Hee Jung Moon

Yonsei University Hospital, Sŏul, Seoul, South Korea

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Publications (134)345.85 Total impact

  • [Show abstract] [Hide abstract]
    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. · 3.37 Impact Factor
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    ABSTRACT: The 5th edition of Breast Imaging Reporting and Data System subdivides suspicious calcifications into two categories: 4B-amorphous, coarse heterogeneous, and fine pleomorphic calcifications; 4C-fine linear or fine linear branching calcifications. We investigated whether these revised categories are appropriate for malignancy risk stratification. We studied 246 patients (mean age 48.2 years) with suspicious microcalcifications detected on mammography who underwent stereotactic biopsy (n = 154) or surgical excisional biopsy with preoperative mammogram-guided needle localization (n = 92). Pre-biopsy mammograms were reviewed retrospectively, and imaging features were analyzed according to the revised morphology and distribution descriptors. Pathological results of stereotactic biopsy and surgical excision were considered, with the surgical results being the reference standard. Positive predictive values (PPVs) were calculated and compared using the χ (2) test or Fisher's exact test. Overall PPV of suspicious microcalcifications was 22.4 %. PPVs of morphology descriptors were as follows: amorphous 7.9 %, coarse heterogeneous 17.8 %, fine pleomorphic 63.2 %, fine linear/fine linear branching 100 % (p < 0.001). PPVs of distribution descriptors were as follows: regional 8.8 %, grouped 14.3 %, linear 87.5 %, segmental 63.6 % (p < 0.001). For morphology and distribution descriptors combinations, PPVs for amorphous/regional and amorphous/grouped microcalcifications were 4.2 and 7.6 %, resepectively. The PPV for fine pleomorphic/linear or segmental was 93.8 %. Subcategorization of morphology descriptors for suspicious microcalcifications is needed because of the different PPVs for amorphous, coarse heterogeneous, and fine pleomorphic microcalcifications. Combining morphology and distribution descriptors for suspicious microcalcifications provides accurate risk stratification.
    Annals of Surgical Oncology 01/2015; · 3.94 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;
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    ABSTRACT: The aim of this study was to compare the mammography, ultrasound (US) and histologic features of triple-negative (TN) invasive carcinoma of no special type (NST) to non-TN invasive carcinoma of NST. The second aim was to assess whether the distinct imaging characteristics of TN breast cancer would persist after controlling for the histologic features. A total of 344 invasive carcinomas of NST in 337 patients from January 2007 to February 2008 were included in this study. Two radiologists retrospectively reviewed the mammography and US findings using the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon and our institution's criteria. On mammography, TN invasive carcinoma of NST most commonly presented as a mass with round shape and non-spiculated margin. On US, it was more likely to have internal hypoechogenicity, an abrupt boundary and posterior acoustic enhancement. TNBC lacked major suspicious imaging findings such as an irregular shape, spiculated margin and calcification.
    Ultrasound in Medicine & Biology 12/2014; · 2.10 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; · 1.05 Impact Factor
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    ABSTRACT: The purpose of this study was to assess the usefulness of HER2 levels in ultrasonographically guided fine-needle aspiration biopsy (US-FNA) aspirates of axillary lymph nodes (ALNs) in the determination of lymph node metastasis or the characterization of primary breast cancer, and to correlate the HER2 levels in US-FNA aspirates (FNA-HER2s) of metastatic ALNs with the HER2 statuses of corresponding primary breast cancers. An institutional review board approved the study. Between January and October 2010, 164 patients with 167 ALNs examined by US-FNA were included. FNA-HER2s of ALNs were measured by chemiluminescence immunoassay, and they were correlated with cytologic/final diagnoses. Receiver operating characteristics (ROC) curve analysis was performed to evaluate the diagnostic ability to differentiate benign and metastatic ALNs. Additionally, FNA-HER2s of metastatic ALNs were correlated with HER2 status and other clinicopathologic variables of the primary breast cancers. Among the 167 ALNs, 138 were metastatic and 29 were benign. The mean FNA-HER2 (6.3 ng/ml) of metastatic ALNs was higher than that of benign ALNs. All 29 benign ALNs showed no measurable value of FNA-HER2 (0.0 ng/ml). The area under the ROC curves of FNA-HER2 of ALNs was 0.679 for the diagnosis of ALN metastasis. The FNA-HER2 statuses of 108 metastatic ALNs (79.4%) were concordant with the HER2 statuses of the corresponding primary breast cancers. In a subgroup analysis of HER2-positive cancers with ALN metastasis, distant metastasis was significantly associated with FNA-HER2-negativity of metastatic ALNs (P = 0.04). Although FNA-HER2 of ALNs did not improve the diagnostic performance of FNA cytology in preoperative diagnosis of ALN metastasis of overall patients, FNA-HER2-positive metastatic ALNs were significantly associated with HER2-positivity of primary breast cancers. Additionally, FNA-HER2 analysis of ALN may help to develop more personalized treatment protocol for breast cancer patients by determining the concordance or discordance of HER2 status between primary cancers and metastatic ALNs.
    PLoS ONE 11/2014; 9(11):e113065. · 3.53 Impact Factor
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    ABSTRACT: To evaluate the upgrade rate and delayed false-negative results of percutaneous vacuum-assisted removal (VAR) and surgical excision in women with imaging-histologic discordance during ultrasound (US)-guided automated core needle biopsy (CNB) of the breast and to validate the role of VAR as a rebiopsy method for these discordant lesions. Percutaneous US-guided 14-gauge CNB was performed on 7470 patients between August 2005 and December 2010. Our study population included 161 lesions in 152 patients who underwent subsequent rebiopsy due to imaging-histologic discordance. Rebiopsy was performed using VAR (n = 88) or surgical excision (n = 73). We investigated the upgrade rate immediately after rebiopsy and delayed false-negative results during at least 24 months of follow-up after rebiopsy. We also evaluated the clinicoradiological differences between VAR and surgical excision. Total upgrade to malignancy occurred in 13.7% (22/161) of lesions at rebiopsy including both VAR and surgical excision: 4.6% (4/88) of VAR cases (4/88) and 24.7% (18/73) of surgical excision cases (p < 0.001). Surgical excision was performed significantly more frequently in older patients and for larger-sized lesions than that of VAR, and a significant difference was detected between VAR and surgical excision in the Breast Imaging and Reporting and Data System category (p < 0.007). No delayed false-negative results were observed after VAR or surgical excision during the follow-up period. Long-term follow-up data showed no delayed cancer diagnoses after US-guided VAR in imaging-histologic discordant lesions of the breast, suggesting that VAR might be a rebiopsy method for these lesions.
    Korean journal of radiology: official journal of the Korean Radiological Society 11/2014; 15(6):697-703. · 1.32 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; · 3.35 Impact Factor
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    ABSTRACT: Triple-negative breast cancer (TNBC) which expresses neither hormonal receptors nor HER-2 is associated with poor prognosis and shorter survival. Several studies have suggested that TNBC patients attaining pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) show a longer survival than those without pCR.
    Acta Radiologica 09/2014; · 1.35 Impact Factor
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    ABSTRACT: The purpose of our study was to evaluate the underestimation rate of atypical ductal hyperplasia (ADH) on vacuum-assisted breast biopsy (VABB), and to examine the correlation between residual microcalcifications and the underestimation rate of ADH.
    Journal of Breast Cancer 09/2014; 17(3):265-9. · 1.32 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.
    Ultrasound in Medicine & Biology. 09/2014; 40(9):2012–2019.
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    ABSTRACT: We presented the photoacoustic imaging (PAI) tool and to evaluate whether microcalcifications in breast tissue can be detected on photoacoustic (PA) images.
    PLoS ONE 08/2014; 9(8):e105878. · 3.53 Impact Factor
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    ABSTRACT: Purpose To evaluate the malignancy risks of thyroid nodules with nondiagnostic results at ultrasonography (US)-guided fine-needle aspiration biopsy (FNAB) and the criteria for selecting those for repeat US-guided FNAB according to the thyroid imaging reporting and data system (TIRADS). Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. Five hundred forty-eight nondiagnostic nodules were included. US features of internal composition, echogenicity, margin, calcifications, shape, and vascularity were evaluated, and thyroid nodules were classified according to TIRADS. TIRADS category 3 included nodules without any suspicious features of solidity, hypoechogenicity or marked hypoechogenicity, microlobulated or irregular margins, microcalcifications, and taller-than-wide shape. Categories 4a, 4b, 4c, and 5 included nodules with one, two, three or four, or five suspicious US features. The malignancy risk was calculated. Results Of the 548 nodules, 40 (7.3%) were malignant and 508 (92.7%) were benign. The malignancy risks of categories 3 and 4a nodules were 0.8% and 1.8%, respectively, whereas the malignancy risks of categories 4b, 4c, and 5 nodules were 6.1%, 14.4%, and 31%. In the 294 nodules larger than 10 mm, the malignancy risks of categories 3, 4a, 4b, 4c, and 5 nodules were 0.9%, 1.3%, 0%, 15%, and 33%, respectively. In the 254 nodules measuring 10 mm or smaller, the malignancy risks of categories 3, 4a 4b, 4c, and 5 nodules were 0%, 2.7%, 14%, 14.3%, and 31%. Conclusion Nondiagnostic thyroid nodules without suspicious US features and those with one suspicious feature can be followed up with US, but nondiagnostic nodules with two or more suspicious features should undergo repeat US-guided FNAB. © RSNA, 2014.
    Radiology 08/2014; · 6.21 Impact Factor
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    ABSTRACT: The incidence of asymptomatic papilloma has increased with the rising popularity of core needle biopsy for breast lesions. In this study, the risk of benign papilloma without atypia for subsequent breast carcinoma during follow-up was evaluated. From January 2000 to December 2010, among 39,461 women with breast ultrasonography, 37,847 women with benign papilloma on biopsy or excision, with benign diseases on biopsy, and with only ultrasonography performed were recruited. Women with concurrent or prior high-risk lesions (atypia, phyllodes tumor, or lobular neoplasm) or malignancies, or with a follow-up period of less than 12 months were excluded. The eligible 12,302 women were classified into three groups; papilloma (n = 265, patients with benign papilloma without atypia at excision), benign (n = 3,066, patients with benign results other than high risk results on core needle biopsy), and ultrasonography (n = 8,971, patients who underwent ultrasonography only without biopsy or surgery). The relative risks (RRs) of the papilloma and benign groups were calculated with intervals of 2 years using the Poisson regression analysis with age, family history, follow-up period, and breast parenchymal density being adjusted, and the ultrasonography group was used as a reference. The RR of the papilloma group was 4.8 (95% confidence interval [CI], 2.5–9.0), significantly higher than 1.5 (95% CI, 1.0–2.1) of the benign group. In the first 2 years, the RR of the papilloma group was 5.2 (95% CI, 2.2–12.6) but it dropped to 2.2 (95% CI, 0.5–9.2) during the next 2 years. Afterward, the RR increased over time although statistical significance was not achieved. Benign papilloma without atypia increased breast cancer risk fivefold when the ultrasonography group was used as a reference, higher than other benign lesions.
    The Breast Journal 07/2014; · 1.43 Impact Factor
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    ABSTRACT: To evaluate the accuracy of benign core biopsy of probably benign breast lesions (category 3) 2 cm or larger on the basis of excisional biopsy and long-term follow-up.
    Ultrasonography (Seoul, Korea). 07/2014; 33(3):200-205.
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    ABSTRACT: To evaluate the positive predictive value (PPV) of bilateral whole-breast ultrasonography (BWBU) for detection of synchronous breast lesions on initial diagnosis of breast cancer and evaluate factors affecting the PPV of BWBU according to varying clinicoimaging factors.
    Ultrasonography (Seoul, Korea). 07/2014; 33(3):170-177.
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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.
    Ultrasound in Medicine & Biology 06/2014; · 2.10 Impact Factor
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    ABSTRACT: Background We hypothesized that a nomogram constructed of clinical and imaging variables could be applied to predicting the risk of malignancy in thyroid nodules diagnosed as AUS/FLUS. Methods This retrospectively designed study included 393 thyroid nodules in 392 patients (mean age: 49.06 ± 11.86 years) which were diagnosed as AUS/FLUS with US-FNA during the study period. Medical records, US images, and cytopathology results were reviewed and analyzed. The 393 thyroid nodules were divided into training and validation sets. Logistic regression analysis was performed to predict the probability of malignancy and nomograms were constructed using the training set and subsequently applied to the validation set. Results Three sets of nomograms were separately constructed using clinical factors and (a) individual US features, (b) final assessment of US, and (c) the number of suspicious US features. All three sets of nomograms built were proven accurate and discriminative, with an area under the receiver operating characteristic curve (AUC) of 0.817 (95% confidence interval (CI): 0.757-0.877) when using clinical factors and individual US features, of 0.769 (95% CI: 0.705-0.833) when using final assessment, and of 0.779 (95% CI: 0.718-0.840) when using the number of suspicious US features. The AUC of each validation set was 0.754 (95% CI: 0.659-0.850), 0.757 (95% CI: 0.661-0.853), and 0.721 (95% CI: 0.621-0.820), respectively. Conclusions Nomograms constructed in our study using US can be utilized in predicting the probability of malignancy in thyroid nodules diagnosed as AUS/FLUS on US-FNA, and may help in selecting patients who are at high risk for malignancy.
    Surgery 06/2014; · 3.11 Impact Factor
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    ABSTRACT: Our aim was to evaluate intra-observer reproducibility of shear-wave elastography (SWE) in Asian women. Sixty-four breast masses (24 malignant, 40 benign) were examined with SWE in 53 consecutive Asian women (mean age, 44.9 y old). Two SWE images were obtained for each of the lesions. The intra-observer reproducibility was assessed by intra-class correlation coefficients (ICC). We also evaluated various clinicoradiologic factors that can influence reproducibility in SWE. The ICC of intra-observer reproducibility was 0.789. In clinicoradiologic factor evaluation, masses surrounded by mixed fatty and glandular tissue (ICC: 0.619) showed lower intra-observer reproducibility compared with lesions that were surrounded by glandular tissue alone (ICC: 0.937; p < 0.05). Overall, the intra-observer reproducibility of breast SWE was excellent in Asian women. However, it may decrease when breast tissue is in a heterogeneous background. Therefore, SWE should be performed carefully in these cases.
    Ultrasound in medicine & biology 06/2014; · 2.46 Impact Factor
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    ABSTRACT: Recently, higher body mass index (BMI) has been associated with aggressive pathologic features of papillary thyroid carcinoma. The aim of this study was to clarify the relationship between BMI and aggressive pathologic features of papillary thyroid microcarcinoma (PTMC) and to evaluate whether the BMI can be a prognostic factor of PTMC. This retrospective study included 612 PTMC patients who underwent surgical excision at a referral center between April 2006 and December 2007. Patients were grouped according to BMI (<25 or ≥25 kg/m(2)). Multivariable logistic regression analysis was performed to determine independent predictors of aggressive pathologic features (advanced stage, extrathyroidal extension, and lymph node metastasis), with adjustment for age, gender, tumor size, multifocality, thyroid stimulating hormone (TSH) level, and BMI (value/group). PTMC patients with a BMI ≥ 25 kg/m(2) showed significantly higher prevalences of extrathyroidal extension, advanced pathologic TNM stage, and male gender, compared to those of patients with a BMI < 25 kg/m(2). Lymph node metastasis and mean TSH level were not significantly different between the two BMI subgroups. In multivariable analysis, the BMI ≥ 25 kg/m(2) group was positively associated with the presence of extrathyroidal extension (adjusted odds ratio 1.49, P = 0.05). Higher BMI was associated with extrathyroidal extension in PTMC patients. This study suggests that the BMI could be considered as a prognostic factor for predicting the presence of extrathyroidal extension and it may help decide the appropriate surgical extent for PTMC patients.
    Endocrine 05/2014; · 3.53 Impact Factor

Publication Stats

783 Citations
345.85 Total Impact Points

Institutions

  • 2009–2014
    • Yonsei University Hospital
      • Surgery
      Sŏul, Seoul, South Korea
  • 2013
    • Ewha Womans University
      • Department of Radiology
      Sŏul, Seoul, South Korea
    • Jeju National University
      Tse-tsiu, Jeju, South Korea
  • 2010–2013
    • Yonsei University
      • Department of Radiology
      Sŏul, Seoul, South Korea
    • Catholic University of Daegu
      • Department of Internal Medicine
      Kayō, North Gyeongsang, South Korea
  • 2012
    • National Cancer Center Korea
      Kōyō, Gyeonggi Province, South Korea
    • Kyung Hee University
      • College of Medicine
      Seoul, Seoul, South Korea
  • 2011
    • Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo
      San Paulo, São Paulo, Brazil
  • 2009–2011
    • Korea Institute of Radiological & Medical Sciences
      Sŏul, Seoul, South Korea
  • 2008–2009
    • Kosin University
      • College of Medicine
      Pusan, Busan, South Korea
    • Yeungnam University
      • Division of Internal Medicine
      Onyang, South Chungcheong, South Korea