Jin Young Kwak

Wonju Severance Christian Hospital, Genshū, Gangwon-do, South Korea

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Publications (235)629.43 Total impact

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    ABSTRACT: To analyze whether the 5-tiered categorization system without the atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) category is sufficient compared to the 6-tiered Bethesda system. This IRB-approved retrospective study was waived informed consent. The pre-Bethesda period was from March 2008 to December 2008 and the Bethesda period was from January 2012 to January 2013. Of 4677 nodules ≥10 mm with initial ultrasonography-guided fine-needle aspiration, 2553 nodules were from the pre-Bethesda period and 1754 nodules were from the Bethesda period. The utilization and malignancy rates of each category were compared between the two periods. The utilization rate of the benign category decreased from 67.7 % in the pre-Bethesda period to 60.0 % in the Bethesda period (p = 0.001). In the pre-Bethesda period, the malignancy rates of the non-diagnostic, benign, suspicious follicular neoplasm/Hürthle cell neoplasm, suspicious for malignancy, and malignancy categories were 3.8, 1.9, 25, 78.8, and 99.7 %, respectively. The malignancy rate of the benign category decreased from 1.9 to 0.3 % after the Bethesda system (p < 0.001). The utilization and malignancy rates of the AUS/FLUS category were 7 and 22.8 %. When the AUS/FLUS category was included in the benign category, the malignancy rate became 2.6 % which was not significantly different from 1.9 % in the pre-Bethesda period (p = 0.189). The malignancy rates of other categories were not significantly different. The 5-tiered categorization system without the AUS/FLUS category for reporting cytology was sufficient for management of patients with thyroid nodules compared to the 6-tiered categorization of the Bethesda system.
    No preview · Article · Jan 2016 · Endocrine
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    ABSTRACT: To investigate the value of the annual follow-up neck ultrasonography (US) for postoperative surveillance in patients with papillary thyroid microcarcinoma (PTMC).This retrospective study has been approved by our institutional review board (IRB) with waiver for informed consent. A total of 375 patients diagnosed as PTMCs, who underwent total thyroidectomy with radioiodine remnant ablation were included, to identify the recurrence rate and the false-positive rate of annual ultrasound. The number, interval, and the results of follow-up US or fine needle aspiration were obtained from electronic medical records.Four (1.1%, 4/375) recurrences were found 3 years after the initial treatment, and only 1 patient (0.3%, 1/375) had a metastatic lymph node larger than 8 mm in the shortest diameter on US found 7.6 years after initial treatment with biochemical abnormalities. Cumulative risk of having at least 1 false-positive exam was 8.3% by the 8th US, and 8.1% by the 8-9 year follow-up. Cox multivariate regression showed shorter interval of follow-up US and presence of lymph node metastasis at initial surgery are independent predictors affecting the cumulative false-positive results (hazard ratio [HR], 0.60; 95% confidence interval [CI]: 0.49-0.73; P < 0.001 and HR, 2.19; 95% CI: 1.01-4.75; P = 0.048, respectively).Short-term follow-up US can result in higher cumulative false-positive results without detection of meaningful recurrences in patients with PTMCs who do not have biochemical abnormalities.
    No preview · Article · Jan 2016 · Medicine
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    ABSTRACT: The purpose of the study was to compare the diagnostic utility of the combined conventional smear (CS) and liquid-based preparation (LBP) compared to CS with respect to the non-diagnostic rate, the atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) rate, and the diagnostic performances for malignancy. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. In our institution, thyroid FNAs were processed with CS before October 2012, and LBP has been used in combination with CS after October 2012. On-site evaluation for the adequacy of CS was not performed. This study included nodules 5 mm or larger with FNAs performed by faculties: 811 nodules in 773 patients for CS, and 926 nodules in 894 patients for combined CS and LBP. Nodules with surgery or either benign or malignancy cytology on initial or repeat FNA were regarded to have the reference standards needed to calculate diagnostic performances. The proportion of Bethesda categories and diagnostic performances were compared between the two groups with z test. The non-diagnostic rate, the AUS or FLUS rate, and the diagnostic performances for malignancy were similar (All P > 0.05). The follicular neoplasm (FN) or suspicious for FN rate decreased from 1.2 to 0.3 % (P = 0.034). The benign rate increased from 51.4 to 57.0 % (P = 0.019). Combined CS and LBP decreased FN or suspicious for FN diagnoses, and increased benign diagnoses compared to CS with comparable non-diagnostic rates and AUS or FLUS rates, and comparable diagnostic performances.
    No preview · Article · Dec 2015 · Endocrine
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    ABSTRACT: Objective: To evaluate the clinical significance and compare the imaging features according to the Thyroid Image Reporting and Data System (TIRADS) between atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) subcategories. Design & patients: A total of 192 thyroid nodules in 188 patients (mean age: 50.2±11.8 years) that had been initially diagnosed as AUS/FLUS on US-guided fine needle aspiration (US-FNA) were included. One cytopathologist retrospectively reviewed the cytology slides, subcategorizing cytology results into AUS and FLUS. A TIRADS category was assigned to each thyroid nodule according to the number of suspicious US features. Clinical, US features, and malignancy rates were compared between the two subcategories. Results: Of the 192 AUS/FLUS lesions, 149 (77.6%) were subcategorized as AUS, and 43 (22.4%) as FLUS. Of the 192 AUS/FLUS nodules, 82 (42.7%) were malignant. The malignancy rates between AUS and FLUS subcategories were not significantly different, 45.6% to 32.6%, respectively (P=0.127). When applying TIRADS, significant differences were seen in TIRADS category between benign and malignant nodules in the AUS subcategory (P<0.001), but not in the FLUS subcategory (P=0.414). The malignancy rates in TIRADS categories 3, 4a, 4b, 4c, and 5 were 15.4%, 22.2%, 33.3%, 57.1%, and 80.0% (P<0.001) in AUS nodules and 40.0%, 50.0%, 23.5%, 22.2%, and 0.0% (P=0.414) in FLUS nodules, respectively. Conclusion: Suspicious US features are useful in predicting malignancy among AUS subcategories but not in FLUS subcategories. Subcategorization into AUS and FLUS cytology may be helpful in deciding upon treatment or management of thyroid nodules. This article is protected by copyright. All rights reserved.
    No preview · Article · Dec 2015 · Clinical Endocrinology
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    ABSTRACT: Purpose: The goal of this study was to evaluate the clinicopathological and imaging features of thyroid nodules surgically diagnosed as hyaline trabecular tumor (HTT), and to assess the role of cytology and frozen sections (FS) in the diagnosis of HTT. Methods: This study included 21 thyroid nodules in 21 patients treated from August 2005 to March 2015 (mean age, 53.3 years) who were either diagnosed as HTT or had HTT suggested as a possible diagnosis based on cytology, FS, or the final pathology report. Patients' medical records were retrospectively reviewed for cytopathologic results and outcomes during the course of follow-up. Sonograms were reviewed and categorized. Results: Twelve nodules from 12 patients were surgically confirmed as HTT. Ultrasonography (US)-guided fine needle aspiration (FNA) was performed on 11 nodules, of which six (54.5%) were papillary thyroid carcinoma (PTC) or suspicious for PTC and three (27.3%) were HTT or suspicious for HTT. Intraoperative FS suggested the possibility of HTT in seven nodules, of which three (42.9%) were confirmed as HTT. US-FNA suggested the diagnosis of HTT in 10 nodules, of which three (30.0%) were confirmed as HTT. Common US features of the 12 pathologically confirmed cases of HTT were hypoechogenicity or marked hypoechogenicity (83.4%), absence of calcifications (91.7%), parallel shape (100.0%), presence of vascularity (75.0%), and probable benignity (66.7%). Conclusion: HTT should be included in the differential diagnosis of solid tumors with hypoechogenicity or marked hypoechogenicity and otherwise benign US features that have been diagnosed as PTC through cytology.
    No preview · Article · Nov 2015
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    ABSTRACT: The Thyroid Imaging Reporting and Data System (TIRADS) has been found to be accurate in the stratification of malignancy risk, and elastography has been found to have a high negative predictive value in non-diagnostic thyroid nodules. Through assessment of 104 solid non-diagnostic thyroid nodules, this study investigated the role of both in recommending repeat ultrasonography-guided fine-needle aspiration for solid thyroid nodules with non-diagnostic cytology. All nodules were classified by TIRADS (categories 4a, 4b, 4c and 5), and elastography scores were assigned according to the Rago and Asteria criteria. The malignancy risks for TIRADS categories 4a, 4b, 4c and 5 were 12.5%, 25.0%, 25.8% and 16.7%, respectively. Elastography revealed the highest diagnostic performance for TIRADS category 4a, with a sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 100%, 85.7%, 100%, 50% and 87.5% for the Asteria criteria. Observation may be considered for non-diagnostic solid nodules that have no other suspicious ultrasonographic features and are also benign on real-time strain elastography using the Asteria criteria.
    No preview · Article · Nov 2015 · Ultrasound in medicine & biology
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    ABSTRACT: We investigated whether follow-up ultrasound (US) is enough for thyroid nodules 5-10 mm, and whether 3 years of interval between the initial US and next US is appropriate. This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. The study included 447 thyroid nodules 5-10 mm from 378 patients who underwent initial thyroid US, and underwent 3 years or more of follow-up US. The presence and characteristics of malignancy detected on follow-up were reviewed. Maximal diameters of each nodule at the initial and last US were measured. Univariate and multivariate analysis were used to assess association with nodule growth 3 mm or larger. Seven malignancies (1.6 %, 7 of 447) were detected on a mean 70.6 ± 20.3 months (range 36-104 months). Only one had growth 3 mm or larger, and all malignancies did not have extensive extrathyroidal extension, lateral lymph nodes, or distant metastasis. 6.0 % (27 of 447) of nodules had growth 3 mm or larger. Nodules in older patients were less likely to grow, and benign-looking nodules were more likely to grow. Longer follow-up time 6 years or more was not associated with growth, and no cancers were detected during the long follow-up time. Immediate US-FNA for thyroid nodules 5-10 mm are discouraged, unless suspicious metastatic lymph nodes are present. Also, a follow-up US 3 years after the initial US may be enough for these nodules.
    No preview · Article · Sep 2015 · Endocrine
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    ABSTRACT: The aim of this study was to validate inter-observer variability for strain ultrasound elastography (USE) and to compare the diagnostic performance of a combination of gray-scale ultrasound (US) and USE with that of gray-scale US. Three observers from different institutions evaluated gray-scale US images and USE video files of 443 cytopathologically proven benign or malignant thyroid nodules over a 3-mo period. Inter-observer variability did not statistically differ between USE using the Asteria criteria and gray-scale US; however, USE using the Rago criteria had the lowest inter-observer agreement (p < 0.043). For all three observers, sensitivity was increased by adding USE to gray-scale US (81.3%-88.3%, 75.4%-85.4%) compared with gray-scale US (70.4%-80.8%). Specificity was decreased by adding USE to gray-scale US (51.7%-59.1%, 59.1%-73.9%) compared with gray-scale US (69.0%-82.8%). USE and gray-scale US had comparable inter-observer variability. However, on addition of USE to gray-scale US, the additional diagnostic yield was limited compared with that of gray-scale US alone.
    No preview · Article · Sep 2015 · Ultrasound in medicine & biology
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    ABSTRACT: Purpose To compare malignancy risk stratification of thyroid nodules with the 2014 American Thyroid Association (ATA) management guidelines and the Thyroid Imaging Reporting and Data System (TIRADS). Materials and Methods This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. From November 2013 to July 2014, 1293 thyroid nodules in 1241 patients (mean age, 50.8 years ± 13.5) were included in this study. All nodules measured at least 10 mm. Solidity, hypoechogenicity or marked hypoechogenicity, microlobulated to irregular margin, microcalcifications or mixed calcifications, and nonparallel shape were considered suspicious features at ultrasonography (US). A TIRADS category and the US pattern as determined with ATA guidelines were assigned to each nodule. The correlation between the TIRADS category or ATA pattern and the malignancy rate was evaluated with the Spearman rank test. Results Of the 1293 thyroid nodules, 1059 (81.9%) were benign and 234 (18.1%) were malignant. Forty-four of the 1293 nodules (3.4%) did not meet the criteria for the ATA patterns and were classified as "not specified." The malignancy rates of TIRADS category 3, 4a, 4b, 4c, and 5 nodules were 1.9% (six of 316 nodules), 4.2% (17 of 408 nodules), 12.9% (33 of 256 nodules), 49.8% (130 of 261 nodules), and 92.3% (48 of 52 nodules), respectively, with significant differences between categories (P < .001). Malignancy rates of nodules with very low, low, intermediate, and high suspicion for malignancy with the ATA guidelines and not specified patterns were 2.7% (11 of 407 nodules), 3.1% (10 of 323 nodules), 16.7% (39 of 233 nodules), 58.0% (166 of 286 nodules), and 18.2% (eight of 44 nodules), respectively, with significant differences between patterns (P < .001). There was high correlation between classification with TIRADS (r = 1.000, P < .001) and ATA guidelines (r = 0.900, P = 0.037), without statistically significant differences (P = .873). Conclusion Both TIRADS and the ATA guidelines provide effective malignancy risk stratification for thyroid nodules. Nodules that do not meet the criteria for a specific pattern with the ATA guidelines have a relatively high risk of malignancy (18.2%). (©) RSNA, 2015 Online supplemental material is available for this article.
    No preview · Article · Sep 2015 · Radiology
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    ABSTRACT: Objectives: The purpose of this study was to investigate the level of conclusive results obtained with ultrasound (US)-guided core needle biopsy (CNB) and how this method should be applied for diagnosis of thyroid nodules. Methods: From January 2013 to November 2014, US-guided CNB was performed in 84 thyroid lesions of 83 patients. Based on CNB pathologic reports, thyroid nodules were divided into 2 categories: conclusive (nodules reaching a definite pathologic diagnosis suggesting benignity or malignancy) and inconclusive (nodules that were not able to reach a definite diagnosis because of ambiguous results). Medical records and US examinations were reviewed and compared. Results: The mean age of the 83 patients ± SD was 49.7 ± 14.1 years. Of the 84 thyroid nodules, 73 (86.9%) were diagnosed as benign or malignant and 11 (13.1%) as inconclusive by CNB pathologic analysis. Among the 11 nodules with inconclusive results, the possibility of a follicular neoplasm was suggested in 8 nodules (72.7%). No significant difference was seen in tumor size and US features when comparing the nodules with conclusive and inconclusive results (all P >.05). Conclusions: Ultrasound-guided CNB may have supplemental roles in addition to US-guided fine-needle aspiration for diagnosis of selected cases. A considerable proportion of inconclusive results are seen on US-guided CNB, especially for diagnosis of follicular lesions, which must be considered when using this method for diagnosis of thyroid nodules.
    No preview · Article · Sep 2015 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
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    ABSTRACT: Objective: The purposes of this study were to investigate the optimal subset for texture analysis by use of a histogram and cooccurrence matrix in the differential diagnosis of benign and malignant thyroid nodules and to compare the results with those of gray-scale ultrasound and elastography. Materials and methods: From a retrospective search of an institutional database between June and November 2009, 633 solid nodules 5 mm or larger from 613 patients who underwent gray-scale ultrasound and elastography and subsequent ultrasound-guided fine-needle aspiration were included in this study. Each nodule was categorized as probably benign or suspicious of being malignant according to findings at gray-scale ultrasound and elastography. Histogram parameters (mean, SD, skewness, kurtosis, and entropy) and cooccurrence matrix parameters (contrast, correlation, uniformity, homogeneity, and entropy) were extracted from gray-scale ultrasound and elastographic images. The diagnostic performances of gray-scale ultrasound, elastography, and texture analysis for differentiating thyroid nodules were evaluated. Results: Gray-scale ultrasound had the best diagnostic performance with an ROC AUC (Az) of 0.809 among all parameters. Elastography had significantly poorer performance (Az = 0.646) than gray-scale ultrasound (p < 0.001). Mean extracted from gray-scale ultrasound had the highest Az (0.675) among all histogram and cooccurrence matrix parameters extracted from gray-scale ultrasound and elastographic images. However, mean and the combination of mean and gray-scale ultrasound had poorer performance than gray-scale ultrasound alone. Conclusion: Using texture analysis does not improve diagnostic performance in the evaluation of thyroid cancers.
    No preview · Article · Aug 2015 · American Journal of Roentgenology
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    ABSTRACT: The purpose of this study was to evaluate the usefulness of a quantitative vascular index in predicting thyroid malignancy. A total of 1309 thyroid nodules in 1257 patients (mean age: 50.2 y, range: 18-83 y) were included. The vascularity pattern and vascular index (VI) measured by quantification software for each nodule were obtained from 2-D power Doppler ultrasonography (US). Gray-scale US + vascularity pattern was compared with gray-scale US + VI with respect to diagnostic performance. Of the 1309 thyroid nodules, 927 (70.8%) were benign and 382 (29.2%) were malignant. The area under the receiver operating characteristics curve (Az) for gray-scale US (0.82) was significantly higher than that for US combined with vascularity pattern (0.77) or VI (0.70, all p < 0.001). Quantified VIs were higher in benign nodules, but did not improve the performance of 2-D US in diagnosing thyroid malignancy. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Aug 2015 · Ultrasound in medicine & biology
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    ABSTRACT: The aim of this study was to investigate and compare the diagnostic performances of the Thyroid Imaging Reporting and Data System (TIRADS) in differentiating benign and malignant thyroid nodules according to the level of physician experience. From March to October 2013, 1102 patients with 1128 thyroid nodules who underwent initial ultrasound-guided fine needle aspiration were included in this study. Thyroid nodules were categorized according to TIRADS. Diagnostic performances of ultrasound were compared according to performer experience using the χ test or Fisher exact test. Of 1128 thyroid nodules, 281 were malignant, and 847 were benign. The risk of malignancy of each TIRADS category by the experienced and less experienced physicians were as follows: category 3 (0.9% vs 0%), category 4a (3.5% vs 1.3%), category 4b (7.3% vs 12.1%), category 4c (67.5% vs 44.9%), and category 5 (97.7% vs 76.5%). Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 99.1%, 35.9%, 52.5%, 35.5%, and 99.1%, respectively, for experienced physicians and 100%, 20.9%, 37.6%, 35.2%, and 100%, respectively, for less experienced physicians. Specificity, accuracy, and positive predictive value were statistically higher for experienced physicians than those for less experienced physicians (P < 0.001, 0.001, and 0.004). There was a significant difference in areas under the curve between the 2 groups (P < 0.001). In conclusion, the diagnostic performance of the stratification of malignancy risk according to TIRADS categories was comparable between the experienced and less experienced physician groups. The application of TIRADS is reproducible, and it was easy to predict the probability of thyroid malignancy in both the experienced and less experienced physician groups.
    No preview · Article · Aug 2015 · Ultrasound quarterly
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    ABSTRACT: The goal of this study was to validate the ultrasonography (US) and cytopathological features that are used in the diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) and to characterize the role of BRAFV600E mutation analysis in the diagnosis of FVPTC. From May 2012 to February 2014, 40 thyroid nodules from 40 patients (mean age, 56.2 years; range, 26 to 81 years) diagnosed with FVPTC were included in this study. The US features of the nodules were analyzed and the nodules were classified as probably benign or suspicious for malignancy. Twenty-three thyroid nodules (57.5%) underwent BRAFV600E mutation analysis. Clinical information and histopathologic results were obtained by reviewing the medical records of the patients. Thirty nodules (75.0%) were classified as suspicious for malignancy, while 10 (25.0%) were classified as probably benign. Seven of the eight nodules (87.5%) with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) cytology showed suspicious US features, while one of the two nodules (50.0%) with follicular neoplasm cytology presented suspicious US features. Five of the 23 nodules (21.7%) that underwent BRAFV600E mutation analysis had positive results, all of which were diagnosed as suspicious for malignancy or malignant based on cytology. None of the nodules with benign, AUS/FLUS, or follicular neoplasm cytology were positive for the BRAFV600E mutation. US features allow nodules to be classified as suspicious for malignancy, and the presence of suspicious US features in nodules with ambiguous cytology may aid in the diagnosis of FVPTC. BRAFV600E mutation analysis is of limited value in the diagnosis of FVPTC.
    No preview · Article · Jul 2015
  • Hyeong Ju Kwon · Eun-Kyung Kim · Jin Young Kwak
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    ABSTRACT: Some morphologic parameters have been studied to help predict the BRAF(V600E) mutation using cytopathologic specimens, which can indicate which nodules should undergo further testing. The aim of this study was to investigate the value of cytomorphologic parameters to predict the BRAF(V600E) mutation in nodules read as "suspicious for malignancy" on cytology. This study included 142 resected nodules which were diagnosed as "suspicious for malignancy" on cytology in 142 patients. At our institution, BRAF(V600E) mutation analysis was performed at the request of the referring clinicians based on the clinical features of the patients, or the judgment of the radiologists performing US-FNA because suspicious US features were observed on the targeted nodule during this study period. Cytology smears were re-reviewed to assess the presence and amount of polygonal eosinophilic (plump) cells and microfollicles, and the presence of intranuclear pseudoinclusions, irregular nuclear membranes, nuclear grooves, sickles cells, psammoma bodies, and cystic changes. We evaluated the diagnostic performances of the cytomorphologic features to predict the BRAF(V600E) mutation. Polygonal eosinophilic (plump) cells, microfollicles, intranuclear pseudoinclusions, sickle cells, and cystic changes were significantly associated with the BRAF(V600E) mutation. The mutation was not present in all 6 thyroid nodules with microfollicles larger than 20% on cytology. Additionally, polygonal eosinophilic (plump) cells larger than 20%, cystic changes, and sickle cells on cytology had a high specificity of 95%, 96.7%, and 81.7%, respectively. Excluding 6 nodules with microfollicles larger than 20% on cytology, there were 82 (60.3%) nodules with the BRAF(V600E) mutation among the 136 nodules. Among the 136 nodules, there were 95 nodules with polygonal eosinophilic (plump) cells larger than 20%, cystic changes, or sickle cells on cytology. Of the 95 nodules, 69 (72.6%) had the mutation. Cytomorphologic features can help select nodules for the BRAF(V600E) mutation test among nodules read as "suspicious for malignancy" on cytology. Copyright © 2015 Elsevier GmbH. All rights reserved.
    No preview · Article · Jul 2015 · Pathology - Research and Practice
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    ABSTRACT: Papillary thyroid microcarcinoma (PTMC) usually has excellent prognosis, but a small subset shows aggressive behavior. Although the B-Raf proto-oncogene, serine/threonine kinase (BRAF)V600E mutation is the most common oncogenic alteration in PTMCs, it is frequently heterogeneously distributed within tumors. The aim of this study was to investigate the association of the BRAFV600E mutation found in fine needle aspirates from PTMCs with known clinicopathologic prognostic factors, based on both its presence and a quantitative approach that uses cycle threshold (Ct) values obtained by a real-time PCR technique. The 460 PTMC patients were included, with 367 patients having the BRAFV600E mutation. Clinicopathologic variables were compared between patients with and without the BRAFV600E mutation. BRAFV600E Ct values were compared according to clinicopathologic prognostic factors. Multivariate analyses were performed to evaluate factors predicting extrathyroidal extension and central and lateral lymph node metastasis (LNM). Each analysis used either the BRAFV600E mutation status or the Ct value as an independent variable for all the study patients and the 367 BRAFV600E-positive patients. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of BRAFV600E Ct values in predicting central and lateral LNM. The BRAFV600E mutation status was not associated with clinicopathologic prognostic factors among the 460 PTMC patients. Of the 367 BRAFV600E-positive patients, Ct values were significantly lower in patients with central and lateral LNM (P < 0.001, P = 0.007). The Ct value was the only independent factor to predict central LNM (OR 0.918, P = 0.025). The area under the ROC curve (AUC) for diagnosing central LNM was 0.623 (sensitivity, 50.0%; specificity, 71.9%) and for diagnosing lateral LNM, it was 0.796 (sensitivity, 71.4%; specificity, 94.7%). In conclusion, real-time PCR Ct values for the BRAFV600E mutation obtained from fine needle aspirates can be associated with central LNM in PTMC patients. Although BRAFV600E Ct values did not reach statistical significance for predicting lateral LNM in our study, further validation through larger studies can be used to overcome any possible type-II errors. With further studies, Ct values for the BRAFV600E mutation obtained from fine needle aspirates may have important implications for predicting both central and lateral LNM in patients with PTMCs.
    Preview · Article · Jul 2015 · Medicine
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    ABSTRACT: The object of this study is to evaluate the additional role of RAS mutation in detecting thyroid malignancy among BRAFV600E mutation-negative nodules diagnosed as atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) on cytology. From December 2009 to December 2011, 202 BRAFV600E mutation-negative thyroid nodules diagnosed as AUS/FLUS cytology in 201 patients were included in this study. RAS mutation analysis was performed using residual material from ultrasonography-guided fine needle aspiration (US-FNA) cytology testing for K-RAS, N-RAS, and H-RAS codons 12/13 and 61 point mutations. The authors evaluated the association between RAS mutation status and cytopathologic characteristics. Of the 202 BRAFV600E mutation-negative thyroid nodules with AUS/FLUS cytology, 4 were considered insufficient for mutation analysis. Of the 198 thyroid nodules, 148 (74.7%) were confirmed as benign and 50 (25.3%) as malignant. Thirty-one (15.7%) of the 198 thyroid nodules were positive for any RAS mutation, 4 positive for K-RAS 12/13, 26 for N-RAS 61, and 1 positive for H-RAS 61. Seven (22.6%) of the RAS mutation positive nodules were malignant, 1 with K-RAS 12/13, 6 with N-RAS 61. Twenty-four (77.4%) of the 31 nodules positive for K-RAS 12/13 (N = 3), N-RAS 61 (N = 20), or H-RAS 61 (N = 1) mutations were proven benign. None of the 198 thyroid nodules were positive for K-RAS 61, N-RAS 12/13, or H-RAS 12/13 mutations. N-RAS 61 mutation is the most common mutation detected among BRAFV600E mutation-negative nodules with AUS/FLUS cytology. RAS mutation has limited value in predicting malignancy among BRAFV600E mutation-negative thyroid nodules with AUS/FLUS cytology and further, investigation is anticipated to evaluate the true role of RAS mutation in thyroid malignancy.
    Preview · Article · Jul 2015 · Medicine
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    ABSTRACT: Thyroglobulin measurement in fine-needle aspiration washout fluid (FNA-Tg) is widely used for detection of lymph node metastasis (LNM) in patients with papillary thyroid cancer (PTC). Recent studies suggested that serum anti-thyroglobulin antibodies (TgAbs) could interfere with FNA-Tg. We evaluated whether TgAbs can affect FNA-Tg when diagnosing LNM in postoperative patients with PTC. From November 2006 to June 2011, a total of 239 LNs from 201 patients who underwent bilateral thyroidectomy and radioactive iodine ablation therapy were included. The interactions between FNA-Tgs and serum TgAbs, and diagnostic performances between FNA with additional FNA-Tg and FNA alone according to the presence of serum TgAbs were evaluated using the generalized linear mixed model and the bootstrap method. From 106 (44.4%) malignant and 133 (55.6%) benign LNs, there were 32 (13.4%) LNs with detectable serum TgAb levels and 207 (86.6%) LNs with undetectable serum TgAb levels. In logistic regression analysis, a significant negative interaction was observed between FNA-Tgs and serum TgAbs (p = 0.031). In the absence of serum TgAbs, the diagnostic performances were superior in the FNA with FNA-Tg than in the FNA only. However, in the presence of serum TgAbs, the diagnostic performances of the FNA with FNA-Tg were not significantly different from the FNA only, even with a different cutoff value of FNA-Tg. Serum TgAbs may interfere with FNA-Tg studies and caution is advised while analyzing FNA-Tg for detection of LNM in patients with PTC.
    Full-text · Article · Jun 2015 · PLoS ONE
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    ABSTRACT: Purpose To investigate whether ultrasonographic (US) features of thyroid nodules are associated with tumor recurrence in classic papillary thyroid carcinoma (PTC). Materials and Methods This retrospective study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. A total of 515 patients (mean age, 45.8 years ± 13.2 [standard deviation]; range, 17-80 years) who underwent total thyroidectomy and central lymph node dissection for classic PTC greater than 10 mm from January 2003 to February 2006 and who were followed up for 12 months or longer were included. Malignant-appearing PTCs were defined as those showing at least one suspicious US feature among marked hypoechogenicity, irregular or microlobulated margin, microcalcifications, and taller-than-wide shape. Benign-appearing PTCs were defined as those without any suspicious US features. Kaplan-Meier cumulative-event curves for recurrence were compared by using the log-rank test. The multivariate Cox proportional hazard regression analysis was used to estimate hazard ratios (HRs) of the malignant-appearing US features for recurrence in the preoperative, postoperative, and combined models. Results Fifty-six (10.9%) of 515 patients had recurrence. Malignant-appearing PTCs had lower 5- and 10-year disease-free survival rates compared with benign-appearing PTCs (P = .01). In the preoperative model, malignant-appearing US features (HR, 3.523; 95% confidence interval [CI]: 1.263, 9.830) and larger nodule size (HR, 1.074; 95% CI: 1.051, 1.098) were independently associated with recurrence. In the combined model, male sex (HR, 1.990; 95% CI: 1.098, 3.610), malignant-appearing US features (HR, 2.828; 95% CI: 1.016. 7.870), larger nodule size (HR, 1.067; 95% CI: 1.043, 1.092), extrathyroidal extension (HR, 2.590; 95% CI: 1.160, 5.780), and lymph node metastasis (HR, 2.511; 95% CI: 1.163, 5.421) were independently associated with recurrence. Conclusion The presence of malignant-appearing US features was independently associated with recurrence in patients with classic PTC. (©) RSNA, 2015.
    No preview · Article · May 2015 · Radiology
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    ABSTRACT: Our aim was to evaluate the role of the Thyroid Imaging Reporting and Data System (TIRADS) in the risk stratification of thyroid incidentalomas detected on (18)F-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)F-FDG-PET/CT) scans. Eighty-seven thyroid nodules in 84 patients showing incidentally detected increased uptake on (18)F-FDG-PET/CT who also had ultrasonography (US)-guided fine needle aspiration performed were included. On review of the US images, a TIRADS category was assigned to each thyroid nodule based on the number of suspicious US features. The correlation between the TIRADS category and the standard uptake values (SUV) on (18)F-FDG-PET/CT were calculated and compared. Of the 87 thyroid nodules, 47 (54%) were benign, and 40 (46%) were malignant. The malignancy rate of the TIRADS categories were as follows: 9% for category 3, 15% for category 4a, 39% for category 4b, 72% for category 4c, and 100.0% for category 5. Combining the TIRADS with the SUV showed increased specificity and positive predictive value but decreased sensitivity and negative predictive value compared with TIRADS alone (all P < .05). The area under the receiver operating characteristics curve value of TIRADS was the greatest, comparable with the combined TIRADS and SUV (0.737 to 0.724, P = .788). TIRADS may be applied in the risk stratification of thyroid incidentalomas detected on (18)F-FDG-PET/CT. Considering the high malignancy rate of thyroid incidentalomas showing increased (18)F-FDG uptake, ultrasonography-guided fine needle aspiration is mandatory even if there are no suspicious features present on US. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · May 2015 · Surgery

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3k Citations
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Institutions

  • 2008-2015
    • Wonju Severance Christian Hospital
      Genshū, Gangwon-do, South Korea
  • 2007-2015
    • Korea Institute of Radiological & Medical Sciences
      Sŏul, Seoul, South Korea
  • 2006-2015
    • Yonsei University
      • • Department of Radiology
      • • College of Medicine
      Sŏul, Seoul, South Korea
  • 2004-2014
    • Yonsei University Hospital
      • Surgery
      Sŏul, Seoul, South Korea
  • 2004-2006
    • CHA University
      • College of Medicine
      Sŏul, Seoul, South Korea