Background: Elastography is a relatively new technology that can generate images reflective of tissue stiffness (elasticity). Neoplastic tissue is usually stiffer than normal structures. Objectives: The aim of this study was to evaluate the feasibility and utility of elastography when combined with convex-probe endobronchial ultrasound (CP-EBUS) for predicting and localizing metastatic lymph nodes during endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA). Methods: Consecutive results of endobronchial elastography of lymph nodes performed using EBUS- TBNA were prospectively collected and retrospectively analyzed. Elastography images were acquired as JPEG images and also recorded as video clips. Stiff area ratios [(stiff areas as blue pixels) / (lymph node areas as region of interest pixels)] for each lymph node determined by elastography were collated with the results of pathological diagnosis. We also performed elastography of surgically resected lymph nodes and compared image findings with pathological sections. Results: We evaluated 49 lymph nodes in 21 patients by CP-EBUS. There were 16 metastatic nodes (10 lung cancer metastases and 6 metastases from extrathoracic malignancies). Mean stiff area ratios were significantly greater for metastatic lymph nodes (0.478) than for benign nodes (0.216; p = 0.0002). Using a cutoff value of 0.311 for stiff area ratios, the sensitivity and specificity for predicting metastatic disease were 0.81 and 0.85, respectively. The stiff area was histologically compatible with metastatic distribution in surgically resected lymph nodes. Conclusions: Endobronchial elastography is feasible for lymph nodes when combined with CP-EBUS. Stiff area ratios are useful for predicting metastatic lymph nodes, which may be an efficient guide for TBNA.

Lung adenocarcinoma is classified morphologically into five histological subtypes according to the WHO classification. While each histological subtype correlates with a distinct prognosis, the molecular basis has not been fully elucidated. Here we conducted DNA methylation analysis of 30 lung adenocarcinoma cases annotated with the predominant histological subtypes and three normal lung cases using the Infinium BeadChip. Unsupervised hierarchical clustering analysis revealed three subgroups with different methylation levels: high‐, intermediate‐, and low‐methylation epigenotypes (HME, IME, and LME). Micropapillary pattern (MPP)‐predominant cases and those with MPP components were significantly enriched in HME (p = 0.02 and p = 0.03, respectively). HME cases showed a significantly poor prognosis for recurrence‐free survival (p < 0.001) and overall survival (p = 0.006). We identified 365 HME marker genes specifically hypermethylated in HME cases with enrichment of “cell morphogenesis” related genes; 305 IME marker genes hypermethylated in HME and IME, but not in LME, with enrichment “embryonic organ morphogenesis”‐related genes; 257 Common marker genes hypermethylated commonly in all cancer cases, with enrichment of “regionalization”‐related genes. We extracted surrogate markers for each epigenotype and designed pyrosequencing primers for five HME markers (TCERG1L, CXCL12, FAM181B, HOXA11, GAD2), three IME markers (TBX18, ZNF154, NWD2) and three Common markers (SCT, GJD2, BARHL2). DNA methylation profiling using Infinium data was validated by pyrosequencing, and HME cases defined by pyrosequencing results also showed the worse recurrence‐free survival. In conclusion, lung adenocarcinomas are stratified into subtypes with distinct DNA methylation levels, and the high‐methylation subtype correlated with MPP‐predominant cases and those with MPP components and showed a poor prognosis.

Anastomotic failure of a gastric tube inserted for reconstruction following esophagectomy, which is relatively rare, causes pleural infection and persistent pleural irritation, leading to communication with the pulmonary parenchyma. Although several interventions have been reported to treat such broncho-gastric tube fistulas, refractory cases remain. We herein report the successful treatment by endoscopic bronchial occlusion with an endobronchial Watanabe spigot in 2 patients who suffered from the above complication.

Background: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a relatively rare subtype of lung malignancy. According to revised 2015 World Health Organization (WHO) criteria for the pathological diagnosis of LCNEC, neuroendocrine markers must be examined by immunohistochemistry. In this study, we reevaluated endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) samples of patients previously diagnosed with LCNEC using the revised WHO criteria.Methods: Clinical tissue samples that had been obtained by EBUS‐TBNA between January 2004 and December 2011, and that had been pathologically diagnosed as LCNEC according to the previous criteria, were reevaluated according to the revised WHO criteria.Results: The records of 471 lung cancer patients with mediastinal or hilar lymph node metastasis diagnosed by EBUS‐TBNA were analyzed. Thirteen patients were diagnosed with LCNEC; one of which was diagnosed based on cytology alone because the histological material was insufficient for a histological examination. Among the 12 cases in which a histological examination was performed, nine were diagnosed with possible LCNEC based on neuroendocrine marker positivity, while three were diagnosed with suspected LCNEC because they did not meet the immunostaining criteria. The patient who was cytologically diagnosed was found to have non‐small cell carcinoma with neuroendocrine morphology.Conclusion: LCNEC could be pathologically diagnosed based on 2015 WHO criteria using EBUS‐TBNA samples.

Background: The limited negative predictive value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has often been discussed. Objective: The aim of this study was to identify a highly sensitive molecular biomarker for lymph node staging by EBUS-TBNA. Methods: Five microRNAs (miRNAs) (miR-200a, miR-200b, miR-200c, miR-141, and let-7e) were selected as biomarker candidates for the detection of nodal metastasis in a miRNA expression analysis. After having established a cutoff level of expression for each marker to differentiate malignant from benign lymph nodes among surgically dissected lymph nodes, the cutoff level was applied to snap-frozen EBUS-TBNA samples. Archived formalin-fixed paraffin- embedded (FFPE) samples rebiopsied by EBUS-TBNA after induction chemoradiotherapy were also analyzed. Results: The expression of all candidate miRNAs was significantly higher in metastatic lymph nodes than in benign ones (p < 0.05) among the surgical samples. miR-200c showed the highest diagnostic yield, with a sensitivity of 95.4% and a specificity of 100%. When the cutoff value for miR-200c was applied to the snap-frozen EBUS-TBNA samples, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 97.4, 81.8, 95.0, 90.0, and 94.0%, respectively. For restaging FFPE EBUS- TBNA samples, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 100, 60.0, 80.0, 100, and 84.6%, respectively. Among the restaged samples, 4 malignant lymph nodes were false negative by EBUS-TBNA, but they were accurately identified by miR-200c. Conclusions: miR-200c can be used as a highly sensitive molecular staging biomarker that will enhance nodal staging of lung cancer.

Narrative review—how to access nodules: role of new technology including navi- and robo-bronchoscopy Alexander Gregor, Tsukasa Ishiwata, Terunaga Inage, Kazuhiro Yasufuku