Bilateral Pneumothorax after a Transbronchial Lung Cryobiopsy for Interstitial Lung Disease.

We herein report a case of bilateral pneumothorax after a unilateral transbronchial lung cryobiopsy (TBLC). A 73-year-old man with no history of cardiothoracic surgery underwent a TBLC for the reevaluation of interstitial lung disease. Five hours later, he developed bilateral pneumothorax, pneumomediastinum, and subcutaneous emphysema. He underwent bilateral chest drainage and was discharged 18 days later. The lung biopsy specimens obtained from the TBLC contained visceral pleura and bronchial cartilage, suggesting bronchial injury as the cause of the bilateral pneumothorax.

High efficacy of brigatinib for brain metastases in ALK fusion gene-positive non-small cell lung cancer: A case series.

Anaplastic lymphoma kinase (ALK) fusion gene-positive lung cancer often shows brain metastasis at initial diagnosis or during the course of treatment. However, molecular-targeted drugs are known to pass through the blood-brain barrier and present positive effects for central nervous system lesions. There are few reports suggesting how effective molecular-targeted drug therapy alone is for brain metastasis lesions of ALK fusion-positive lung cancer, especially after the first use of ALK-tyrosine kinase inhibitor (TKI) or for bulky brain metastases. A patient in his mid-fifties with stage IV pleural dissemination developed brain metastases after 10 years of crizotinib use, but showed a complete response after switching to brigatinib. Moreover, a patient in her early sixties with stage III recurrent large brain metastases 5 years after chemoradiation therapy experienced dramatic tumor shrinkage with brigatinib. In each case of ALK fusion gene-positive lung cancer with brain metastases, brigatinib showed a high efficacy and was well-tolerated after previous ALK-TKI and for bulky lesions.

EML4-ALK Gene Mutation Detected with New NGS Lung Cancer Panel CDx Using Sputum Cytology in a Case of Advanced NSCLC.

The detection of driver gene mutations has become essential for lung cancer; however, insufficient sample sizes make gene panel tests difficult to use. We previously reported that the lung cancer compact panel TM (LCCP) could detect EGFR and MET gene mutations with sputum cytology. To date, the detection of gene mutation using RNA from sputum samples is considered practically difficult. We report a case in which the EML4-ALK fusion gene was successfully detected from a sputum sample using the LCCP that was just released in Japan as a new next-generation sequencing lung cancer panel, CDx.

Pre-treatment bronchoscopic evaluation in a case of relapsing polychondrits.

BACKGROUND: Relapsing polychondritis (RP) is a chronic and recurrent inflammatory disease of the cartilage tissues in the body. The cause of RP is unknown, and since it is a rare disease with symptoms that affect multiple organs, diagnosis is often delayed. CASE PRESENTATION: A 62-year-old woman with no smoking history visited our institution complaining of fever, cough, and dyspnoea. Chest CT showed a stenosis from the left main bronchus to the left lower lobe branch. Bronchoscopy visualised intense erythema and oedema at the left main bronchus, with airway narrowing. Biopsy of the ear revealed degenerative vitreous cartilage and fibrous connective tissue with a mild inflammatory cell infiltrate. She was subsequently diagnosed with RP and administered systemic corticosteroid therapy. Her symptoms improved rapidly, and post-treatment bronchoscopy revealed that although mild erythema of the airway epithelium remained, oedema markedly improved, and the airway stenosis was resolved. CONCLUSIONS: We report a case where pre-treatment bronchoscopy was able to visually confirm RP at the acute stage. Since RP is difficult to diagnose, severe airway narrowing can occur prior to diagnosis. Therefore, to determine the stage of the disease, it is helpful to perform bronchoscopic observation before treatment. However, bronchoscopic observation before treatment should be performed by experienced bronchoscopists due to the risk of airway obstruction.

Case report: Electrocardiographic changes in pembrolizumab-induced fatal myocarditis.

Immune checkpoint inhibitor (ICI)-induced myocarditis is rare but fatal. Because of the rapid course of ICI-induced myocarditis, understanding of clinical course is only possible through information from case reports. We report a case of pembrolizumab-induced myocarditis in which we were able to document the course of electrocardiographic changes from onset to death. A 58-year-old woman with stage IV lung adenocarcinoma, who had completed her first cycle of pembrolizumab, carboplatin, and pemetrexed, was admitted with pericardial effusion. She underwent pericardiocentesis after admission. A second cycle of chemotherapy was administered 3 weeks after the first cycle. Twenty-two days after admission, she developed a mild sore throat and tested positive for SARS-CoV-2 antigen. She was diagnosed with mild coronavirus disease 2019 (COVID-19), isolated, and treated with sotrovimab. Thirty-two days after admission, an electrocardiogram showed monomorphic ventricular tachycardia (VT). Suspecting myocarditis caused by pembrolizumab, the patient was started on daily methylprednisolone after coronary angiography and endocardial biopsy. Eight days after the start of methylprednisolone administration, she was considered to have passed the acute stage. However, four days later, R-on-T phenomenon triggered polymorphic VT and she died. The impact of viral infections such as COVID-19 on patients be treated with immune checkpoint inhibitors is still unknown and we need to be careful with systemic management after viral infections.

Efficacy of combined transbronchial lung cryobiopsy and conventional forceps biopsy for lung malignancies: a prospective cohort study.

There are few prospective reports of transbronchial lung cryobiopsy (TBLC) for malignant tumors in combination with forceps biopsy. We investigated the clinical parameters in which TBLC is superior to forceps biopsy. This is a prospective cohort study to analyse the efficacy of TBLC for suspected malignancy. TBLC was performed after brushing cytology and forceps biopsy, and the diagnostic yield for TBLC, brushing cytology, and forceps biopsy were examined. Adverse events were defined as those requiring additional procedures. Next-generation sequencing (NGS) analysis was performed in each case of non-small cell lung cancer. Of the 100 patients, malignancy was confirmed in 94 cases. The diagnostic yield for TBLC/forceps biopsy/brushing cytology was 86/81/82% respectively, while the diagnostic yield for all procedures combined was 94%. There was no significant difference in the diagnostic yield between TBLC and forceps biopsy. When comparing the biopsy site, the diagnostic yield for TBLC at the lower lobe was significantly higher than forceps biopsy (P < 0.01). Endobronchial ultrasonography imaging using a guide-sheath did not significantly differ in the diagnostic yield of TBLC. The success rate of NGS for TBLC specimens was 100% (26 cases). Adverse events included two cases of severe bleeding. TBLC of peripheral lesions may improve the diagnostic yield when combined with forceps biopsy and brushing cytology. The diagnostic yield of TBLC was higher at the lower lobes. Furthermore, TBLC provided sufficient specimen quality for NGS.

RET fusion mutation detected by re-biopsy 7 years after initial cytotoxic chemotherapy: A case report.

Personalized medicine using molecular-targeted drugs to achieve better therapeutic response and long-term prognosis is common practice for lung cancer treatment. However, in cases before gene batch tests were available, medical treatment continued without the detection of rare mutations. We report a sixty-seven-old year man diagnosed with adenocarcinoma T1cN3M1a, stage IVA. Initial screening performed 7 years earlier using EGFR mutation and ALK immunohistochemical tests were negative. Although first-line cytotoxic combination chemotherapy was remarkably effective, a gradual regression of the primary lesion was noted. After a recent bronchoscopic re-biopsy, RET fusion was detected by gene panel test. In addition, we were able to confirm RET from FFPE specimens obtained from 7-year-old pleural effusion cell blocks. Subsequent administration of the molecular-targeted drug selpercatinib, was highly effective for the primary lesion and all metastatic lesions including brain metastases. We describe a case of RET fusion-positive lung cancer where molecular targeted therapy and cytotoxic drug showed a drastic response and long-term therapy was well maintained. Next generation sequencing was able to correctly diagnose RET fusion mutation using re-biopsy specimen after going undiagnosed for 7 years.

Nationwide retrospective observational study of idiopathic dendriform pulmonary ossification: clinical features with a progressive phenotype.

BACKGROUND: Diffuse pulmonary ossification is a specific lung condition that is accompanied by underlying diseases. However, idiopathic dendriform pulmonary ossification (IDPO) is extremely rare, and the clinical features remain unclear. In this study, we aimed to report the clinical characteristics of IDPO. METHODS: We conducted a nationwide survey of patients with IDPO from 2017 to 2019 in Japan and evaluated the clinical, radiological, and histopathological findings of patients diagnosed with IDPO. RESULTS: Twenty-two cases of IDPO were identified. Most subjects (82%) were male, aged 22-56 years (mean (SD), 37.9 (9.1)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed.)) at diagnosis. Nearly 80% of the subjects were asymptomatic, and the condition was discovered during a medical check-up. However, 36% of the subjects showed a decline in forced vital capacity (%FVC) predicted <80% at diagnosis. The typical radiological features of high-resolution CT (HRCT) are calcified branching structures that are predominantly distributed in the lower lung fields without any other conspicuous finding. Histopathological analysis also showed dendriform ossified lesions from the intraluminal areas to interstitial areas. Notably, during the follow-up period of 20 years, disease progression was found in 88% on HRCT and more than 50% on pulmonary function tests (FVC and/or forced expiratory volume in 1 s). Two cases with rapid decline of 10% /year in %FVC predicted were observed. CONCLUSIONS: IDPO develops at a young age with gradually progressive phenotype. Further research and long-term (>20 years) follow-up are required to clarify the pathogenesis and clinical findings in IDPO.

Serum gasdermin D levels are associated with the chest computed tomography findings and severity of COVID-19.

BACKGROUND: The role of programmed cell death, especially pyroptosis and apoptosis, in unfavorable immune responses in COVID-19 remains to be elucidated. METHODS: We conducted a cross-sectional analysis to investigate the association between the serum gasdermin D (GSDMD) levels, a pyroptotic marker, and caspase-cleaved cytokeratin 18 fragment (M30), an apoptotic marker, and the clinical status and abnormal chest computed tomography (CT) findings in patients with COVID-19. RESULTS: In this study, 46 patients diagnosed with COVID-19 were divided into the following three groups according to the disease severity: mild to moderate group (n = 10), severe group (n = 14), and critical group (n = 22). The serum GSDMD levels were higher in the critical group than in the mild to moderate group (P = 0.016). In contrast, serum M30 levels were lower in the critical group than in the severe group (P = 0.048). Patients who required mechanical ventilation or died had higher serum GSDMD levels than those who did not (P = 0.007). Area of consolidation only and of ground glass opacity plus consolidation positively correlated with serum GSDMD levels (r = 0.56, P < 0.001 and r = 0.53, P < 0.001, respectively). CONCLUSION: Higher serum GSDMD levels are associated with critical respiratory status and the consolidation area on chest CT in patients with COVID-19, suggesting that excessive activation of pyroptosis may affect the clinical manifestations in patients with COVID-19.

A Prospective Validation Study of Lung Cancer Gene Panel Testing Using Cytological Specimens.

Background: Genetic panel tests require sufficient tissue samples, and therefore, cannot always be performed. Although collecting cytological specimens is easier than tissue collection, there are no validation studies on the diagnostic accuracy of lung cancer gene panel tests using cytology samples. Methods: Using an amplicon-based high-sensitivity next-generation sequencing panel test capable of measuring eight druggable genes, we prospectively enrolled consecutive patients who underwent diagnostic procedures. We evaluated the analysis accuracy rate, nucleic acid yield, and the quality of cytological specimens under brushing, needle aspiration, and pleural effusion. We then compared these specimens with collected tissue samples. Results: In 163 prospectively enrolled cases, nucleic acid extraction and analysis accuracy was 100% in cases diagnosed with adenocarcinoma. Gene mutations were found in 68.7% of cases with 99.5% (95% CI: 98.2-99.9) concordance to companion diagnostics. The median DNA/RNA yield and DNA/RNA integrity number were 475/321 ng and 7.9/5.7, respectively. The correlation coefficient of the gene allele ratio in 64 cases compared with tissue samples was 0.711. Conclusion: The success of gene analysis using cytological specimens was high, and the yield and quality of the extracted nucleic acid were sufficient for panel analysis. Moreover, the allele frequency of gene mutations in cytological specimens showed high correlations with tissue specimens.

Changes in Pulmonary Function Test Results and Respiratory Symptoms before and after Airway Stent Removal.

BACKGROUND: Airway stenting is a useful form of palliation for patients with airway stenosis/fistulas; the stent can be removed after addressing the cause of the airway disorder. Patients with airway stents often complain of coughing and difficulty with expectoration, so the use of such stents can negatively affect pulmonary function and worsen symptoms. OBJECTIVES: The aim of this study was to compare pulmonary function and respiratory symptoms before and after stent removal. METHODS: Patients who would later undergo simple airway stent removal were prospectively recruited in two institutions. All stents were removed using both rigid and flexible bronchoscopes with patients under general anesthesia. Pulmonary function tests were performed before stent removal and at 1 and 4 weeks after stent removal. All patients self-reported their respiratory symptoms using a 100-mm visual analog scale (VAS). RESULTS: Of the 31 patients enrolled, 28 (23 with malignant stenoses, 3 with benign stenoses, and 2 with fistulas [21 silicone and 7 metallic stents]) were included in analyses. Pulmonary function measurements before stent removal and at 1 and 4 weeks after stent removal were as follows: vital capacity, 3.00, 3.04, and 3.08 L (p = 0.387); forced expiratory volume in 1 s, 1.96, 1.96, and 2.12 L (p = 0.034); and peak expiratory flow, 3.60, 4.28, and 5.06 L/s, respectively (p < 0.001). Symptoms (cough, sputum production, difficulty with expectoration, and dyspnea) evaluated using the VAS improved significantly after stent removal. No complications were encountered during removal. CONCLUSION: Removal of unnecessary airway stents improves pulmonary function and respiratory symptoms. Any stent that is no longer functioning should be removed.

Preliminary Results of NGS Gene Panel Test Using NSCLC Sputum Cytology and Therapeutic Effect Using Corresponding Molecular-Targeted Drugs.

As more molecular-targeted drugs for advanced non-small cell lung cancer are brought to market, batch tests for the identification of gene mutations are needed at initial diagnosis. However, since current gene panel tests require a sufficient amount of tissue sample, there are many instances where panel tests cannot be performed. Therefore, we have developed a highly sensitive next generation sequencing (NGS) panel test to facilitate cytological specimens. Herein, we describe three cases positive for epidermal growth factor receptor (EGFR) exon 19 deletion, MET exon 14 skipping, and KRAS G12A using NGS analysis from sputum. In each case, genetic information was consistent with companion diagnostic analysis obtained from tissue samples collected under bronchoscopy. In cases of EGFR and MET mutations, the corresponding tyrosine kinase inhibitors were highly effective. This is the first report to demonstrate that a novel panel test could detect gene mutations in sputum samples in clinical practice and compare the gene allele ratio with the sample directly collected from the lesion.

Successful Treatment with Radiation Therapy in an Older Patient with Endobronchial Schwannoma.

Bronchial schwannoma is extremely rare, accounting for a small percentage of benign bronchial tumors, with no determined standardized treatment. An 89-year-old woman with a persistent cough underwent CT scan which revealed a tracheal tumor. A diagnosis of endobronchial schwannoma was confirmed based on tissue obtained by high-frequency snare polypectomy. A hybrid stent was implanted in the trachea due to tumor regrowth; however, stent migration occurred, and it was removed after 1 month. Subsequently, radiation therapy was performed, and airway patency was well maintained for over 3 years. In general, surgical resection is recommended for endobronchial schwannoma; however, due to the age of this patient, resection was deemed invasive. Therefore, radiation therapy was administered as an alternative treatment.

Flexible bronchoscopy for lung cancer diagnosis in patients aged ≥85 years.

AIM: Flexible bronchoscopy (FB) is a common modality for the diagnosis of lung cancer. Recently, the number of older patients with lung cancer is increasing, and FB is being utilized more for these patients. METHODS: FB carried out in patients aged ≥85 years at St. Marianna University Hospital, Kawasaki, Japan, were reviewed. The indication of FB was decided on a case-by-case basis, taking into consideration the condition of the patient, which included mental status and accessibility of the lesion. Outcomes included complications, diagnostic yields, treatment options and survival after FB evaluation. RESULTS: From April 2015 to March 2019, 1604 diagnostic FBs were carried out. A total of 28 were carried out for the diagnosis of lung cancer (19 transbronchial lung biopsy, 9 transbronchial needle aspiration) in patients aged ≥85 years. Although there were three complications reported (pneumonia, fever, asthma exacerbation), they were successfully treated. A total of 19 cases were diagnosed with malignancy; five were treated with stereotactic body radiation therapy, five were prescribed targeted therapy, two underwent surgery and one was treated by cytotoxic monotherapy. Six patients were not included for active treatment. A total of 12 patients who received active treatment for lung cancer reported a 2-year survival rate of >60%. CONCLUSIONS: FB for lung cancer diagnosis in patients aged ≥85 years were carried out with acceptable safety and diagnostic yield. Considering the development of less invasive therapeutic measures for lung cancer, FB is safe and valuable in individuals aged ≥85 years suspected of lung cancer with therapeutic indications. Geriatr Gerontol Int 2022; 22: 32-35.

Solid histological component of adenocarcinoma might play an important role in PD-L1 expression of lung adenocarcinoma.

BACKGROUND: In this study we aimed to clarify the PD-L1 positive expression in lung adenocarcinoma, including various adenocarcinoma subtypes paying particular attention to its component. METHODS: A total of 307 lung adenocarcinoma patients who underwent lobectomy or segmentectomy, as well as systematic lymph node dissection (ND2a), from February 2008 to March 2020 at our hospital, were enrolled into the study. A final diagnosis of adenocarcinoma was obtained from the resected lung specimens of all 307 patients to determine the histological type, adenocarcinoma subtype, and component of adenocarcinoma by ethics of 5%. PD-L1 was immunohistochemically stained using the murine monoclonal antibody clone 22C3. RESULTS: When PD-L1 expression-positive was defined by tumor proportion score (TPS) ≥1%, the positive cases were 6/33 in adenocarcinoma (Ad) in situ (AIS), 2/26 in minimally invasive Ad (MIA), 12/60 in lepidic predominant Ad (LPA), 44/91 in papillary predominant Ad (PPA), 24/49 in acinar predominant Ad (APA), 23/28 in solid predominant Ad (SPA), 4/7 in micropapillary predominant Ad (MPA), and 0/13 in invasive mucinous Ad (IMA). In the high proportion group (APA, PPA, SPA, and MPA) of PD-L1 expression, SPA was the only subtype which was statistically significant when both PD-L1 expression-positive was defined by TPS ≥ 1% (p < 0.0001) and TPS â‰§ 50% (p < 0.0001). We then considered the solid component. We investigated 279 cases of the other subtype group excluding SPA. The group containing a solid component (≥5%) tended to be PD-L1 expression-positive both when defined by TPS ≥1% (p < 0.0001) and TPS â‰§50% (p = 0.0049). CONCLUSIONS: The PD-L1 expression tended to be positive when a solid component was confirmed (≥5%) in specimens of lung adenocarcinoma patients.

Thoracic mesenchymal malignant tumors and programed cell death ligand-1 status: Clinicopathologic and prognostic analysis of eight pulmonary sarcomatoid carcinomas and eight malignant mesotheliomas.

BACKGROUND: The current study aimed to evaluate the significance of clinicopathological factors, particularly the immunohistochemistry of programed cell death ligand-1 (PD-L1), in eight cases each of pulmonary sarcomatoid carcinoma (PSC) and malignant pleural mesothelioma (MPM) at our hospital. METHODS: From January 2004 to December 2020, a total of 16 consecutive patients (eight with PSC and eight with MPM diagnosed via surgical resection or biopsy) were included in this study. After retrospectively reviewing the patient characteristics, the associations between PD-L1 status and age, sex, stage, histological type, and prognosis were investigated. RESULTS: PD-L1-positive staining was observed in four (50%) PSC cases and one (12.5%) MPM case. Among the four PD-L1-positive PSC cases, two showed high PD-L1 expression in the vimentin-positive sarcomatoid compartment. Moreover, among those with PSC, two survived for about 10 years, whereas the others died within 5 years. No clear correlation was found between PD-L1 expression and prognosis. Among the patients with MPM, four survived for more than 2 years, with the longest being 9 years. Among MPM cases who received nivolumab, one patient with positive PD-L1 staining in the sarcomatoid survived, whereas the other with negative PD-L1 staining did not. CONCLUSION: The present study showed that sarcomatoid carcinoma had a higher PD-L1 expression compared to non-small-cell lung cancer and that both PSC and MPM tended to exhibit PD-L1 positivity in the sarcomatoid compartment. Moreover, while immune checkpoint inhibitors may somewhat prolong the prognosis of both tumors, further studies with a larger cohort are necessary to confirm our results.

A case of advanced adenocarcinoma genetically confirmed with EGFR/BRAF co-mutation in both primary and metastatic lesions.

Driver mutations in lung cancer have been generally considered mutually exclusive; however, multiple gene screenings have recently become mainstream. Therefore, it is not uncommon to identify two or more mutations at first diagnosis, making it difficult to determine which tyrosine kinase inhibitor to administer. A 69-year-old woman complaining of back pain was diagnosed with adenocarcinoma T4N3M1c, stage IVB. Although PCR mutation test detected exon21 L858R point mutation by bronchoscopic sample, the therapeutic effect of afatinib was poor. Subsequently, next-generation sequencing (NGS) panel test of a metastasized bone specimen confirmed BRAF V600E. Furthermore, high sensitivity NGS panel system found the gene mutation allele frequency was higher for BRAF V600E than EGFR exon21 L858R for both primary lung tissue and the metastasized specimen. Subsequent BRAF/MEK inhibitor administration showed a remarkable treatment effect. When two or more driver mutations are detected in lung cancer, confirming the allelic frequency of the mutant gene might be useful in selecting more effective agents for front-line treatment.

Combining PD-L1 Expression and Standardized Uptake Values in FDG-PET/CT Can Predict Prognosis in Patients With Resectable Non-Small-Cell Lung Cancer.

BACKGROUND: This study aimed to determine the relationship of programmed death-ligand 1 (PD-L1) expression and standardized uptake values in fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) with prognosis in non-small-cell lung cancer (NSCLC). METHODS: We retrospectively analyzed 328 NSCLC patients who underwent lobectomy/segmentectomy with lymph node dissection. PD-L1 expression was detected by immunohistochemically stained using the murine monoclonal antibody clone 22C3. The preoperative maximum standardized uptake value (SUVmax) of FDG-PET/CT at the primary lesion; pathological factors including histological type, microscopic lymphatic, venous, and pleural invasion; and lymph node metastases in resected specimens was determined. Significant prognostic clinicopathologic factors were analyzed by univariate and multivariate analyses. RESULTS: PD-L1 expression was higher in men, smokers, squamous cell carcinoma, advanced pathologic stages, positive venous invasion, positive pleural invasion, and high preoperative SUVmax (≥3). Postoperative survival analysis showed that both PD-L1 expression and preoperative SUVmax were significantly negative prognostic factors in univariate analysis for overall survival (OS) (P = 0.0123 and P < 0.0001) and relapse-free survival (RFS) (P = 0.0012 and P < 0.0001). Kaplan-Meier survival curves showed that the OS and RFS were the best in patients with negative PD-L1 expression and SUVmax < 3, intermediate in patients with positive PD-L1 expression and SUVmax < 3 and those with negative PD-L1 expression and SUVmax ≥ 3, and poor in patients with positive PD-L1 expression and SUVmax ≥ 3. CONCLUSION: Combining PD-L1 expression and preoperative FDG-PET/CT SUVmax in primary tumor might help in accurate prediction of postoperative prognosis in NSCLC patients.

Pleurodesis After Bronchial Occlusion for Inoperable Secondary Spontaneous Pneumothorax.

BACKGROUND: In many cases of secondary spontaneous pneumothorax (SSP), surgery is not feasible. Furthermore, in cases with a collapsed lung or numerous air leaks, pleurodesis is ineffective, and treatment options are severely limited. For these cases, bronchial occlusion might be the only effective treatment, despite the low success rate. If, however, bronchial occlusion can expand the lung and reduce air leakage, it can positively amplify later effects on pleurodesis, resulting in a powerful treatment. We reviewed the clinical data of patients who underwent bronchial occlusion with endobronchial Watanabe spigot (BO-EWS) and pleurodesis to investigate the usefulness of bronchial occlusion therapy in inoperable SSP patients. MATERIALS AND METHODS: This single-center, retrospective study reviewed 36 cases of inoperable SSP patients who underwent pleurodesis after BO-EWS from April 2007 to October 2018. Twenty cases were allocated to the air leak analysis group, and 16 cases were included in the pneumothorax volume analysis group. The Robert David Cerfolio classification and the Collins method were used to evaluate air leak and pneumothorax volume, respectively. RESULTS: Pneumothorax volumes decreased significantly after BO-EWS from 29.1%±17.3% to 12.1%±8.8%, while the air leak score decreased from 2.9±1.4 to 1.2±1.0. The success rate for chest tube removals in cases that underwent pleurodesis after BO-EWS was 85.0% (17/20). CONCLUSIONS: This study demonstrated the synergistic effectiveness of BO-EWS and the usefulness of pleurodesis treatment in inoperable SSP patients with lung collapse or numerous air leaks. We believe that this treatment will benefit patients with inoperable SSP which, until now, has had few treatment options.