Table of Contents
- Key Points
- Background: Why This Research Matters
- Study Methods: How the Evidence Was Gathered
- Ultrasound: The Gold Standard for Imaging
- The Role of CT, MRI, and PET/CT Scans
- Nuclear Thyroid Scans (Scintigraphy)
- Fine-Needle Aspiration Biopsy (FNAB)
- Molecular Testing: A Genetic Look at Nodules
- Management and Follow-Up
- Surgical Treatment Options
- Nonsurgical Treatment Options
- Conclusion: Key Takeaways
- Study Limitations
- Recommendations for Patients
- Frequently Asked Questions
- Source Information
Key Points
- Most thyroid nodules are benign; fewer than 5% are cancerous in the general population.
- Ultrasound risk-stratification systems guide biopsy decisions, often avoiding biopsy for nodules under 1 centimeter.
- Molecular testing of indeterminate biopsy samples can reduce unnecessary diagnostic surgeries.
- Active surveillance is a recommended option for papillary microcarcinoma, a thyroid cancer smaller than 1 centimeter.
- Nonsurgical treatments like ethanol ablation and thermal ablation are alternatives for benign symptomatic nodules.
Background: Why This Research Matters
Thyroid nodules (TN) are one of the most common reasons for an endocrinology consultation. Studies show they are present in 20% to 60% of people when healthy volunteers are randomly selected and screened with ultrasound. Most thyroid nodules cause no symptoms at all and are found by accident when a patient undergoes imaging—such as a CT scan, MRI, or ultrasound—for an unrelated reason. This is why they are often called "incidentalomas."
Although the number of thyroid cancer cases has risen in recent decades, the vast majority of thyroid nodules are benign (non-cancerous). The rate of malignancy is less than 5% in the general population, though the abstract of this paper cites a 7%–15% risk range based on broader pooled data. That distinction matters: doctors need to determine which nodules deserve closer attention and which can simply be left alone.
When a new thyroid nodule is discovered, the physician's goals are twofold: first, to determine whether it is benign or malignant (cancerous), and second, for symptomatic benign nodules, to establish whether treatment is needed to relieve pressure-related symptoms. The authors of this review article emphasize that routine population screening for thyroid nodules is not recommended. However, they stress that extra attention should be paid to people with known risk factors for thyroid cancer.
Those risk factors include:
- A history of exposure to ionizing radiation during childhood
- Variations in dietary iodine intake (both low and high iodine can affect thyroid health)
- Inherited genetic syndromes linked to thyroid cancer, including familial adenomatous polyposis, Carney complex, Cowden syndrome, PTEN hamartoma tumor syndrome, and Peutz-Jeghers syndrome
- A family history of medullary thyroid cancer or multiple endocrine neoplasia (MEN) syndrome
Study Methods: How the Evidence Was Gathered
This article is a comprehensive literature review, not a single clinical trial. The authors—Dr. Victor J. Bernet and Dr. Ana-Maria Chindris from the Division of Endocrinology at the Mayo Clinic in Florida—conducted a systematic search of two major medical databases, PubMed and Medline, looking for articles published in the past 5 years that focused on the epidemiology, diagnosis, and management of thyroid nodules.
The search identified 135 relevant articles, which the authors reviewed in depth. They also examined the reference lists of those articles to find additional pertinent studies, ensuring the review captured both the latest evidence and important older foundational studies.
Ultrasound: The Gold Standard for Imaging
Thyroid ultrasound (US) is the single most important imaging test for evaluating thyroid nodules. It is considered the gold standard for assessing nodule shape, size, and internal characteristics. Ultrasound is generally recommended for any nodule discovered either by physical examination or through other imaging tests, such as CT or MRI. Thanks to significant technological improvements, modern ultrasound can provide a remarkably detailed picture of thyroid anatomy.
Several ultrasound features have been linked to an increased risk of thyroid cancer. These include:
- Size of the nodule
- Echogenicity—whether the nodule appears darker (hypoechoic) or brighter (hyperechoic) than the surrounding thyroid tissue
- Nodule borders—irregular or lobulated edges are more concerning
- Vascular pattern—increased blood flow inside the nodule (a type III vascular pattern)
- Shape—nodules that are "taller than wide" on a transverse (cross-sectional) view are suspicious
- Tissue stiffness, measured by a technique called elastography
- The presence of microcalcifications (tiny calcium deposits) or macrocalcifications
- Abnormally appearing cervical lymph nodes in the neck
However, the authors caution that no single ultrasound feature is accurate enough to diagnose cancer on its own. Each feature has a broad range of sensitivity and specificity, meaning some cancers show none of these signs, and many benign nodules show several of them. For this reason, doctors now use risk-stratification systems that combine multiple features to estimate the probability of malignancy and guide whether a biopsy is needed.
TI-RADS: The American College of Radiology System
In 2017, the American College of Radiology (ACR) published a standardized scoring system called TI-RADS (Thyroid Imaging, Reporting and Data System). This system assigns points based on five categories: nodule composition (solid vs. cystic), echogenicity, shape, margins, and the presence of echogenic foci (calcifications). The total score determines the TI-RADS level, and the recommendation for fine-needle aspiration biopsy (FNAB) is based on a combination of the TI-RADS score and nodule size.
The American Thyroid Association (ATA) System
The ATA system takes a different approach. Instead of point scoring, it relies on sonographic pattern recognition, classifying nodules into 5 categories based on their overall appearance. Each category has an associated range of cancer risk:
- Benign: less than 1% cancer risk
- Very low suspicion: less than 3% cancer risk
- Low suspicion: 5%–10% cancer risk
- Intermediate suspicion: 10%–20% cancer risk
- High suspicion: more than 70%–90% cancer risk
As with TI-RADS, the ATA system uses nodule size combined with appearance to recommend when a biopsy should be performed. Importantly, both systems recommend against automatically biopsying nodules smaller than 1 centimeter, even when they look suspicious. Instead, they favor active surveillance with close follow-up for these small nodules, a departure from older practices.
Similar scoring systems have been developed by other professional societies around the world, including:
- The Korean Society of Thyroid Radiology (K-TIRADS)
- The European Thyroid Association (EU-TIRADS)
- The American Association of Clinical Endocrinologists (AACE/ACE/AME)
The recommended biopsy size thresholds vary slightly between systems. For example, in the ACR TI-RADS system, a moderately suspicious (TI-RADS 4) nodule generally needs to reach 1.5 cm before biopsy is recommended, while a highly suspicious (TI-RADS 5) nodule warrants biopsy at 1.0 cm. In the ATA system, low-suspicion nodules need to be at least 2 cm for consideration of FNA, intermediate-suspicion nodules at 1.5 cm, and high-suspicion nodules at 1.0 cm. The European Thyroid Association's EU-TIRADS system recommends FNA at 2 cm for low-risk nodules (EU-TIRADS 3), 1.5 cm for intermediate-risk (EU-TIRADS 4), and 1.0 cm for high-risk (EU-TIRADS 5).
The Role of CT, MRI, and PET/CT Scans
CT (computed tomography) and MRI (magnetic resonance imaging) have only limited roles in the routine evaluation of thyroid nodules. They are generally reserved for specific situations, such as:
- Patients with signs of advanced thyroid malignancy
- Pre-surgical planning for thyroid cancer
- Assessment of lymph nodes in the central and lateral neck compartments
- Evaluation of involvement of nearby structures, including the airway, digestive tract, or blood vessels
18F-FDG PET/CT scans — a type of imaging that measures metabolic activity — sometimes reveal thyroid nodules that were not previously known. The prevalence of such incidentally discovered thyroid nodules is 1%–2% of all 18F-FDG PET/CT scans. When a nodule shows increased FDG uptake (meaning it is metabolically active), the reported rate of cytology-proven malignancy ranges from 24% to 58.2%. By contrast, diffuse (widespread) uptake throughout the thyroid is associated with a much lower malignancy rate of just 4.4%.
A meta-analysis of 18 studies (with a total of 55,160 patients) found that 1% of patients had thyroid incidentalomas detected on FDG PET scans, with a 33.2% incidence of malignancy. Among those cancers, papillary thyroid cancer made up 82.2% of cases.
Despite this concerning rate, the authors point out that newly discovered incidental thyroid cancers on PET/CT do not appear to affect overall survival. In a retrospective review of 45,000 PET/CT scans, the incidence of thyroid cancer among thyroid incidentalomas was 36%. Over a median follow-up of 24 months, most of the 181 deaths that occurred were related to the patient's primary (original) malignancy — not the thyroid cancer.
Nuclear Thyroid Scans (Scintigraphy)
When a newly diagnosed thyroid nodule is accompanied by a subnormal TSH level (a blood test that indicates the thyroid may be overactive), the next step should be a radioactive iodine uptake test and thyroid scan to determine whether the nodule is "hyperfunctioning" (producing excess thyroid hormone on its own). In this setting, ultrasound can also be used to look for coexistent non-functioning nodules that might require additional evaluation.
One practical tip from the authors: small hyperfunctioning nodules may not fully suppress TSH. So if TSH is in the lower end of the normal range and there is clinical suspicion, scintigraphy should still be considered.
Historically, thyroid scintigraphy using 99mTc-pertechnetate and radioactive iodine (131I and 123I) played a major role in evaluating thyroid nodules and multinodular goiters. In the United States today, nuclear thyroid imaging is primarily reserved for cases where TSH suppression is evident and thyrotoxicosis (overactive thyroid) is suspected. In Europe and other parts of the world, scintigraphy is used more commonly.
The key principle is simple: "cold" nodules (those that do not take up radioactive material) can represent cancer, but many benign nodules also appear cold. "Hot" or hyperfunctioning nodules (those that take up excess radioactive material) are rarely malignant — so a hot nodule generally does not require a biopsy.
The authors cite an older but important review from 1981, which examined 6 articles and found the following cancer rates based on scintigraphy results:
- Hypofunctioning (cold) nodules: 16% cancer rate
- Normofunctioning nodules: 29% cancer rate
- Hyperfunctioning (hot) nodules: 24% cancer rate
Interestingly, discrepancies have been reported between how nodules take up 99mTc versus 131I, particularly in follicular thyroid cancer. Some nodules showed uptake on 99mTc imaging but appeared "cold" on 131I imaging. For this reason, when scintigraphy is used, 123I is preferred over 99mTc as the imaging agent.
A recent study comparing 123I scintigraphy and thyroid ultrasound for guiding biopsy decisions found concordant recommendations in 79.4% of cases. Among the discordant cases, ultrasound recommended FNA for functional (hot) nodules in 3.8% of cases, while 123I scintigraphy recommended FNA in 7.9% of cases where either no nodule was seen on ultrasound or the nodule did not meet ultrasound-guided FNA criteria.
The 2015 American Thyroid Association guidelines recommend limited use of thyroid scintigraphy, primarily for patients with suppressed TSH. The rationale is that identifying an autonomous (self-functioning) nodule would eliminate the need for FNA biopsy of that nodule — except in the rare cases where ultrasound appearance suggests malignancy. The European Association for Nuclear Medicine and the Society of Nuclear Medicine and Molecular Imaging have jointly published guidelines noting additional potential uses for scintigraphy, including:
- Evaluation of a multinodular goiter to identify a hyperfunctioning "hot" nodule that does not need FNA
- Evaluation of suspicious hypofunctioning "cold" areas within a multinodular goiter that may need FNA
- Evaluation of nodules with indeterminate FNA cytology, to identify autonomous functioning nodules
TSH suppression from autonomous nodules can vary based on local dietary iodine intake. In populations with lower dietary iodine intake, autonomous nodules with low-reference-range TSH levels are more common. Scintigraphy has also been proposed as a way to identify autonomous nodules early, allowing close follow-up to detect the possible future development of full-blown thyrotoxicosis.
The bottom line: while most patients with normal thyroid function (euthyroid) do not need scintigraphy, local factors may influence the decision to use this imaging tool.
Fine-Needle Aspiration Biopsy (FNAB)
When a thyroid nodule meets the morphologic criteria on ultrasound (based on risk-stratification systems), it should be further assessed by fine-needle aspiration biopsy (FNAB). This is the standard method for determining whether a nodule is benign or malignant.
FNAB is a straightforward outpatient procedure performed under ultrasound guidance. It typically uses 27-gauge and 25-gauge sterile needles — very thin needles, similar to those used for routine blood draws. Local anesthesia is sometimes used, although its benefit in reducing discomfort with such fine needles has been challenged in the literature. Complications are uncommon and are generally limited to local bruising and, rarely, a hematoma (a collection of blood under the skin).
Studies examining the relationship between nodule size and FNAB accuracy have produced conflicting results. For nodules smaller than 1 centimeter, FNAB accuracy ranged from 60% to 94%. For nodules larger than 4 centimeters, accuracy ranged from 80.3% to 87.5%. Interestingly, very large nodules are not always easier to sample accurately, because they may contain areas of degeneration or cystic fluid that dilute the cellular sample.
Core needle biopsy (which uses a slightly larger needle to obtain a small tissue core) is currently considered when:
- FNAB yields nondiagnostic results (not enough cells to interpret), or
- Thyroid lymphoma or anaplastic thyroid cancer is suspected
The Korean Society of Thyroid Radiology goes further, recommending core needle biopsy as a first-line alternative to FNAB. However, core needle biopsy carries a higher rate of complications, including post-biopsy hematomas, bleeding from the incision site, pain, infections, transient coughing up of blood (hemoptysis), and nerve injuries.
The Bethesda System for Reporting Cytology
Cytology results from FNAB are classified according to the Bethesda criteria, which divide nodules into 6 categories. Each category has an associated malignancy risk and corresponding management recommendation. The two categories that create the most clinical uncertainty are:
- Bethesda III (atypia of undetermined significance): 10%–30% malignancy risk
- Bethesda IV (follicular neoplasm or suspicious for follicular neoplasm): 25%–40% malignancy risk
These are known as indeterminate cytology results. Historically, the only way to get a definitive diagnosis in these cases was to perform surgery to remove the nodule. Not surprisingly, this led to a significant number of unnecessary surgeries, because many of these nodules ultimately turned out to be benign.
Molecular Testing: A Genetic Look at Nodules
In recent years, a major advance has been the introduction of molecular testing of cytology samples from indeterminate nodules. These tests look for genomic alterations associated with thyroid malignancy—including gene mutations, gene fusions, and differences in RNA and microRNA expression—that are linked to a higher risk of cancer.
The most prevalent commercially available molecular tests for thyroid nodule malignancy assessment include:
- Afirma Genomic Sequencing Classifier with add-on Xpression Atlas (Veracyte)
- ThyroSeq 3.0 (Sonic Healthcare USA Thyroseq Laboratory)
- ThyGenX/ThyraMIR (Thyramir Interpace Diagnostics)
- Rosetta GX Reveal (Rosetta Genomics)
Mutations identified by these tests can also help guide management. For example, the simultaneous presence of BRAF V600E and TERT C228T mutations in papillary thyroid cancer is associated with poorer outcomes, so this finding may have both prognostic value and implications for management decisions. Conversely, the RAS mutation has been identified in a wide spectrum of conditions—from benign nodules and follicular adenomas to noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), classic and follicular variant papillary thyroid cancer, poorly differentiated thyroid cancer, and even anaplastic and medullary thyroid cancers. This broad range means RAS mutations alone do not definitively diagnose cancer.
The authors temper this enthusiasm with an important caveat: using molecular marker results to guide therapeutic recommendations (such as the extent of surgery or whether to give radioactive iodine) has not yet been proven to improve outcomes and is not yet considered the standard of care. In addition, the relatively high cost of these tests may be a limiting factor for many patients.
Management and Follow-Up
Once a thyroid nodule has been evaluated, the management plan depends heavily on the biopsy results and ultrasound characteristics. There is no single unanimous consensus on every scenario, but several general principles guide clinical practice.
Benign Nodules
For nodules with benign cytology (Bethesda II) that are asymptomatic, routine follow-up is recommended. The follow-up strategy—including the frequency of repeat ultrasound—should be based on ultrasound characteristics rather than simply on an increase in volume. The chance of cancer being found later in a nodule with benign cytology is low, and it essentially becomes zero if a second sampling also yields benign cytology. Current guidelines recommend repeating FNA when concerning ultrasound characteristics develop or when the nodule grows by at least 50% in volume—though the authors note that this growth criterion alone has been shown to have low specificity for malignancy.
There is ongoing debate about surveillance of subcentimeter nodules (smaller than 1 cm). Highly suspicious subcentimeter nodules warrant repeat ultrasound at 6–12 months. On the other end of the spectrum, nodules with very low suspicion, regardless of size, do not require follow-up imaging at all. The American College of Radiology recommends against scanning intervals of less than 1 year, except for biopsy-proven cancers under active surveillance.
Nondiagnostic Cytology
Nodules with nondiagnostic cytology should undergo a repeat biopsy about 4–6 weeks later. Alternatively, core needle biopsy can be considered, especially if concerning ultrasound features are present.
The Challenging "High-Risk" Small Nodule
Nodules that are below the size threshold for FNAB but have "high-risk" ultrasound features represent a challenging category. Most guidelines recommend monitoring these high-risk subcentimeter nodules with repeat ultrasound every 6–12 months, unless additional risk factors are present. However, in clinical practice, many patients prefer not to wait, and they push for FNAB despite the small size.
This is understandable, but sample adequacy is a real concern. For tiny nodules, getting enough cells to interpret can be difficult:
- Adequacy rates are reported to be as low as 72.2% for nodules 3–6 mm
- 84.9% for nodules 7–10 mm
- And only 63% in the presence of macrocalcifications
Why TSH Suppression Therapy Fell Out of Favor
For many years, doctors treated benign thyroid nodules with thyroid hormone (levothyroxine) suppression therapy, aiming to shrink nodules by keeping TSH levels low. A meta-analysis published in 2005 found an 88% likelihood of achieving a reduction in nodule volume of greater than 50% compared with placebo or no treatment. That sounds impressive.
But the authors highlight a crucial problem: the number needed to treat was 8:1 — meaning 8 patients had to receive suppressive therapy for 1 patient to benefit. Worse, TSH suppression therapy exposed patients to the risks of bone loss and cardiac complications from chronic iatrogenic (medically induced) hyperthyroidism. Current American Thyroid Association guidelines now explicitly recommend against TSH suppression therapy as a standard treatment for benign nodules in patients with normal thyroid function and sufficient iodine intake.
Surgical Treatment Options
Surgery for benign thyroid nodules may be considered when there are compression symptoms, such as:
- Difficulty swallowing (dysphagia)
- Hoarseness
- A choking sensation
Cosmetic concerns are also a legitimate reason to consider surgery. Some researchers advocate that nodules larger than 3–4 cm should be considered for removal, although practical experience suggests that close follow-up of cytologically proven benign, asymptomatic nodules of this size is also a reasonable approach.
Nodules found to harbor cancer, as well as those with indeterminate cytology or molecular test results indicating a significant cancer risk, typically undergo surgical resection. The extent of surgery (lobectomy versus total thyroidectomy) is influenced by several risk factors:
- A history of childhood radiation exposure
- Histology of the tumor (aggressive differentiated thyroid cancer variants, medullary thyroid cancer, or anaplastic thyroid cancer)
- The presence of bilateral nodules (particularly those larger than 1 cm on the opposite side)
- A family history of thyroid cancer
Active surveillance is an option for micropapillary thyroid cancers (papillary cancers smaller than 1 cm) that appear to be limited to the thyroid. Ideally, these microcarcinomas should be surrounded by a rim of normal thyroid tissue, and the patient must be willing to undergo close follow-up with serial ultrasound imaging.
The authors strongly recommend that thyroid surgery be performed by experienced, high-volume thyroid surgeons, as this minimizes surgical risks. Those risks include:
- Transient or permanent postoperative hypoparathyroidism (damage to the parathyroid glands, causing low calcium levels)
- Hoarseness and voice changes from recurrent laryngeal nerve damage
Patients considering surgery should also be counseled about the risk of hypothyroidism after surgery. After hemithyroidectomy (removal of half the thyroid), approximately 15%–50% of patients develop hypothyroidism requiring lifelong thyroid hormone replacement. The risk is higher in patients with a smaller amount of residual thyroid tissue, a higher preoperative TSH level, or underlying chronic lymphocytic thyroiditis (Hashimoto's disease). Of course, all patients develop hypothyroidism after total thyroidectomy and will need lifelong thyroid hormone therapy.
Nonsurgical Treatment Options
Nonsurgical management of benign thyroid nodules is a growing field, offering patients alternatives to surgery. These minimally invasive approaches include:
- Ethanol ablation — injection of alcohol directly into the nodule, particularly appropriate for treating pure thyroid cysts or autonomous (hyperfunctioning) nodules
- Sclerotherapy — a related technique for thyroid cysts
- Thermal techniques, including radiofrequency ablation, laser ablation, microwave ablation, and high-intensity focused ultrasound (HIFU)
The authors stress an important safety rule: before any nonsurgical therapeutic option is used, the nodule should be proven benign, preferably by two FNAB samples. One sample may suffice in very low-risk nodules. In addition, anticoagulation (blood-thinning) therapy should be held before the procedure to reduce bleeding risk.
Complications from thermal treatments vary depending on patient selection and operator experience. One notable complication of ethanol ablation is intraprocedural perithyroidal ethanol leakage, which can cause significant patient discomfort.
These nonsurgical techniques are particularly valuable for patients who are poor surgical candidates, who wish to avoid general anesthesia and surgery, or who have had prior thyroid surgery and develop recurrent nodules.
Conclusion: Key Takeaways
The authors conclude with several clear messages for clinicians and patients alike:
- Most thyroid nodules are benign and can be safely monitored without intervention.
- The indications for biopsy and the frequency of imaging should be individualized, based on a patient's specific risk stratification rather than a one-size-fits-all approach.
- Treatment options should be personalized to each patient's particular situation—there is no single "best" approach for everyone.
- Active surveillance should be considered in certain cases of papillary microcarcinoma (papillary thyroid cancers smaller than 1 cm), rather than rushing to surgery.
- Advances in molecular testing have reduced the number of diagnostic surgeries for asymptomatic nodules with indeterminate cytology.
- Emerging nonsurgical techniques—including ethanol ablation, sclerotherapy, and thermal ablation methods—offer effective alternatives for patients with benign symptomatic nodules.
Study Limitations
As a narrative review article, this paper has several inherent limitations that patients should understand. First, it is not a randomized controlled trial, so it cannot provide definitive comparative data on which treatment strategy is superior; instead, it synthesizes the best available evidence from multiple studies of varying designs and quality. Second, the literature search was limited to the past 5 years, meaning older foundational studies are only included if referenced by more recent papers—though the authors did examine reference lists to capture older key works. Third, the rapid evolution of both imaging technology and molecular testing means that some recommendations may become outdated quickly. Fourth, the authors note areas of genuine controversy, such as the management of subcentimeter nodules and the appropriate role of molecular testing, where expert opinion differs and high-quality outcomes data are still lacking. Finally, the cost-effectiveness considerations mentioned in the article (particularly for molecular tests) are based on U.S. healthcare pricing and may not generalize to other countries.
Recommendations for Patients
If you have been diagnosed with a thyroid nodule, here are practical steps to consider based on this review:
- Know your TSH levels. A simple blood test determines whether your thyroid function is normal, overactive, or underactive. If your TSH is low, a nuclear thyroid scan may be recommended to see if the nodule is "hot" (hyperfunctioning and very unlikely to be cancer).
- Ask about your nodule's ultrasound features. Your doctor should be able to tell you whether your nodule falls into a low, intermediate, or high suspicion category. This directly affects whether and when a biopsy is needed. Don't be surprised if nodules smaller than 1 cm are monitored rather than biopsied—this is now standard of care.
- If biopsy is recommended, understand what the results mean. The Bethesda category of your FNA result (I–VI) determines the next steps. If you receive an indeterminate result (Bethesda III or IV), ask your doctor whether molecular testing is appropriate. These tests can often clarify whether surgery is necessary.
- Ask about active surveillance. If you have a small papillary microcarcinoma, active surveillance with regular ultrasound is a legitimate and increasingly preferred option in appropriate cases—not every cancer requires immediate surgery.
- Explore nonsurgical options if surgery is undesirable. If you have a benign nodule that is causing symptoms, techniques like radiofrequency ablation, ethanol ablation, or sclerotherapy may be options. Make sure the nodule has been confirmed benign, ideally by two biopsies.
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Match the follow-up plan to your risk, not just nodule size.
Frequently Asked Questions
What is a thyroid nodule and how common are they?
A thyroid nodule is a growth in the butterfly-shaped thyroid gland. They are common, present in 20% to 60% of adults when healthy volunteers are screened with ultrasound. Most cause no symptoms and are found incidentally. Fewer than 5% of nodules in the general population are cancerous.
How do doctors tell if a thyroid nodule is cancer?
Doctors use ultrasound to assess features like size, shape, margins, and calcifications. Based on risk-stratification systems like TI-RADS or ATA, they decide if a biopsy is needed. No single ultrasound feature is enough to diagnose cancer. A fine-needle aspiration biopsy provides cells for diagnosis.
What is fine-needle aspiration biopsy (FNAB) and when is it recommended?
FNAB uses a very thin needle under ultrasound guidance to sample cells from a thyroid nodule. It is recommended when ultrasound features and nodule size meet risk-based criteria from systems like TI-RADS or ATA. Nodules smaller than 1 centimeter are often monitored rather than biopsied.
What are the treatment options for a benign thyroid nodule?
If a benign nodule causes no symptoms, active monitoring is usually all that is needed. For symptomatic benign nodules, options include surgery or nonsurgical techniques like ethanol ablation, sclerotherapy, or thermal ablation such as radiofrequency or laser. The choice depends on your individual situation.
What is active surveillance for thyroid cancer?
Active surveillance is a management option for papillary microcarcinomas, which are papillary thyroid cancers smaller than 1 centimeter. It involves close follow-up with serial ultrasounds rather than immediate surgery. This is increasingly preferred in appropriate cases, such as when the tumor appears limited to the thyroid.
Why might I need a nuclear thyroid scan if my TSH is low?
A low TSH level suggests the thyroid may be overactive. In this case, a radioactive iodine uptake test and thyroid scan can determine if a nodule is hyperfunctioning, or 'hot.' Hot nodules are rarely malignant and generally do not require biopsy, so this scan can help avoid an unnecessary procedure.
