A nomograph model for prediction of central lymph node metastasis of papillary thyroid carcinoma / 预防医学

Objective@#To establish a nomograph model for prediction of cervical central lymph node metastasis (CLNM) among patients with thyroid papillary carcinoma (PTC), so as to provide the evidence for designing personalized treatment plans for PTC.@* Methods @#The data of patients that underwent thyroidectomy and were pathologically diagnosed with PTC post-surgery in the Affiliated Traditional Chinese Medicine Hospital of Xinjiang Medical University from 2018 to 2021 were collected. Patients' data captured from 2018 to 2020 and from 2021 were used as the training set and the validation set, respectively. Predictive factors were screened using a multivariable logistic regression model, and the nomograph model for prediction of CLNM risk was established. The predictive value of the model was evaluated using the receiver operating characteristic (ROC) curve and the adjusted curve.@* Results@#Totally 1 820 PTC cases were included in the training set, including 458 cases with CLNM (25.16%), and 797 cases in the validation set, including 207 cases with CLNM (25.98%). The prediction model is p=ey/(1+ey), y=0.761 + 0.525 × sex + (-0.039) ×age + 0.351 × extrathyroid invasion + 0.368 × neck lymph node enlargement + 1.021×maximum tumor diameter + (-0.009) × TT4 + (-0.001) × anti-TPOAb. The area under the ROC curve was 0.732 for the training set and 0.731 for the validation set, and Hosmer-Lemeshow test showed a good fitting effect (P=0.936, 0.722).@*Conclusion@# The nomograph model constructed in this study has a high predictive value for CLNM among patients with PTC.

Clinicopathologic factors and preoperative ultrasonographic characteristics for predicting central lymph node metastasis in papillary thyroid microcarcinoma: a single center retrospective study / Fatores clínico-patológicos e características ultrassonográficas pré-operatórias na previsão de metástase em linfonodos centrais no microcarcinoma papilífero da tireoide: um estudo retrospectivo de centro único

Abstract Introduction The treatment of papillary thyroid microcarcinoma remains controversial. Central lymph node metastasis is common in papillary thyroid microcarcinoma and it is an important consideration in treatment strategy selection. Objective The aim of this study was to investigate clinicopathologic risk factors and thyroid nodule sonographic characteristics for central lymph node metastasis in papillary thyroid microcarcinoma. Methods We retrospectively reviewed the data of 599 papillary thyroid microcarcinoma patients who underwent surgery from 2005 to 2017 at a single institution. Univariate and multivariate analyses were used to identify the clinicopathologic factors and preoperative sonographic features of central lymph node metastasis. A receiver-operating characteristic, ROC curve analysis, was performed to identify the efficacy of ultrasonographic features in predicting central lymph node metastasis. A nomogram based on the risk factors was established to predict central lymph node metastasis. Results The incidence of central lymph node metastasis was 22.4%. The univariate and multivariate analyses suggested that gender, age, multifocality, extrathyroidal invasion, and lateral lymph node metastasis were independent risk factors for central lymph node metastasis. The univariate and multivariate analyses revealed that nodular shape, margin, and calcification were independently associated with central lymph node metastasis. The ROC curve analysis revealed that the combination of shape, margin and calcification had excellent accuracy in predicting central lymph node metastasis. The nomogram was developed based on the identified risk factors for predicting central lymph node metastasis, and the calibration plot analysis indicated the good performance and clinical utility of the nomogram. Conclusions Central lymph node metastasis is associated with male gender, younger age (<5 years), extrathyroidal invasion, multifocality and lateral lymph node metastasis in papillary thyroid microcarcinoma patients. The ultrasongraphic features, such as irregular shape, ill-defined margin and calcification, may improve the efficacy of predicting central lymph node metastasis. Surgeons and radiologists should pay close attention to the patients who have these risk factors. The nomogram may help guide surgical decision making in papillary thyroid microcarcinoma.

Resumo Introdução O tratamento do microcarcinoma papilífero de tireoide permanece controverso. A metástase em linfonodos centrais é comum e é uma consideração importante na seleção da estratégia de tratamento. Objetivo Investigar os fatores de risco clínico-patológicos e as características ultrassonográficas de nódulos tireoidianos para metástase em linfonodos centrais em microcarcinoma papilífero de tireoide. Método Foram analisados retrospectivamente os dados de 599 pacientes com microcarcinoma papilífero de tireoide submetidos à cirurgia de 2005 a 2017 em uma única instituição. Análises univariadas e multivariadas foram usadas para identificar os fatores clínico-patológicos e as características ultrassonográficas pré-operatórias das metástases em linfonodos centrais. Uma análise de curva ROC (receiver-operating characteristic) foi feita para identificar a eficácia das características ultrassonográficas na previsão dessas metástases. Um nomograma baseado nos fatores de risco foi estabelecido para prever a metástase em linfonodos centrais. Resultados A incidência de metástase em linfonodos centrais foi de 22,4%. As análises univariadas e multivariadas sugeriram que sexo, idade, multifocalidade, invasão extratireoidiana e metástase em linfonodos laterais eram fatores de risco independentes para a metástase em linfonodos centrais. As análises univariadas e multivariadas revelaram que o formato nodular, a margem e a calcificação estavam independentemente associadas à metástase em linfonodos centrais. A análise da curva ROC mostrou que a combinação do formato, margem e calcificação apresentou excelente precisão na previsão dessas metástases. O nomograma foi desenvolvido com base nos fatores de risco identificados para predizer a metástase em linfonodos centrais e a análise do gráfico de calibração indicou o bom desempenho e a utilidade clínica do nomograma. Conclusões Em pacientes com microcarcinoma papilífero de tireoide, metástase em linfonodos centrais está associado ao sexo masculino, menor idade ( < 45 anos), invasão extratireoidiana, multifocalidade e presença de metástase em linfonodos laterais. As características ultrassonográficas, como formato irregular, margem mal definida e calcificação, podem melhorar a eficácia da previsão de metástase em linfonodos centrais. Cirurgiões e radiologistas devem ficar mais atentos aos pacientes que apresentam esses fatores de risco. O nomograma pode ajudar a orientar a tomada de decisão cirúrgica para o microcarcinoma papilífero de tireoide.

Clinical analysis of risk factors and preventive dissection of lymph node metastasis in central region of stage cN0 isthmus papillary thyroid carcinoma / 国际外科学杂志

Objective:To explore the risk factors affecting central lymph node metastasis in cN0 isthmus papillary thyroid carcinoma and the significance and feasibility of preventive dissection, so as to provide reference for clinical treatment.Methods:The clinical data of 108 patients with cN0 stage isthmus papillary thyroid cancer who underwent surgery in the General Surgery Department of Lianyungang Oriental Hospital from January 2014 to December 2021 were retrospectively analyzed. There were 32 males and 76 females, with an age range of 24 to 70 years, with a mean age of (46.0±12.7) years. Statistical analysis was performed using the SPSS 22.0 statistical software. Chi-square test and logistic regression were used to analyze the relationship between central lymph node metastasis and patients Relationship between clinical case factors.Explore the feasibility of preventive cleaning.Results:The positive rate of lymph node metastasis in central region of isthmic papillary thyroid carcinoma was 37.9% (41/108). Univariate analysis showed that central lymph node metastasis was associated with tumor diameter ( χ2=5.36, P=0.021), capsular infiltration ( χ2=7.69, P=0.006), and elevated thyroglobulin ( χ2=7.73, P=0.005). Multivariate analysis showed that capsular infiltration ( HR=2.75, P=0.037) and tumor diameter ( HR=4.454, P=0.004) were independent risk factors for central lymph node metastasis. The ROC curve of tumor diameter to predict central lymph node metastasis was drawn, and the AUC value of the area under the curve was calculated to be 0.720. When the diameter was 0.695 cm, the Youden index was 0.326, the sensitivity was 0.878, and the specificity was 0.448. 6 cases (5.56%) had temporary recurrent laryngeal nerve palsy, 13 cases (12.04%) had temporary hypoparathyroidism, no permanent complications occurred. Conclusions:cN0 stage PTCI has the risk of early occult lymph node metastasis. Prophylactic CLND can clarify the stage of the tumor, assess the risk, and guide the follow-up treatment of patients. CLND should be routinely performed for patients with tumor diameter >0.695 cm and capsular invasion.

Predictive value of lymph node size for ipsilateral central lymph node metastasis of single papillary thyroid microcarcinoma in CT examination / 中华内分泌外科杂志

Objective:To investigate the predictive value of lymph node size for ipsilateral central lymph node metastasis (ICLNM) of papillary thyroid microcarcinoma (PTMC) in CT examination.Methods:The CT data of 229 patients with single PTMC admitted to the Department of Oncology, Hangzhou First People’s Hospital, Affiliated to Zhejiang University School of Medicine from Jan. 2018 to Jun. 2019 were retrospectively analyzed. All cases were confirmed by surgery and pathology. The ipsilateral central lymph nodes were divided into <0.2 cm group, 0.2-0.4 cm group and ≥0.4 cm group according to their maximun diameters, and the distribution difference of positive and negative ICLNM among the three groups were observed and analyzed by χ 2 test. Results:In 229 PTMCs, the proportion of positive and negative ICLNM were 29.69% (68/229) and 70.31% (108/155) , respectively. Positive ICLNM in <0.2 cm group, 0.2-0.4 cm group and ≥0.4 cm group accounted for 11.43% (16/140) , 64.29% (36/56) and 81.82% (27/33) , respectively. When 0.2 cm and 0.4 cm were used as the threshold to determine positive ICLNM, the values of χ 2 and P between groups were 87.663 and <0.001. The sensitivity and specificity of diagnosing lymph node metastasis were 79.75% (63/79) and 82.67% (124/150) , 34.18% (27/79) and 96% (144/150) , respectively. The proportions of high enhancement, calcification and cystic degeneration were 3.2% (5/155) , 0.7% (1/155) and 0 (0/155) , respectively. Conclusions:In CT examination of patients with PTMC, the diameter of lymph nodes less than 0.2 cm highly indicates negative ICLNM. The proportion of positive ICLNM increased with increasing lymph node diameter, and the diameter of lymph nodes less than 0.4 cm highly indicates positive ICLNM.

Clinicopathological characteristics and risk factors of lymph node metastasis in isthmus papillary thyroid microcarcinoma / 中华内分泌外科杂志

Objective:To investigate the clinicopathological characteristics of papillary thyroid microcarcinoma in the isthmus (PTMCI) and the independent risk factors of central lymph node metastasis.Methods:58 consecutive patients with PTMCI admitted from Jan. 2016 to Dec. 2018 (isthmus group) were retrospectively analyzed, including 15 males and 43 females,age (42.93±12.69) years old; According to the specific location of papillary thyroid microcarcinoma (PTMC) in isthmus, PTMCI were subdivided into the right PTMCI and the left PT-MCI 67 patients with a single PTMC located in the unilateral lobe were randomly selected as a control (lobe group) , including 13 cases of male and 54 cases of female, age (47.18±11.34) years old. Index included the patient’s age, gender, tumor diameter, TPOAb, aspect ratio, microcalcification, capsular invasion, lymph node metastasis, surgical methods, operation method, and scope of lymph node dissection. SPSS 21.0 software was used for statistical analysis. The quantitative data of normal distribution was expressed as ± s,and the difference between the two groups was compared by chi-square test.The risk factors of CLNM of the isthmus group were analyzed with univariate chi-square test and multivariate Logistic regression analysis.The difference was statistically significant if P<0.05. Results:Compared with PTMC, PTMCI showed a higher rate of capsule invasion ( P=0.003) ,lymph node metastasis ( P=0.049) ,lymph node metastasis in central region ( P=0.033) ,and surgical methods between the two groups were statistically significant ( P<0.05) ;But PTMCI was significantly lower than PTMC in aspect ratio>1 ( P<0.05) . Univariate analysis showed that capsule invasion ( P=0.001) and microcalcification ( P=0.012) were risk factors for PTMCI lymph node metastasis. Multivariate Logistic regression analysis showed that capsule invasion ( P=0.016) and microcalcification ( P=0.046) were independent risk factors for central lymph node metastasis in PTMCI. Conclusions:Compared with PTMC,PTMCI indicates a higher rate of capsular invasion,lymph node metastasis in prelaryngeal and central lymph node;Compared with PTMC, PTMCI indicates a lower rate of aspect ratio>1; Capsule invasion and microcalcification are independent risk factors for central lymph node metastasis in PTMCI. For patients with the right PTMCI or the left PTMCI and also without capsular invasion and calcification,ipsilateral central lymph node dissection should be considered.

Radiomics for prediction of central lymph node metastasis in the neck in patients with thyroid papillary carcinoma / 南方医科大学学报

OBJECTIVE@#To explore the feasibility of radiomics for predicting lymph node metastasis in the central region of the neck in patients with thyroid papillary carcinoma (PTC).@*METHODS@#A total of 189 patients with PTC confirmed by thyroid fine needle aspiration biopsy were prospectively enrolled in this study. The cross-sectional and longitudinal ultrasound images and the images of both sections were analyzed for predicting central lymph node metastasis using a radiomics approach with pathological results as the gold standard.@*RESULTS@#In the 189 patients, the accuracy, sensitivity and specificity of preoperative thyroid ultrasonography for diagnosis of central lymph node metastasis was 69.39%, 64% and 73%, respectively. Based on the ultrasound images of the cross-sections, longitudinal sections and both sections, the accuracy, sensitivity and specificity of radiomics for predicting central lymph node metastasis was 66.06%/68.12%/77.69%, 53%/46%/40%, and 52%/53%/51%, respectively.@*CONCLUSIONS@#Radiomics with combined analysis of the ultrasound images on the cross-section and longitudinal section images achieves a higher accuracy for predicting central lymph node metastasis than analysis a single section, and its diagnostic accuracy is much higher than that of conventional ultrasound examination.

The value of preoperative clinical and sonographic characteristics of clinically node‐negative papillary thyroid carcinomain predicting central lymph node metastasis / 中华超声影像学杂志

To investigate the association of preoperative clinical and sonographic characteristics of clinically node‐negative ( cN0) papillary thyroid carcinoma ( PTC) with central lymph node metastasis ( CLNM ) . Methods A total of 514 patients with PTC confirmed by pathology in our hospital were included in the retrospective analysis . Clinical and sonographic characteristics were assessed including age ,gender ,tumor size ,and the distance between the tumor and the capsule . These cases were all diagnosed as cN0 according to clinical and sonography examinations . And the cases were divided into CLNM ( + ) group and CLNM ( －) group based on the pathological results . T hen statistical analysis was used to evaluate the correlation between CLNM and risk factors of cN 0 PTCs . Results ① Of the 514 cN0 PTC cases ,211 cases ( 41 .1% ) were CLNM ( + ) and 303 cases ( 58 .9% ) were CLNM ( －) . ② With the presence of capsule invasion in the ultrasound examination ,the probability of CLNM ( + ) group was higher than that of CLNM ( －) group ( 62 .1% vs 37 .9% ) . ③ In the 364 cases without capsule invasion ,the probability of CLNM ( + ) was significantly increased when the distance between the tumor and the capsule was ＜ 1 .5 mm ( 88 .8% vs 11 .2% ) . ④ M ultivariate analysis showed that risk factors independently associated with CLNM included age ＜45 years old ,tumor maximum diameter ≥10 mm ,and the distance between the tumor and the capsule ＜ 1 .5 mm ,among w hich the distance between the tumor and the capsule ＜1 .5 mm had the highest OR value . Conclusions In cN0 PTC patients ,CLNM is associated with age ,size and the distance between the tumor and the capsule .

Analysis of risk factors for central compartment lymph node metastasis of papillary thyroid microcarcinoma / 中国现代普通外科进展

Objective:To analysis the risk factors for central compartment lymph node metastasis in patients with papillary thyroid microcarcinoma.Methods:The clinical data of 200 patients with PTMC were retrospectively analyzed,and the risk factors for central compartment lymph node metastasis were ananlyzed also.Results:200 patients with PTMC includes 70 cases for central lymph node metastasis with metastasis rate as 35％.Univariate logistic regression analysis showed that tumor size,clinical stage,with or without membrane invasionwere risk factorsfor central lymph node metastasis of papillary thyroid microcarcinoma(P＜0.05).Multivariate logistic regression analysis showed that tumor size,clinical stage,with or without membrane invasion were independent risk factors forcentral lymph node metastasis of papillary thyroid microcarcinoma (P＜0.05).Conclusion:Tumor size,clinical stage,with or without membrane invasion were independent risk factors for central lymph node metastasis of papillary thyroid microcarcinoma,and the central lymph node clearance could prolong the survival time of patients and improve the clinical prognosis when necessary.

The Correlation between the Location of Thyroid Papillary Microcarcinoma and Cervical Lymph Node Metastasis / 昆明医科大学学报

Objective To investigate the relationship between the location of thyroid papillary microcarcinoma and cervical lymph node metastasis. Methods The clinical data of 334 cases of thyroid papillary microcarcinoma were retrospectively analyzed. The location of the lesion, the size of the lesion, the situation of the capsule and other factors were compared in patients with central lymph nodes or/and cervical lymph node metastasis. Results The lymph node metastasis rate were 33.33% (26/104),39.81% (43/108),and 52.46% (64/122), when the papillary thyroid microcarcinoma was located at the upper pole, median pole,and lower pole respectively (P＜0.005) . There were 46 cases (46/334, 13.77%) with cervical lymph node metastasis. The metastasis rate of cervical lymph node were 21.15% (22/104), 11.11% (12/108),and 9.83% (12/122), when the papillary thyroid microcarcinoma was located at the upper pole, median pole,and lower pole respectively (P=0.003) . 3 patients (6.5%) had no central lymph node metastasis and direct skipping of the cervical lymph nod trensfer. The rate of tumor break through through the membrane in patients with cervical lymph node metastases was 30.43% (14/46), which was higher than the 19.09% (55/288) of patients without lymph node metastasis (P＜0.005).Conclusions There is a certain correlation between the location of papillary thyroid microcarcinoma and cervical lymph node metastasis.

Risk factors analyses for lateral lymph node metastases in papillary thyroid carcinomas: a retrospective study of 356 patients

ABSTRACT Objective The aim of this study was to investigate the incidence and risk factors for lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC). Subjects and methods 356 patients diagnosed with PTC who underwent total thyroidectomy and central lymph node dissection and lateral lymph node dissection between January 2005 and December 2011 were enrolled. The relation between LLNM and clinicopathological features such as gender, age, tumor size, tumor spread, psammoma bodies, tumor multifocality, extrathyroidal extension (ETE), unilateral or bilateral disease, tumor primary location and central lymph node metastases (CLNM) was analyzed. Results The rate of LLNM was 75.0%. In the univariate analysis, it was significantly associated with age, tumor size, tumor spread, extrathyroidal extension, primary tumor location and central lymph node metastasis (p < 0.05). In contrast, in the multivariate analysis, it was significantly associated with primary tumor location, central lymph node metastasis (p < 0.05) and tumor size > 1.5 cm with p = 0.05 but was unrelated to the other factors. Conclusion Patients with PTC, with the primary tumor located in the upper part of the lobe and positive central compartment lymph node metastasis with a tumor size > 1.5 cm diameter are more likely to have LLNM. Therefore, more meticulous evaluations including the lateral lymph nodes should be performed before surgery.

Patterns and predictive factors of central lymph node metastasis in cN0 papillary thyroid carcinoma / 第二军医大学学报

Objective To evaluate the patterns and predictive factors of ipsilateral and contralateral central lymph node metastasis (CLNM) in the unilateral papillary thyroid carcinoma (PTC) patients with clinically node-negative neck (cN0). Methods We retrospectively reviewed the clinicopathological characteristics of 46 patients with cN0 unilateral PTC, including gender, age, multiplicity, tumor size, extrathyroidal extension, Hashimoto thyroiditis (HT), and T stage. Chi-square test and logistic regression were used to evaluate the patterns and predictive factors of ipsilateral and contralateral CLNM in cN0 unilateral PTC patients. Results Ipsilateral CLNM and contralateral CLNM were present in 32.6%(15/46) and 21.7% (10/46) of the patients, respectively. In patients with contralateral CLNM, 70.0% (7/10) had isolated contralateral CLNM without ipsilateral CLNM. Twenty patients of the 41 (48.8%) with T1/T2 stage had CLNM. Univariate analysis showed that tumor size >1 cm, age 1 cm (OR=4.890,P=0.044) was the independent predictor of ipsilateral CLNM, and HT (OR=0.086, P=0.034) was a protective factor of ipsilateral CLNM. Multifocal cancer was an independent predictor of contralateral CLNM (OR=7.60, P=0.038). Compared with isolated ipsilateral CLNM, contralateral CLNM occured more often in patients with HT (P1 cm, while contralateral PCND may be more valuable for patients with multifocal cancer or HT.

Diagnosis and treatment of papillary thyroid micro-carcinoma：An analysis of 61 cases / 中国癌症杂志

Background and purpose:During recent years, the incidence of papillary thyroid micro-carcinoma (PTMC) has increased year by year. There are many differences in its diagnosis and treatment. This research investigated and summarized the clinical diagnosis and treatment of thyroid papillary carcinoma by means of analyzing the patients’ data.Methods:Sixty-one cases underwent high resolution ultrasound examination before operation, and the accuracy rate was 86.9%. All patients underwent surgical treatment. Thirty-nine patients had thyroid lobectomy and ipsilateral central lymph node dissection (CLND), 11 underwent concurrent partial thyroidectomy, 22 had total thyroidectomy and bilateral central lymph node dissection and 5 underwent concurrent cervical lymph node dissection. The incidences of central and cervical lymph node metastasis were 44.3% and 8.2%, respectively. Univariate analysis showed that the risk factors for central lymph node metastasis were age <45 years, multifocality, tumor location near or across the midline, tumor diameter≥5 mm. The rates of central lymph node metastasis were 66.7%, 60.7%, 66.7% and 53.8, respectively.Conclusion:High resolution ultrasound examination has a high sensitivity for the detection of PTMC. It is important to implement standardized and individualized treatment plan to the patients with PTMC.

Central lymph node metastasis of cN0 papillary thyroid microcarcinoma: risk factors and operation methods / 中华内分泌外科杂志

Objective To study the relationship between clinicopathological features and central lymph nodes metastasis in patients with papillary thyroid microcarcinoma(PTMC).Methods From Jan.2013 to Jun.2013,400 cases with PTMC in cN0 stage undergoing thyroidectomy and central neck dissection were collected.Results Univariate analysis showed that the rate of central lymph node metastasis in PTMC was 28.0％,nevertheless,the rate of central lymph node metastasis was 32.5％,42.6％,44.1％,33.3％,and 37.4％ respectively in patients aging below 45 years old,in male patients,in patients with extrathyroidal extension,in patients with tumor diameter larger than 5 mm and in patients with multifocality.Gender,age,extrathyroidal extension,tumor diameter,multifocality of patients had correlation with central lymph node metastasis.Multivariate binary logistic regression analysis revealed that the rate of lymph node metastasis significantly increased in cases of male,ageing below 45 years old,with extrathyroidal extension and multifocality(P ＜ 0.05).Conclusions The treatment for central lymph node metastasis of PTMC should be different considering elements including gender,age,multifocality of the tumor,and extrathyroidal extension.Prophylactic central lymphadenectomy should be performed when the primary lesion was resected.

Incidence and Predictive Factors of Central Neck Node Metastasis in Patients with T1, T2 Papillary Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Thyroidectomy without prophylactic central neck dissection may be recommended for small (T1 or T2) papillary thyroid carcinoma (PTC). The aim of this study was to determine the incidence and predictive factors of central cervical lymph node metastasis in T1/2 papillary thyroid carcinoma. METHODS: A retrospective review of 877 patients with T1/2 PTC who underwent thyroidectomy and central lymph node dissection with or without lateral lymph node dissection from March 2007 to February 2014 was performed. The clinicopathologic results were reviewed and the incidence and predictive factors of central cervical lymph node metastasis (LNM) were analyzed. RESULTS: The overall frequency of central LNM was 29.8%. In univariate analysis, male, younger age, bilaterality, multifocality, larger tumor size, lymphovascular invasion, and lateral lymph node metastasis were associated with central LNM. In multivariate analysis, younger age, larger tumor size, lymphovascular invasion, and lateral lymph node metastasis were independent variables of central LNM. CONCLUSION: Central LNM is associated with younger age, larger tumor, lymphovascular invasion, and lateral lymph node metastasis in small (T1/2) PTC patients. Prophylactic central lymph node dissection should be considered in patients with risk factors.

Impact of Clinicopathologic Factors on Subclinical Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

PURPOSE: We evaluated whether the clinicopathological factors of papillary thyroid microcarcinoma (PTMC), especially tumoe size, are associated with subcinical central lymph node metastasis. MATERIALS AND METHODS: A total of 160 patients diagnosed with PTMC who underwent total thyroidectomy with bilateral central lymph node dissection were enrolled in this study. All patients were clinically lymph node negative PTMC. Patients were divided into 2 groups according to the size of tumor (5 mm). Clinicopathologic risk factors for subclinical central lymph node metastasis were analyzed. RESULTS: Subclinical central lymph node metastasis was detected in 61 (38.1%). Patients with tumors 5 mm were independent predictors of subclinical central lymph node metastasis; age, multifocality, bilaterality, extrathyroidal extension, lymphvascular invasion and lymphocytic thyroiditis were not. CONCLUSION: In this study, male and tumor size >5 mm were two independent predictive factors for subclinical central lymph node metastasis in PTMC. These are easier factors to assess before surgery than other factors when planning the central lymph node dissection. However, further long-term follow-up studies are needed to confirm the prognostic significance of subclinical central lymph node metastasis in PTMC.

Risk Factors of Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

PURPOSE: Despite the overall excellent prognosis for patients with papillary thyroid microcarcinoma (PTMC), these tumors are also associated with a 5% relatively high lymph node (LN) recurrence rate and the optimal surgical extent of papillary thyroid microcarcinoma has been controversial. Cervical LN metastases (LNMs) are found in about 40~65% of patients with PTMC. The aim of this study is to identify the factors affecting lymph node metastases (LNMs) in patients with PTMC. METHODS: We performed a retrospective study of 335 patients with PTMC who underwent total thyroidectomy or lobectomy with elective central lymph node dissection (CLND) at Kangnam St. Mary's Hospital between Jan. 2006 and Dec. 2008. We investigated the association of LNMs and clinicopathologic factors such as sex, age, multiplicity, extrathyroidal extension, and tumor size. RESULTS: LNMs were present in 88 patients (26.3%). Univariate analysis showed that less than 45 years of age, male, multiplicity, a tumor size of greater than 5 mm, thyroid capsular invasion and extrathyroidal extension were predictive factors for LNMs (P5 mm), male, age (<45) and extrathyroidal extension were determined as the predictive factors for LNMs, which occurred in about one fourth of the patients with PTMC. Therefore, elective CLND should be considered in patients with PTMC who have these factors through a thorough investigation before surgery.