Adequacy of surgeon-performed ultrasound-guided thyroid fine-needle aspiration biopsy

Comprehensive Review of the Imaging Recommendations for Diagnosis, Staging, and Management of Thyroid Carcinoma

Thyroid cancer is the most common head and neck cancer (HNC) in the world. In this article, we comprehensively cover baseline, posttreatment, and follow-up imaging recommendations for thyroid carcinomas along with the eighth edition of the tumor, node, metastasis (TNM) staging system proposed by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC). We include characterization and risk stratification of thyroid nodules on ultrasound (US) proposed by various international bodies. Management guidelines (depending upon the type of thyroid carcinoma) based on the international consensus recommendations (mainly by the American Thyroid Association) are also extensively covered in this article, including the role of a radioiodine scan. The management of recurrent disease is also briefly elucidated in this article. In addition, we cover the risk factors and etiopathogenesis of thyroid carcinoma along with the non-imaging diagnostic workup essential for thyroid carcinoma management, including the significance of genetic mutations. US is the diagnostic imaging modality of choice, with US-guided fine needle aspiration (FNA) being the procedure of choice for tissue diagnosis. The roles of computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) in thyroid carcinoma staging are also specified. Through this article, we aim to provide a comprehensive reference guide for the radiologists and the clinicians in the pursuit of optimal care for patients with thyroid carcinoma.

Assessing Adequacy: A Meta-Analysis of Rapid Onsite Evaluation of Thyroid Nodules

INTRODUCTION

Fine-needle aspiration (FNA) is the standard form of preoperative evaluation of thyroid nodule cytological status. A significant number FNAs are classified as inadequate for interpretation, requiring a repeat FNA which is potentially avoidable, costly, and delays treatment. To address these concerns and maximize first-time FNA adequacy, rapid onsite evaluation (ROSE) of FNA specimens was introduced. Our study aims to determine the impact of ROSE on FNA adequacy.

METHODS

PubMed, Embase, and Web of Science were searched for primary articles assessing the adequacy of ROSE in thyroid nodules.

RESULTS

A total of 17 studies were included for a total of 24,649 thyroid nodes. Thirteen thousand two hundred fifteen (53.6%) thyroid nodules were assessed utilizing ROSE and 11,434 (46.4%) were not. Pooled adequacy increased significantly from 76% without ROSE to 92% with rose (P = 0.001). Use of ROSE increased the odds of adequate FNA by 22% (risk ratio (RR) = 1.22, 95% confidence interval (CI) = 1.12-1.32). At institutions with less than 85% effective diagnostic adequacy without ROSE, the risk for diagnostic adequacy increased by 28% with ROSE implementation (RR = 1.28, 95% CI = 1.20-1.37). In contrast, in studies reported from institutions with an effective diagnostic rate greater than 85% without the use of ROSE, the diagnostic adequacy only increased by 5% with ROSE implementation (RR = 1.05, 95% CI = 1.03-1.06).

CONCLUSIONS

The use of ROSE during first-time FNA of thyroid nodules can significantly improve adequacy, especially at institutions with baseline high inadequacy rates. Implementation of ROSE can reduce repeat FNAs and its associated consequences.

Surgeon-performed ultrasound-guided head and neck procedures during COVID-19 pandemic

Background

The ultrasonographic procedure is a common diagnostic and therapeutic method in daily medical practice. Surgeon-performed ultrasound (SUS) has been gaining popularity, especially during this COVID-19 pandemic.

Methods

Two ENT surgeons performed US-guided diagnostic or therapeutic procedures in the outpatient clinic. A successful SUS is defined as the diagnostic procedure's ability to facilitate the final histopathological diagnosis that can guide the subsequent treatment and disease resolution following the therapeutic procedure without the need for more invasive open surgical intervention.

Results

Out of 10 participants, 6 are males, and 4 are females. There were no complications noted. All subjects had successful tissue sampling or intervention on the first attempt for diagnostic and therapeutic SUS.

Conclusions

With COVID-19, there has been a significant shift in ordinary medical practice. SUS is proven to be a safe and effective method to facilitate the management of head and neck pathologies.

The comparison of the histopathological results of the thyroid fine-needle aspiration biopsies in the 795 patients with thyroidectomy

BACKGROUND

We aimed to evaluate the effectiveness of preoperative fine-needle aspiration biopsies (FNAB) by the postthyroidectomy pathology results.

METHOD

Seven hundred and ninety-five patients with FNAB and following thyroid operations which have been performed between April 2008 and December 2019 were included in this study. By comparing the results of the FNAB and final pathologies, the specificity, sensitivity, FNR, false positivity ratio (FPR), accuracy and also the effect of nodule diameter on these have been evaluated. In Bethesda III subgroup according to FNAB, we investigated the malignancy rates and in whom this risk has been increased more.

RESULTS

In our study, the sensitivity of FNAB is 73.40%, the specificity is 95.33%, the accuracy is 91.81%, FNR is 26.60% and FPR is 4.67%. In the patients with nodules ≥4 cm and < 4 cm respectively, we calculated the sensitivity 20.0% vs 79.76%, specificity 95.73% vs 95.19%, accuracy 89.82% vs 92.78%, FNR 80.0% vs 20.24%, FPR 4.27% vs 4.8%.

CONCLUSION

Thyroid FNAB is an easy procedure with a high specificity and sensitivity. Nevertheless, when the nodule diameter was ≥4 cm, increased FNR and decreased sensitivity should be kept in mind while evaluating the patients.

Standardization of thyroid fine needle aspiration procedure and outcomes within an endocrine surgery department

Background

Fine needle aspiration (FNA) biopsy is an essential procedure for thyroid nodules. Although, the efficacy of surgeon-performed thyroid FNA biopsies has been demonstrated in the literature, there are insufficient data regarding how to establish an efficient program with a low insufficiency rate within a group practice.

Methods

An endocrine surgery thyroid FNA biopsy program was established in 2000 by one surgeon, with training of additional partners during fellowship and upon recruitment. The results within 18 years were analyzed. The FNA biopsies were performed by endocrine surgeons under ultrasound guidance without on-site pathologist review.

Results

A total of 5,469 FNA biopsies were performed by 7 surgeons. The total number of FNA biopsies performed by each surgeon varied between 291-1,378. FNA biopsies were performed in 2 passes using 22-gauge needles under constant suction. The overall insufficiency rate was 4.3%, with individual surgeon rates ranging between 2.7% and 7.2%. The insufficiency rate for the whole team ranged between 3.3% and 5% when examined in 5-year blocks.

Conclusions

This study shows that an establishment of a highly efficient thyroid FNA biopsy program within a group practice is possible with a structured endocrine surgical training and adoption of a standard technique.

Ultrasound-Guided Fine-Needle Biopsy of First 1000 Consecutive Thyroid Nodules: Single-Surgeon Experience

Objective

To study the feasibility, safety, and learning curve of ultrasound-guided fine-needle biopsy (USGFNB) performed by a newly trained otolaryngologist in a community office in a setting.

Study Design

Collect USGFNB data of all thyroid nodules in a prospective manner.

Setting

A dedicated ultrasound clinic in a large community-based practice, operated by a single surgeon with the purpose of providing office-based point-of-care diagnostic ultrasonography and USGFNB.

Subjects and Methods

Data on the first 1000 unselected consecutive thyroid nodules that underwent USGFNB over a 3-year period were analyzed. Chi-square analysis was used to assess the statistical significance of characteristics of diagnostic vs nondiagnostic nodules. A multivariate regression analysis was conducted to determine nodule characteristics predictive of adequate sampling. Diagnostic yield and time efficiency data were plotted over a 3-year period to study the learning curve for the USGFNB procedure performed by an operator with no previous experience.

Results

A total of 1000 nodules in 734 patients including 142 males and 592 females (age range, 17-87 years) were studied. Of the patients, 188 of 734 had more than 1 nodule biopsied, with a maximum of 4 nodules biopsied in 1 setting. The procedure was successfully completed in all patients, with no major complications. A steep learning curve was observed, and adequate samples were obtained in 91.9% of the patients on the first attempt. The cystic nature of the nodule was the biggest predictor of a nondiagnostic yield.

Conclusions

Otolaryngologist-performed USGFNB of the thyroid is safe, effective, and desirable.

Determining whether surgeons perform thyroid fine-needle aspiration as well as radiologists: an analysis of the adequacy and efficiency of ultrasound-guided fine-needle aspiration performed by newly trained head and neck surgeons and radiologists

Background

Ultrasound-guided fine-needle aspiration (FNA) cytology is a crucial diagnostic technique used to assess thyroid nodules. In the past, ultrasound-guided FNA was performed mainly by radiologists. However, many surgeons are increasingly being trained for this procedure now. In this study, we aimed to compare the adequacy and efficiency of ultrasound-guided FNA performed by newly trained head and neck surgeons with experienced radiologists in a single institution. We also assessed the malignancy rates in nondiagnostic nodules and the differences between benign and malignant nodules.

Methods

This is a retrospective study. The data from patients who underwent ultrasound-guided FNA performed by surgeons or radiologists in two consecutive years were collected. Medical records, cytology results, and surgical pathology results were analyzed.

Results

During the study period, a total of 2,405 ultrasound-guided FNAs were performed on 2,163 patients. The head and neck surgeons and radiologists performed 1,132 and 1,273 ultrasound-guided FNA procedures, respectively. The nondiagnostic rate was 14.49% for surgeons and 15.40% for radiologists (P=0.533). There were no differences in patient age, gender, nodule size, and other sonographic characteristics between the groups of patients who were treated by radiologists versus surgeons. The median waiting time from biopsy appointment to performing ultrasound-guided FNA was 0 days for head and neck surgeons, and 6 days for radiologists (P<0.001). Of the 40 patients who had a repeat FNA or surgery, 19 (47.50%) had a malignancy. Preoperative information about age, gender, operator, and characteristics of nodules did not predict the outcome of nodules with Bethesda category I.

Conclusions

The adequacy of ultrasound-guided FNAs performed by head and neck surgeons is similar to that of skilled radiologists, while surgeons are more efficient than radiologists. Nondiagnostic FNA reports should not be considered benign, and repeat FNA or selective surgical treatment is recommended.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC): A report of 2,781 cases in a Chinese population

Objective

To evaluate the diagnostic utility of The Bethesda System for Reporting Thyroid Cytology (TBSRTC) at Peking University Cancer Hospital, the incidence of noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP), and the impact of reclassification on cytopathological outcomes.

Methods

We performed a retrospective study of thyroid fine-needle aspiration (FNA) cases between April 2014 and March 2019. The FNA results were classified according to TBSRTC. Post-surgery histological findings were followed up.

Results

A total of 2,781 thyroid FNAs were performed. The incidences of the 6 diagnostic categories (DCs I-VI) were 14.8%, 17.1%, 15.8%, 2.3%, 11.6% and 38.5%, respectively. A total of 1,122 patients (40.3%) had corresponding histological results. NIFTP accounted for 0.4% of papillary thyroid carcinoma (PTC) cases, and there was no significant difference in the risk of malignancy (ROM) for each TBSRTC DC between "NIFTP=carcinoma (Ca)" and "NIFTP≠Ca". When "NIFTP=Ca", the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TBSRTC were 98.0%, 84.0%, 99.4%, 58.3%, and 97.5%, respectively. When "NIFTP≠Ca", the sensitivity, specificity, PPV, NPV and accuracy of the TBSRTC were 98.1%, 81.5%, 99.3%, 61.1%, and 97.5%, respectively.

Conclusions

TBSRTC is effective in the preoperative diagnosis of thyroid nodules in Peking University Cancer Hospital. The impact of the reclassification of NIFTP on cytopathological outcomes is limited because of its low incidence, and the revised ROMs are not suitable for Asian patients.

Value of rapid on-site evaluation for ultrasound-guided thyroid fine needle aspiration

Objective

Application of rapid on-site evaluation (ROSE) for thyroid fine needle aspiration (FNA) is controversial. Therefore, ROSE has not been universally applied. This study aimed to evaluate the value of ROSE for ultrasound-guided thyroid FNA.

Methods

A total of 997 patients with 1103 suspicious thyroid nodules had ultrasound-guided FNA performed from January 2016 to February 2018. There were 513 nodules with ROSE and 590 nodules without ROSE. The cytological nondiagnostic rate, needle passes, and procedural times of thyroid FNA with or without ROSE were compared. The nondiagnostic rates of subsets of suspicious thyroid nodules were further compared.

Results

There was no significant effect of ROSE on the nondiagnostic rate of FNA. However, FNA with ROSE significantly reduced the numbers of sub-centimeter, mixed solid-cystic, macrocalcified, and hypervascular nodules. There was a significantly smaller number of needle passes and less procedural times with ROSE than without ROSE. There was no significant difference in the complication rate of FNA with and without ROSE.

Conclusion

ROSE for thyroid FNA reduces the number of needle passes and procedural times. ROSE has a higher clinical application value in subsets of thyroid nodules, which tend to be difficult to diagnose with FNA.

Efficacy of surgeon-performed, ultrasound-guided lymph node fine needle aspiration in patients with thyroid pathologic conditions

BACKGROUND

Although the concept of surgeon-performed fine needle aspiration of thyroid nodules is established, experience with surgeon-performed lymph node fine needle aspiration is scant. We aimed to study the efficacy of surgeon-performed lymph node fine needle aspiration in patients with thyroid pathologic conditions.

METHODS

This is an institutional review board-approved study of patients with thyroid pathologic conditions who underwent surgeon-performed lymph node fine needle aspiration between 2002 and 2017. Efficacy and utility were analyzed.

RESULTS

A total of 201 patients with benign nodular goiter (n = 30) and thyroid cancer (n = 200) underwent 230 lymph node fine needle aspirations (89 during preoperative workup, 141 at postoperative follow-up). Insufficient aspiration rate was 6% and indeterminate cytologic results 3%. In 91% of patients with suspicious lymph nodes, definite diagnosis could be obtained by fine needle aspiration; 51% (n = 118) of fine needle aspirations indicated metastasis from thyroid cancer and 40% (n = 91) benign findings. Sensitivity and specificity of lymph node fine needle aspiration in diagnosing nodal metastasis were 92% and 89%, respectively. Cytologic testing and thyroglobulin washout indicated 95% concordance. On logistic regression, spherical shape, microcalcifications, cystic appearance, and loss of hilum on ultrasound independently predicted lymph node metastasis.

CONCLUSION

Our data indicate that an adequate surgeon-performed lymph node fine needle aspiration is highly accurate in diagnosing nodal status in thyroid pathologic conditions. We recommend adoption of this technique, when feasible, to develop an efficient, comprehensive thyroid practice.

Investigation of thyroid nodules: A practical algorithm and review of guidelines

BACKGROUND

High resolution ultrasound has led to early detection of subclinical tumors and drastic increase in incidence of thyroid malignancy. To achieve a balance in appropriate investigation without perpetuating an overdiagnosis phenomenon, a concise set of evidence-based recommendations to stratify risk is required.

METHODS

We sought to assemble an evidence-based diagnostic algorithm and accompanying pictorial review for workup of thyroid nodules that summarizes the most recent guidelines. In addition, we conducted a literature search and analysis of our imaging databases.

RESULTS

Although many imaging features of benign and malignant nodules can be nonspecific, others, such as microcalcifications, lymphadenopathy, and peripheral invasion, are highly suggestive of malignancy. The predictive values of salient imaging characteristics are presented.

CONCLUSION

Evidence-based guidelines are available such that a cost-effective algorithm for thyroid nodule workup can be devised. Conservative management with a focus on periodic monitoring is the working clinical consensus on the approach to thyroid nodules.

Importance of FNA Technique for Decreasing Non-diagnostic Rates in Thyroid Nodules

To identify potential interventions that may lower the high non-diagnostic rates associated with ultrasound guided (US) fine needle aspiration (FNA) biopsy of the thyroid nodule. A case series of 164 thyroid nodule US-guided FNA was identified retrospectively. The following variables were analyzed in regards to diagnostic and non-diagnostic sampling: patient age, gender, size of nodule, biopsy technique (capillary vs. aspiration), needle gauge (23 vs. 25), and physician experience. The FNA diagnosis, and final pathology, when applicable, was recorded for each sample using the Bethesda criteria. Data was analyzed using the Fisher's exact test or the chi square test. After multivariate logistic regression, capillary action was independently associated with lower non-diagnostic rates (p = 0.01), while increasing patient age was associated with higher non-diagnostic rates (p = 0.018). Physician experience (p = 0.014) was not independently associated with lower non-diagnostic rates. Nodules that were "cystic >50%" were significantly more likely to yield a non-diagnostic result (p < 0.0001). After taking into account confounding variables, including physician experience, our data reveals a statistically significant decrease in non-diagnostic rates with the use of capillary action vs. aspiration technique in US-guided FNA. A major focus in healthcare today is providing cost-effective and minimally invasive care to the patient. In the setting of a rising incidence of thyroid disease, we believe our study demonstrates the need for a prospective analysis of the relationship between technique and non-diagnostic rates.

Thyroid Ultrasound-Guided Fine-Needle Aspiration Cytology Results: Observed Increase in Indeterminate Rate over the Past Decade

Objectives To evaluate changes in distribution of reported thyroid nodule fine-needle aspiration (FNA) cytopathology results since implementation of the Bethesda classification and revised 2015 American Thyroid Association (ATA) guidelines for selecting nodules for biopsy. Study Design Retrospective review. Setting Tertiary academic medical center. Subjects and Methods Evaluation of ultrasound (US)-guided thyroid FNA by a single surgeon using 2015 ATA nodule selection criteria and Bethesda reporting on 211 thyroid nodules in a 1-year period (2015). Comparison is made to an earlier sample wherein any nodule >1 cm underwent US FNA with cytology reported prior to Bethesda consensus (2006). Results The current cohort involved mostly women (79%); nodules ranged from 1 to 7 cm (mean ± SEM, 2.4 ± 0.07 cm). Mean ± SEM age was 53.5 ± 1.1 years. Bethesda reporting yielded 6% nondiagnostic, 57% benign, 3% malignant, and 34% indeterminate (27% atypia of undetermined significance [AUS]/follicular lesion of undetermined significance [FLUS], 4% follicular neoplasm [FN]/Hürthle neoplasm [HN], and 2% suspicious for malignancy [SFM]). The malignancy rate in indeterminate nodules was 26% (18% AUS/FLUS, 33% FN/HN, and 80% SFM). Age, sex, or nodule size did not correlate with indeterminate cytology. The comparator sample of 447 nodules had significantly different distribution, with 7% nondiagnostic, 80% benign, 5% malignant, and 8% indeterminate ( P < .00001). Conclusion We observed a significantly increased proportion of indeterminate cytology and corresponding decrease in benign nodules compared with an earlier sample, predominately from an increase in AUS/FLUS. Multiple factors are likely involved, including selection of sonographically suspicious nodules for biopsy based upon 2015 ATA guidelines coupled with cytopathological interpretation by a new generation of cytopathologists trained in the era of Bethesda reporting; further study is required to make a definitive conclusion.

Comparison of 1869 thyroid ultrasound-guided fine-needle aspiration biopsies between general surgeons and interventional radiologists

BACKGROUND

Thyroid nodules are commonly encountered problems in clinical practice. For patients who have a thyroid nodule, the fine-needle aspiration biopsy (FNAB) is the most important test, as it is the most reliable diagnostic method for distinguishing between benign thyroid nodules and cancerous nodules. FNAB is able to be performed either via an ultrasound (USG) or alone and is the first choice when it comes to diagnosing thyroid nodules, given that it is cheap, safe and provides accurate results.

OBJECTIVE

In this study-a retrospective analysis of FNAB via USG - our aim is to evaluate the multiple variables related to FNAB procedures, including the experience of the person performing the biopsy, the age and gender of the patient, the number of nodules, the size of the nodule(s) and the number of lams recorded from the cytopathology report on non-diagnostic rates, conducted at an invasive radiology clinic and at a general surgery clinic.

MATERIALS AND METHODS

A total of 1062 patients involving 1869 nodules, examined using FNAB via USG, were reviewed retrospectively from records dated between November 2011 and July 2014 and from pathology reports taken from the ANEAH General Surgery clinic and Interventional Radiology clinic. Cytopathology results were classified according to the 2007 Bethesda System for Reporting. Gender, age, number of nodules, diameter of the nodules, biopsied nodules, location of the nodules, number of lams, symptoms and the date of biopsies were the parameters used to examine the factors involved in non-diagnostic cytopathology invasive radiology. These parameters were inspected at both of the clinics (ANEAH General Surgery clinic and Interventional Radiology clinic). In analyzing the results, the statistical significance level was set at 0.05, where in cases that the p value was under 0.05 (p < 0.05), it was determined that no significant relationship existed. In this study, data were analyzed using SPSS 20 software.

RESULTS

Of the nodules reviewed, 1620 were found on females and 249 on males. The age of the patients ranged from 10 to 87 years, with the mean age being 50 years. In the general surgery clinic, 470 nodules of 341 patients were aspirated, and in the interventional radiological clinic, 1399 nodules of 721 patients were aspirated. In the literature review conducted to compare statistical assessments of FNAB via USG, no significant difference was found between the ANEAH General Surgery clinic and the Invasive Radiology clinic (p > 0.05). In the invasive radiology clinic, non-diagnostic rates decreased with the increase in experience of the person who conducted the biopsy (p = 0.001).

CONCLUSION

The results from both of the clinic's rates of non-diagnostic FNAB, performed via USG, were found to be acceptable. Our study also demonstrates that USG-guided FNAB can be performed with a low non-diagnostic rate as experience grows.

Malignancy risk and false-negative rate of fine needle aspiration cytology in thyroid nodules ≥4.0 cm

BACKGROUND

We aimed to evaluate malignancy rate and to determine false negativity of fine needle aspiration biopsy (FNAB) in thyroid nodules ≥4.0 cm.

METHODS

The medical records of patients who underwent thyroidectomy between January 2007 and December 2014 were reviewed. Demographic and clinical data as well as preoperative ultrasonography findings were analyzed. The nodules in these patients were grouped as ≥4.0 cm and <4.0 cm according to ultrasonography measurements. Nodules <4.0 cm were further divided into 1.0-3.9 cm and <1.0 cm. Histopathologically malignant nodules with preoperative benign cytology were defined as having false-negative FNAB.

RESULTS

There were 1,008 nodules that measured ≥4.0 cm, 4,013 nodules that measured 1.0-3.9 cm, and 540 that measured nodules <1.0 cm. Based on histopathologic findings, 8.5%, 10.2%, and 25.6% of nodules ≥4.0 cm, 1.0-3.9 cm, and <1.0 cm were malignant, respectively (P < .001). There was no significant difference between 1.0-3.9-cm and ≥4.0-cm nodules with respect to malignancy (P = .108). False-negativity rates were 4.7% in nodules ≥4.0 cm, 2.2% in nodules measuring 1.0-3.9 cm, and 4.8% in <1.0-cm nodules. Nodules measuring <1.0 cm and ≥4.0 cm had similar false-negativity rates (P = .93), while 1.0-3.9-cm nodules had statistically lower false-negativity rates than those found in the other two groups (P = .03 and P < .001, respectively).

CONCLUSION

Of the nodules that were operatively excised, nodules ≥4.0 cm had a similar risk of malignancy as nodules 1.0-3.9 cm. The rate of false-negative FNAB in nodules ≥4.0 cm was twice as high as in nodules 1.0-3.9 cm; however, we do not think it is high enough to recommend a routine operation when cytology results are benign.

Surgeon-performed ultrasound guided fine-needle aspirate biopsy with report of learning curve; a consecutive case-series study

Background

Fine-needle aspiration biopsy has become the standard of care for the evaluation of thyroid nodules. More recently, the use of ultrasound guided fine-needle aspiration biopsy (UG-FNAB) has improved adequacy of sampling. Now there has been improved access to UG-FNAB as ultrasound technology has become more accessible. Here we review the adequacy rate and learning curve of a single surgeon starting at the adoption of UG-FNAB into surgical practice.

Methods

UG-FNABs performed at Sunnybrook Health Sciences Centre from 2010 to 2015 were reviewed retrospectively. Nodule characteristics were recorded along with cytopathology and final pathology reports. Chi-square analysis, followed by the reporting of odds ratios with confidence intervals, were used to assess the statistical significance and frequencies, respectively, of nodule characteristics amongst both diagnostic and non-diagnostic samples. A multiple regression analysis was conducted to determine if any nodule characteristic were predictive of adequacy of UG-FNABs. The learning curve was assessed by calculating the eventual adequacy rates across each year, and its statistical significance was measured using Fischer’s Exact Test.

Results

In total 423 biopsies were reviewed in 289 patients. The average nodule size was 23.05 mm. When examining if each patient eventually received a diagnostic UG-FNAB, regardless of the number attempts, adequacy was seen to increase from 70.8 % in 2010 to, 81.0 % in 2011, 90.3 % in 2012, 85.7 % in 2013, 89.7 % in 2014, and 94.3 % in 2015 (Fischer’s Exact Test, p = 0.049). Cystic (χ² = 19.70, p <0.001) nodules were found to yield higher rates of non-diagnostic samples, and their absence are predictive of obtaining an adequate biopsy as seen in a multiple regression analysis (p < 0.001) Adequacy of repeat biopsies following an initial non-diagnostic sample was 75.0 %.

Conclusions

Surgeons are capable of performing UG-FNAB with a learning curve noted to achieve standard adequacy rates. Cystic nodules are shown to yield more non-diagnostic samples in the surgeon’s office.

Surgeon performed ultrasound-guided fine-needle aspirates of the thyroid: 1067 biopsies and learning curve in a teaching center

BACKGROUND

Surgeon performed ultrasound-guided fine-needle aspirates (UG-FNAs) reduce delay in diagnosis and allow for surgeon surveillance. We present the first report on a learning curve and impact of head and neck surgical trainees on adequacy rates.

METHODS

Thyroid UG-FNA biopsies from 2009 to 2013 were reviewed retrospectively. Specimen adequacy, cytologic diagnosis, and surgical pathology were used to calculate adequacy and accuracy.

RESULTS

One thousand sixty-seven biopsies were examined in 723 individuals. The adequacy rate from adoption into practice improved from 71% to 78% to 85% over 300 cases. When UG-FNA was subsequently taught to trainees, adequacy rates varied among trainees (p < .037), and there were higher nondiagnostic rates earlier in training (p = .04). Adequacy was not related to size or palpability, but cystic lesions yielded more inadequate specimens (p < .001).

CONCLUSION

Surgeon performed UG-FNA biopsy can be performed adequately in an outpatient setting. Adequacy rates reach acceptable levels after 300 cases, whereas trainee involvement impacts adequacy rates. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1281-E1284, 2016.

The diagnostic accuracy of ultrasound-guided fine-needle aspiration biopsy for thyroid nodules three centimeters or larger in size

BACKGROUND AND PURPOSE

Whether under ultrasonography (US) guidance or not, fine-needle aspiration biopsy (FNAB) has some limitations, particularly in larger nodules. In this study, we aimed to evaluate the diagnostic value of US-guided fine-needle aspiration biopsy (US-FNAB) in thyroid nodules equal to or larger than 3 cm.

MATERIALS AND METHODS

Data of 267 patients operated for nodular goiter in the period of January 2006 and March 2012 were reviewed retrospectively. The study group (40 males, 104 females; mean age 42.3 ± 12.3, between 17 and 71) consisted of patients with nodules with a diameter of 3 cm or larger. Patients with nodules less than 3 cm in diameter were considered as the control group (27 males, 96 females; mean age 44.4 ± 11.9, between 18 and 71).

RESULTS

For nodules smaller than 3 cm, US-FNAB had an accuracy rate of 60% and a false negativity rate of 21.9%. In nodules equal to or larger than 3 cm, the accuracy rate of US-FNAB was 80%, with a false negativity rate of 6.7%. Malignancy was observed in 16% of the study group and 42.3% of the control group.

CONCLUSION

This study showed that increased nodule diameter is not associated with limitations in the diagnostic value of US-FNAB. We also found that the malignancy rate was smaller for larger nodules. This finding reflects the importance of accurate and rational diagnostic work-up and clinical management for detecting malignancy and surgical decision-making.

American Thyroid Association statement on preoperative imaging for thyroid cancer surgery

BACKGROUND

The success of surgery for thyroid cancer hinges on thorough and accurate preoperative imaging, which enables complete clearance of the primary tumor and affected lymph node compartments. This working group was charged by the Surgical Affairs Committee of the American Thyroid Association to examine the available literature and to review the most appropriate imaging studies for the planning of initial and revision surgery for thyroid cancer.

SUMMARY

Ultrasound remains the most important imaging modality in the evaluation of thyroid cancer, and should be used routinely to assess both the primary tumor and all associated cervical lymph node basins preoperatively. Positive lymph nodes may be distinguished from normal nodes based upon size, shape, echogenicity, hypervascularity, loss of hilar architecture, and the presence of calcifications. Ultrasound-guided fine-needle aspiration of suspicious lymph nodes may be useful in guiding the extent of surgery. Cross-sectional imaging (computed tomography with contrast or magnetic resonance imaging) may be considered in select circumstances to better characterize tumor invasion and bulky, inferiorly located, or posteriorly located lymph nodes, or when ultrasound expertise is not available. The above recommendations are applicable to both initial and revision surgery. Functional imaging with positron emission tomography (PET) or PET-CT may be helpful in cases of recurrent cancer with positive tumor markers and negative anatomic imaging.

Predictors of non-diagnostic cytology in surgeon-performed ultrasound guided fine needle aspiration of thyroid nodules

BACKGROUND

Fine needle aspiration (FNA) is the standard of care for the diagnostic work-up of thyroid nodules but despite its proven utility, the non-diagnostic rate for thyroid FNA ranges from 6-36%. A non-diagnostic FNA is problematic for the clinician and patient because it can result in repeated procedures, multiple physician visits, and a delay in definitive treatment. Surgeon-performed FNA has been shown to be safe, cost-effective, as accurate as those performed by other clinicians, and has the added benefit of decreasing wait times to surgery. Several studies have examined rates and factors that may be predictive of a non-diagnostic cytology in non-surgeon FNA, but none have evaluated this in surgeon-performed thyroid FNA. If these factors are unique in surgeon-performed vs. non-surgeon performed thyroid FNA, then patients may be more appropriately triaged to FNA by alternate clinicians.

OBJECTIVES

The purpose of this study was to determine the rate and factors predictive of a non-diagnostic FNA in surgeon performed ultrasound-guided FNA of thyroid nodules.

METHODS

We conducted a retrospective review of all adult patients who underwent thyroid FNA by a staff, fellow, or resident Otolaryngologist at the University of Alberta between January 2011 and June 2013. Factors analyzed included patient factors, thyroid characteristics, nodule characteristics, and surgeon level of training and experience. Univariate and multivariate binary logistic regression analysis were performed.

RESULTS

131 patients (180 nodules) were reviewed. The non-diagnostic rate was 23%. Nodules with predominant cystic component, those less than 1 cm, and resident-performed FNA were associated with non-diagnostic cytology (p = 0.001, p = 0.02, p = 0.04 respectively). A cystic nodule was the only independent predictor of non-diagnostic FNA on multivariate analysis (OR = 4.441, 95% CI [1.785-11.045], p = 0.001).

CONCLUSIONS

The rate of non-diagnostic thyroid FNA performed by a surgeon with ultrasound guidance is similar to other clinicians. A cystic nodule is a strong independent predictor of non-diagnostic cytology. Non-cystic nodules may particularly benefit from surgeon-performed thyroid FNA due to the high diagnostic rate and potential for earlier definitive management.

A systematic review of ultrasound-guided FNA of lesions in the head and neck--focusing on operator, sample inadequacy and presence of on-spot cytology service

The objective of this review is to perform a systematic review of ultrasound-guided fine-needle aspiration (FNA) services for head and neck lesions with assessment of inadequacy rates and related variables such as the presence of immediate cytological assessment. A computer-based systematic search of articles in English language was performed using MEDLINE (1950 to date) from National Health Service evidence healthcare database and PubMed. Full texts of all relevant articles were obtained and scrutinized independently by two authors according to the stated inclusion and exclusion criteria. The primary search identified 932 articles, but only 78 met all the study criteria. The overall inadequacy rate was 9.3%, 16 studies had on-site evaluation by a cytopathologist/specialist clinician with a rate of 6.0%. In seven studies, a cytotechnician was available to either assess the sample or prepare the slides with an average inadequacy rate of 11.4%. In 1 study, the assessment was unclear, but the inadequacy rate for the remaining 54 studies, without immediate assessment, was 10.3%. The rate for the cytopathologist/specialist clinicians was significantly different to no on-site assessment but this was not found for assessment by cytotechnicians. The review suggests that the best results are obtained with a cytopathologist-led FNA service, where the pathologist reviews the specimen immediately, in relation to the clinical context, thereby deciding on adequacy and need for further biopsies. A systematic review looking at ultrasound-guided FNA of head and neck lesions has not been published previously.

Surgeon-performed ultrasound-guided fine-needle aspiration cytology of head and neck mass lesions: sampling adequacy and diagnostic accuracy

BACKGROUND

Studies of surgeon-performed ultrasound-guided fine-needle aspiration cytology (US-FNAC) have been limited largely to thyroid nodules. This study evaluated the sampling adequacy and diagnostic accuracy of surgeon-performed US-FNAC for a large range of head and neck mass lesions, including lesions of the thyroid, salivary glands, and lymph nodes.

METHODS

The study included 617 cases of US-FNAC performed by a single surgeon between 2009 and 2013. Their medical histories and ultrasound (US) findings were retrospectively reviewed. Sample adequacy was analyzed according to the surgeon's experience, anatomic tumor location, and US tumor characteristics. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of FNAC were calculated after correlation with the surgical histopathologic results.

RESULTS

The overall adequacy rate for surgeon-performed US-FNAC was 91.9 % (567/617). Inadequate specimens were obtained from 9.7 % (29/282) of the thyroid glands, 6.1 % of the salivary glands (6/98), and 6.3 % (15/237) of the lymph nodes. The effect of the surgeon's experience plateaued (inadequate sampling rate, 6-8 %) after 100 US-FNAC procedures. Inadequate sampling was associated with tumor characteristics such as cystic change and rim calcification. Overall, US-FNAC showed a sensitivity of 88.2 %, a specificity of 98.2 %, a PPV of 98.5 %, an NPV of 85.7 %, and a diagnostic accuracy of 91.6 %.

CONCLUSION

With proper training and experience managing at least 100 US-FNAC cases, surgeons can ensure a low inadequate sampling rate and good diagnostic accuracy for a range of head and neck mass lesions.

Diagnostic adequacy of surgeon-performed ultrasound-guided fine needle aspiration biopsy of thyroid nodules

BACKGROUND

Surgeon-performed ultrasonography (US) of thyroid nodules might serve as a potential therapeutic guide to designate accurate surgical or clinical intervention.

OBJECTIVE

To evaluate the diagnostic adequacy of surgeon-performed ultrasonography guided fine needle aspiration biopsy (FNAB) of thyroid nodules, the factors responsible for diagnostic adequacy and the impact of surgeon-performed US on treatment approach.

METHODS

Retrospective review of a single surgeon performed 621 US-guided FNABs without on-site cytological specimen assessment. Outside US findings were compared to the surgeon-performed US. Measured variables and outcomes for the study included diagnostic adequacy rates and the effects of detected differences between US reports on treatment variability.

RESULTS

Diagnostic adequacy rate of surgeon-performed US-guided FNAB was determined to be 94.52% without on-site specimen evaluation by cytologist. Non-diagnostic specimens occurred in 34 of 621 (5.48%) nodules. The differences detected between the outside US and surgeon-performed US altered invasive treatment algorithm in 30 (5.47%) patients. FNAB was avoided for 15 (2.7%) patients. Total thyroidectomy became the preferred surgical option in 15 (2.7%) patients after the discovery of additional nodules in the contralateral lobe.

CONCLUSION

Surgeon-performed US offers clear clinical benefits in terms of diagnostic yield of FNAB with providing valuable additional data that might alter surgical treatment approach.

Diagnostic accuracy of surgeon-performed ultrasound-guided fine-needle aspiration of thyroid nodules

BACKGROUND

There is scant data concerning surgeon-performed thyroid fine-needle aspiration (FNA), and controversy regarding its accuracy in larger nodules. This study aimed to specifically assess accuracy of surgeon-performed ultrasound (US)-guided FNA on a per-nodule basis, with a subanalysis of nodule size.

METHODS

Data of 1,000 surgeon-performed US-guided thyroid FNAs at a single institution from 2000 to 2010 were prospectively collected. Standard clinical information, FNA results using the Bethesda criteria, and final histology were recorded.

RESULTS

Fine-needle aspiration results were reported as: cancer (7%), suspicious for cancer (2%), suspicious for follicular neoplasm (17%), atypia of unknown significance (AUS) (1%), benign (67%), and insufficient (6%). Of nodules with FNA results of cancer, suspicious for cancer, suspicious for follicular neoplasm, and atypia of unknown significance, 94% were operated on, with malignancy rates of 97%, 58%, 21%, and 12%, respectively. Of nodules with benign FNA, 26% underwent surgery for associated symptoms, concerning features, or other remote pathology. A total of 56% were followed, and 18% were lost to follow-up. Of nodules with insufficient FNA, 46% had repeat FNA (yielding a diagnosis in 81%), 23% underwent surgery, 21% with hypocellular features were followed, and 9% were lost to follow-up. In size subanalysis, there was no statistically significant difference in risk of malignancy or increased rate of falsely negative FNA with increasing nodule size.

CONCLUSIONS

The Bethesda system appropriately stratified lesions for risk of malignancy, and repeat FNA had high diagnostic yield in lesions with inadequate FNA. The results suggest no trend toward larger lesions harboring thyroid malignancy nor an increased likelihood of false-negative benign FNA.

Fine-needle aspiration biopsy of thyroid nodules: comparison of diagnostic performance of experienced and inexperienced physicians

OBJECTIVE

To determine whether a difference exists in terms of obtaining adequate cytologic samples from ultrasound-guided fine-needle aspiration cytology (US-FNAC) between experienced and inexperienced physicians in a tertiary referral center.

METHODS

In a prospective design, all patients with thyroid nodules of at least 10 mm in diameter were referred for US-FNAC tissue sampling as a part of their diagnostic work-up. Between May 2006 and September 2009, 997 euthyroid patients with 1,320 thyroid nodules were referred for US-FNAC by the attending endocrinologist (experienced physician) or 1 of 2 endocrinology fellows (inexperienced physicians).

RESULTS

Of the 1,320 nodules, 713 biopsy specimens were obtained by the experienced physician and 607 were obtained by the inexperienced physicians. Nodule size was significantly larger in the endocrinologist's group of patients than in the fellows' group of patients (17 mm versus 14 mm, respectively; P<.001). The inadequacy rate of the US-FNAC procedures performed by the experienced physician (22 of 713 thyroid nodules or 3.1%) was significantly lower than for those performed by the inexperienced physicians (102 of 607 thyroid nodules or 16.8%) (P<.001).

CONCLUSION

We conclude that, with increasing operator experience, the number of inadequate cytologic specimens generated by US-FNAC procedures is substantially reduced. This limits both direct and indirect costs and also minimizes the risks of possibly unnecessary surgical procedures.

Surgeon-performed ultrasound in patients referred for thyroid disease improves patient care by minimizing performance of unnecessary procedures and optimizing surgical treatment

BACKGROUND

Ultrasonography has become an indispensable tool in the evaluation of thyroid nodular disease, and most patients will have had a thyroid ultrasound prior to initial surgical evaluation. This study examines the added benefit of office-based, surgeon-performed ultrasonography in patients referred for thyroid disease.

METHODS

All patients referred to a single endocrine surgeon for evaluation of thyroid disease over a 2-year period were reviewed. Outside ultrasonographic findings were compared to the surgeon-performed ultrasound that was used to formulate treatment decisions.

RESULTS

Of 286 consecutive patients referred for surgical evaluation of thyroid disease, 261 had an outside ultrasound available for comparison. There were 239 women and 47 men. Mean age was 54.7 +/- 16.6. In 46 patients (17.6%), differences between the two ultrasounds were significant enough to alter treatment plans. For 18 patients no distinct nodule was identified and biopsy was avoided. Nine of these patients had ultrasound characteristics of Hashimoto's disease. In five patients the nodule was significantly smaller than reported and biopsy was not warranted. Twelve patients had nonpalpable, enlarged lymph nodes not previously identified; these were biopsied. Three were positive for metastatic thyroid cancer, which prompted the addition of neck dissection to the operative procedure. In 8 of 132 patients undergoing thyroidectomy, the surgical procedure was significantly altered by the ultrasound findings.

CONCLUSIONS

This study demonstrates a clear advantage for patients who undergo a surgeon-performed ultrasound. For many, unnecessary procedures were prevented. For others, substantial modifications to the extent of surgery were made when new ultrasonographic findings were identified during the preoperative investigation.

Use of ultrasound in the management of thyroid cancer

The use of ultrasound for thyroid cancer has evolved dramatically over the last few decades. Since the late 1960s, ultrasound has become essential in the examination of the thyroid gland with the increased availability of high-frequency linear array transducers and computer-enhanced imaging capabilities of modern day portable ultrasound equipment in a clinic- or office-based setting. As a noninvasive, rapid, and easily reproducible imaging study, ultrasound has been demonstrated to have a broadened utility beyond the simple confirmation of thyroid nodules and their sizes. Recently, office-based ultrasound has become an integral part of clinical practice, where it has demonstrated overwhelming benefits to patients being evaluated and treated for thyroid cancer. Ultrasound has become useful in the qualitative characterization of thyroid nodules based on benign or malignant features. On the basis of such classifications and the relative risk for thyroid malignancy, the need for ultrasound-guided fine-needle aspiration, preoperative and intraoperative staging, lymph node mapping, and the extent of surgery can subsequently be determined. Furthermore, ultrasound has additional value in the surveillance of patients treated for thyroid cancer.

Diagnostic efficacy of surgeon-performed ultrasound-guided fine needle aspiration: A randomized controlled trial

Objective: To evaluate the clinical efficacy of surgeon-performed, office-based head and neck ultrasound in facilitating diagnostic fine needle aspiration (FNA) of lesions in the head and neck.

Study Design: A randomized controlled trial of ultrasound-guided FNA versus traditional palpation-guided technique for palpable masses in the head and neck.

Setting: An office-based study performed in a military academic medical center.

Subjects and Methods: Eighty-one adults older than 18 years of age with a palpable head and neck mass (less than 3 cm in largest diameter) were randomized to ultrasound-guided or traditional palpation-guided FNA of a head and neck mass. Measured variables and outcomes for the study included tissue adequacy rates, tissue type, and operator variability.

Results: Following three passes using either palpation or ultrasound guidance, a comparative tissue adequacy rate of 84 percent for ultrasound guidance versus 58 percent for standard palpation was established ( P < 0.014). With regard to tissue type, a statistically significant comparative diagnostic advantage for ultrasound guidance was observed in thyroid tissue while remaining statistically insignificant for lymphatic and salivary tissues. No statistical significance was found when comparing the ability of otolaryngology residents versus attending otolaryngologists to obtain ultrasound-guided diagnostic samples.

Conclusion: Office-based surgeon-performed ultrasound-guided FNA of palpable lesions in the head and neck yields a statistically significant higher diagnostic rate compared to standard palpation technique. Our institutional experience supports the utility of surgeon-performed ultrasound as a core competency in clinical practice.

Developments in the use of ultrasound for thyroid cancer

PURPOSE OF REVIEW

This article reviews the recent developments in neck ultrasound for thyroid cancer published in the last 18 months, with emphasis on the emerging role of surgeon-performed ultrasound in clinical endocrine practice.

RECENT FINDINGS

Ultrasound has evolved beyond the simple differentiation of solid and cystic thyroid nodules and their measurement. Although no single ultrasound feature has the highest accuracy in distinguishing between benign and malignant thyroid lesions, the combination of several ultrasound characteristics (e.g. hypoechogenicity, irregular borders and microcalcifications) within such thyroid nodules may have a stronger correlation for thyroid cancer. Based on these ultrasound features and risk for thyroid malignancy, the need for ultrasound-guided fine needle aspiration, preoperative staging, lymph node mapping and extent of surgery can subsequently be determined and performed. Furthermore, ultrasound has an additional value intraoperatively and in the postoperative surveillance of patients treated for thyroid cancer. Surgeon-performed ultrasound has recently become indispensible in clinical practice where endocrine surgeons have integrated this versatile imaging modality in the evaluation and treatment of patients with thyroid cancer.

SUMMARY

Ultrasound is an essential modality in the evaluation of thyroid malignancy. Surgeon-performed ultrasound has proved invaluable in the preoperative, intraoperative and postoperative setting. Future developments in ultrasound may lead to further improvement in the diagnostic accuracy of this modality.

Role of operator experience in ultrasound-guided fine-needle aspiration biopsy of the thyroid

PURPOSE

Thyroid nodules are commonly encountered in clinical practice, and ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) is the gold standard in diagnosing the pathological nature of undetermined thyroid nodules. The aim of this study was to evaluate whether operator experience influences the diagnostic accuracy of US-guided FNAB.

MATERIALS AND METHODS

A total of 700 consecutive US-guided FNAB done by a single radiologist between 2000 and 2007 were retrospectively analysed. The same freehand technique and capillary-action technique with 22- or 25-gauge needles was used for all nodules, All specimens were prepared and fixed without the cytologist on site and were subsequently analysed by two expert cytologists. The procedures were chronologically divided into seven groups and classified as diagnostic or nondiagnostic.

RESULTS

The rate of nondiagnostic procedures for each group was 32% in group 1, 13% in group 2, 17% in group 3, 11% in group 4, 10% in group 5, 5% in group 6 and 8% in group 7. No major complications were recorded.

CONCLUSIONS

The rate of nondiagnostic US-guided FNAB is heavily dependent on the operator's experience. We estimated that at least 200 procedures need to be performed in order to achieve the levels of diagnostic accuracy reported in the literature. We therefore suggest specific training before operators routinely perform this procedure in clinical practice.

Accuracy of fine-needle aspiration biopsy for predicting neoplasm or carcinoma in thyroid nodules 4 cm or larger

HYPOTHESIS

All thyroid nodules 4 cm or larger should be surgically removed regardless of fine-needle aspiration biopsy (FNAB) results because of an unacceptably high rate of false-negative preoperative biopsy results in these large nodules.

DESIGN

Retrospective cohort study.

SETTING

Single-institution, tertiary academic referral center.

PATIENTS

A retrospective analysis was performed on all patients who underwent surgery for a thyroid nodule 4 cm or larger from May 1, 1994, through January 31, 2007.

MAIN OUTCOME MEASURES

Preoperative FNAB results were correlated with final surgical pathologic results. The FNAB results were reported as nondiagnostic, benign, inconclusive (follicular neoplasm), or malignant, whereas the final surgical pathologic data were reported as benign or malignant.

RESULTS

Of 155 patients who underwent a thyroidectomy for a nodule 4 cm or larger, 21 patients (13.5%) had a clinically significant thyroid carcinoma within the nodule on final pathologic analysis. Preoperative cytologic testing of the mass was performed on 97 patients, and the results read as benign for 52, inconclusive for 23, nondiagnostic for 11, and malignant for 11. In lesions 4 cm or larger, 26 of 52 FNAB results reported as benign (50.0%) turned out to be either neoplastic (22) or malignant (4) on final pathologic analysis. Among patients with nondiagnostic FNAB results, the risk of malignant neoplasms was 27.3%.

CONCLUSIONS

In patients with thyroid nodules 4 cm or larger, the FNAB results are highly inaccurate, misclassifying half of all patients with reportedly benign lesions. Furthermore, those patients with a nondiagnostic FNAB result display a high risk of differentiated thyroid carcinoma. Therefore, we recommend that diagnostic lobectomy be strongly considered in patients with thyroid nodules 4 cm or larger regardless of FNAB cytologic test results.