Approximately 20 million Americans suffer from some type of thyroid disease, and up to 60% of them might be unaware of their condition. Thyroid problems can influence mood, weight, fertility, and cardiac health. Therefore, it’s crucial to obtain a timely and precise diagnosis to start treatment promptly.
Fine needle aspiration (FNA) is an essential diagnostic technique for evaluating thyroid nodules. This minimally invasive procedure uses a thin, hollow needle to collect tissue samples for biopsy, enabling your physician to detect abnormalities in the thyroid.
Understanding how to prepare for FNA, the specifics of the procedure, and how to interpret the results can help you anticipate what to expect and alleviate any concerns you may have.
Indications and Criteria for Fine Needle Aspiration Biopsy Procedure
FNA allows for a detailed examination of the thyroid’s cellular makeup, equipping doctors with a clear roadmap for treatment strategies. Here are some scenarios where an FNA biopsy is valuable for prompt and precise diagnosis:
Suspicious Thyroid Nodules
If you have a thyroid nodule that’s growing quickly, is larger than ⅜-⅝”, is abnormally shaped, or has calcium deposits, your doctor may recommend an FNA biopsy for further investigation.
While an ultrasound can detect these atypical characteristics, an FNA biopsy can provide a more accurate diagnosis by closely analyzing the cells. This can help your doctor determine if the nodule is a benign growth or a more severe issue.
Sometimes, the first biopsy of a thyroid nodule might not provide a definitive result, leaving your doctor uncertain about the benign or malignant nature of the nodule’s cells.
An FNA can help your healthcare team gather more detailed information. Based on these findings, the subsequent course of your treatment—whether surgery, radiofrequency ablation (RFA), or close monitoring of the nodule—can be determined.
Family History of Thyroid Cancer
If there’s a history of thyroid cancer in your family, your risk of contracting the disease increases. The American Thyroid Association suggests that individuals with a relative diagnosed with papillary thyroid cancer face a 5 to 10 times greater risk of developing the condition.
Cancer is often present in a more aggressive variant. In these cases, an FNA biopsy can spot early signs of cancer in those who are at higher risk, sometimes even before imaging tests can provide results.
Recurrent Thyroid Cancer
Patients who have previously been diagnosed with thyroid cancer should remain vigilant for any new lumps or growths in the thyroid region, as these may indicate a recurrence of the disease. Conducting an FNA biopsy promptly can assess these growths, ensuring that if the cancer reoccurs, it’s detected and addressed early on.
Fine Needle Aspiration Procedure
FNA is the only non-surgical way to determine if a thyroid nodule is benign or cancerous. The fine needle aspiration procedure is quick, straightforward, and minimally invasive. It is an outpatient procedure, so you can resume regular activities on the same day.
Here’s what you can expect during an FNA biopsy procedure:
Positioning of the Patient
You’ll be placed on the examination table with a pillow beneath your head to hyperextend your neck. This positioning allows the doctor optimal access to your thyroid gland and enhances imaging accuracy with the ultrasound wand. It also allows the doctor to insert the needle with greater precision.
Sterilization of the Skin
The skin covering your thyroid will be cleansed and sterilized. Maintaining cleanliness is crucial to prevent any infections after the procedure.
Following that, you’ll receive an injection of an anesthetic, such as lidocaine, to numb the region. You may feel a brief sting and burning sensation, but this ensures the remainder of the procedure is comfortable.
The doctor will also apply lubricating jelly on the side of your neck, allowing the ultrasound wand to glide more smoothly across your neck and produce clearer images.
After the ultrasound identifies your thyroid, the images will be projected onto a screen for your doctor’s reference. Your physician will then gently insert the thin, hollow needle into the appropriate location on your thyroid gland.
Aspiration and Sample Collection
The doctor moves the needle back and forth in the nodule a few times—usually 4-6 passes—to get enough cells for testing. After each pass, the collected material is placed on a slide to be dispatched to the laboratory.
You may feel mild pressure on your neck with each pass. However, you mustn’t move, cough, sneeze, or swallow while the needle is inside your neck to avoid an accidental injury.
Following the biopsy, there should be minimal bleeding, and a small bandage will be placed over the site where the needle was inserted. You might feel some soreness in your neck for a day, but using an ice pack or taking Tylenol can help alleviate the pain. It’s advisable to avoid ibuprofen to minimize the chance of excessive bleeding.
Possible Complications and Risks
Fine needle aspiration procedures are safe and typically cause little discomfort to patients. However, like all medical procedures, there are some inherent risks and potential complications, including:
Pain and Discomfort
Many individuals who undergo FNA report minimal or no pain. Research comparing various needle sizes indicates no major difference in pain levels, implying that discomfort isn’t necessarily tied to the needle’s gauge.
However, the depth of the nodule appears to influence the level of discomfort, suggesting that deeper nodules may require increased amounts of local anesthesia to reduce pain throughout the procedure.
Bleeding and Hematoma
Bleeding is a rare side effect of FNA. Studies contrasting FNA with core needle biopsy have shown that FNA typically leads to fewer bleeding issues. Even among patients taking anticoagulant drugs, the rate of patients with excessive bleeding remains low, indicating the safety of the FNA procedure.
In rare instances, patients might exhibit neurological symptoms post-FNA biopsy, which could include numbness, alterations in voice, or episodes of fainting. However, this occurs in less than 1% of cases.
Needle Track Seeding
There’s a small risk that cancer cells could be spread along the path of the needle, known as needle track seeding. This occurrence is rare, and even when it does happen, it can often be effectively treated with surgery.
Infection and Thyrotoxicosis
While infection is a risk with any procedure that breaks the skin, it is not common with FNA. However, doctors need to be careful about the possibility of infection, especially in immunocompromised patients at higher risk. Another rare complication is thyrotoxicosis, where the procedure triggers symptoms associated with an overactive thyroid.
Understanding the Results
Receiving the results from a thyroid FNA can understandably cause some anxiety. However, it’s reassuring that this test has a 95% accuracy rating when a sufficient tissue sample is available for examination.
Below is a brief overview to help you interpret the possible results and their implications for your thyroid health.
Benign Thyroid Nodules
When an FNA result indicates that a thyroid nodule is benign, it essentially means the growth is non-cancerous and doesn’t represent a significant health risk. Benign nodules are the most frequent outcome of thyroid biopsies. Even if they’re non-threatening, your doctor will likely monitor them to ensure no changes or issues arise.
Should these nodules grow substantially or begin impeding functions such as breathing, speaking, or swallowing, treatment options are available. One method is thyroid radiofrequency ablation (RFA), which can reduce their size and mitigate any associated discomfort or complications.
Atypia or Follicular Lesion of Undetermined Significance (AUS/FLUS)
This outcome falls into an ambiguous category. It indicates that the cells are atypical, but their exact nature is unclear. While they don’t raise red flags for cancer, they aren’t entirely normal. Your doctor will probably recommend further tests, possibly a repeat biopsy, for clearer insights.
Follicular Neoplasm or Suspicious for Follicular Neoplasm
This means the nodule could be a follicular neoplasm, a type of growth that could be benign or malignant. These indeterminate results might point to several possibilities like a follicular adenoma, a benign adenomatoid nodule, or even a non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), which means the growth resembles cancerous cells when observed under a microscope but exhibits the behavior of a benign nodule.
On the other hand, it also implies an elevated risk for malignant conditions, such as follicular carcinoma or the follicular variant of papillary thyroid carcinoma, which is more serious. To determine the exact nature of the growth, your doctor might recommend further investigations, including additional biopsies or genetic testing.
Suspicious for Malignancy
The label “Suspicious for Malignancy” doesn’t definitively diagnose cancer, but it certainly sounds an alarm. This suggests there’s a likelihood of about 65-70% that the nodule might be malignant.
The tissue sample could exhibit a combination of features: some that resemble cancerous indicators, like minuscule calcium deposits or irregular borders, and others that appear benign, such as a distinct boundary around the nodule and an absence of blood vessels. This result indicates that the nodule has enough concerning characteristics to warrant a closer look.
Malignant Thyroid Nodule
A result specifying a “Malignant Thyroid Nodule” confirms that the thyroid nodule is cancerous. These findings are present in approximately 7% of biopsies. The majority of these malignant nodules are identified as papillary thyroid cancer.
The standard treatments for this condition usually involve the partial or full surgical removal of the thyroid gland or the application of radioactive iodine treatments.
Support Your Thyroid Health With Help From Associated Endocrinologists
Your thyroid is critical for numerous bodily processes, so when you notice a lump on your throat or find it challenging to speak or swallow, it can be distressing. Fine needle aspiration procedure is a simple, low-risk way for your doctor to determine if your thyroid nodules require monitoring or treatment.
If you’re experiencing signs that point to a thyroid issue, don’t wait. Contact our team at Associated Endocrinologists for a full range of thyroid services, from scans and ultrasounds to guided fine needle aspiration procedures.
Schedule an appointment today. Our experienced and compassionate healthcare professionals can walk you through each step, ensuring you understand your treatment options, whether radioactive iodine therapy or thyroid RFA, to manage any malignant or benign nodules.