Aspiration Biopsy Of Thyroid Nodules Research Articles

Important Role of Ultrasonography Immediately After Fine-Needle Aspiration Biopsy of Thyroid Nodules to Detect Acute Transient Thyroid Swelling.

We aimed to determine whether early detection of acute transient thyroid swelling (ATTS) is possible using ultrasonography (US) surveillance immediately after fine-needle aspiration biopsy (FNAB) and discuss the usefulness of routine US after FNAB. We retrospectively evaluated the incidence, clinical features, and US and computed tomography findings of ATTS in patients with thyroid nodules who underwent FNABs at our hospital. The study period was divided into two time periods: only symptomatic patients after FNAB were examined using US in the first period (period A: January 2016 to November 2020), whereas all patients were routinely examined using US shortly after FNAB in the second period (period B: December 2020 to December 2022). We found that the frequency of ATTS increased from 0.18% (10/5,685) in period A to 1.58% (31/1,958) in period B because the majority of ATTS cases in period B were asymptomatic. Follow-up US performed 15 minutes to 3 hours later confirmed no exacerbation of thyroid swelling in patients diagnosed with ATTS during period B. Routine US examinations, shortly after FNAB, significantly reduced the number of return visits after discharge (from 5/10 to 2/31, p=0.006). Furthermore, the incidence of unilateral swelling was higher than previously reported. Routine US examinations shortly after FNAB may be useful in identifying ATTS regardless of the presence of symptoms; moreover, they may reduce patients' return visits after leaving the hospital. It is also important to inform patients that delayed complications are possible and that severe cases, although rare, do exist.

The Analgesic Efficacy of Lidocaine/Prilocaine Cream during Fine-needle Aspiration Biopsy of Thyroid Nodules: A Randomized Double-blind Clinical Trial

Introduction: Fine-needle aspiration biopsy (FNAB) method is an effective method in diagnosis and approach to patients with thyroid nodules that create pain. This study investigates the analgesic effect of lidocaine/prilocaine cream during fine-needle aspiration (FNA) of thyroid nodules to reduce discomfort in patients during the procedure. Materials and Methods: In a double-blind clinical trial, two groups including patients with thyroid nodules who were rubbed with lidocaine + prilocaine 5% on their skin before FNA and patients with thyroid nodules, who have had topical placebo cream applied to their skin before FNA, were recruited. The Numerical Rating Scale was used to check the pain level. The Chi-square test, Fisher’s exact test, independent t-test, and Mann–Whitney’s nonparametric test were used for data analysis in SPSS software. Results: The average pain sensation in the intervention group is lower than the scores obtained in the control group, but despite the existing difference, this difference was not statistically significant (P = 0.7). The investigations showed that with the increase in the size and diameter of the thyroid nodules, the amount of pain that the patient feels during the procedure is reduced. Moreover, increasing the size of the nodule significantly reduces the amount of pain felt by the patient in the intervention group (P = 0.04). Conclusion: The results of this study indicated that the use of lidocaine/prilocaine cream in patients who are candidates for thyroid nodule biopsy did not have a significant effect on reducing their pain in contrast with literature. Therefore, based on the findings of the study, the use of lidocaine/prilocaine cream in these patients does not offer any significant decrease in pain sensation compared to using just a placebo.

Influencing Factors of Bethesda Ⅲ Results in Fine-Needle Aspiration Biopsy of Thyroid Nodules

Objective To investigate the influencing factors of Bethesda Ⅲ results in fine-needle aspiration biopsy of thyroid nodules.Methods A total of 300 thyroid nodules with cytological diagnosis results were analyzed retrospectively,including 100 Bethesda Ⅲ nodules and 50 nodules of Bethesda Ⅱ,Ⅳ,Ⅴ,and Ⅵ categories,respectively.Univariate analysis and Logistic regression analysis were performed on the clinical data of patients and the ultrasound signs of thyroid nodules to clarify the factors influencing the diagnosis of Bethesda Ⅲ nodules.Results Univariate analysis showed that Bethesda Ⅲ nodules were mostly adjacent to the capsule(P<0.001),with no blood flow in the color Doppler assessment(P=0.011)and lack of blood supply(P=0.033)and maximum diameter ≤0.9 cm(P=0.038)as revealed by the contrast-enhanced ultrasound.Logistic regression showed that the position close to the capsule(OR=5.110,95%CI=2.153-12.130,P<0.001)and color Doppler without blood flow signal(OR=3.015,95%CI=1.094-8.311,P=0.033)were independent risk factors for the diagnosis of Bethesda Ⅲ nodules.Conclusions The puncture difficulty caused by the dangerous position of thyroid nodules close to the capsule and the aspiration difficulty caused by the absence of blood flow signal in color Doppler are the main factors influencing the diagnosis of Bethesda Ⅲ nodules.Therefore,corresponding avoidance measures should be taken during the aspiration process to reduce the diagnosis results of Bethesda Ⅲ nodules.

Effects of brief mindfulness on anxiety-provoked adverse events during ultrasound-guided fine-needle aspiration biopsy of thyroid nodules

PurposeThis study aims to test the effectiveness of brief mindfulness for anxiety-provoked adverse events during ultrasound-guided fine needle aspiration biopsy (FNAB). ResultsA total of 439 patients were randomized to two groups. The ratio of anxiety in all patients with TN before FNAB was 25.3%, which was correlated with the intraoperative stress index. The FNAB-related adverse events in the control group were significantly higher than in the intervention group (65.0% vs. 17.3%; odds ratio [OR], 0.11 [95%CI, 0.56–0.74]; P < 0.001), especially for emotional stress (61.5% vs. 15.5%, odds ratio [OR], 0.12 [95%CI, 0.53–0.70]; P < 0.001) and patient's noncooperation (12.0% vs. 1.8%, odds ratio [OR], 0.14 [95%CI, 0.06–0.18]; P = 0.002). The stress index in control group were significantly higher than in the intervention group (87.82 [range, 27–99] vs 83.48 [range, 31–95]; P < 0.001). ConclusionsBrief mindfulness decreased anxiety-provoked adverse events and stress index in patients with thyroid nodules during FNAB.

Endocrine side effects of immunotherapeutic drugs

BACKGROUND. Immunotherapy is an innovative approach to treatment that is changing the paradigm in oncology and is achieving significant results in the fight against malignant tumors including leukemia, melanoma, lung cancer, kidney cancer and many others. This treatment uses the power of the body’s immune system to fight cancer cells. Immunotherapy can lead to long-term remission or even complete disappearance of tumors in patients with certain types of cancer. The success of therapy depends on many factors, including the type of cancer and individual patient characteristics. As with any treatment, patients with immunotherapy may experience side effects. As a result of treatment with pembrolizumab (and other immunotherapeutic drugs), patients may develop endocrine disorders. The most common endocrine side effects include thyroiditis (which can lead to hyper- or hypothyroidism), inflammation of the parathyroid glands, hypophysitis, and diabetes mellitus.&#x0D; OBJECTIVE. Based on the literature data, to investigate the possible side effects of immunotherapeutic drugs on the endocrine system.&#x0D; MATERIALS AND METHODS. Object: endocrine complications due to immunotherapy. Research method: review of literary sources.&#x0D; RESULTS. Among the manifestations of the endocrine system, the most common are thyroid dysfunction and diabetes mellitus. It is important to monitor the levels of thyroid-stimulating hormone (TSH), free T4, blood glucose and glycated hemoglobin for timely detection of endocrine pathology, prevention of unwanted complications and improvement of patients’ quality of life.&#x0D; CONCLUSIONS. Immunotherapy is vital for cancer patients. Given the possible development of various side effects, including those from the endocrine system, patients should monitor the main indicators of the thyroid gland (TSH, free T4) and carbohydrate metabolism (blood glucose, glycated hemoglobin) both before starting immunotherapy and during treatment. Patients with pre-existing endocrine disorders require more careful monitoring. It is possible that such patients, in the process of immunotherapy, may require correction of hypoglycemic drugs: speaking of diabetes mellitus, a possible option may be a dose correction of tableted antidiabetic drugs, a change in the therapy regimen or insulin therapy; in diseases of the thyroid gland, the doctor may suggest dose adjustment of thyroid drugs, ultrasound diagnostics and/or fine-needle aspiration biopsy of thyroid nodules.

Stratifying High-Risk Thyroid Nodules Using a Novel Deep Learning System.

The current ultrasound scan classification system for thyroid nodules is time-consuming, labor-intensive, and subjective. Artificial intelligence (AI) has been shown to increase the accuracy of predicting the malignancy rate of thyroid nodules. This study aims to demonstrate the state-of-the-art Swin Transformer to classify thyroid nodules. Ultrasound images were collected prospectively from patients who received fine needle aspiration biopsy for thyroid nodules from January 2016 to June 2021. One hundred thirty-nine patients with malignant thyroid nodules were enrolled, while 235 patients with benign nodules served as controls. Images were fed to Swin-T and ResNeSt50 models to classify the thyroid nodules. Patients with malignant nodules were younger and more likely male compared to those with benign nodules. The average sensitivity and specificity of Swin-T were 82.46% and 84.29%, respectively. The average sensitivity and specificity of ResNeSt50 were 72.51% and 77.14%, respectively. Receiver operating characteristics analysis revealed that the area under the curve of Swin-T was higher (AUC=0.91) than that of ResNeSt50 (AUC=0.82). The McNemar test evaluating the performance of these models showed that Swin-T had significantly better performance than ResNeSt50.Swin-T classifier can be a useful tool in helping shared decision-making between physicians and patients with thyroid nodules, particularly in those with high-risk characteristics of sonographic patterns.

Factors affecting the false negativity of fine-needle aspiration biopsy in thyroid nodules with indeterminate cytology

Purpose: False negative results of fine needle aspiration biopsies (FNAB) remain one of the most important problems in the management of thyroid nodules. The aim of this study was to evaluate the factors affecting the false negative results of FNAB, especially in thyroid nodules with indeterminate cytology.&#x0D; Materials and Methods: Patients with thyroid nodules who underwent FNAB and subsequent thyroidectomy between January 2017 and January 2020 were included in the study. FNAB was performed on suspicious nodules according to the TIRADS classification. Nodules with "atypia/follicular lesion of undetermined significance (AUS/FLUS)", "non-diagnostic (ND)" cytology or "follicular neoplasm/suspicious for follicular neoplasm (FN/SFN)" according to FNAB were defined as "indeterminate cytology (IC)". Nodules were analyzed in two groups. Nodules with false negative FNAB were included in Group-1, while nodules with true positive and true negative FNAB were included in Group-2. Demographic and clinical data, pathologic results and genetic profiles of the patients were statistically compared for all patients and IC group separately.&#x0D; Results: The results of FNAB and final pathology were discordant in 94 patients (Group-1) and concordant in 233 patients (Group-2). In the IC subgroup, 56 of 95 patients were in IC/Group-1 and 39 patients were in IC/Group-2. The accuracy of FNAB was statistically significantly higher in the presence of extrathyroidal extension (71.4% vs. 30.8%), perineural/lymphovascular invasion (60.0% vs. 29.6%), classical variants (68.5% vs. 50.7%), non-encapsulated tumors (67.9% vs. 50.0%) and multicentricity (47.2% vs. 24.1%). In the IC group, the presence of thyroiditis (75.0% vs. 49.2%) and high serum Anti-TPO levels (60.0% vs. 30.7%) increased the rate of false negativity on FNAB. High serum Neutrophil to Lymphocyte Ratio (NLR) and small tumor size also increase the false negativity of FNAB, especially in IC group patients.&#x0D; Conclusion: The diagnostic accuracy of FNAB is increased in classical variant tumors and in tumors expected to be aggressive due to presence of extra-thyroidal extension, perineural/lymphovascular invasion, non-encapsulated tumors and multicentricity. It should be kept in mind that the false negative results of FNAB increase in the presence of thyroiditis, high level of serum anti-TPO and high level of NLR.

Risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy in thyroid nodules with diameters greater than 4 centimeters.

The risk of malignancy and diagnostic accuracy of fine-needle aspiration biopsy (FNAB) of thyroid nodules (TN) with diameters ≥ 3-4 cm remains controversial. However, some groups have indicated surgical treatment in these patients regardless of the FNAB results. We aimed to evaluate the diagnostic accuracy of the FNAB in systematically resected ≥4 cm TN and if the risk of malignancy is higher in these patients. We retrospectively evaluated 138 patients (142 nodules) with TN with diameters ≥4 cm who underwent thyroidectomy. The FNAB results were nondiagnostic/unsatisfactory (ND/UNS) in 2.1% of the cases and benign in 51.4%. They indicated atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) in 23.9% of cases, follicular neoplasia/suspicious for a follicular neoplasm (FN/SFN) in 9.2%, suspicion of malignancy (SUS) in 8.5%, and malignant in 4.9%. The histopathological analysis after thyroidectomy revealed a thyroid cancer rate of 100% in the FNABs classified as malignant, 33.3% in SUS cases, 7.7% in FN/SFN, 17.6% in AUS/FLUS, and 4.1% in benign FNABs. None of the ND/UNS FNABs were malignant. The global malignancy diagnosis was 14.8% (n = 21). However, the rate of false negatives for FNAB was low (4.1%). We showed that the risk of malignancy in nodules with diameters ≥4 cm was higher compared to the risk of thyroid cancer in TN in general. However, we found a low rate of false-negative cytological results; therefore, our data do not justify the orientation of routine resection for these larger nodules.

Does timing of repeat fine needle aspiration biopsy in thyroid nodules alter the adequate or AUS/FLUS cytology result?

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Adverse events unlikely after fine-needle aspiration biopsies of thyroid nodules in patients on low-dose aspirin: a prospective controlled systematic single center analysis.

Our aim was to test the assertion that in terms of rate or severity level, adverse events (AEs) after fine-needle aspiration biopsies (FNABs) of thyroid nodules are unfazed by daily low-dose (100 mg) aspirin (acetylsalicylic acid, ASA) intake. We selected 268 patients for study, grouped as ASA-treated (PASA, n=78) or control (PCtrl, n=190) subjects. Controls received no antithrombotic medication. AE rates and severities were then analyzed based on patient- and nodule-related factors. We also compared group rates of non-diagnostic cytology results. AEs arising after FNABs (PASA, 5%; PCtrl, 8%) did not differ significantly by group in rate (p=0.4873) or severity level (p=0.3399). All were classifiable as minor incidents, none warranting any intervention. The data from the present study suggest, AEs after FNABs of thyroid nodules seldom occur and qualify as minor incidents. Such procedures may be safely conducted in patients taking daily low-dose ASA. There is no evidence to support preemptive therapeutic withdrawal.

Effect of local anesthesia on pain scale and specimen adequacy in fine-needle aspiration biopsy of thyroid nodules for liquid-based cytology

Fine-needle aspiration biopsy (FNAB) is a routine diagnostic test for thyroid nodules. The use of local anesthesia (LA) before the procedure is still controversial. This prospective study aimed to evaluate the degree of pain and specimen adequacy in liquid-based cytology (LBC) for FNAB of thyroid nodules with and without LA. A total of 100 consecutive patients with thyroid nodules who underwent FNAB with and without LA between January and December 2020 were included. Patients who received LA had a significantly lower immediate pain scale score (P = 0.01). Multivariate analysis demonstrated that no use of LA (odds ratio [OR] = 3.48, 95% confidence interval [CI] = 1.50–8.10, P = 0.004) and lesion abutting the trachea (OR = 6.14, 95% CI = 1.56–24.12, P = 0.009) were independently and significantly associated with pain degree immediately after FNAB. A higher proportion of patients who previously underwent FNAB thought that LA was helpful and should be performed prior to FNAB. However, the use of LA did not improve the specimen adequacy (P = 0.075). The results showed that administration of LA with a proper technique before ultrasound-guided FNAB might reduce immediate pain after the procedure, and patients may experience more pain when the aspirated nodules abut the trachea.

Towards De-Implementation of low-value thyroid care in older adults.

This review discusses the current literature regarding low-value thyroid care in older adults, summarizing recent findings pertaining to screening for thyroid dysfunction and management of hypothyroidism, thyroid nodules and low-risk differentiated thyroid cancer. Despite a shift to a "less is more" paradigm for clinical thyroid care in older adults in recent years, current studies demonstrate that low-value care practices are still prevalent. Ineffective and potentially harmful services, such as routine treatment of subclinical hypothyroidism which can lead to overtreatment with thyroid hormone, inappropriate use of thyroid ultrasound, blanket fine needle aspiration biopsies of thyroid nodules, and more aggressive approaches to low-risk differentiated thyroid cancers, have been shown to contribute to adverse effects, particularly in comorbid older adults. Low-value thyroid care is common in older adults and can trigger a cascade of overdiagnosis and overtreatment leading to patient harm and increased healthcare costs, highlighting the urgent need for de-implementation efforts.

Routine molecular testing of fine needle aspiration biopsies of thyroid nodules

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Diagnostic value of 2017 ACR Thyroid Imaging Reporting and Data System (TI-RADS) combined with fine needle aspiration biopsy in thyroid nodules

To evaluate diagnostic value of Thyroid Imaging Reporting and Data System published by American College of Radiology (ACR TI-RADS) in 2017, ultrasound-guided fine-needle aspiration (US-FNA), and the combination of both methods in differentiation between benign and malignant thyroid nodules. The data of US-FNA and ACR TI-RADS are collected from 159 patients underwent thyroid surgery in our hospital, which include a total of 178 thyroid nodules. A Bethesda System for Reporting Thyroid Cytopathology category of ≥IV and an ACR TI-RADS category ≥4 are regarded as diagnosis standards for malignancy in US-FNA and ACR TI-RADS, respectively. The pathological results after surgery are considered as the gold standard. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the ACR TI-RADS, US-FNA and the combination of both methods for the differential diagnosis of thyroid nodules are calculated, respectively. The sensitivity, specificity and accuracy of ACR TI-RADS are 85.4%, 37.5%and 72.5%, respectively. The sensitivity, specificity and accuracy of US-FNA are 70.0%, 100%and 78.1%, respectively. After combining these two methods, the sensitivity, specificity and accuracy increase to 99.23%, 37.50%and 82.58%, respectively. The sensitivity of ACR TI-RADS is higher than that of US-FAN, and the sensitivity of combining these two methods is also higher than that of using ACR TI-RADS and US-FNA alone. The established ACR TI-RADS can help in selecting the target during nodule puncture, while the combination of ACR TI-RADS and US-FAN can further improve diagnostic ability for detecting malignant thyroid nodules.

Role of the cytopathologist during the procedure of fine-needle aspiration biopsy of thyroid nodules

PurposeThis study aimed to conduct a diagnostic and cost-effective analysis of the cytopathology assistance in the ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) for characterising thyroid nodules.Materials and methodsWe reviewed the reports relative to 9061 US-guided FNABs for the histologic definition of the nature of thyroid nodules: 45.4% completed with the cytopathologist assistance and 54.6% by the radiologist alone.We also performed the cost-effectiveness analysis (CEA) of the procedure with and without the cytopathologist assistance.ResultsWe found a significant positive correlation between the adoption/non-adoption of cytopathologist assistance and the number of indeterminate (TIR1) (Chi-square; z-score, Z = 10.22; critical value 5%, C = 1.96; p < 0.001). The cytopathologist's absence was correlated with the number of TIR 1 (Pearson correlation, product–moment correlation r = 0.059; critical value 5%, C = 0.008; p < 0.001).The total cost of the model's cytopathologist-assistance branch is 109.87€, while the total cost of the non-cytopathologist-assistance branch is 95.08€.ConclusionThe cytopathologist assistance resulted in fewer nondiagnostic results, thus excluding the procedure's repetition but involved a higher expense, mainly due to the professional cost of the pathologist's participation. These data may provide decision-makers in healthcare with a practical evidence based on the opportunity to include the cytopathologist assistance in the thyroid nodule's FNAB depending on the available resources and the population's expectance.

Predictive factors for recurrent non-diagnostic fine-needle aspiration biopsy in thyroid nodules

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Prevalence and Spectrum of DICER1Mutations in Adult-Onset Thyroid Nodules

Abstract Context: DICER1 mutations are found in multinodular goiter and differentiated thyroid carcinoma in children, and can be a manifestation of DICER1 syndrome, but the prevalence of DICER1 mutations and their significance in adult-onset thyroid nodules is unknown. Objective: Determine 1) the prevalence of DICER1 hotspot mutations in thyroid nodules; 2) the frequency of a second DICER1 pathogenic variant in thyroid nodules with DICER1 hotspot mutations; 3) the prevalence of other thyroid cancer driver mutations in thyroid nodules with and without DICER1 hotspot mutations. Design: Population-based study of 14,993 consecutive fine needle aspiration biopsies of thyroid nodules evaluated by ThyroSeq v3. From 214 DICER1 hotspot-positive cases, we selected 61, matched to DICER1 hotspot-negative nodules. We performed full sequencing of all exons and exon-intron boundaries of DICER1. Setting: Commercial and university-based laboratories in the United States and Canada Results: Among 14,993 thyroid nodules, 214 (1.4%) revealed a DICER1 hotspot mutation. A second pathogenic/likely pathogenic variant in DICER1 was found in 45/59 (76%) DICER1 hotspot-positive nodules studied while no other DICER1 variant was identified in the DICER1 hotspot-negative group by full DICER1 sequencing. Other alterations in thyroid-related genes were significantly more frequent in DICER1 hotspot-negative nodules (32/61) than in DICER1 hotspot-positive nodules (4/59) (p&amp;lt;0.0001). Conclusions: DICER1 alterations occur in a proportion of adult thyroid nodules and appear mutually exclusive with alterations in other thyroid cancer-related genes. DICER1 hotspot mutations occur with a second hit in most cases and could suggest occult DICER1 syndrome in adults with thyroid nodules.

Prevalence and Spectrum of DICER1 Mutations in Adult-onset Thyroid Nodules with Indeterminate Cytology.

DICER1 mutations are found in multinodular goiter and differentiated thyroid carcinoma in children, and can be a manifestation of DICER1 syndrome, but the prevalence of DICER1 mutations and their significance in adult-onset thyroid nodules is unknown. Determine (1) the prevalence of DICER1 hotspot mutations in thyroid nodules; (2) the frequency of a second DICER1 pathogenic variant in thyroid nodules with DICER1 hotspot mutations; (3) the prevalence of other thyroid cancer driver mutations in thyroid nodules with and without DICER1 hotspot mutations. Population-based study of 14 993 consecutive fine needle aspiration biopsies of thyroid nodules evaluated by ThyroSeq v3. From 214 DICER1 hotspot-positive cases, we selected 61, matched to DICER1 hotspot-negative nodules. We performed full sequencing of all exons and exon-intron boundaries of DICER1. Commercial and university-based laboratories in the United States and Canada. Among 14 993 thyroid nodules, 214 (1.4%) revealed a DICER1 hotspot mutation. A second pathogenic/likely pathogenic variant in DICER1 was found in 45/59 (76%) DICER1 hotspot-positive nodules studied while no other DICER1 variant was identified in the DICER1 hotspot-negative group by full DICER1 sequencing. Other alterations in thyroid-related genes were significantly more frequent in DICER1 hotspot-negative nodules (32/61) than in DICER1 hotspot--positive nodules (4/59) (P < .0001). DICER1 alterations occur in a proportion of adult thyroid nodules and appear mutually exclusive with alterations in other thyroid cancer-related genes. DICER1 hotspot mutations occur with a second hit in most cases and could suggest occult DICER1 syndrome in adults with thyroid nodules.

Ultrasound-guided fine-needle aspiration biopsy of thyroid nodules.

Fine needle aspiration biopsy (FNAB) remains crucial in the evaluation of thyroid nodules with suspicious clinical findings or ultrasound (US) features suggestive of malignancy. The use of US-guidance for FNAB allows real-time visualization of the needle, but is also highly operator-dependent. Physicians from many specialties (endocrinologists, otolaryngologists/endocrine surgeons, nuclear medicine physicians, radiologists, and pathologists) are involved in the diagnostic workup of thyroid nodules and a standardized and meticulous technique for US-FNAB is essential for lowering the yield of nondiagnostic specimens and false-negative results. This video, therefore, demonstrates a well-proved technique and technical tips to increase the diagnostic results from US-FNAB.

Nondiagnostic Fine-Needle Aspiration Biopsy of Thyroid Nodules: Outcomes and Determinants.

Background: Nondiagnostic results are common following fine-needle aspiration biopsy (FNAB) of thyroid nodules, but recommendations for the management of these patients vary. We sought to determine the outcomes and predictors of nondiagnostic FNABs in a single-center cohort of patients undergoing thyroid nodule evaluation. Methodology: We identified all first time ultrasound-guided FNABs performed between May 2007 and June 2013 at the Beth Israel Deaconess Medical Center Thyroid Nodule Clinic and examined demographic data, follow-up ultrasounds, repeated FNABs, and histopathologic findings. We examined the likelihood of diagnostic findings and of cancer with increasing numbers of nondiagnostic evaluations with their exact binomial confidence intervals [CIs] and potential predictors of nondiagnostic status using generalized estimating equations. Results: During the six-year period, 2234 unique individuals underwent ultrasound-guided FNAB of a thyroid nodule. The probability of obtaining a diagnostic biopsy declined from 84.4% [95% CI 82.8-85.8%] for initial FNABs to 57.6% [CI 50.8-64.2%] for the first re-FNAB and further to 42.4% [CI 25.5-60.8%] for second re-FNABs. Adjusted risk of nondiagnostic FNAB strongly increased with increasing numbers of previous biopsies and was also higher among whites. The overall rate of diagnosis of malignancy after a nondiagnostic FNAB was 8.1% [CI 4.2-13.7%] and was similar regardless of the number of previous nondiagnostic aspirations. Conclusion: Following an initial nondiagnostic FNAB, the probability of yielding a diagnostic result declines with each sequential repeat FNAB. Nonetheless, a tangible possibility of malignancy remains even after repeated nondiagnostic FNABs.