Fine-needle aspiration biopsy of the thyroid: comparison between thyroid palpation and ultrasonography

Real-time ultrasound elastography in the diagnosis of newly identified thyroid nodules in adults: the ElaTION RCT

Background

Strain and shear wave elastography which is commonly used with concurrent real-time imaging known as real-time ultrasound shear/strain wave elastography is a new diagnostic technique that has been reported to be useful in the diagnosis of nodules in several organs. There is conflicting evidence regarding its benefit over ultrasound-guided fine-needle aspiration cytology alone in thyroid nodules.

Objectives

To determine if ultrasound strain and shear wave elastography in conjunction with fine-needle aspiration cytology will reduce the number of patients who have a non-diagnostic first fine-needle aspiration cytology results as compared to conventional ultrasound-only guided fine-needle aspiration cytology.

Design

A pragmatic, unblinded, multicentre randomised controlled trial.

Setting

Eighteen centres with a radiology department across England.

Participants

Adults who had not undergone previous fine-needle aspiration cytology with single or multiple nodules undergoing investigation.

Interventions

Ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology (intervention arm) - strain or shear wave elastography-guided fine-needle aspiration cytology. Ultrasound-only guided fine-needle aspiration cytology (control arm) - routine ultrasound-only guided fine-needle aspiration cytology (the current standard recommended by the British Thyroid Association guidelines).

Main outcome measure

The proportion of patients who have a non-diagnostic cytology (Thy 1) result following the first fine-needle aspiration cytology.

Randomisation

Patients were randomised at a 1 : 1 ratio to the interventional or control arms.

Results

A total of 982 participants (80% female) were randomised: 493 were randomised to ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology and 489 were randomised to ultrasound-only guided fine-needle aspiration cytology. There was no evidence of a difference between ultrasound shear/strain wave elastography and ultrasound in non-diagnostic cytology (Thy 1) rate following the first fine-needle aspiration cytology (19% vs. 16% respectively; risk difference: 0.030; 95% confidence interval -0.007 to 0.066; p = 0.11), the number of fine-needle aspiration cytologies needed (odds ratio: 1.10; 95% confidence interval 0.82 to 1.49; p = 0.53) or in the time to reach a definitive diagnosis (hazard ratio: 0.94; 95% confidence interval 0.81 to 1.10; p = 0.45). There was a small, non-significant reduction in the number of thyroid operations undertaken when ultrasound shear/strain wave elastography was used (37% vs. 40% respectively; risk difference: -0.02; 95% confidence interval -0.06 to 0.009; p = 0.15), but no difference in the number of operations yielding benign histology - 23% versus 24% respectively, p = 0.70 (i.e. no increase in identification of malignant cases) - or in the number of serious adverse events (2% vs. 1%). There was no difference in anxiety and depression, pain or quality of life between the two arms.

Limitations

The study was not powered to detect differences in malignancy.

Conclusions

Ultrasound shear/strain wave elastography does not appear to have additional benefit over ultrasound-guided fine-needle aspiration cytology in the diagnosis of thyroid nodules.

Future work

The findings of the ElaTION trial suggest that further research into the use of shear wave elastography in the diagnostic setting of thyroid nodules is unlikely to be warranted unless there are improvements in the technology. The diagnostic difficulty in distinguishing between benign and malignant lesions still persists. Future studies might examine the role of genomic testing on fine-needle aspiration samples. There is growing use of targeted panels of molecular markers, particularly aimed at improving the diagnostic accuracy of indeterminate (i.e. Thy3) cytology results. The application of these tests is not uniform, and their cost effectiveness has not been assessed in large-scale trials.

Study registration

This study is registered as ISRCTN (ISRCTN18261857).

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/19/04) and is published in full in Health Technology Assessment; Vol. 28, No. 46. See the NIHR Funding and Awards website for further award information.

Comparison of thyroid fine needle aspiration biopsy and ultrasonography results

Thyroid nodules are one of the most common health problems in the community. Although most of the nodules are benign, Fine needle aspiration biopsy (FNAB) is requested due to malignancy concerns. In this research, the aim was to make a comparison of the results of thyroid ultrasonography (USG) and FNAB for thyroid nodules. This study was conducted retrospectively on the data of 532 patients. Detail Edu ultrasonographic assessment was conducted before the FNAB procedure and FNAB was performed by an endocrinology specialist. FNAB results and Thyroid USG features were compared, and thyroid FNAB results were graded using the classification of World Health Organization Bethesda-2017. The average age of the individuals included in the research was 49.99 ± 13.65 (min = 18-max = 97). According to the 2017 Bethesda classification, 74.6% of FNAB results were benign, 16% follicular lesion of undated mined significance or A type of undated mined significance, 0.9% were malignant, and 1.1% were suspicious for malignancy. When USG findings were compared according to FNAB results, it was found that malignant lesions were significantly higher in single nodules (non- cystic and non- mixed lesions). Lesions with a single nodule on USG were found to be 3.6 times more likely to be malignant (OR 95% CI: 1.172-11.352). The gold standard method for the diagnosis the presence of thyroid nodules is thyroid fine needle aspiration biopsy with ultrasound guidance. Taking samples from the correct nodule and component increases its value. The presence of a single nodule from the thyroid USG features was found to be an important predictor of malignancy according to the biopsy results.

Solitary and multiple thyroid nodules as predictors of malignancy: a systematic review and meta-analysis

BACKGROUND

The debate on whether or not there is a difference in the incidence of thyroid cancer between the patients with Solitary thyroid Nodule (STN) and Multinodular Goiter (MNG) has been constantly present for the last few decades. With newer studies yielding mixed results, it was imperative to systematically compile all available literature on the topic.

METHODS

PubMed/MEDLINE, Cochrane Central, ScienceDirect, GoogleScholar, International Clinical Trials registry, and reference lists of the included articles were systematically searched for article retrieval. No filter was applied in terms of time, study design, language or country of publication. Rigorous screening as per PRISMA guidelines was undertaken by 2 independent reviewers in order to identify the articles that were most relevant to the topic.

RESULTS

Twenty-two studies spanning from 1992 to 2018 were included in this analysis and encompassed 50,321 patients, 44.2% of which belonged to the STN subgroup and 55.37% to the MNG subgroup. MNG was found to be associated with a significantly lower risk of thyroid cancer (OR = 0.76; 95% CI 0.61-0.96) when compared with STN. Papillary carcinoma was the most frequently occurring carcinoma across both groups, followed by follicular and medullary carcinomas. A subgroup analysis was performed to assess the efficacy of the two most commonly employed diagnostic tools i.e. surgery and fine needle aspiration cytology (FNAC), however it yielded nonsignificant results, indicating a comparable usefulness of the two. Another subgroup analysis run on the basis of the presumed iodine status of the participants also yielded nonsignificant results.

CONCLUSION

There is a higher incidence of thyroid cancer among patients of STN, however, given the low quality of existing evidence on the topic, it is crucial to conduct larger studies that can establish association with a greater precision.

In-Office Ultrasonographic Evaluation of Neck Masses/Thyroid Nodules

Office-based ultrasonography is increasingly becoming an integral part of an otolaryngology-head and neck surgery practice. A thorough knowledge of the ultrasonic appearance of normal and abnormal pathology are key for performing/interpreting office-based head and neck ultrasonography. A focused but systematic approach allows for efficient and effective office-based head and neck ultrasonography. Office-based ultrasonography also allows for imaging procedures expanding the otolaryngologist's armamentarium. Ultrasound-guided fine needle aspiration (USgFNA) is an integral part of clinician-performed ultrasonography because it allows cytologic diagnosis of suspicious lesions. Understanding the successful techniques and pitfalls in this procedure are critical for the otolaryngologist performing USgFNA.

Primary Imaging Test and Appropriate Biopsy Methods for Thyroid Nodules: Guidelines by Korean Society of Radiology and National Evidence-Based Healthcare Collaborating Agency

The Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency developed guidelines for primary imaging tests and appropriate biopsy methods for thyroid nodules. These guidelines were developed using an adaptation process by collaboration between the development committee and the working group. The development committee, composed of research methodology experts, established the overall plan and provided support about methodological strategies. The working group, composed of radiologist experts in thyroid imaging, wrote the proposals. The guidelines recommend neck ultrasound (US) as a first-line imaging modality for the diagnosis of thyroid nodules in patients with suspected nodules, and US-guided fine-needle aspiration as a primary method for histologic examination of thyroid nodules.

Interventional radiology of the thyroid gland: critical review and state of the art

Thyroid nodules are a common incidental finding during a routinely ultrasound (US) exam unrelated to the thyroid gland in the healthy adult population with a prevalence of 20-76%. As treated before with surgery, in the last years new minimally invasive techniques have been developed as an alternative to surgery. The aim of this review, based on newly revised guidelines, is to provide some information regarding the basic principles, indications, materials, techniques, and results of mini-invasive procedures or treatments for thyroid nodules. We performed a narrative review including both newest and representative papers and guidelines based on the different procedures of ablation techniques developed in the last years for the diagnosis and the treatment of thyroid nodules. All examined papers referred very good results in term of volume nodule reduction, improvement in related symptoms and cosmetic problems, with a very low rate of complications and side effects for all the minimally invasive technique analyzed. Obviously, some differents between technique based on different kind of thyroid nodules and different indication were found. In conclusion, many thyroid nodules nowadays could be treated thanks to the advent of new mini-invasive technique that are less expensive and present a lower risk of major complications and side effects compared to surgery.

Ultrasound Risk Categories for Thyroid Nodules and Cytology Results: A Single Institution's Experience after the Adoption of the 2016 Update of Medical Guidelines by the American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi

Objectives

In 2016, the American Association of Clinical Endocrinologists (AACE) and Associazione Medici Endocrinologi (AME) released updated guidelines for the diagnosis and management of thyroid nodules. The aim of this study was to evaluate the AACE/AME recommendations for FNA in clinical practice, by comparing the (US) stratification risk and indications for FNA with cytologic results.

Methods

From May to December 2016, we collected the cytologic results from FNAs of nodules that were classified using a three-tier US category system (low, intermediate, and high risk).

Results

We obtained 859 FNAs from 598 patients: 341 (39.7%) from low, 489 (56.9%) from intermediate, and 29 (3.4%) from high risk nodules. Of these, 88.5% and 74.9% of low and intermediate risk nodules, respectively, were cytologically benign, whereas 84.6% of high risk nodules had a moderate-to-elevated risk of malignancy or were malignant. If FNAs had been limited to intermediate risk nodules >20 mm, we would have missed 13/17 (76.5%) nodules that had moderate-to-elevated risk of malignancy or were malignant (11/13 were malignant based on histology).

Conclusions

A nonnegligible number of cytologically malignant nodules or nodules that were suspected to be malignant would be missed if intermediate US risk nodules <20 mm were not biopsied.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS, AMERICAN COLLEGE OF ENDOCRINOLOGY, AND ASSOCIAZIONE MEDICI ENDOCRINOLOGI MEDICAL GUIDELINES FOR CLINICAL PRACTICE FOR THE DIAGNOSIS AND MANAGEMENT OF THYROID NODULES--2016 UPDATE

Thyroid nodules are detected in up to 50 to 60% of healthy subjects. Most nodules do not cause clinically significant symptoms, and as a result, the main challenge in their management is to rule out malignancy, with ultrasonography (US) and fine-needle aspiration (FNA) biopsy serving as diagnostic cornerstones. The key issues discussed in these guidelines are as follows: (1) US-based categorization of the malignancy risk and indications for US-guided FNA (henceforth, FNA), (2) cytologic classification of FNA samples, (3) the roles of immunocytochemistry and molecular testing applied to thyroid FNA, (4) therapeutic options, and (5) follow-up strategy. Thyroid nodule management during pregnancy and in children are also addressed. On the basis of US features, thyroid nodules may be categorized into 3 groups: low-, intermediate-and high-malignancy risk. FNA should be considered for nodules ≤10 mm diameter only when suspicious US signs are present, while nodules ≤5 mm should be monitored rather than biopsied. A classification scheme of 5 categories (nondiagnostic, benign, indeterminate, suspicious for malignancy, or malignant) is recommended for the cytologic report. Indeterminate lesions are further subdivided into 2 subclasses to more accurately stratify the risk of malignancy. At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data, US signs, elastographic pattern, or results of other imaging techniques to improve the management of these lesions. Most thyroid nodules do not require any treatment, and levothyroxine (LT4) suppressive therapy is not recommended. Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while US-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules. Surgery remains the treatment of choice for malignant or suspicious nodules. The present document updates previous guidelines released in 2006 and 2010 by the American Association of Clinical Endocrinologists (AACE), American College of Endocrinology (ACE) and Associazione Medici Endocrinologi (AME).

Evidence-based evaluation of the thyroid nodule

This article reviews the most current literature on thyroid nodule evaluation, with particular attention to the problem of the incidentally identified thyroid nodule. Although traditional risk factors for thyroid cancer, such as age, gender, and familial syndromes, are still important, the manner in which a thyroid nodule comes to attention is of great importance these days when considering how to proceed in a workup. Most thyroid nodules today are discovered through radiologic imaging tests performed for other reasons. This article covers the key considerations that are vital in balancing the risks and benefits of thyroid nodule workup and treatment.

Protection and Dissection of Recurrent Laryngeal Nerve in Salvage Thyroid Cancer Surgery to Patients with Insufficient Primary Operation Extent and Suspicious Residual Tumor

Some thyroid cancer patients undergone insufficient tumor removal in the primary surgery in China . our aim is to evaluate the impact of dissection of the recurrent laryngeal nerve during a salvage thyroid cancer operation in these patients to prevent nerve injury. Clinical data of 49 enrolled patients who received a salvage thyroid operation were retrospectively reviewed. Primary pathology was thyroid papillary cancer. The initial procedure performed included nodulectomy (20 patients), partial thyroidectomy (19 patients) and subtotal thyroidectomy (10 patients). The effect of dissection and protection of the recurrent laryngeal nerve and the mechanism of nerve injury were studied. The cervical courses of the recurrent laryngeal nerves were successfully dissected in all cases. Nerves were adherent to or involved by scars in 22 cases. Three were ligated near the place where the nerve entered the larynx, while another three were cut near the intersection of inferior thyroid artery with the recurrent laryngeal nerve. Light hoarseness occurred to four patients without a preoperative voice change. In conclusion, accurate primary diagnosis allows for a sufficient primary operation to be performed, avoiding insufficient tumor removal that requires a secondary surgery. The most important cause of nerve damage resulted from not identifying the recurrent laryngeal nerve during first surgery , and meticulous dissection during salvage surgery was the most efficient method to avoid nerve damage.

Thyroid fine needle aspiration biopsy: do nodule volume and cystic degeneration ratio affect specimen adequacy and cytological diagnosis time?

BACKGROUND

A fine needle aspiration biopsy (FNAB) of thyroid nodules - the least invasive and most accurate method used to investigate malignant lesions - may yield non-diagnostic specimens even under ultrasonographic guidance.

PURPOSE

To evaluate the effects of thyroid nodule volume and extent of cystic degeneration on both the non-diagnostic specimen ratio as well as cytopathologist's definitive cytological diagnosis time.

MATERIAL AND METHODS

In this single center study, FNAB was performed on 505 patients with single thyroid nodules greater than 10 mm. Nodule volume was calculated prior to FNAB and cystic degeneration ratio was recorded. All biopsies were performed by a single radiologist who also prepared specimen slides. Specimen adequacy and final diagnosis were made in the pathology laboratory by a single-blinded cytopathologist based on the Bethesda system. Definitive cytological diagnosis time was recorded upon reaching a definitive diagnosis.

RESULTS

The specimen adequacy ratio was 85.3%. The mean nodule volume of adequate specimens was larger than those of non-diagnostic samples (6.00 mL vs. 3.05 mL; P = 0.001). There was no correlation between nodule volume and cytopathologist's definitive cytological diagnosis time (r = 0.042). Biopsy of predominantly solid nodules yielded better specimen adequacy ratios compared to predominantly cystic nodules (87.8% vs. 75.3%; P = 0.028). Definitive cytological diagnosis times were longer in predominantly cystic nodules compared to predominantly solid nodules (376 s vs. 294 s; P = 0.019).

CONCLUSION

Predominantly cystic nodules are likely to benefit from repeated nodular sampling until the specimen is declared adequate by an on-site cytopathologist. If a cytopathologist is not available, obtaining more specimens per nodule may achieve desired adequacy ratios.

Comb-push ultrasound shear elastography (CUSE) for evaluation of thyroid nodules: preliminary in vivo results

In clinical practice, an overwhelming majority of biopsied thyroid nodules are benign. Therefore, there is a need for a complementary and noninvasive imaging tool to provide clinically relevant diagnostic information about thyroid nodules to reduce the rate of unnecessary biopsies. The goal of this study was to evaluate the feasibility of utilizing comb-push ultrasound shear elastography (CUSE) to measure the mechanical properties (i.e., stiffness) of thyroid nodules and use this information to help classify nodules as benign or malignant. CUSE is a fast and robust 2-D shear elastography technique in which multiple laterally distributed acoustic radiation force beams are utilized simultaneously to produce shear waves. Unlike other shear elasticity imaging modalities, CUSE does not suffer from limited field of view (FOV) due to shear wave attenuation and can provide a large FOV at high frame rates. To evaluate the utility of CUSE in thyroid imaging, a preliminary study was performed on a group of five healthy volunteers and 10 patients with ultrasound-detected thyroid nodules prior to fine needle aspiration biopsy. The measured shear wave speeds in normal thyroid tissue and thyroid nodules were converted to Young's modulus (E), indicating a measure of tissue stiffness. Our results indicate an increase in E for thyroid nodules compared to normal thyroid tissue. This increase was significantly higher in malignant nodules compared to benign. The Young's modulus in normal thyroid tissue, benign and malignant nodules were found to be 23.2 ±8.29 kPa, 91.2±34.8 kPa, and 173.0±17.1 kPa, respectively. Results of this study suggest the utility of CUSE in differentiating between benign and malignant thyroid nodules.

Does elastography reduce the need for thyroid FNAs?

OBJECTIVE

Ultrasound elastography (USE) assesses lesion stiffness by evaluating tissue distortion in response to stress; it is emerging as a potentially useful tool to augment the ultrasound characterisation of thyroid nodules. The aim of this study was to assess the accuracy of USE examination of thyroid nodules compared with pathological outcome, especially to determine whether USE could reliably detect benign nodules and reduce the numbers of ultrasound guided fine needle aspiration cytology (USgFNAC).

DESIGN

Over a three-year period, thyroid nodules were initially characterised by B-mode ultrasound (US) findings. Where USgFNAC was indicated by clinical concern and/or the sonographic appearances, the lesion was then subjected to USE by an experienced operator prior to the USgFNAC.

PATIENTS

147 thyroid nodules were examined by USE and USgFNAC in 146 patients.

MEASUREMENTS

The elastographic appearance was subjectively categorized at the time of the examination (soft, intermediate or hard) and subsequently compared with the cytological/histological outcome.

RESULTS

A total of 122 nodules were non-neoplastic, 5 nodules were benign neoplasms, 10 nodules had indeterminate cytology and 10 were malignant neoplasms. The sensitivity of USE for malignancy was 90.0%, specificity was 79.6%, PPV was 24.3%, NPV was 99.1% and accuracy was 80.3%.

CONCLUSION

Thyroid nodules that are soft at USE have a high likelihood of being non-neoplastic and subjective USE assessment of thyroid nodules by an experienced operator can be a useful means of avoiding USgFNAC for benign nodules. In contrast, we suggest that all nodules that are intermediate or hard on USE undergo USgFNAC.

Prevalence of thyroid cancer in multinodular goiter versus single nodule: a systematic review and meta-analysis

BACKGROUND

Whether the prevalence of thyroid cancer is different in thyroid glands with a single nodule (SN) versus multinodular goiter (MNG) remains uncertain. Therefore, a meta-analysis was performed to evaluate the extant literature on the comparative prevalence of thyroid cancer in SN compared with MNG.

METHODS

We searched MEDLINE, EMBASE, Scopus, Cochrane Central, and reference list for selected observational, cross-sectional, and longitudinal studies evaluating thyroid cancer in SN and MNG. Toxic nodules were not included in the analysis. Two reviewers working independently extracted descriptive, methodological and outcome data from each study with consensus resolution of discrepancies. Meta-analytic estimates of treatment effects were generated using a random-effect model.

RESULTS

Fourteen studies encompassing 23565 patients with MNG and 20723 patients with SN were eligible for inclusion. Most eligible studies were at a moderate risk of bias. MNGs were associated with a lower risk of thyroid cancer than SN (pooled odds ratio 0.8 [95% confidence interval 0.67-0.96]; I(2)=35%). Subgroup analysis suggested that this difference depends on the inclusion of studies conducted outside the United States (odds ratio 0.71 [95% confidence interval 0.60-0.83]; I(2)=11%).

CONCLUSIONS

Thyroid cancer may be less frequent in MNG compared to SN, particularly outside the United States and perhaps in iodine-deficient areas.

Histological diagnosis of thyroid disease using ultrasound-guided core biopsies

BACKGROUND

Thyroid core biopsies obtained with ultrasound (US)-guided needles are an alternative to conventional fine-needle aspiration and, according to various authors, have greater sensitivity and specificity. The technique is inexpensive, rapid and reliable with a low rate of complications, similar to conventional fine-needle aspiration procedures.

OBJECTIVES

This paper critically reviews the methodology for obtaining samples and processing them in the pathology laboratory.

METHODS

Accumulated experience with 1,065 cases of US-guided core biopsy of the thyroid gland in a 15-year period.

RESULTS

US-guided core biopsy is a useful, inexpensive and safe method in the histological diagnosis of thyroid gland pathology. Thyroid samples obtained this way are not a substitute for fine-needle aspiration cytology. Indeed, some authors assert that the best results are obtained by combining the two approaches, the methods being complementary.

CONCLUSIONS

To take best advantage of the findings from these techniques, pathologists must know which types of diagnoses can be made and the fundamentals of how and, lastly, what cannot be diagnosed and the reasons why. Best results are obtained with a multidisciplinary approach in a hospital committee composed of endocrinologists, surgeons, radiologists and pathologists, who analyse and provide a background on each case.

Follicular adenoma and carcinoma of the thyroid gland

Follicular neoplasms of the thyroid gland include benign follicular adenoma and follicular carcinoma. Currently, a follicular carcinoma cannot be distinguished from a follicular adenoma based on cytologic, sonographic, or clinical features alone. The pathogenesis of follicular carcinoma may be related to iodine deficiency and various oncogene and/or microRNA activation. Advances in molecular testing for genetic mutations may soon allow for preoperative differentiation of follicular carcinoma from follicular adenoma. Until then, a patient with a follicular neoplasm should undergo a diagnostic thyroid lobectomy and isthmusectomy, which is definitive treatment for a benign follicular adenoma or a minimally invasive follicular cancer. Additional therapy is necessary for invasive follicular carcinoma including completion thyroidectomy, postoperative radioactive iodine ablation, whole body scanning, and thyrotropin suppressive doses of thyroid hormone. Less than 10% of patients with follicular carcinoma will have lymph node metastases, and a compartment-oriented neck dissection is reserved for patients with macroscopic disease. Regular follow-up includes history and physical examination, cervical ultrasound and serum TSH, and thyroglobulin and antithyroglobulin antibody levels. Other imaging studies are reserved for patients with an elevated serum thyroglobulin level and a negative cervical ultrasound. Systemic metastases most commonly involve the lung and bone and less commonly the brain, liver, and skin. Microscopic metastases are treated with high doses of radioactive iodine. Isolated macroscopic metastases can be resected with an improvement in survival. The overall ten-year survival for patients with minimally invasive follicular carcinoma is 98% compared with 80% in patients with invasive follicular carcinoma.

Management of thyroid nodules and surgery for differentiated thyroid cancer

The incidence of well-differentiated thyroid cancer has seen a worldwide increase in the last three decades. Whether this is due to a 'true increase' in incidence or simply increased detection of otherwise subclinical disease remains unclear. The treatment of thyroid cancer revolves around appropriate surgical intervention, minimising complications and the use of adjuvant therapy in select circumstances. Prognostic features and risk stratification are crucial in determining the appropriate treatment. There continues to be considerable debate in several aspects of management in these patients. Level 1 evidence is lacking, and there are limited prospective data to direct therapy, hence limiting decision-making to retrospective analyses, treatment guidelines based on expert opinion and personal philosophies. This overview focuses on the major issues associated with the investigation of thyroid nodules and the extent of surgery. As overall survival in well-differentiated thyroid cancer exceeds 95%, it is important to reduce over-treating the large majority of patients, and focus limited resources on high-risk patients who require aggressive treatment and closer attention. The onus is on the physician to avoid treatment-related complications from thyroid surgery and to offer the most efficient and cost-effective therapeutic option.

Fine-needle aspiration biopsy versus ultrasound-guided fine-needle aspiration biopsy: cost-effectiveness as a frontline diagnostic modality for solitary thyroid nodules

BACKGROUND

Ultrasound-guided fine-needle aspiration biopsy (ultrasound-guided FNAB) is considered the diagnostic test of choice when a fine-needle aspiration biopsy (FNAB) returns an inconclusive diagnosis because of cytologic ambiguity or paucity of specimen.

METHODS

Cost-effectiveness analysis utilizing a decision tree was used to model the diagnostic strategies. The decision analysis model was parameterized using costs from a large, academic medical center and probabilities from existing literature. Outcomes included the incremental cost per additional case correctly diagnosed.

RESULTS

All data are reported as frontline ultrasound-guided FNAB strategy versus FNAB strategy-expected cost: $1329 versus $1312; expected number of cases correctly diagnosed (per 1000 biopsies): 980 versus 920; incremental cost per additional correctly diagnosed case: $289.

CONCLUSION

The use of ultrasound-guided FNAB as the initial modality for tissue biopsy of a thyroid nodule is more effective than traditional FNAB at an additional cost of $289 per additional correct diagnosis.

Management of the solitary thyroid nodule

Thyroid nodules are common, with up to 8% of the adult population having palpable nodules. With the use of ultrasound, up to 10 times more nodules are likely to be detected. Increasing numbers of nodules are being detected serendipitously because of the rising use of imaging to investigate unrelated conditions. The primary aim in investigating a thyroid nodule is to exclude the possibility of malignancy, which occurs in about 5% of nodules. This begins with a thorough history, including previous exposure to radiation and any family history of thyroid cancer or other endocrine diseases. Clinical examination of the neck should focus on the thyroid nodule and the gland itself, but also the presence of any cervical lymphadenopathy. Biochemical assessment of the thyroid needs to be followed by thyroid ultrasound, which may demonstrate features that are associated with a higher chance of the nodule being malignant. Fine-needle aspiration biopsy is crucial in the investigation of a thyroid nodule. It provides highly accurate cytologic information about the nodule from which a definitive management plan can be formulated. The challenge remains in the management of nodules that fall under the "indeterminate" category. These may be subject to more surgical intervention than is required because histological examination is the only way in which a malignancy can be excluded. Surgery followed by radioactive iodine ablation is the mainstay of treatment for differentiated thyroid cancers, and the majority of patients can expect high cure rates.

The radiologist and the cytologist in diagnosing thyroid nodules: results of cooperation

PURPOSE

This study was done to evaluate the effectiveness of cooperation between the radiologist and the cytopathologist in ultrasound-guided fine-needle aspiration biopsy (FNAB) of thyroid nodules.

MATERIALS AND METHODS

Since 1995, FNAB of thyroid nodules at our department has been performed under ultrasound guidance by the radiologist with a cytopathologist present on-site. The results of ultrasound-guided FNAB procedures performed at our department in 1995, 1999, and 2005 were retrospectively evaluated and compared with those of other departments in the Trieste Province where thyroid nodules are sampled by palpation-guided FNAB performed by a clinician.

RESULTS

From 1995 to 2005, the number of ultrasound-guided FNAB procedures performed at our department rose steadily, whereas the number of inadequate samples fell progressively. In patients who underwent surgery, the number of discrepancies between the cytological findings and the final histological diagnoses decreased progressively.

CONCLUSIONS

Ultrasound-guided FNAB performed by the radiologist with a cytopathologist present on-site is superior to palpation-guided FNAB. The results are optimised by cooperation between the radiologist and cytologist.

Predicting Malignant Involvement in a Thyroid Nodule: Role of Ultrasonography

OBJECTIVE

To assess how ultrasonography can contribute during the evaluation of a thyroid nodule and whether this technique can have a role in predicting malignant involvement.

METHODS

In this retrospective study, data were analyzed on 220 consecutive patients (with 348 thyroid nodules) who underwent thyroidectomy and had previously undergone assessment by high-resolution thyroid ultrasonography. Nodule size, echogenicity, regularity of margins, halo sign, presence or absence of calcifications, and invasion of surrounding tissues were evaluated. The nodules were classified as low, medium, or high risk for malignant involvement on the basis of nodule characteristics found on ultrasonography. All nodules were submitted to cytologic examination by fine-needle aspiration (FNA) before thyroidectomy. Ultrasound, FNA, and pathologic postoperative results were compared.

RESULTS

Among the 348 thyroid nodules, 56 were ultrasonographically classified as low risk, 268 as medium risk, and 24 as high risk for malignant potential. Fifty of 56 (89.3%) low-risk nodules and 213 of 268 (79.5%) medium-risk nodules were diagnosed as benign at pathologic postoperative examination. In contrast, however, only 6 of 24 (25%) high-risk nodules were diagnosed as benign. Among the 18 high-risk nodules of 1-cm diameter or larger, FNA showed a 20% false-negative result.

CONCLUSION

High-risk classification of a thyroid nodule on ultrasonography had a positive predictive value for malignant involvement of 75%. Nodule characteristics analyzed by ultrasonography should be considered at the time of surgical intervention.

Sonographic diagnosis of thyroid nodules: correlation with the results of sonographically guided fine-needle aspiration biopsy

PURPOSE

To assess the reliability of sonography in differentiating benign from malignant thyroid nodules and selecting lesions for fine-needle aspiration (FNA).

METHODS

During a 2-year period, the following 7 sonographic parameters were assessed in 129 patients with thyroid nodules: size, number, echogenicity, echotexure, margin regularity, presence of calcifications, and presence of a hypoechoic rim. Sonographically guided FNA was performed on thyroid nodules 5 mm in diameter. Out of 184 FNAs, we obtained 168 specimens adequate for cytologic analysis and 16 (9%) nondiagnostic specimens.

RESULTS

FNA diagnoses included 150 (89%) benign and 18 (11%) malignant nodules. Among 53 solitary nodules, 11 were carcinomas and 42 were benign (p < 0.01). The mean size of the carcinomas was 28 +/- 12 mm versus 18 +/- 10 mm for benign nodules (p < 0.01). The following sonographic features were significantly associated with malignancy: hypoechogenicity, irregular margins, calcifications, and absence of a hypoechoic rim. Differences in echotexure between malignant and benign nodules were not statistically significant.

CONCLUSION

Sonographically guided FNA should be performed on thyroid nodules 5 mm in diameter with sonographic characteristics that suggest malignancy.

Prevalence and distribution of carcinoma in patients with solitary and multiple thyroid nodules on sonography

CONTEXT

Controversy remains as to the optimal management of patients with multiple thyroid nodules.

OBJECTIVE

The objective of this study was to determine the prevalence, distribution, and sonographic features of thyroid cancer in patients with solitary and multiple thyroid nodules.

DESIGN

We describe a retrospective observational cohort study that was carried out from 1995 to 2003.

SETTING

The study was conducted in a tertiary care hospital.

PATIENTS

Patients with one or more thyroid nodules larger than 10 mm in diameter who had ultrasound-guided fine needle aspiration (FNA) were included in the study.

MAIN OUTCOME MEASURES

The main outcome measures were prevalence and distribution of thyroid cancer and the predictive value of demographic and sonographic features.

RESULTS

A total of 1985 patients underwent FNA of 3483 nodules. The prevalence of thyroid cancer was similar between patients with a solitary nodule (175 of 1181 patients, 14.8%) and patients with multiple nodules (120 of 804, 14.9%) (P = 0.95, chi(2)). A solitary nodule had a higher likelihood of malignancy than a nonsolitary nodule (P < 0.01). In patients with multiple nodules larger than 10 mm, cancer was multifocal in 46%, and 72% of cancers occurred in the largest nodule. Multiple logistic regression analysis of statistically significant features demonstrates that the combination of patient gender (P < 0.02), whether a nodule is solitary vs. one of multiple (P < 0.002), nodule composition (P < 0.01), and presence of calcifications (P < 0.001) can be used to assign risk of cancer to each individual nodule. Risk ranges from a 48% likelihood of malignancy in a solitary solid nodule with punctate calcifications in a man to less than 3% in a noncalcified predominantly cystic nodule in a woman.

CONCLUSIONS

In a patient with one or more thyroid nodules larger than 10 mm in diameter, the likelihood of thyroid cancer per patient is independent of the number of nodules, whereas the likelihood per nodule decreases as the number of nodules increases. For exclusion of cancer in a thyroid with multiple nodules larger than 10 mm, up to four nodules should be considered for FNA. Sonographic characteristics can be used to prioritize nodules for FNA based on their individual risk of cancer.

Comparison of palpation-guided fine-needle aspiration biopsy to ultrasound-guided fine-needle aspiration biopsy in the evaluation of thyroid nodules

OBJECTIVE

Although fine-needle aspiration biopsy (FNAB) of thyroid nodules is a reliable and simple method, the diagnostic value may be limited by inadequate and false-negative results. In this prospective study, we compared palpation-guided FNAB (PGFNAB) with ultrasound-guided FNAB (UGFNAB) to establish the rates of inadequate material and cost-effectiveness.

DESIGN

A total of 285 thyroid nodules in 215 patients were included in the study. Palpable nodules with the greatest diameter between 1 and 2.5 cm were included in the study. PGFNAB and UGFNAB techniques were applied to the same nodule by the same operator. Cytologic evaluations were performed by the same cytologist in a blinded fashion. To provide cost analysis, the prices obtained from different hospitals were evaluated.

MAIN OUTCOME

The rates of inadequate material for PGFNAB and UGFNAB were significantly different as 32.3% and 21.4%, respectively (p = 0.004). There was significantly higher inadequate material rate in PGFNAB group for small-sized nodules (greatest nodule diameter between 10 and 15 mm) (p = 0.009), despite inadequate material rate was not significant for both procedures for larger sized nodules. False-negative results were 15.8% for PGFNAB and 5.6% for UGFNAB. Regarding cost analysis, the difference between the two methods was 20 dollars on average for each patient.

CONCLUSIONS

We consider UGFNAB to be superior to PGFNAB for obtaining adequate material especially for small-sized nodules, as well as providing more accurate cytologic evaluation. Indeed, the difference between the costs of two procedures might be acceptable.

The impact of assessing specimen adequacy and number of needle passes for fine-needle aspiration biopsy of thyroid nodules

Fine-needle aspiration biopsy (FNAB) of thyroid nodules is a safe, cost-effective procedure but the rates of inadequate cytology specimens range from approximately 1% to 15%. This study tests the hypothesis that ultrasonographically (US) guided FNAB and onsite assessment of cytology improves the adequacy rate of FNAB. A retrospective analysis was performed on 693 thyroid FNAB specimens obtained with and without ultrasound guidance and with or without onsite cytology assessment. Overall, 29 specimens (4%) were inadequate for diagnosis. Among 163 cystic nodules and 530 solid nodules, inadequacy rates were 15% (n = 24) and 1% (n = 5) respectively (p = 0.0001). An onsite assessment of cytology for adequacy was done in 550 cases (83%), which was more accurately performed by a cytopathologist (97%) than a cytotechnologist (93%, p = 0.015). With US-guided FNAB, 3% of the cytology specimens were inadequate, compared to a 7% rate when US was not done (p = 0.003). The mean number of needle punctures necessary for an adequate specimen was 3.8 +/- 0.06 (median, 3.0; range, 1-11), which was different among various types of doctors, ranging from 3.2 +/- 0.07 to 5.4 +/- 0.12 (p = 0.001 analysis of variance [ANOVA]). The fewest number of needle passes to achieve an adequate specimen were required by university endocrinologists and pathologists working together (average, 3.2 +/- 0.07; median, 3.0; range, 1-11). Sample inadequacy rate varied significantly among physician groups, ranging from 3% to 18% (p = 0.0001 ANOVA). Stepwise regression analysis showed that onsite assessment of cytology, US-guided FNAB (p = 0.16), and cystic nature of the nodule (p < 0.0001 for all) correlated with adequacy of the specimen. We conclude that US-guided FNAB with onsite evaluation of cytology specimens substantially increases the adequacy of cytology specimens and decreases the number of required needle passes, which ultimately reduces patient discomfort and diagnostic errors, thus raising the question as to whether this should eventually become the standard of care. We believe this is a goal that training programs should strive to achieve.

Brief report: Use and misuse of thyroid ultrasound in the initial workup of patients with suspected thyroid problems referred by primary care physicians to an endocrine clinic

BACKGROUND AND OBJECTIVES

Thyroid ultrasound (TUS) plays an important but limited role in the evaluation of some complaints related to the thyroid gland. This study was designed to examine how primary care physicians use TUS before referring patients to an endocrine clinic.

DESIGN

We audited all charts of first-time referrals for appropriateness of TUS use. Recommendations in practice guidelines and current textbooks defined appropriate indications for TUS: (1) patients with a thyroid nodule and a history of head or neck irradiation; (2) follow-up of patients with nodules not surgically removed; and (3) evaluation of patients with amiodarone-induced thyrotoxicosis.

SETTING

Endocrine referral clinic in a teaching hospital in Israel.

RESULTS

Two hundred and eight unselected referrals were reviewed. Sixty-nine (33%) of the patients presented with a TUS. Documented reasons for TUS were suspected thyroid mass (n=35, 51%), thyroid dysfunction (n=21, 30%), neck pain (n=5, 7%), dyspnea (n=4, 6%), and dysphagia (n=2, 3%). Of the 69 TUS reviewed, 64 (93%) were not appropriate.

CONCLUSIONS

Primary care clinicians obtain TUS studies in patients without recommended indications prior to referral to an endocrinologist.

An alternate model of thyroid cytology: practical not perfect

A sample of 384 thyroid cytology specimens prepared by cytospin over a 2.5-year period was classified by original report into inadequate, non-neoplastic and suspicious of neoplasia or worse. This was then compared with subsequent histology. The resulting data showed an inadequacy rate of 33%, a sensitivity of 55%, a specificity of 59%, a positive predictive value of 64% and a negative predictive value of 93%. On review of the cytology, in knowledge of the subsequent histology, the maximum achievable results were determined to have a positive predictive value of 79% and a negative predictive value of 97%. No clinically significant adverse event was detected.