Jin Young Kwak

Yonsei University, Sŏul, Seoul, South Korea

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Publications (222)600.98 Total impact

  • 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.
    Pathology - Research and Practice 07/2015; DOI:10.1016/j.prp.2015.06.010 · 1.56 Impact Factor
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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) 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 BRAF 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 BRAF mutation. Clinicopathologic variables were compared between patients with and without the BRAF mutation. BRAF 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 BRAF mutation status or the Ct value as an independent variable for all the study patients and the 367 BRAF-positive patients. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of BRAF Ct values in predicting central and lateral LNM.The BRAF mutation status was not associated with clinicopathologic prognostic factors among the 460 PTMC patients. Of the 367 BRAF-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 BRAF mutation obtained from fine needle aspirates can be associated with central LNM in PTMC patients. Although BRAF 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 BRAF mutation obtained from fine needle aspirates may have important implications for predicting both central and lateral LNM in patients with PTMCs.
    Medicine 07/2015; 94(28):e1149. DOI:10.1097/MD.0000000000001149 · 4.87 Impact Factor
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    ABSTRACT: The object of this study is to evaluate the additional role of RAS mutation in detecting thyroid malignancy among BRAF 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 BRAF 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 BRAF 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 BRAF mutation-negative nodules with AUS/FLUS cytology. RAS mutation has limited value in predicting malignancy among BRAF mutation-negative thyroid nodules with AUS/FLUS cytology and further, investigation is anticipated to evaluate the true role of RAS mutation in thyroid malignancy.
    Medicine 07/2015; 94(27):e1084. DOI:10.1097/MD.0000000000001084 · 4.87 Impact Factor
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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.
    Radiology 05/2015; DOI:10.1148/radiol.2015142470 · 6.21 Impact Factor
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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.
    Surgery 05/2015; DOI:10.1016/j.surg.2015.03.017 · 3.11 Impact Factor
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    ABSTRACT: Fine needle aspiration (FNA) is currently accepted as an easy, safe, and reliable tool for the diagnosis of thyroid nodules. Nonetheless, a proportion of FNA samples are categorized into non-diagnostic or indeterminate cytology, which frustrates both the clinician and patient. To overcome this limitation of FNA, core needle biopsy (CNB) of the thyroid has been proposed as an additional diagnostic method for more accurate and decisive diagnosis for thyroid nodules of concern. In this review, we focus on the effectiveness and limitations of CNB, and what factors should be considered when CNB is utilized in the diagnosis of thyroid nodules.
    05/2015; 49(3):230-5. DOI:10.4132/jptm.2015.03.21
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    ABSTRACT: Purpose To compare the malignancy rates and the effectiveness of the Thyroid Imaging Reporting and Data System (TIRADS) for risk stratification of nodules with nondiagnostic results classified before and after application of the Bethesda System for Reporting Thyroid Cytopathology. Materials and Methods This retrospective study was approved by an institutional review board, with waiver of informed consent. A total of 763 patients with 790 thyroid nodules and nondiagnostic cytologic results were included (mean age ± standard deviation, 52.3 years ± 11.5), 485 nodules from the pre-Bethesda period (from March 2007 to December 2008) and 305 nodules from the post-Bethesda period (from May 2011 to May 2012). A TIRADS category was assigned to each thyroid nodule on the basis of the number of features that appeared suspicious for cancer at ultrasonography (US). Malignancy rates and TIRADS categories during the two periods were compared. Correlation between TIRADS category and malignancy risk between the two periods was evaluated and compared. Results The malignancy rates of nodules with nondiagnostic cytologic results were not significantly different between the two periods (P = .148). Malignancy risk of TIRADS category 3, 4a, 4b, 4c, and 5 was 1.8%, 5.7%, 4.1%, 29.8%, and 16.7%, for the pre-Bethesda period, and 1.6%, 3.0%, 7.1%, 16.3%, and 25.0% for the post-Bethesda period, respectively. Near-perfect correlation was seen between the TIRADS category and malignancy risk in the post-Bethesda period (r = 0.961, P = .009), while no significant correlation was found in the pre-Bethesda period (r = 0.731, P = .161). Conclusion Malignancy risk stratification with TIRADS was more effective for nodules with nondiagnostic cytologic results classified according to the Bethesda System. When these Bethesda-classified nodules with nondiagnostic results are evaluated as TIRADS category 3 or 4a, they may be treated conservatively with follow-up US, but when other cytologic classifications are applied, follow-up US and fine- needle aspiration must be considered for nodules showing one or more features suspicious for cancer at US. (©) RSNA, 2015.
    Radiology 04/2015; DOI:10.1148/radiol.15142308 · 6.21 Impact Factor
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    ABSTRACT: To evaluate the malignancy risk and characteristics of thyroid nodules with two "Atypia of Undetermined Significance" or "Follicular Lesion of Undetermined Significance" (AUS/FLUS) results, and compare characteristics of malignancies with two AUS/FLUS results to those with one AUS/FLUS result. Of 441 thyroid nodules with initial AUS/FLUS results, 236 underwent repeat fine-needle-aspiration (FNA), with 58 obtaining repeated AUS/FLUS results. Thyroid Imaging Reporting and Data System (TIRADS) categories were assigned, and clinico-pathological characteristics were compared between benign and malignant nodules and between malignancies with two consecutive AUS/FLUS results and those with one AUS/FLUS result. Thirty-one percent (18/58) of nodules with two AUS/FLUS results and 58.1 % (18/31) of confirmed nodules were malignant. Age, gender, nodule size, ultrasound features and TIRADS categories did not differ between benign and malignant nodules or between malignancies with one and two AUS/FLUS results. Malignancies with two AUS/FLUS results had a higher proportion of a follicular variant of papillary thyroid carcinoma (PTC) (46.7 % vs. 13.6 %, P = 0.009). Thyroid nodules with two AUS/FLUS results had a high malignancy risk of at least 31.0 % and a higher proportion of a follicular variant of PTC. Surgery should be considered regardless of ultrasound features. • Thyroid nodules with two consecutive AUS/FLUS results had a high malignancy risk. • Ultrasound features are less useful in nodules with two AUS/FLUS results. • The follicular variant of PTC is more frequent in malignancies with two AUS/FLUS results.
    European Radiology 03/2015; DOI:10.1007/s00330-015-3668-5 · 4.34 Impact Factor
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    ABSTRACT: Ultrasound (US)-guided fine needle aspiration (US-FNA) has played a crucial role in managing patients with thyroid nodules, owing to its safety and accuracy. However, even with US guidance, nondiagnostic sampling and infrequent complications still occur after FNA. Accordingly, the Task Force on US-FNA of the Korean Society of Thyroid Radiology has provided consensus recommendations for the US-FNA technique and related issues to improve diagnostic yield. These detailed procedures are based on a comprehensive analysis of the current literature and from the consensus of experts.
    Korean journal of radiology: official journal of the Korean Radiological Society 03/2015; 16(2):391-401. DOI:10.3348/kjr.2015.16.2.391 · 1.81 Impact Factor
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    ABSTRACT: BRAF(V600E) mutation analysis has been used as a complementary diagnostic tool to ultrasonography-guided, fine-needle aspiration (US-FNA) in the diagnosis of thyroid nodule with high specificity reported up to 100%. When highly sensitive analytic methods are used, however, false-positive results of BRAF(V600E) mutation analysis have been reported. In this study, we investigated the clinical, US features, and outcome of patients with thyroid nodules with benign cytology but positive BRAF(V600E) mutation using highly sensitive analytic methods from US-FNA. This study included 22 nodules in 22 patients (3 men, 19 women; mean age, 53 years) with benign cytology but positive BRAF(V600E) mutation from US-FNA. US features were categorized according to the internal components, echogenicity, margin, calcifications, and shape. Suspicious US features included markedly hypoechogenicity, noncircumscribed margins, micro or mixed calcifications, and nonparallel shape. Nodules were considered to have either concordant or discordant US features to benign cytology. Medical records and imaging studies were reviewed for final cytopathology results and outcomes during follow-up. Among the 22 nodules, 17 nodules were reviewed. Fifteen of 17 nodules were malignant, and 2 were benign. The benign nodules were confirmed as adenomatous hyperplasia with underlying lymphocytic thyroiditis and a fibrotic nodule with dense calcification. Thirteen of the 15 malignant nodules had 2 or more suspicious US features, and all 15 nodules were considered to have discordant cytology considering suspicious US features. Five nodules had been followed with US or US-FNA without resection, and did not show change in size or US features on follow-up US examinations. BRAF(V600E) mutation analysis is a highly sensitive diagnostic tool in the diagnosis of papillary thyroid carcinomas. In the management of thyroid nodules with benign cytology but positive BRAF(V600E) mutation, thyroidectomy should be considered in nodules which have 2 or more suspicious US features and are considered discordant on image-cytology correlation. Copyright © 2015 Elsevier Inc. All rights reserved.
    Surgery 02/2015; 157(2):354-61. DOI:10.1016/j.surg.2014.09.003 · 3.11 Impact Factor
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    ABSTRACT: The incidence of small thyroid malignancy has increased. However, there is no evidence-based guideline for managing thyroid nodules ≤5 mm on ultrasonography (US). We evaluated how to manage thyroid nodules ≤5 mm. Thyroid nodules ≤5 mm in size on US that had undergone surgery and US-guided fine-needle aspiration were eligible. A total of 3,117 thyroid nodules in 3,012 patients were included. The size changes of malignant and benign nodules during follow-up were evaluated. Thyroid malignancies were classified according to follow-up and surgery time within and after 12 months. Clinico-pathological characteristics were compared. Of 3,117 nodules, 1,639 nodules in 1,619 patients were benign and 1,478 in 1,427 were malignant. Only 5.8 and 1.2 % of malignant nodules and 6.8 and 4.2 % of benign nodules increased in size when a 2-mm and 3-mm change on US were referenced. Of 1,079 patients with an index malignancy ≤5 mm, extrathyroidal extension, lymph node metastasis, recurrence, and mortality were not significantly different between patients with and without follow-up and between patients with surgery within 12 months and after 12 months. None of the patients who underwent surgery had distant metastasis and none died of thyroid malignancy. In thyroid nodules ≤5 mm found on US, US-FNA could be recommended in cases of increased size during US follow-up if lateral LNM was not found because a delay in surgery did not impact cancer recurrence and mortality.
    Endocrine 01/2015; 49(3). DOI:10.1007/s12020-015-0526-9 · 3.53 Impact Factor
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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.
    PLoS ONE 01/2015; 10(6):e0131096. DOI:10.1371/journal.pone.0131096 · 3.53 Impact Factor
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    ABSTRACT: We investigated the adjunctive role of preoperative serum thyroglobulin (Tg) in the diagnosis of thyroid nodules. A retrospective study was performed on 374 thyroid nodules (363 benign and 11 malignant) in 360 patients (296 women and 64 men; mean age, 50.1 years; range, 16-86 years) between December 2010 and July 2011. We evaluated clinicopathologic characteristics of patients and ultrasonographic (US) features of the lesions including presurgical Tg levels. Univariate and multivariate analysis were used to determine independent predictors of malignancy. Serum Tg was positively correlated with nodule size and thyroid volume (P < 0.001). There was no difference in serum Tg levels between malignant and benign nodules. Suspicious US features of thyroid nodules were the only independent predictors of malignancy (P< 0.001). Preoperative serum Tg was not useful in differentiating thyroid cancer from benign nodules. Suspicious US features were the only predicting factors for malignancy.
    Ultrasound Quarterly 12/2014; 30(4):287-90. DOI:10.1097/RUQ.0000000000000056 · 1.40 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate the diagnostic utility of PAI at detecting thyroid microcalcifications at 700 nm laser wavelengths. This study included 36 resected samples in 18 patients. To evaluate the PA manifestation of microcalcifications in PAI, gray level histogram and co-occurrence matrix (COM) texture parameters were extracted from the 3 fixed ROI US and PA images, respectively, per sample. We compared the textural parameters obtained from specimen PAIs between samples with punctate microcalcifications on specimen radiography and those without microcalcifications. On specimen US, the mean value (2748.4±862.5) of samples with microcalcifications on specimen radiography was higher than that (1961.9±780.2) of those without microcalcifications (P = 0.007). However, there were no significant differences in textural parameters obtained from specimen PAIs between samples with punctate microcalcifications on specimen radiography and those without when applying both the mean value of the three slices of thyroid specimens and the value of the thyroid specimen slice which had the highest value of the mean values in specimen US. PAI did not show significant PA contrast on thyroid microcalcifications indicating that the experimental setup and protocols should be enhanced, e.g., method of complete blood rejection from ex vivo specimens, the multi-wavelength spectroscopic PA imaging method which can solely extract the PA signal from microcalcifications even with high spectral interferences, or PA imaging with narrower slice thickness using 2-dimensional array transducer, etc.
    PLoS ONE 11/2014; 9(11):e113358. DOI:10.1371/journal.pone.0113358 · 3.53 Impact Factor
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    ABSTRACT: We investigated the additional diagnostic yield of the mutation test and evaluated the frequency of the BRAF mutation in conventional PTC (cPTC) according to ultrasound (US) features and the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) based on the BRAF(V600E) mutation status. During the study period, 279 patients who underwent FNA with an additional BRAF(V600E) mutation test were diagnosed as cPTC after surgery. We analyzed the association between the mutation and several clinical factors. Of the 279 cPTCs, 250 (89.6%) had the BRAF(V600E) mutation. The BRAF mutation test was helpful in diagnosing an additional 19% (53/279) of cPTCs. The frequency of the BRAF mutation in cPTCs with suspicious US features was higher than that of cPTCs with negative US features regardless of the BSRTC. Suspicious US features may be helpful in deciding whether an additional BRAF(V600E) mutation test should be done in thyroid nodules with indeterminate cytology. © The Author(s) 2014.
    The Annals of otology, rhinology, and laryngology 11/2014; 124(5). DOI:10.1177/0003489414560433 · 1.05 Impact Factor
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    ABSTRACT: Objective. To determine the role of imaging-cytology correlation in reducing false negative results of fine-needle aspiration (FNA) at thyroid nodules. Methods. This retrospective study included 667 nodules 1 cm or larger in 649 patients diagnosed as benign at initial cytologic evaluation and that underwent follow-up ultrasound (US) or FNA following a radiologist's opinion on concordance between imaging and cytologic results. We compared the risk of malignancy of nodules classified into subgroups according to the initial US features and imaging-cytology correlation. Results. Among included nodules, 11 nodules were proven to be malignant (1.6%) in follow-up FNA or surgery. The malignancy rate was higher in nodules with suspicious US features (11.4%) than in nodules without suspicious US features (0.5%, P < 0.001). When a thyroid nodule had discordant US findings on image review after having benign FNA results, malignancy rate increased to 23.3%, significantly higher than that of nodules with suspicious US features (P < 0.001). However, no significant difference was found in the risk of malignancy between the nodules without suspicious US features (0.5%) and imaging-cytology concordant nodules (0.6%, P = 0.438). Conclusions. Repeat FNA can be effectively limited to patients with cytologically benign thyroid nodules showing discordance in imaging-cytology correlation after initial biopsy, which reduces unnecessary repeat aspirations.
    International Journal of Endocrinology 10/2014; 2014:491508. DOI:10.1155/2014/491508 · 1.52 Impact Factor
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    ABSTRACT: Objective The aim of this study was to investigate the diagnostic performance of preoperative staging ultrasound (US) according to body mass index (BMI) in patients with papillary thyroid carcinoma (PTC)Patients and Methods This retrospective study included 625 PTC patients who underwent preoperative staging US and surgical excision at a referral center between December 2012 and April 2013. Four experienced radiologists prospectively evaluated the extent of primary tumors, multifocality, and the presence of lymph node metastasis. Patients were grouped according to BMI (normal < 25; overweight 25 ≤ and < 30; obese ≥ 30,/non-obese < 30; obese ≥ 30 kg/m2). Diagnostic performances of preoperative staging US (sensitivity, specificity, positive predictive value, negative predictive value, and accuracy) were compared according to BMI based on pathologic findings of surgical specimens.ResultsPreoperative staging US in the obese group (BMI ≥ 30 kg/m2) showed a significantly lower negative predictive value and accuracy in the detection of central lymph node metastasis (P=0.010 and P=0.025, respectively) than in the non-obese (BMI < 30 kg/m2) group. However, there were no significant differences in the diagnostic performance of preoperative staging US for extrathyroidal extension, bilateral multifocality, and lateral lymph node metastasis in analyses using the two (non-obese vs. obese) and three BMI (normal vs. overweight vs. obese) groups, respectively.Conclusion Obesity (BMI ≥ 30 kg/m2) may affect the preoperative US staging of central lymph node metastasis in PTC patients.This article is protected by copyright. All rights reserved.
    Clinical Endocrinology 10/2014; DOI:10.1111/cen.12638 · 3.35 Impact Factor
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    ABSTRACT: Background. To evaluate the role of ultrasonography (US), US-guided fine-needle aspiration (USFNA) and intraoperative frozen section (FS) in follicular neoplasm. Methods. US features, USFNA cytology, and FS results were compared based on the pathology results of patients with follicular adenoma (FA), follicular carcinoma (FC), and follicular variant of papillary thyroid carcinoma (FVPTC). Results. FC and FVPTC showed significantly higher rates of suspicious US features (P < 0.05) and positive findings on either US or cytology, 80.0% and 90.7%, compared to FA, 64.5% (P = 0.001). Intraoperative FS showed higher malignant rates in FVPTC and FC (81.8% and 75.0%, resp.), compared to FA (3.8%, P < 0.001). Conclusion. Suspicious US features were more significantly seen in FC and FVPTC compared to FA. Intraoperative FS is useful in the differential diagnosis of these lesions and supplements cytology results of USFNA.
    International Journal of Endocrinology 09/2014; 2014:321595. DOI:10.1155/2014/321595 · 1.52 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the diagnostic performance of quantitative histogram parameters using real-time tissue elastography (RTE) in the diagnosis of patients with diffuse thyroid disease. One hundred and sixteen patients (mean age, 43.7 ± 10.97 y) who had undergone pre-operative staging ultrasonography and RTE were included. For each patient, 11 parameters were obtained from RTE images, from which the “elastic index” was calculated. Diagnostic performance of the elastic index and that of the 11 parameters on RTE were calculated and compared. Of the 116 patients, 31 had diffuse thyroid disease and 85 had normal thyroid parenchyma. Area under the receiver operating characteristic curve (Az) of MEAN (average relative value) elasticity was high (0.737), without significant differences from other elasticity values. Diagnostic performance of the elastic index was higher than the MEAN, Az = 0.753, without significance (p = 0.802). In conclusion, RTE using the elastic index was found to have good diagnostic performance and may be useful in the diagnosis and management of patients with diffuse thyroid disease.
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    ABSTRACT: Background We presented the photoacoustic imaging (PAI) tool and to evaluate whether microcalcifications in breast tissue can be detected on photoacoustic (PA) images. Methods We collected 21 cores containing microcalcifications (n = 11, microcalcification group) and none (n = 10, control group) in stereotactic or ultrasound (US) guided 8-gauge vacuum-assisted biopsies. Photoacoustic (PA) images were acquired through ex vivo experiments by transmitting laser pulses with two different wavelengths (700 nm and 800 nm). The presence of microcalcifications in PA images were blindly assessed by two radiologists and compared with specimen mammography. A ratio of the signal amplitude occurring at 700 nm to that occurring at 800 nm was calculated for each PA focus and was called the PAI ratio. Results Based on the change of PA signal amplitude between 700 nm and 800 nm, 10 out of 11 specimens containing microcalcifications and 8 out of 10 specimens without calcifications were correctly identified on blind review; the sensitivity, specificity, accuracy, positive predictive and negative predictive values of our blind review were 90.91%, 80.0%, 85.71%, 83.33% and 88.89%. The PAI ratio in the microcalcification group was significantly higher than that in the control group (the median PAI ratio, 2.46 versus 1.11, respectively, P = .001). On subgroup analysis in the microcalcification group, neither malignant diagnosis nor the number or size of calcification-foci was proven to contribute to PAI ratios. Conclusion Breast microcalcifications generated distinguishable PA signals unlike breast tissue without calcifications. So, PAI, a non-ionizing and non-invasive hybrid imaging technique, can be an alternative in overcoming the limitations of conventional US imaging.
    PLoS ONE 08/2014; 9(8):e105878. DOI:10.1371/journal.pone.0105878 · 3.53 Impact Factor

Publication Stats

2k Citations
600.98 Total Impact Points

Institutions

  • 2007–2015
    • Yonsei University
      • • Department of Radiology
      • • Natural Science Research Institute
      Sŏul, Seoul, South Korea
  • 2006–2015
    • Yonsei University Hospital
      • Surgery
      Sŏul, Seoul, South Korea
  • 2008–2014
    • Korea Institute of Radiological & Medical Sciences
      Sŏul, Seoul, South Korea
    • Wonju Severance Christian Hospital
      Genshū, Gangwon-do, South Korea
  • 2000–2006
    • CHA University
      • College of Medicine
      Sŏul, Seoul, South Korea