Risk factors of lymph node metastasis in T1 esophageal squamous cell carcinoma

Background and Aim: To perform endoscopic mucosal resection (EMR) for T1 esophageal cancer, it is essential to estimate the lymph node status exactly. In order to evaluate the feasibility of EMR for esophageal cancers, we evaluated the clinicopathological features of T1 esophageal squamous carcinomas with an emphasis on the risk factors and distribution patterns of lymph node metastasis. Methods: From 1994 to 2006, a total of 200 patients with T1 esophageal carcinoma were treated surgically in our institution. Among them, clinicopathological features were evaluated for 197 consecutive patients with T1 squamous cell carcinoma. Results: The frequency of lymph node involvement was 6.25% (4/64) in mucosal cancers and 29.3% (39/133) in submucosal cancers (P < 0.001). In patients with M1 (n = 32) and M2 (n = 14) cancers, no lymph node metastasis was found. In multivariate analysis, size larger than 20 mm, endoscopically non‐flat type, and endo‐lymphatic invasion were significant independent risk factors for lymph node metastasis. The differentiation of tumor cell was not a risk factor for lymph node metastasis. Conclusions: We suggest that EMR may be attempted for flat superficial squamous esophageal cancers smaller than 20 mm. After EMR, careful histological examination is mandatory.     

Clinicopathologic factors predicting lymph node metastasis in superficial esophageal squamous cell carcinoma

Abstract

Objective. Surgical resection is the treatment of choice for superficial esophageal squamous cell carcinoma (SESCC), but it is associated with high mortality and morbidity rates. Recently, endoscopic resection for SESCC has been indicated for patients with a low risk of lymph node metastasis (LNM). Therefore, to successfully treat SESCC with endoscopic resection, it is very important to identify patients with a low risk for LNM. The objective of this study was to investigate clinicopathologic factors that predict LNM in patients who underwent esophagectomy for SESCC. Methods. The study included 104 patients with SESCC from three university hospitals in Pusan, Korea. Clinicopathologic factors were evaluated to identify independent factors predicting LNM by univariate and multivariate analyses. Results. In univariate analysis, the depth of tumor invasion and lymphovascular invasion had significant influences on LNM (p = 0.001 and p < 0.001, respectively). Gross type, tumor size, and tumor differentiation were not predictive for LNM. In multivariate analysis, the depth of tumor invasion and lymphovascular invasion were signi?cantly associated with LNM in patients with SESCC (OR 9.04, p = 0.049; OR 11.61, p = 0.002, respectively). Conclusions. The depth of tumor invasion and lymphovascular invasion were independent predictors of LNM in patients with SESCC. Therefore, endoscopic resection could be performed in patients with SESCC that is limited to the mucosa, without lymphovascular invasion.     

Neoadjuvant chemoradiotherapy followed by esophagectomy does not increase morbidity in patients over 70

Esophagectomy in elderly esophageal carcinoma patients is correlated with a high morbidity and even mortality. Studies on neoadjuvant chemoradiotherapy (NT) in elderly patients are scarce. The aim of this study was to evaluate the effect of advanced age in combination with NT in esophageal carcinoma patients who underwent an esophagectomy. Patients who underwent NT prior to esophagectomy between 1993 and 2010 were divided into three groups: <70, 70–74, and ≥75 years. Toxicity of NT and postoperative morbidity were compared between groups. Primary endpoints were toxicity, complication rate, and survival. Two hundred thirteen patients underwent NT during the study period, 26 were aged 70–74 years, and 17 were ≥70 years. Toxicity of NT was comparable for younger and elderly patients (46% vs. 54% vs. 47%, P = 0.263). Overall complications occurred in 62% of younger patients versus 73% and 71% among patients aged 70–74 years and ≥75 years, respectively (P = 0.836). Cardiac complications occurred in 14% of younger patients versus 27% and 41% of elderly patients (P = 0.021). Three‐year survival rates were 59% versus 44% versus 31% among patients aged <70, 70–74, and ≥75 years, respectively (P = 0.237). Higher age (odds ratio 1.750, P < 0.001) was an independent risk factor for development of cardiac complications. Toxicity of NT and postoperative complications are comparable for patients aged <70, 70–74, and ≥75 years, with the exception of cardiac complications. Therefore, we consider NT followed by esophagectomy in elderly patients a safe treatment modality in our center.     

胸段食管鳞癌淋巴结转移规律及淋巴结清扫方式探讨

目的探讨胸段食管鳞癌淋巴结转移规律及术中淋巴结清扫方式。方法 480例行根治术的胸段食管鳞癌患者,标记各部位清扫淋巴结分别送检,进行临床病理资料分析。结果本组386例患者有淋巴结转移。全组清扫淋巴结5 424枚,平均每例清扫11.3枚,689枚淋巴结有转移。22例患者出现跳跃性淋巴结转移,其中胸上段3例、中段9例、下段1例。胸上段食管鳞癌颈部淋巴结转移率47.6%,高于胸中段（10.5%）和胸下段（1.3%）,P均〈0.05。胸下段食管鳞癌向腹腔淋巴结转移率为33.1%,高于胸中段（19.4%）和胸上段（3.8%）,P均〈0.05。胸中段食管鳞癌有上纵隔淋巴结（23.5%）及下纵隔淋巴结（29%）和腹腔淋巴结（19.4%）的双向转移趋势,隆突下淋巴结转移多见,转移率54.2%。结论 胸上段食管癌淋巴结转移以颈段食管旁、锁骨上、上中纵隔转移多见,胸中段食管癌淋巴结转移具有明显的上下双向转移和跳跃性转移特点,胸下段食管癌淋巴结转移以腹部、中下纵隔转移多见。胸上段食管癌行颈、胸、腹三野淋巴结清扫,重点清扫颈段食管旁及锁骨上、下界包括隆突下淋巴结;胸下段食管癌可行胸、腹两野淋巴结清扫,重点清扫隆突下、下胸段食管旁、胃左动脉旁淋巴结;胸中段食管癌淋巴结清扫方式应根据具体情况设定。     

Predictive value of preoperative serum squamous cell carcinoma antigen level for lymph node metastasis in early-stage cervical squamous cell carcinoma

To explore the predictive value of preoperative serum squamous cell carcinoma antigen (SCC-Ag) level for lymph node metastasis (LNM), particularly, in patients surgically treated for early-stage cervical squamous cell carcinoma.We enrolled 162 patients with cervical squamous cell carcinoma stages IB to IIA following the International Federation of Gynecology and Obstetrics (FIGO) 2009 classification. The patients had previously undergone radical surgery. Correlation of the SCC-Ag level with clinicopathological features and the predictive value of SCC-Ag for LNM were analyzed.High preoperative SCC-Ag level was correlated with FIGO stage (P = .001), tumor diameter >4 cm (P < .001), stromal infiltration (P < .001), LNM (P < .001) and lymphovascular space invasion (LVSI), (P = .045). However, it was not correlated with age, histological differentiation, parametrial involvement, and positive vaginal margin (P > .05). Univariate analysis revealed that FIGO stage (P = .015), tumor diameter (P = .044), stromal infiltration (χ² = 10.436, P = .005), SCC-Ag ≧ 2.75 ng/mL (χ² = 14.339, P < .001), LVSI (χ² = 12.866, P < .001), parametrial involvement (χ² = 13.784, P < .001) were correlated with LNM, but not with age, histological differentiation, and positive vaginal margin. Moreover, multivariate analysis demonstrated that SCC-Ag ≧2.75 ng/mL (P = .011, OR = 3.287) and LVSI (P = .009, OR = 7.559) were independent factors affecting LNM. The area under the receiver operator characteristic curve of SCC-Ag was 0.703 (P < .001), while 2.75 ng/mL was the best cutoff value for predicting LNM. The sensitivity and specificity of diagnosis were 69.4% and 65.9%, respectively.High SCC-Ag level was revealed to be an independent risk factor for the prognosis of squamous carcinoma of the cervix before an operation. Besides, SCC-Ag (2.75 ng/mL) can be utilized as a potential marker to predict LNM in early stage cervical cancer before an operation.     

Study of abnormal chromosome regions in esophageal squamous cell carcinoma by comparative genomic hybridization: relationship of lymph node metastasis and distant metastasis to selected abnormal regions

Squamous cell carcinoma of the esophagus (ESCC) has a poor prognosis among digestive tract cancers. Lymph node metastasis and distant metastasis are the major factors determining its prognosis. We used comparative genomic hybridization (CGH) to evaluate primary tumor lymph nodes and metastatic areas from ESCC patients in order to determine the relationship between abnormal chromosome regions and outcome. Tumor tissues and lymph nodes were collected from 51 patients with ESCC, and abnormal chromosome regions were detected by CGH. We searched for regions that were significantly more common in patients with lymph nodes metastases (n≥ 6) or distant metastases, and correlated those chromosomal changes with survival. Regions showing amplification in more than 65% of esophageal squamous cell cancers were as follows: 17q12 (90.2%), 17q21 (86.3%), 3q29 (82.4%), 3q28 (78.4%), 8q24.2 (76.5%), 22q12 (76.5%), 3q27 (74.5%), 8q24.3 (74.5%), 1q22 (70.6%), 5p15.3 (70.6%), 22q13 (70.6%), 3q26.3, 8q23, 8q24.1, 9q34, 11q13, 17p12, 17q25, 20q12, 20q13.1 (68.6%), 1q32, 1q42, and 20q13.2 (66.7%). Regions showing deletion in more than 50% of the tumors were as follows: Yp11.3 (62.7%), 3p26 (56.9%), Yq12 (54.9%), 13q21 (52.9%), 4q32 (51.0%), and 13q22 (51.0%). When Fisher's test was used to assess associations of these regions with metastases to lymph nodes, amplification at 2q12–14 (P= 0.012), 3q24–26 (P= 0.005), and 7q21–31 (P= 0.026) were significant. Survival was worse for patients with amplification at all 3 regions. In patients with distant organ metastases, amplification at 7p13–21 was significant (P= 0.008), and survival was worse. Chromosomal amplifications in ESCC at 2q12–14, 3q24–26, and 7q21–31 were associated with lymph node metastasis, while amplification at 7p13–21 was related to distant metastasis. Amplification at these regions correlated with worse survival. Genes involved in the phenotype of ESCC may exist in these regions. Identification of these genes is a theme for future investigation.     

Tumor cell dissociation score highly correlates with lymph node metastasis in superficial esophageal carcinoma

BACKGROUND: It is still not clear which parameters are important for predicting the metastatic potential of superficial esophageal squamous cell carcinoma (SESCC). The purpose of the present paper was thus to investigate tumor cell dissociation (TCD) in SESCC as a predictive factor of lymph node metastasis. METHODS: Thirty-three SESCC were classified into four groups based on the depth of tumor invasion. Carcinomas not invading as far as the muscularis mucosa were classified as group A; carcinomas invading to the muscularis mucosa or less than one-third of the upper submucosa were classified as group B; those invading to the middle layer of the submucosa were classified as group C; and those invading one-third of the lower submucosa were classified as group D. The TCD score was calculated by dividing the length of the TCD region by the maximal longitudinal length of the area of invasion into or beyond the lamina propria, and multiplying by 100. E-cadherin expression of the carcinomas was investigated in the TCD area and the successive area of mucosal invasive carcinoma (SAM). RESULTS: The incidence of lymph node metastasis was 0% in group A, 10% in group B, 36.4% in group C and 57.1% in group D. The mean TCD scores (+/-SEM) of SESCC with lymph node metastasis were higher than that without (85.3 +/- 5.7, 16.3 +/- 3.9, respectively; P < 0.001). In group C, the TCD score of cases with lymph node metastases was higher than in those without lymph node metastasis (P < 0.001). E-cadherin expression was significantly reduced in the area of TCD compared with the SAM located over the TCD area (P < 0.001). CONCLUSIONS: The TCD score is an important predictive marker for lymph node metastasis in SESCC. Clinical evaluation of TCD scores in endoscopic mucosal resection (EMR) specimens would enable accurate prediction of lymph node metastasis and extend the indication of EMR treatment for SESCC.     

Development and validation of a nomogram for preoperative prediction of lymph node metastasis in pathological T1 esophageal squamous cell carcinoma

Endoscopic resection is increasingly used to treat patients with pathological T1 (pT1) esophageal squamous cell carcinoma (ESCC) because of its small surgical trauma. However, reports of the risk factors for lymph node metastasis (LNM) have been controversial. Therefore, we aim to build a nomogram to individually predict the risk of LNM in pT1 ESCC patients, to make an optimal balance between surgical trauma and surgical income.One hundred seventy patients with pT1 esophageal cancer in our hospital were analyzed retrospectively. Logistic proportional hazards models were conducted to find out the risk factor associated with LNM independently, and those were imported into R library “RMS” for analysis. A nomogram is generated based on the contribution weights of variables. Finally, decision analysis and clinical impact curve were used to determine the optimal decision point.Twenty-five (14.7%) of the 170 patients with pT1 ESCC exhibited LNM. Multivariable logistic regression analysis showed that smoking, carcinoembryonic antigen, vascular tumor thromboembolus, and tumor differentiation degree were independent risk factors for LNM. The nomogram had relatively high accuracy (C index of 0.869, 95% confidence interval: 0.794–0.914, P < .0001). The decision curve analysis provided the most significant clinical benefit for the entire included population, with scores falling just above the total score of 85 in the nomogram.Smoking, carcinoembryonic antigen, vascular tumor thromboembolus, and tumor differentiation degree may predict the risk of LNM in tumor 1 ESCC. The risk of LNM can be predicted by the nomogram.     

食管鳞癌患者根治性手术后早期死亡的危险因素分析

[目的]分析导致食管鳞癌患者手术后早期死亡的危险因素。[方法]回顾性分析确诊为食管鳞癌并行根治性手术切除的249例患者的临床资料,随访5年。采用χ2或Fisher精确概率法、t检验等分析所有可能导致患者在术后1年内死亡的因素。单因素及多因素Cox回归模型分析确定影响患者早期死亡最主要的危险因素,使用Kaplan-Meier法中的log-rank法对患者生存率进行统计学分析。[结果]249例中39例在术后1年内死亡(早期死亡组),其肿瘤的长度、浸润深度、淋巴结转移、TNM分期、淋巴结转移区域等与非早期死亡组相比差异有统计学意义(χ2=12.688、12.042、16.202、6.685、15.654,均P0.05)。行多因素分析发现发现肿瘤的长度≥4cm及淋巴结转移区域≥2个时是导致患者早期死亡最主要的危险因素(OR=2.305、4.370,95%CI:1.090~4.876、1.510~12.653,均P0.05)。根据这2个主要危险因素进行生存率分析,发现有0个、1个、2个危险因素的患者的1年生存率分别为90.5%、78.2%、46.1%。Log-rank统计学方法分析显示0个、1个、2个危险因素之间差异具有统计学意义(χ2=9.377、29.019、5.981,均P0.05)。[结论]导致食管鳞癌患者早期死亡的最主要因素是肿瘤长度及淋巴结转移,因此对于存在肿瘤的长度≥4cm及淋巴结转移区域≥2个危险因素的患者,术后有必要进行其他干预治疗如辅助放化疗等,以尽可能延长患者的生存时间。     

Effects of neoadjuvant chemotherapy on primary tumor and lymph node metastasis in esophageal squamous cell carcinoma: additive association with prognosis

SUMMARY.  Neoadjuvant chemotherapy (NACT) is widely used to treat esophageal squamous cell carcinoma with lymph node metastasis (ESCC). However, NACT frequently has differential effects on primary tumor (PT) and lymph node metastasis (LNM). The clinical significance of this phenomenon remains unclear. Reduction in tumor size of PT and LNM was evaluated separately in 47 node-positive ESCC patients undergoing NACT, followed by surgical resection. We analyzed the prognostic significance and various clinicopathological parameters. NACT resulted in an average reduction rate of 45.5% for PT and 36.6% for LNM; the correlation between these rates was weak but significant ( r ² = 0.122, P  = 0.016). The reduction rates in both PT and LNM were significant prognostic factors, with the maximal significance with cut-off at 30% size reduction for PT (3-year survival, 47.3 vs. 8.3%, P  = 0.0004) and 20% for LNM (51.3 vs . 7.1%, P  = 0.0013). When these cut-off values were used to define NACT response, 28 patients (59%) were deemed responders for both PT and LNM, while 7 (15%) were nonresponders for both, and the response was inconsistent in 12 patients (26%). Only both PT/LNM responders showed good survival rates, with the remaining categories showing poor survival (3-year survival 60.5 vs . 5.3% P  < 0.0001). Multivariate analysis identified neither the PT nor the LNM response alone as an independent prognostic factor; however the combined PT/LNM response was identified as an independent prognostic factor (hazard ratio [HR] 2.861, P  = 0.0255) in addition to the number of histological lymph node metastases (HR 2.551, P  = 0.0328). The response to NACT in LNM and PT correlates closely with postoperative survival. A good response in both enhances the postoperative prognosis.     

Salvage lymphadenectomy for cervical lymph node recurrence after esophagectomy for squamous cell carcinoma of the thoracic esophagus

Prognosis of patients with recurrent esophageal cancer is usually unsatisfactory. We have successfully treated five patients with cervical node recurrence after esophagectomy with multimodal treatment including salvage lymphadenectomy. In order to clarify the efficacy of salvage surgery for cervical node recurrence, we have reviewed the clinical course and prognosis of these patients. From August 2004 to December 2007, 30 patients with 33 recurrent sites were treated in the Department of Surgery, Iizuka Hospital. Among these patients, there were five patients with recurrence limited within the cervical nodes. Salvage cervical lymphadenectomy was performed for all five patients. Curative resection was achieved in four patients and reduction surgery followed by planned chemoradiotherapy was performed in another patient. All stations including the suspicious node were dissected and a partial sternotomy was added for one patient whose recurrent tumor was located in the right recurrent nerve node. There was no mortality and one minor complication (subcutaneous hemorrhage) was observed. Median duration of hospital stay was 7 days. Adjuvant chemotherapy was performed for all patients. Median follow‐up period was 54 months and all patients are alive without relapse of the disease. Salvage cervical lymphadenectomy is a safe and effective treatment for patients with cervical node recurrence after esophagectomy.     

Preoperative chemotherapy for clinically node-positive patients with squamous cell carcinoma of the esophagus

Lymph node metastasis is one of the strongest prognostic factors for patients with esophageal cancer. Whether neoadjuvant chemotherapy is effective for metastatic nodes and improves the prognosis of clinically node-positive patients is unknown. Seventy-seven patients with clinically node-positive esophageal cancer, who were given preoperative chemotherapy (5-fluorouracil, cisplatin and adriamycin) followed by surgery, were retrospectively analysed. The histological effectiveness of the chemotherapy against the main tumor in the resected specimen was correlated with nodal status and prognosis. Of the 77 patients, the histological effects in the main tumors were grade 3 in one patient (1.3%), grade 2 in 10 (13.0%), grade 1b in seven (9.1%), grade 1a in 50 (64.9%) and grade 0 in nine (11.7%). Eleven patients (14.3%) were found to be pathologically node-negative. The pathological stages were significantly earlier in responders (grades 3-1b) than in non-responders (grades 1a-0) (P = 0.0001). The responders showed a significantly lesser degree of lymph node metastasis (P = 0.0005), fewer metastatic nodes (2.2 +/- 3.1 vs. 12.0 +/- 20.5, P = 0.0482) and better survival (P = 0.002) than the non-responders. The most common failure pattern for the non-responders was lymphatic recurrence, with an incidence of 47.5% (28/59), while that for the responders was 16.7%. Responders to neoadjuvant chemotherapy show fewer metastatic nodes and better prognosis than non-responders. Neoadjuvant chemotherapy may offer clinical benefit to responders.     

Two-step three-field lymph node dissection is beneficial for thoracic esophageal carcinoma

Aggressive surgery including extensive lymph node dissection is considered necessary to improve the long-term survival of patients with esophageal carcinoma. While three-field lymph node dissection is widely performed for patients with thoracic esophageal carcinoma, cervical lymph node metastasis is uncommon. In order to reduce surgical stress, we have developed a two-step three-field lymph node dissection procedure for thoracic esophageal carcinoma. In the first-step operation, total thoracic esophagectomy through a right thoracotomy is performed. Mediastinal and abdominal lymph node dissection is performed synchronously. When recurrent nerve lymph node metastasis is pathologically positive, cervical lymph node dissection is performed about 3 weeks after the first operation (second step). Of 343 patients with carcinoma of the esophagus surgically treated in our department between 1990 and 2001, 146 underwent the operation described above. Three-field dissection was performed in 68 patients (group A), while two-field dissection was performed in 78 patients (group B). In the 68 group A patients, cervical lymph node metastasis was positive in 15 patients (22%). There was no marked difference in the onset of major complications between the two groups. The 5-year survival rate was 58% for group A and 61% for group B, not a statistically significant difference. In 78 of the 146 patients, it was possible to avoid cervical lymph node dissection without negatively affecting therapeutic outcomes. Two-step three-field lymph node dissection can reduce surgical stress of patients with good clinical outcome.     

112例非小细胞肺癌淋巴结转移规律分析

目的分析112例非小细胞肺癌淋巴结的转移规律。方法对112例肺癌患者施行手术切除并行广泛肺门、叶间及纵隔淋巴结清扫术。术后病理资料进行统计分析。结果在共清除898组淋巴结中,单纯N1淋巴结转移率为24.1%,N2(包括N1+N2)淋巴结转移率30.4%。原发肺癌(T)分期T1、T2、T3间淋巴结转移率差异有统计学意义(P0.01)。跳跃式转移占N2转移的35.3%。结论非小细胞肺癌的淋巴结转移与T分期有关,具有较多的跳跃性纵隔淋巴结转移发生,肿瘤部位及肺癌的病理学类型与淋巴结的转移无明显关系。外科治疗中应注意广泛清扫肺内、同侧纵隔淋巴结才有可能达到根治目的。     

A case of primary gastric small cell carcinoma with a rare pattern of lymph node metastasis

We report a very rare case of primary gastric small cell carcinoma (GSCC) that was accompanied with gastric tubular adenocarcinoma. A male in his 60s had an elevated tumor with a central ulceration in the middle stomach. The patient underwent a distal gastrectomy with lymph node dissection. The pathological examination showed two separated lesions of the stomach, which contained the components of primary GSCC and primary gastric tubular adenocarcinoma. Immunohistochemical (IHC) examination demonstrated that the tumor cells in the small cell carcinoma stained positive for synaptophysin, chromogranin A, and neural cell adhesion molecule (NCAM). GSCC cells and adenocarcinoma cells independently metastasized to each regional lymph node. Further studies on the biological behavior of individual tumors may allow the development of new treatment strategies for GSCC.     

Independent histological risk factors for lymph node metastasis of superficial esophageal squamous cell carcinoma; implication of claudin‐5 immunohistochemistry for expanding the indications of endoscopic resection

Endoscopic resection is curative for superficial esophageal squamous cell carcinoma (ESCC) limited to the lamina propria. Endoscopic resection is not recommended for superficial ESCC invading muscularis mucosa or submucosa, however, because of the high frequency of lymph node metastasis (LNM) in such patients. Methods to more accurately predict LNM by analysis of endoscopically resected specimens are needed. Patients with superficial ESCC who underwent surgery without prior chemoradiotherapy (n= 110) were retrospectively examined to determine whether LNM correlated with immunohistochemical parameters and conventional histological parameters, including depth of invasion and vascular permeation. Cancer cell expression of claudins‐1, 5, and 7, E‐cadherin, β‐catenin, and matrix metalloproteinase 7 was evaluated. Univariate analysis revealed that LNM correlated with claudin‐5 expression, but not any other immunohistochemical parameter examined. Multivariate analysis revealed three independent risk factors for LNM: aberrant claudin‐5 expression in cancer cells (odds ratio; OR [95% confidence interval]= 4.61[1.44–14.77]), depth of submucosal invasion greater than 200 µm (3.55 [1.02–13.17]), and positive lymphatic permeation (3.34 [1.22–9.15]). LNM was found in one of 29 (3.4%) patients with none of these three risk factors, and in 32 of 81 (39.5%) patients with one or more of these risk factors. In superficial ESCC, routine analysis of claudin‐5 expression in cancer cells together with depth of invasion and lymphatic permeation may be useful for predicting LNM and thereby reducing the number of patients undergoing additional surgery after successful endoscopic resection.     

Endosonographic detection of mediastinal lymph node metastasis in superficial carcinoma of the esophagus: assessment by type classification and histogram

Background Endoscopic ultrasonography (EUS) has been shown to be useful for detecting lymph node metastasis in esophageal cancer. The evaluation of nodal metastasis requires both objective and subjective analyses. In the present study, mediastinal lymph nodes in superficial esophageal carcinoma (SEC) were examined by both EUS appearance and histography, using NIH image software.Methods One hundred and seventy-one lymph nodes of 56 patients with SEC were detected by EUS. These lymph nodes were diagnosed by type classification, based on boundary and internal echo, and by the construction of internal echo histograms using NIH image software. The results were compared with the histological findings.Results The sensitivity, specificity, and accuracy in assessing mediastinal lymph node metastasis by type classification were 83.3%, 88.2%, and 87.7%, respectively. The mean and SD of the histogram correlated well with histological findings and type classification (P < 0.0001). All lymph nodes with a mean value of less than 185 of the histogram were negative nodes. When positive nodes by type classification were reevaluated according to the threshold value of 185 using the histogram, the sensitivity, specificity, and accuracy improved to 83.3%, 100%, and 98.2%, respectively.Conclusions Type classification assisted by histography improved the diagnostic accuracy of mediastinal lymph node metastasis in SEC.