sound waves and records returning echoes. When pressed against the skin, the transducer sends small pulses of inaudible, high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids, and tissues, the receiver in the transducer records tiny changes in the sound’s pitch and direction. A computer instantly measures these signature waves and displays them as real-time pictures on a monitor. The technologist typically captures one or more frames of the moving pictures as still images and may also save short video loops of the images.
Utilizing an ultrasound probe to visualize the location of the breast mass, distortion, or abnormal tissue change, the radiologist inserts a biopsy needle through the skin, advances it into the targeted finding, and removes tissue samples. If a surgical biopsy is being performed, ultrasound may be used to guide a wire directly into the targeted finding to help the surgeon locate the area for excision. With continuous ultrasound imaging, the physician can view the biopsy needle or wire as it advances to the lesion in real-time.
The Ultrasound Equipment
Ultrasound machines include a computer console, video monitor, and a transducer. The transducer, a small handheld device resembling a microphone, emits inaudible, high-frequency sound waves into the body and listens for the returning echoes. Different transducers with varying capabilities may be used during a single exam. This principle is similar to sonar used by boats and submarines.
Alt text: A modern ultrasound machine used for medical imaging.
A small amount of gel is applied to the area under examination to facilitate the sound waves’ travel between the transducer and the area. The ultrasound image is immediately displayed on a video monitor. The computer creates the image based on the loudness (amplitude), pitch (frequency), and time taken for the ultrasound signal to return to the transducer, as well as the type of body structure and/or tissue the sound is traveling through.
The doctor will use one of four instruments: a fine needle attached to a syringe, a core needle (automatic, spring-loaded needle), a vacuum-assisted device (VAD), or a thin guide wire for surgical biopsy.
Procedure Steps
Image-guided, minimally invasive procedures like ultrasound-guided breast biopsies are typically performed by a radiologist with specialized training. Breast biopsies are usually performed on an outpatient basis.
You will be positioned lying face up on the examination table or turned slightly to the side.
The doctor will inject a local anesthetic into the skin and more deeply into the breast to numb it.
Pressing the transducer to the breast, the sonographer or radiologist will locate the lesion.
The doctor will make a very small nick in the skin at the site where they will insert the biopsy needle.
The radiologist, monitoring the lesion site with the ultrasound probe, will insert the needle and advance it directly into the mass.
The doctor removes tissue samples using one of three methods: fine needle aspiration, core needle biopsy, or vacuum-assisted device (VAD).
After sampling, the doctor will remove the needle.
If a surgical biopsy is to be performed, the doctor will insert a wire into the suspicious area as a guide for the surgeon.
The doctor may place a small marker at the biopsy site so they can locate it in the future if necessary.
Once the biopsy is complete, the doctor or nurse will apply pressure to stop any bleeding. They will cover the opening in the skin with a dressing. No sutures are needed.
The doctor may use mammography to confirm that the marker is in the proper position.
The procedure is usually completed within an hour.
What to Expect After the Biopsy
During the biopsy, you will be awake and should experience minimal discomfort. Many women report little pain and no scarring. However, some patients with dense breast tissue or abnormalities near the chest wall or behind the nipple may be more sensitive during the procedure.
When the local anesthetic is injected, you will feel a pin prick followed by a mild stinging sensation. You will likely feel some pressure when the doctor inserts the biopsy needle and during tissue sampling; this is normal.
The area will become numb within seconds.
You must remain very still during the imaging and biopsy.
As tissue samples are taken, you may hear clicks or buzzing sounds from the sampling instrument, which is normal.
If you experience swelling and bruising following your biopsy, your doctor may recommend an over-the-counter pain reliever and a cold pack. Temporary bruising is normal.
Contact your doctor if you experience excessive swelling, bleeding, drainage, redness, or heat in the breast.
If a marker is left inside the breast, it will cause no pain, disfigurement, or harm. Biopsy markers are MRI compatible and will not trigger metal detectors.
Avoid strenuous activity for at least 24 hours after the biopsy. Your doctor will provide more detailed post-procedure care instructions.
Understanding Your Results
A pathologist examines the removed specimen and provides a final diagnosis. Depending on the facility, the radiologist or your referring physician will share the results with you. The radiologist will also evaluate the biopsy results to ensure that the pathology and image findings are consistent. In some cases, even if cancer is not diagnosed, surgical removal of the entire biopsy site and imaging abnormality may be recommended if the pathology does not match the imaging findings.
A follow-up exam may be necessary. If so, your doctor will explain the reason. Sometimes, a follow-up exam further evaluates a potential issue with more views or a special imaging technique or to see if there has been any change over time. Follow-up exams are often the best way to see if treatment is working or if a problem needs attention.
Benefits and Risks
Benefits
- Less invasive than surgical biopsy, with minimal or no scarring.
- Can be performed in under an hour.
- No ionizing radiation is used.
- Provides reliable tissue samples to determine if a breast lump is benign or malignant.
- Faster than stereotactic breast biopsy and avoids ionizing radiation exposure.
- Allows real-time monitoring of the biopsy needle’s movement.
- Can evaluate lumps under the arm or near the chest wall, which are difficult to reach with stereotactic biopsy.
- Less expensive than open surgical or stereotactic biopsy.
- Brief recovery time, allowing patients to resume usual activities quickly.
Risks
- Risk of bleeding and hematoma formation (less than 1%).
- Occasional discomfort, manageable with over-the-counter pain medication.
- Risk of infection (less than 1 in 1,000).
- Slight risk of needle passing through the chest wall during deep tissue biopsies, potentially causing lung collapse (extremely rare).
- Small chance of inconclusive results requiring further investigation.
Limitations of Ultrasound-Guided Breast Biopsy
Ultrasound-guided biopsy may occasionally miss a lesion or underestimate the extent of disease. If the diagnosis remains uncertain after a technically successful procedure, surgical biopsy may be necessary.
This method is only applicable if the lesion is visible on ultrasound. Clustered calcifications are not as clearly visualized with ultrasound as with X-rays.
Very small lesions may be challenging to target accurately with ultrasound-guided core biopsy.
Additional Resources
- RTAnswers.org: Radiation Therapy for Breast Cancer
This information aims to provide a comprehensive understanding of ultrasound-guided breast biopsies and should not substitute professional medical advice. Always consult with your healthcare provider for personalized guidance and treatment.
