Using the combined C-reactive protein and controlling nutritional status index for elderly non-small cell lung cancer.

Background: We found that conventional controlling nutritional status (CONUT) score can serve as a sensitive prognostic marker. Some prognostic indicators do include C-reactive protein (CRP), such as the CRP-lymphocyte ratio (CLR), CRP-albumin-lymphocyte index (CALLY), and CRP-albumin ratio (CAR). However, CRP has not been combined with the CONUT score, which we believe could result in a more sensitive marker. This study evaluated the combined use of the CONUT score and CRP to predict prognostic outcomes in elderly non-small cell lung cancer (NSCLC) patients undergoing surgical resection. Methods: This study involved the retrospective analysis of 114 NSCLC patients who were over 80 years old and underwent curative resection. The summation of the CRP score and CONUT score was defined as the combined CRP and controlling nutritional status (C-CONUT) score. The capacity of CRP, CONUT score, and C-CONUT score to predict overall survival (OS) was evaluated via receiver operating characteristics (ROC) curves. Prognostic markers for OS were then identified using the Cox proportional hazards regression model. Results: The ROC curves identified the C-CONUT score as the most reliable marker of prognosis (area under the curve =0.745). Forty-seven patients were included in the high C-CONUT (≥3) group, while 67 patients were included in the low C-CONUT (0 to 2) group. Worse prognosis rates were observed in the high C-CONUT group in comparison to the low C-CONUT group in terms of OS (five-year OS: 39.8% versus 87.4%, P<0.001). Lymphatic invasion (P<0.001), histological findings (P=0.02), and C-CONUT score [hazard ratio (HR): 5.07, 95% confidence interval (CI): 2.39-10.8, P<0.001] were identified as exclusive markers for OS prognosis in the multivariate analysis. Conclusions: Our current findings indicate that C-CONUT score may serve as an innovative prognostic marker in the elderly NSCLC population.

Mean computed tomography value to predict spread through air spaces in clinical N0 lung adenocarcinoma.

BACKGROUND: The aim of this study was to assess the ability of radiologic factors such as mean computed tomography (mCT) value, consolidation/tumor ratio (C/T ratio), solid tumor size, and the maximum standardized uptake (SUVmax) value by F-18 fluorodeoxyglucose positron emission tomography to predict the presence of spread through air spaces (STAS) of lung adenocarcinoma. METHODS: A retrospective study was conducted on 118 patients those diagnosed with clinically without lymph node metastasis and having a pathological diagnosis of adenocarcinoma after undergoing surgery. Receiver operating characteristics (ROC) analysis was used to assess the ability to use mCT value, C/T ratio, tumor size, and SUVmax value to predict STAS. Univariate and multiple logistic regression analyses were performed to determine the independent variables for the prediction of STAS. RESULTS: Forty-one lesions (34.7%) were positive for STAS and 77 lesions were negative for STAS. The STAS positive group was strongly associated with a high mCT value, high C/T ratio, large solid tumor size, large tumor size and high SUVmax value. The mCT values were - 324.9 ± 19.3 HU for STAS negative group and - 173.0 ± 26.3 HU for STAS positive group (p < 0.0001). The ROC area under the curve of the mCT value was the highest (0.738), followed by SUVmax value (0.720), C/T ratio (0.665), solid tumor size (0.649). Multiple logistic regression analyses using the preoperatively determined variables revealed that mCT value (p = 0.015) was independent predictive factors of predicting STAS. The maximum sensitivity and specificity were obtained at a cutoff value of - 251.8 HU. CONCLUSIONS: The evaluation of mCT value has a possibility to predict STAS and may potentially contribute to the selection of suitable treatment strategies.

Prognostic Significance of CONUT Score in Elderly NSCLC.

PURPOSE: This study evaluated the Controlling Nutritional Status (CONUT) score as a prognostic predictor in elderly non-small cell lung cancer (NSCLC) patients with surgical resection. METHODS: Overall, 114 patients over 80 years old undergoing curative resection for NSCLC were retrospectively analyzed. Receiver operating characteristic (ROC) analysis was conducted to evaluate the capacity of immune-inflammatory markers to predict overall survival (OS). Cox-proportional hazards regression analysis was implemented to investigate prognostic markers for OS. RESULTS: Based on ROC curves, the CONUT score was found to be the most valuable prognostic marker (area under the curve = 0.716). The high CONUT (≥2) group included 54 patients, and the low CONUT (0 or 1) group included 60 patients. The high CONUT group had poorer prognosis rates compared to the low CONUT group with regard to OS (5-year OS: 46.3% vs. 86.0%, p = 0.0006). In the multivariate data analysis, histology, lymphatic invasion, and CONUT score (hazard ratio: 4.23, p = 0.0003) were found to be exclusive and independent prognostic markers for OS. CONCLUSION: Preoperatively, the CONUT score can be used as a novel prognostic marker in elderly NSCLC patients. CONUT evaluations can also be used to design nutritional interventions to improve patient outcomes.

[Indocyanine Green Fluorescence Intraoperative Imaging for Fistula Identification of Pleuroperitoneal Communication by Continuous Ambulatory Peritoneal Dialysis:Report of a Case].

A 64-year-old female with chronic renal failure had been receiving continuous ambulatory peritoneal dialysis (CAPD). She developed acute hydrothorax in the right pleural cavity 1 year after the commencement of CAPD. Scintigraphy revealed a diagnosis of pleuroperitoneal communication, and we performed video-assisted thoracoscopic surgery. We infused a dialysis solution containing indocyanine green (ICG) through CAPD catheter. Near-infrared fluorescence thoracoscopy revealed a fistula that could not be identified by white light. We sutured the fistula covered with a polyglycolic acid sheet and fibrin glue. The CAPD was able to be resumed 8 days after surgery, and there was no recurrence of pleural effusion 10 months since surgery. Identification of the diaphragmatic fistula is important in the treatment of pleuroperitoneal communication. This technique using near-infrared fluorescence thoracoscopy with ICG was useful in identifying the fistula, and it emitted sufficient fluorescence even at low concentration ICG.

Rapidly developing intrathoracic low-grade fibromyxoid sarcoma: A case report.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare mesenchymal tumor that primarily arises in the limbs and trunk of young adults, and rarely in the thoracic cavity. An 84-year-old Japanese woman presented with a right intrathoracic mass which was 8 cm in size. CT-guided needle biopsy did not provide a definitive diagnosis. Perioperatively, a mass was found in the right lower lobe of the lung and was suspected to have invaded the chest wall at the sixth-eighth ribs. A right lower lobectomy and combined chest wall resection were performed. Microscopic examination revealed that the tumor was a low-grade spindle cell tumor originating from the pleura demonstrating focal invasion of the lung. The tumor exhibited positivity for MUC4, and FUS gene translocation was confirmed through fluorescence in situ hybridization. Unfortunately, 10 months postoperatively, tumor recurrence was noted as peritoneal dissemination, and the patient passed away 13 months postoperatively. Although LGFMS may be diagnosed histologically as a low-grade tumor by needle biopsy, in this case, it was highly malignant. Postoperative long-term regular medical follow-up is recommended considering the highly malignant nature of the tumor and the high risk of local recurrence and pulmonary metastasis.

A case of pulmonary pleomorphic carcinoma associated with cystic airspace.

Lung cancer associated with a cystic airspace is frequently misdiagnosed or overlooked. Adenocarcinoma, followed by squamous cell carcinoma, is the most typical histologic type of lung cancer connected to a cystic airspace. Here we present the rare case of lung pleomorphic carcinoma associated with a cystic airspace. We encountered a 74-year-old Japanese man diagnosed by computed tomography (CT) as having a nodule outside a cystic airspace in the lung. Several previous CT images showed that the cystic airspace preceded the nodule. Postsurgery, pathology indicated a diagnosis of pleomorphic carcinoma. Since pulmonary pleomorphic carcinomas pursue an aggressive clinical course, their early detection may contribute to an improved prognosis. Our case demonstrated that pleomorphic carcinoma can arise with cystic airspaces. For early diagnosis of those aggressive lung cancers, chest physicians should carefully examine the walls of cystic airspaces on CT.

Combined treatment with beaded EWS, Gore-tex patch and N-butyl-2-cyanoacrylate for bronchial fistula: The novel "sandwich method".

An 84-year-old man underwent right basal segmentectomy for primary lung cancer and developed empyema accompanied by a bronchopleural fistula (BPF). Emergency open-window thoracotomy was performed. Although the general and nutritional conditions improved, the fistula did not close naturally, and we planned to close it 6 months after surgery. In this report, we describe, for the first time, a novel method for closing BPF using an endobronchial Watanabe spigot (EWS), polyglycolic acid (PGA) sheet and N-butyl-2-cyanoacrylate (NBCA). We named this method the"sandwich method."

Surgical ligation level of the bronchial artery influences tissue oxygen saturation of the bronchus and the incidence of postoperative bronchofistula after pulmonary lobectomy.

BACKGROUND: Lobectomy, or the removal of a lobe of the lung, is the most commonly performed lung cancer surgery. One of the most severe postoperative complications is a bronchial stump fistula, which often occurs following a right lower lobectomy. During lymph node dissection, the bronchial arteries, which supply blood to the bronchus, are cut. Subsequently, reduced blood supply to the bronchus may result in bronchofistula. We investigated the relationship between the level of the surgical ligation of the bronchial arteries and the decrease in blood flow at the bronchial stump during a right lower lobectomy. This study aimed to clarify the relationship between the anatomical amputation level of the bronchial artery and the decrease in tissue oxygen saturation at the bronchial stump, allowing us to identify a surgical procedure that reduces the risk of a bronchopleural fistula following pulmonary lobectomy and an appropriate bronchial artery amputation site that could be used in future lobectomies. METHODS: We developed a new system (micro-tissue oxygen saturation) that enabled the semi-quantification of the oxygen saturation of thin tissues in pinpoint during video-assisted thoracic surgery. Changes in the blood flow at the bronchial stump were examined during lymph node dissection and bronchial artery amputation using a biological pig lobectomy model. RESULTS: The regional oxygen saturation level at the bronchial wall was 95.5%±1.0% in normal conditions. A gradual decrease in regional oxygen saturation was observed, as the cutting point of the bronchial artery was moved higher. When the bronchial artery coursing into the middle lobe bronchus was preserved, the blood flow in the bronchus was preserved at 82.8%±1.3%. When the branches of the bronchial arteries running both inside and outside of the intermediate bronchial trunk were cut at high positions, regional oxygen saturation level decreased to 55.7%±1.2%. CONCLUSIONS: The preservation of at least one bronchial artery at the level of the middle lobe bronchus minimizes the reduction of tissue oxygen saturation at the lower lobe bronchial stump. The ligation of bronchial arteries at a higher position results in desaturation <60%, which may increase the risk of bronchial stump fistula.

Fluorescence visualization of the intersegmental plane by bronchoscopic instillation of indocyanine green into the targeted segmental bronchus: determination of the optimal settings.

OBJECTIVE: To determine the appropriate amount of indocyanine green for bronchial insufflation. METHODS: We enrolled 20 consecutive patients scheduled for anatomical segmentectomy in the Kochi Medical School Hospital. After inducing general anesthesia, 6 to 60 mL of 200-fold-diluted indocyanine green (0.0125 mg/mL) was insufflated into the subsegmental bronchi in the targeted pulmonary segmental bronchus. The volume of the targeted pulmonary segments was calculated using preoperative computed tomography. Fluorescence spread in the segmental alveoli was visualized using a dedicated near-infrared thoracoscope. RESULTS: The targeted segment was uniformly visualized by indocyanine green fluorescence in 16/20 (80.0%) cases after insufflating indocyanine green. A receiver operating characteristic curve indicated that the area under the curve was 0.984; the optimal cut-off volume of diluted indocyanine green for insufflation was 8.91% of the calculated targeted pulmonary segment volume. CONCLUSIONS: The setting for indocyanine green insufflation was optimized for near-infrared fluorescence image-guided anatomical segmentectomy. By injecting the correct amount of indocyanine green, fluorescence-guided anatomical segmentation may be performed more appropriately.

The accuracy of cone-beam computed tomography and augmented fluoroscopy-guided bronchoscopic marking of multiple small-sized pulmonary nodules in a hybrid operating room: a retrospective cohort study.

BACKGROUND: For the minimally invasive excision of small-sized pulmonary nodules, bronchoscopic markings are increasingly being performed owing to advancements in video-assisted thoracic surgery (VATS). Hybrid operating room equipment is utilized for bronchoscopic VATS markings. We aimed to compare the marking accuracy between bronchoscopic VATS and other marking techniques such as computed tomography-guided percutaneous marking and conventional X-ray fluoroscopy-guided bronchoscopic marking. METHODS: Patients with small-sized pulmonary nodules scheduled to undergo VATS were enrolled in the study. A mixture of 50 to 100 µL of diluted indocyanine green and iopamidol was injected adjacent to the pulmonary nodules as a VATS marker. Patients receiving each of the three image-guided techniques were categorized into group A (computed tomography-guided percutaneous injection), group B (X-ray fluoroscopy-guided virtual bronchoscopy-assisted bronchoscope injection), and group C (cone-beam computed tomography and augmented fluoroscopy-guided virtual bronchoscope-assisted bronchoscopic injection in the hybrid operating room). VATS marking accuracy and procedural complications were compared among the three groups. RESULTS: In total, 61 patients with 73 pulmonary nodules were eligible for analysis. VATS marking was successful for 15/16 nodules in group A, 28/30 nodules in group B, and 25/27 nodules in group C. Marking accuracy was 5.75±4.59, 15.00±14.02, and 6.05±6.11 (mm), respectively. Multiple markings were successful in 0/1 (0%), 5/6 (83.3%), and 5/5 (100.0%) nodules in groups A, B, and C, respectively. A small pneumothorax occurred in 3/15 (20.0%) patients in group A. CONCLUSIONS: The cone-beam computed tomography and augmented fluoroscopy-guided bronchoscopic approach performed in a hybrid operating room is accurate and equivalent to the computed tomography-guided percutaneous approach, and it enables the VATS marking of multiple pulmonary nodules without causing a secondary pneumothorax.

Near-infrared fluorescent solid material for visualizing indwelling devices implanted for medical use.

BACKGROUND: In clinical practice, various devices are implanted into the body for medical reasons. As X-ray fluoroscopy is necessary to visualize medical devices implanted into the body, the development of a less-invasive visualization method is highly desired. This study aimed to investigate the clinical applicability of our novel solid material that emits near-infrared fluorescence. METHODS: We developed a solid resin material that emits near-infrared fluorescence. This material incorporates a near-infrared fluorescent pigment, with quantum yield ≥ 20 times than that of indocyanine green. It can be sterilized for medical treatment. This resin material is designed to be molded into a catheter and inserted into the body with an endoscope clip. In this preclinical experiment using a swine model, the resin material was embedded into the body of the swine and visualized with a near-infrared fluorescence camera system. RESULTS: Endoscopic clips were placed in the mucosa of the stomach, esophagus, and large intestine, and the indwelling ureteral catheters were successfully visualized by near-infrared fluorescence laparoscopy. CONCLUSIONS: We confirmed the tissue permeability of the fluorescence emitted by our novel near-infrared fluorescent material and the possibility of its clinical application. This material may allow visualization of devices embedded in the body.

Thoracic endovascular aortic repair of an aberrant arterial aneurysm with pulmonary sequestration.

We describe a treatment strategy for an aberrant arterial aneurysm associated with pulmonary sequestration. A 58-year-old man with impending aberrant arterial aneurysm rupture underwent a 2-stage surgery that included an emergency thoracic endovascular aortic repair (TEVAR) of the descending aorta to occlude the origin of the aberrant artery, followed by lobectomy. TEVAR can lead to faster occlusion of the aneurysm and can avoid operative risk of aneurysm rupture during lobectomy. The aberrant artery was broad where it branched off the aorta and had a short neck, rendering primary ligation or stump-forming unsuitable. Pathological findings revealed the fragility of the aberrant artery; thus, its root was prone to breakdown of the stump after simple aneurysmectomy. Furthermore, TEVAR may reduce graft infection during lobectomy in the second surgery. The 2-stage surgery may be useful for aberrant aneurysms complicated by pulmonary sequestration.

In-vitro proliferation assay with recycled ascitic cancer cells in malignant pleural mesothelioma: A case report.

BACKGROUND: We report the first case, to the best of our knowledge, of massive ascites due to recurrent malignant pleural mesothelioma that was controlled using KM-cell-free and concentrated ascites reinfusion therapy (KM-CART). The tumor cells derived via KM-CART were utilized secondarily in an in vitro cell growth assay using the collagen gel droplet-embedded culture drug sensitivity test (CD-DST) to investigate anticancer drug susceptibility. CASE SUMMARY: A 56-year-old man presented with recurrent malignant mesothelioma with massive ascites; more than 4000 mL of ascitic fluid was removed, filtered, and concentrated using KM-CART, and the cell-free ascitic fluid was reinfused into the patient to improve quality of life. Cancer cells isolated secondarily in an in vitro proliferation assay using CD-DST exhibited low sensitivity to pemetrexed and high sensitivity to gemcitabine. Treatment with gemcitabine maintained stable disease for 4 mo. CONCLUSION: The combination of KM-CART and CD-DST may be a promising treatment option for malignant ascites associated with malignant mesothelioma.

[Indocyanine Green( ICG) Fluorescence Imaging to Visualize Intersegmental Plane].

Early stage lung cancers which localized in the middle layer or the center of the lung become indications for anatomical segmentectomy. As a method of intraoperative identifying the intra-segmental plane, 2 different techniques utilizing indocyanine green (ICG) fluorescence has been clinically applied. The one is a method of systemically intravenous administration of ICG after ligating the objective segmental pulmonary artery. The other is a method of insufflate the diluted ICG into the objective segmental bronchus under the bronchoscope. The segmental alveoli were visualized with a ICG fluorescence thoracoscope. Both methods visualize inter-segmental plane. Both advantages and disadvantages were discussed. These methods may help the repertoire of atypical segmentectomy getting wider. Also, ICG fluorescence imaging is incorporated into a robotic surgery. ICG fluorescence imaging is expected to be applied to various applications of thoracic surgery.

Simultaneous cone beam computed tomography-guided bronchoscopic marking and video-assisted thoracoscopic wedge resection in a hybrid operating room.

The increasing need for pulmonary resection by video-assisted thoracoscopic surgery (VATS) has presented a greater opportunity to detect small-sized pulmonary nodules by computed tomography (CT). In cases where it is difficult to identify tumor localization intraoperatively, it is necessary to place the VATS marker near the pulmonary nodules before surgery. Conventional percutaneous or bronchoscopic VATS marker placement under local anesthesia is accompanied by patient pain. We clinically applied a new technique to place VATS markers using a bronchoscope under general anesthesia in a hybrid operating room. Multiple pulmonary nodules were successfully marked and securely excised simultaneously by VATS. This technique enables secure, minimally invasive resection of multiple small-sized pulmonary nodules without causing distress to the patient.

Indocyanine green fluorescence/thermography evaluation of intercostal muscle flap vascularization.

BACKGROUND: During anatomical lung resection in high-risk patients, the bronchial stump is covered with tissue flaps (e.g. pericardial fat tissue and intercostal muscle) to prevent bronchopleural fistula development. This is vital for reliable reinforcement of the bronchial stump. We evaluated the blood supply of the flap using indocyanine green fluorescence (ICG-FL) and thermography intraoperatively in 27 patients at high risk for developing a bronchopleural fistula. METHODS: Before reinforcing the stump with a flap, the fluorescence agent was intravenously injected and the blood supply was evaluated. The surface temperature of the flap was measured with thermography. The two modalities were then compared. RESULTS: ICG-FL intensity and surface temperature on the distal compared to the proximal side of the flap decreased by 32.6 ± 29.4% (P < 0.0001) and 3.5 ± 2.0°C (P < 0.0001), respectively. In patients with a higher ICG-FL intensity value at the tip than the median, the surface temperature at the tip decreased by 2.7 ± 1.7°C compared to the proximal side. In patients with a lower ICG-FL value at the tip, the surface temperature decreased by 4.6 ± 1.7°C (P = 0.0574). The bronchial stump reinforced the part of the flap with adequate blood supply; none of the patients developed a bronchopleural fistula. CONCLUSIONS: ICG-FL confirmed variation in the blood supply of the intercostal muscle flap, even if prepared using the same surgical procedure. Thermography analysis tends to correlate with the fluorescence method, but may be influenced by the state of flap preservation during surgery.

Near-infrared dye marking for thoracoscopic resection of small-sized pulmonary nodules: comparison of percutaneous and bronchoscopic injection techniques.

BACKGROUND: Minimally invasive video-assisted thoracoscopic surgery for small-sized pulmonary nodules is challenging, and image-guided preoperative localisation is required. Near-infrared indocyanine green fluorescence is capable of deep tissue penetration and can be distinguished regardless of the background colour of the lung; thus, indocyanine green has great potential for use as a near-infrared fluorescent marker in video-assisted thoracoscopic surgery. METHODS: Thirty-seven patients with small-sized pulmonary nodules, who were scheduled to undergo video-assisted thoracoscopic wedge resection, were enrolled in this study. A mixture of diluted indocyanine green and iopamidol was injected into the lung parenchyma as a marker, using either computed tomography-guided percutaneous or bronchoscopic injection techniques. Indications and limitations of the percutaneous and bronchoscopic injection techniques for marking nodules with indocyanine green fluorescence were examined and compared. RESULTS: In the computed tomography-guided percutaneous injection group (n = 15), indocyanine green fluorescence was detected in 15/15 (100%) patients by near-infrared thoracoscopy. A small pneumothorax occurred in 3/15 (20.0%) patients, and subsequent marking was unsuccessful after a pneumothorax occurred. In the bronchoscopic injection group (n = 22), indocyanine green fluorescence was detected in 21/22 (95.5%) patients. In 6 patients who underwent injection marking at 2 different lesion sites, 5/6 (83.3%) markers were successfully detected. CONCLUSION: Either computed tomography-guided percutaneous or bronchoscopic injection techniques can be used to mark pulmonary nodules with indocyanine green fluorescence. Indocyanine green is a safe and easily detectable fluorescent marker for video-assisted thoracoscopic surgery. Furthermore, the bronchoscopic injection approach enables surgeons to mark multiple lesion areas with less risk of causing a pneumothorax. TRIAL REGISTRATION: UMIN-CTR R000027833 accepted by ICMJE. Registered 5 January 2013.

Correction: In Vitro Drug Sensitivity Tests to Predict Molecular Target Drug Responses in Surgically Resected Lung Cancer.

[This corrects the article DOI: 10.1371/journal.pone.0152665.].

In Vitro Drug Sensitivity Tests to Predict Molecular Target Drug Responses in Surgically Resected Lung Cancer.

BACKGROUND: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors have dramatically changed the strategy of medical treatment of lung cancer. Patients should be screened for the presence of the EGFR mutation or echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene prior to chemotherapy to predict their clinical response. The succinate dehydrogenase inhibition (SDI) test and collagen gel droplet embedded culture drug sensitivity test (CD-DST) are established in vitro drug sensitivity tests, which may predict the sensitivity of patients to cytotoxic anticancer drugs. We applied in vitro drug sensitivity tests for cyclopedic prediction of clinical responses to different molecular targeting drugs. METHODS: The growth inhibitory effects of erlotinib and crizotinib were confirmed for lung cancer cell lines using SDI and CD-DST. The sensitivity of 35 cases of surgically resected lung cancer to erlotinib was examined using SDI or CD-DST, and compared with EGFR mutation status. RESULTS: HCC827 (Exon19: E746-A750 del) and H3122 (EML4-ALK) cells were inhibited by lower concentrations of erlotinib and crizotinib, respectively than A549, H460, and H1975 (L858R+T790M) cells were. The viability of the surgically resected lung cancer was 60.0 ± 9.8 and 86.8 ± 13.9% in EGFR-mutants vs. wild types in the SDI (p = 0.0003). The cell viability was 33.5 ± 21.2 and 79.0 ± 18.6% in EGFR mutants vs. wild-type cases (p = 0.026) in CD-DST. CONCLUSIONS: In vitro drug sensitivity evaluated by either SDI or CD-DST correlated with EGFR gene status. Therefore, SDI and CD-DST may be useful predictors of potential clinical responses to the molecular anticancer drugs, cyclopedically.

Comparison of epidermal growth factor receptor mutation analysis results between surgically resected primary lung cancer and metastatic lymph nodes obtained by endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND: Lung cancers with mutations in the epidermal growth factor receptor (EGFR) gene respond well to treatment with EGFR inhibitors. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is considered a useful modality to obtain samples from the mediastinal and hilar lymph nodes. However, the EGFR gene status of EBUS-TBNA samples may not always match that of primary tumors. METHODS: In 14 node-positive patients diagnosed by EBUS-TBNA, EGFR mutation analysis results were compared between EBUS-TBNA samples and surgically removed primary tumors. EGFR mutation was screened with peptide nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamp followed by direct sequence analysis. For one controversial case, gene mutation analyses were performed for the multiple micro-fractions of a metastatic lymph node, which exhibited the heterogeneous immunohistochemical features. RESULTS: EBUS-TBNA diagnosed one case of exon 21 point mutations, one case of exon 19 deletion, and 12 cases of wild-type EGFR. Results were consistent with those of surgically removed primary tumors in 13 of 14 cases. One case of wild-type EGFR diagnosed by EBUS-TBNA exhibited exon 21 point mutation in the surgically removed primary tumor. The metastatic lymph node targeted by EBUS-TBNA mostly consisted of cancer cells with wild-type EGFR; however, a minor component positive for thyroid transcription factor-1 (TTF-1) and surfactant-associated protein A (PE-10) exhibited EGFR mutation. CONCLUSION: The combination of EBUS-TBNA and PNA-LNA clamp is useful for EGFR mutation analysis. However, EGFR mutation status in EBUS-TBNA samples may not be consistent with that of the primary tumor when the tumor contains few EGFR mutations.