Overview of Thyroid Nodule Biopsy
Fine needle aspiration (FNA) is a procedure where a thin needle is used to collect a sample of cells from a lump or a mass in the body. This technique was first developed back in the 1930s by Martin and Ellis. Despite its potential uses in medicine, it didn’t initially gain much attention. This was mainly due to worries about possibly spreading cancer cells during the procedure.
Later, a method combining ultrasound – a technique that uses sound waves to create a picture of the inside of your body – with FNA was introduced by Walfish. This combination enhanced the accuracy of the procedure, making it much easier to correctly identify the cells collected. Over time, the use of ultrasound with FNA has become an essential process in assessing lumps in the thyroid gland.
Important factors to consider during an FNA procedure include:
* Reducing discomfort during the process
* Ensuring the safety of the patient
* Using the ultrasound and the needle properly to clearly see where the needle is going and assist in reaching the right area
* Confirming that enough cells have been collected for the sample.
Anatomy and Physiology of Thyroid Nodule Biopsy
The thyroid gland is a small organ found at the front of your neck, right in front of your windpipe or trachea. It’s made up of two parts, called lobes, that are connected in the center by a section known as the isthmus. The isthmus is located directly above the second and third rings of your windpipe.
When looked at using ultrasound – a medical tool that uses sound waves to create pictures of the inside of your body – the thyroid gland is pretty easy to spot because it generally appears brighter than the muscles on either side of it – the sternocleidomastoid muscle on the outer edge and the sternohyoid muscle at the front.
As you get older, it’s normal for small lumps, or nodules, to appear in your thyroid gland. They show up on the ultrasound image as areas that look different from the regular thyroid tissue. Several studies have looked into how the characteristics of these nodules that can be seen on ultrasound might help doctors understand if they are likely to be cancerous.
The things that might make a doctor worried about cancer include nodules that appear darker on the ultrasound, tiny spots of calcium build-up (microcalcifications), a lumpy shape, being taller than they are wide, having ragged edges, and showing a lot of blood flow inside them on the ultrasound image.
Why do People Need Thyroid Nodule Biopsy
If your doctor is concerned about suspicious features or changes detected in your thyroid during an ultrasound, they may decide to perform a procedure called Fine Needle Aspiration (FNA). This procedure involves using a fine needle to remove a sample of tissue for further examination. Professional associations, like the American Thyroid Association (ATA) and the British Thyroid Association (BTA), have provided guidelines that help doctors determine how likely it is that these features are harmful based on what they see in the ultrasound.
The American College of Radiology (ACR) has also developed a classification system called the Thyroid Imaging, Reporting, and Data System (TI-RADS) which provides recommendations on when to use FNA or when to schedule a follow-up imaging based on what a thyroid ultrasound shows.
One recent study found the recommendations from the ATA and the TI-RADS to be similarly useful in figuring out if nodules, or growths, in the thyroid are cancerous.
No matter what classification system your doctor uses, the main reason they would perform a thyroid nodule FNA is to investigate further if there are any signs that suggest the presence of cancer.
When a Person Should Avoid Thyroid Nodule Biopsy
There are several situations when a person might not be able to undergo a thyroid nodule FNA (Fine Needle Aspiration, which is a procedure that involves using a thin needle to collect cells from a thyroid nodule). These include:
If the person has a bleeding disorder, known as bleeding diathesis, which can increase the risk of bleeding during and after the procedure.
If the person is unable to cooperate during the procedure, which is necessary for its successful and safe completion.
If there is an infection on the skin where the needle would be inserted, it might be risky to perform the procedure.
If the results of the FNA won’t change the course of the person’s care or treatment, then it may not be necessary to go through with the procedure.
Particularly if someone has a history of a bleeding disorder, it’s crucial that this is known beforehand. After the procedure, there is a risk of developing a local hematoma (a collection of blood outside of the blood vessels) that could put pressure on the windpipe and make breathing difficult.
However, studies suggest that the FNA procedure can be performed on patients who are taking blood-thinners (ant thrombotic and anticoagulant agents) without having to stop these medications. In fact, professional guidelines from the Society of Interventional Radiology categorize thyroid biopsies as having a low risk of bleeding and don’t typically require any blood tests to check for bleeding disorders. These guidelines also suggest that it’s generally safe to proceed with the procedure without stopping people from taking their blood thinners.
Equipment used for Thyroid Nodule Biopsy
Here’s a list of the equipment used commonly in medical procedures. The aim is to help you understand why your doctor might need these tools.
First, a fenestrated drape or towel drapes is used. This is a special sheet placed over the patient, leaving only the part being worked on exposed, to maintain cleanliness, and prevent infections.
A high-resolution (7.5 MHz to 15 MHz) linear-array transducer and an ultrasound machine are often used. These are tools that help doctors see structures inside your body by using sound waves. This has no effect on the body and is completely painless.
A sterile cover for the head of the transducer probe is used. This is a protective cover that provides a barrier against bacteria to keep the ultrasound probe clean and safe for use.
Sterile ultrasound gel or iodine-based solution serves as a coupling medium. This is a special gel or liquid that helps the ultrasound waves to travel into the body, giving the doctor a clear image of the area they’re looking at.
Lidocaine hydrochloride (1%) is used for local anesthesia in a quantity of 1 mL to 3 mL. This is a form of numbing medication that is used to decrease pain or discomfort in the area the doctor is looking at.
Lastly, the doctor uses a 22-gauge to 27-gauge needle attached to a syringe for specimen acquisition. This is a thin, sharp tool that’s used to collect a small sample of tissue or fluid from your body for testing.
Who is needed to perform Thyroid Nodule Biopsy?
In this procedure, a doctor or a specialized professional performs the major role. They are assisted by an ultrasound technologist, a professional expert in producing sound wave pictures of what’s going on inside your body. These images help the doctor see the problem clearly.
A pathology technician also plays a key role in this procedure. Their job involves preparing the sample collected during this procedure, which might be a small amount of tissue or fluid from your body.
This sample then goes to a pathologist, another type of specialized doctor. The pathologist examines the specimen under a microscope to make sure it has enough tissue or cells for an accurate result. This process helps your doctor understand what’s going on in your body and choose the best treatment for you.
Preparing for Thyroid Nodule Biopsy
Before a medical procedure, doctors typically explain everything in detail to the patient. They’ll let you know what to expect, how much discomfort you might feel, if local anesthesia will be used to numb the area, and any medical history they need to know about that could affect the procedure. They’ll also discuss what they think might be the issue (diagnosis) and any potential complications.
During the procedure, patients lay on their back, flat out. The doctor first performs a quick ultrasound scan to find out where exactly the problem area (nodule) is located. This also helps the doctor position the patient better, decide where to insert the needle, and examine the surrounding blood vessels.
Some doctors prefer to take extra cleanliness measures (sterile technique) and use local anesthesia, while others do not. Both choices depend on several factors including the institution the doctor works at and the doctor’s own preferences. However, the chance of getting an infection from this procedure is very low. Some studies even suggest that anesthesia might only be necessary for a small group of patients. To ensure safety and patient comfort, it is generally recommended for doctors to use both sterile techniques and local anesthesia.
To get the area ready for the procedure, your skin will be cleaned and a sterile sheet will be placed over you to maintain cleanliness. A special device (transducer) will be used to get a clear picture of the problem area on the ultrasound. A sterile cover will be placed on the transducer to keep it clean as well. Instead of a special ultrasound gel, some doctors may use an iodine-based solution to help improve the ultrasound image after the skin is cleaned. Local anesthesia is then used to numb your skin and the path the needle will take. The amount of anesthesia used depends on where the nodule is and how deep it is. A syringe, attached to a small needle, is then used to collect a tissue sample.
The doctor then performs the procedure while looking at a monitor placed opposite them. This monitor displays the ultrasound image, helping them guide the needle into the right place. This positioning helps the doctor easily see where the needle is going while making it comfortable for them to handle the needle.
How is Thyroid Nodule Biopsy performed
An ultrasound-guided fine-needle aspiration (FNA) is a procedure to remove a sample from a thyroid nodule, which can be thought of as a lump in your thyroid gland. A doctor uses ultrasound images to guide a needle to the nodule and collect a sample of cells. Here’s what usually happens during this procedure:
First, the doctor will lay a special medical instrument called a transducer on your neck, over the thyroid nodule. This transducer helps to produce clear ultrasound images on a screen so your doctor can see the nodule precisely. During this procedure, it is important for you, the patient, to stay as still as possible and avoid talking.
Next, the doctor will prepare a needle to collect the sample. This needle will be inserted into your skin having a mark right above the transducer. Depending on the situation, the needle could be either parallel or perpendicular to the transducer. Once the needle reaches the thyroid nodule, the doctor will move the needle back and forth numerous times to collect enough cells from the nodule.
Now, there are two main ways that the doctor can collect the cells – the nonaspiration technique and the aspiration technique. In the nonaspiration method, the cells naturally move into the needle due to a process called capillary action, with no need for any suction. In the aspiration method, the doctor applies gentle suction to help collect the cells during the back-and-forth movement of the needle. According to scientific research, there is no significant difference in the effectiveness of these two methods.
Different needle-syringes containing the collected samples may be submitted to a specialist called a cytopathologist, who may be present at the time of the procedure. This specialist will check the collected cells to see whether enough cells have been retrieved for testing. If needed, the doctor may repeat the aspiration steps until the cytopathologist confirms a satisfactory sample.
Possible Complications of Thyroid Nodule Biopsy
Most of the time, a thyroid needle biopsy (also known as Fine-Needle Aspiration or FNA) is done smoothly and without any problems. However, a small number of people might experience complications. One of the things that doctors worry about, but is still very rare, is the development of a neck hematoma, which is a pocket of blood that collects outside of the blood vessels in your neck.
Other less common complications may include pain, temporary swelling, infection, and vasovagal reaction – a sudden drop in heart rate and blood pressure causing you to feel faint or possibly to faint. But remember, these complications are quite rare and your doctor will do everything they can to make sure the procedure is safe and comfortable.
What Else Should I Know About Thyroid Nodule Biopsy?
Doctors do a test called Fine Needle Aspiration (FNA) on thyroid nodules because it helps them figure out if the nodule is cancerous or not. This test is guided by ultrasound, which is a type of imaging technology that uses sound waves to create pictures of structures inside your body like the thyroid gland. Ultrasound-guided FNA is a very important tool that helps doctors make quick diagnoses and start treating thyroid cancers more promptly, reducing their cost. Plus, it aids in identifying non-cancerous nodules, and this reduces the need for unnecessary surgeries and also assists in planning treatment.
Thyroid nodules are lumps or growths that can develop in your thyroid, a small butterfly-shaped gland located at the front of your neck. In recent years, the rates of papillary thyroid cancer, one type of thyroid cancer, have gradually increased. The good news is that this type of cancer often responds well to treatment with a low death rate, and commonly, treatment involves either surgery to remove the thyroid or a medicine that uses radioactive iodine.
On the other hand, there’s a more aggressive type of thyroid cancer known as anaplastic thyroid carcinoma. This type usually occurs in older adults and often results in rapid tumor growth and can cause discomfort due to its size affecting nearby structures like the airway. Unfortunately, the survival rate is only around 5% at five years.
That’s why early detection and diagnosis of thyroid cancer are so crucial. According to data from a big database called the Surveillance, Epidemiology, and End Results, people diagnosed with thyroid cancer that hasn’t spread have a better chance of survival compared to those with cancer that has spread to other parts of the body. All in all, ultrasound-guided FNA is an affordable and safe method for checking thyroid nodules and will continue playing an essential role in guiding doctors’ approach to treatment in the future.
