Trapped Lung as a Sequela of Dramatic Tumor Shrinkage of Lung Cancer.

Herein, we report a case of 72-year-old man who had L858R EGFR-mutated lung adenocarcinoma. Chest computed tomography revealed a large lung mass that had completely replaced the right upper lobe. Although the mass dramatically shrank after initiating chemotherapy, non-malignant pleural effusion appeared. Because diffuse pleural thickening and shrinking of the thoracic cage gradually became apparent, the patient was diagnosed with trapped lung. Despite the stabilization of his lung cancer, he experienced severe dyspnea and significant weight loss, ultimately leading to a decreased performance status. Chest physicians should recognize that trapped lung can develop as a sequela of dramatic tumor shrinkage in lung cancer.

Nonfibrotic (cellular) hypersensitivity pneumonitis with and without slight lung distortion.

BACKGROUND: According to international diagnostic guidelines for hypersensitivity pneumonitis (HP), cases with both nonfibrotic and fibrotic lesions are classified by the predominant feature. Therefore, some cases with nonfibrotic HP, have inflammatory lesions alone, while others have a mixture of fibrosis and inflammation. We investigated the impact of slight fibrotic lesions in nonfibrotic HP. METHODS: This retrospective study included nonfibrotic HP cases with <10% of lung distortion on high-resolution CT. We divided the cases into two groups: those with pure ground glass opacities (GGOs) without lung distortion and those with slight lung distortion of <10%. RESULTS: In this study, 37 cases were included. The mean baseline forced vital capacity (FVC) was 109% in the pure GGO group and 96% in the slight lung distortion group (p = 0.038). After 1 year, the reticular shadows appeared or increased more in the slight lung distortion group than in the pure GGO group (16% vs. 8%, p = 0.030). The time to medication initiation was significantly shorter in the slight lung distortion group than in the pure GGO group (p = 0.044). %FVC decreased by ≥ 5% from diagnosis in no cases with the pure GGO and in two cases with the slight lung distortion (-11.0% for 9.5 years and -10.7% for 1.3 years, respectively). CONCLUSIONS: The slight distortion group exhibited a higher rate of worsening and new appearance of reticular shadows after 1 year and a shorter time to first medication compared to the pure GGO group.

Longitudinal changes in serum immunoglobulin G testing in patients with fibrotic avian hypersensitivity pneumonitis.

BACKGROUND: Evaluation of the antigen responsible for fibrotic hypersensitivity pneumonitis (HP) is challenging. Serum immunoglobulin (Ig) G testing against HP-associated antigens is performed. Although single-serum IgG testing has been investigated, multiple-serum IgG testing has not yet been studied. METHODS: This study included patients who underwent histopathological examination and positive inhalation challenge test as well as those with moderate or high HP guideline confidence level. Serum IgG testing against pigeon serum was conducted twice using two methods: enzyme linked-immunosorbent assay (ELISA) and ImmunoCAP. The association between changes in serum IgG antibody titers and changes in forced vital capacity (FVC) and other parameters was investigated. RESULTS: In this study, 28 patients (mean age, 64.5 years; mean FVC, 85.3%) with fibrotic avian HP were selected, of whom 20 and 8 underwent surgical lung biopsy and transbronchial lung cryobiopsy, respectively. Of the 28 patients, 19 had been keeping birds for more than 6 months. A correlation was observed between the annual changes in serum IgG antibody titers by ELISA and changes in relative FVC (r = - 0.6221, p < 0.001). Furthermore, there was a correlation between the annual changes in serum IgG antibody titers by ImmunoCAP and changes in relative FVC (r = - 0.4302, p = 0.022). Multiple regression analysis revealed that the change in serum IgG antibody titers by both ELISA and ImmunoCAP also influenced the relative FVC change (p = 0.012 and p = 0.015, respectively). Moreover, 13 patients were given additional treatments between the first and second blood test; however, the additional treatment group was not significantly different in relative FVC change compared to the group with no additional treatment (p = 0.982). CONCLUSIONS: In patients with fibrotic avian HP, the annual changes in serum IgG testing were correlated with FVC changes, highlighting the importance of serum IgG testing over time.

Early Onset of Severe Interstitial Pneumonitis Associated With Anti-PD-1 Immune Checkpoint Antibody After Pleurodesis.

We present a case of lung adenocarcinoma with malignant pleural effusion. Nineteen days after pleurodesis using minocycline and OK-432 (picibanil), pembrolizumab monotherapy was initiated. Four days later, the patient experienced a persistent cough. Chest computed tomography showed that ground-glass opacity appeared on the same side as pleurodesis and spread bilaterally thereafter, which was diagnostic of immune checkpoint inhibitors (ICI)-related pneumonitis. As he presented a severe respiratory failure, corticosteroid therapy was administered. Two weeks later, respiratory failure completely resolved and the abnormal shadows dramatically improved. Our results indicate that severe ICI-related pneumonitis can develop within a short period after pleurodesis.

Treatment Strategies for Non-Small-Cell Lung Cancer with Comorbid Respiratory Disease; Interstitial Pneumonia, Chronic Obstructive Pulmonary Disease, and Tuberculosis.

Non-small cell lung cancer (NSCLC) patients are often complicated by other respiratory diseases, including interstitial pneumonia (IP), chronic obstructive pulmonary disease (COPD), and pulmonary tuberculosis (TB), and the management of which can be problematic. NSCLC patients with IP sometimes develop fatal acute exacerbation induced by pharmacotherapy, and the establishment of a safe treatment strategy is desirable. For advanced NSCLC with IP, carboplatin plus nanoparticle albumin-bound paclitaxel is a relatively safe and effective first-line treatment option. Although the safety of immune checkpoint inhibitors (ICIs) for these populations remains controversial, ICIs have the potential to provide long-term survival. The severity of COPD is an important prognostic factor in NSCLC patients. Although COPD complications do not necessarily limit treatment options, it is important to select drugs with fewer side effects on the heart and blood vessels as well as the lungs. Active TB is complicated by 2-5% of NSCLC cases during their disease course. Since pharmacotherapy, especially ICIs, reportedly induces the development of TB, the possibility of developing TB should always be kept in mind during NSCLC treatment. To date, there is no coherent review article on NSCLC with these pulmonary complications. This review article summarizes the current evidence and discusses future prospects for treatment strategies for NSCLC patients complicated with IP, severe COPD, and TB.

KRASG12C Inhibitor as a Treatment Option for Non-Small-Cell Lung Cancer with Comorbid Interstitial Pneumonia.

Non-small-cell lung cancer (NSCLC) with comorbid interstitial pneumonia (IP) is a population with limited treatment options and a poor prognosis. Patients with comorbid IP are at high risk of developing fatal drug-induced pneumonitis, and data on the safety and efficacy of molecularly targeted therapies are lacking. KRAS mutations have been frequently detected in patients with NSCLC with comorbid IP. However, the low detection rate of common driver gene mutations, such as epidermal growth factor receptor and anaplastic lymphoma kinase, in patients with comorbid IP frequently results in inadequate screening for driver mutations, and KRAS mutations may be overlooked. Recently, sotorasib and adagrasib were approved as treatment options for advanced NSCLC with KRASG12C mutations. Although patients with comorbid IP were not excluded from clinical trials of these KRASG12C inhibitors, the incidence of drug-induced pneumonitis was low. Therefore, KRASG12C inhibitors may be a safe and effective treatment option for NSCLC with comorbid IP. This review article discusses the promise and prospects of molecular-targeted therapies, especially KRASG12C inhibitors, for NSCLC with comorbid IP, along with our own clinical experience.

Successful pembrolizumab treatment for microsatellite instability-high thymoma: A case report.

Microsatellite instability (MSI) is a valuable biomarker for immune checkpoint inhibitors. We report the first case of MSI-high thymoma successfully treated with pembrolizumab. This patient had pleural dissemination and was treated with two cytotoxic chemotherapy regimens including carboplatin and paclitaxel combination therapy and pemetrexed, which did not have the desired effect. Because MSI status was high by using the surgical specimen, pembrolizumab was administered as 3rd line chemotherapy. After three courses, the pleural lesions dramatically shrunk, which confirmed a partial response. Although MSI-high thymoma is rare, our results suggest the necessity to evaluate MSI status in patients with thymoma.

Drug-related pneumonitis caused by amikacin liposome inhalation suspension: One pathologically proven case and single-center experience.

Amikacin liposome inhalation suspension (ALIS) is known to cause drug-related pneumonitis, which has been described as "hypersensitivity pneumonitis (HP)". However, its clinical and pathological characteristics have never been reported. We retrospectively evaluated 18 patients treated with ALIS. Three (16.7%) patients developed HP-pattern pneumonitis on high-resolution computed tomography. Serum eosinophil counts were elevated up to above 1000/µL in these three patients, which decreased with ALIS discontinuation only. Of note, the specimen obtained by transbronchial lung cryobiopsy in one patient revealed a mild degree of lymphocyte and eosinophil infiltration. Rather, the findings of acute lung injury such as an edematous thickening of the alveolar walls, and an accumulation of foamy degenerative macrophages in the alveolar lumina was prominent. A pulmonary alveolar proteinosis reaction was also observed. HP-pattern pneumonitis due to ALIS may pathologically correspond to acute lung injury and a pulmonary alveolar proteinosis reaction despite increasing serum eosinophil counts.

Favorable treatment response of bevacizumab-combined chemotherapy for advanced or recurrent invasive mucinous adenocarcinoma of the lung: A retrospective observational study.

Invasive mucinous adenocarcinoma (IMA) of the lung is a rare variant of adenocarcinoma characterized by abundant intracytoplasmic mucin within the tumor. Although IMA has poor sensitivity to conventional chemotherapy regimens used for non-small cell lung cancer, we observed a better response to the bevacizumab (BEV) regimen. In this retrospective study, we aimed to investigate the response to BEV-combined regimens in patients with IMA. Among 16 consecutive patients diagnosed with IMA between January 2016 and December 2020 at our institution and treated with systemic chemotherapy, seven patients were treated with BEV-combined regimens. The overall response rate to BEV-combined regimens was 85.7%, with six patients showing a partial response. The median progression-free survival was 6.1 months. One patient experienced respiratory failure, which was improved after administration of BEV-combined regimen. BEV-combined systemic therapy may have a favorable effect on advanced or recurrent IMA of the lung.

Spontaneous regression of acute fibrinous organizing pneumonia induced by COVID-19 vaccination: A case report.

A 42-year-old woman visited our hospital with complaints of fever, muscle pain, and dyspnea one week after receiving the coronavirus disease 2019 (COVID-19) vaccine. Chest high-resolution computed tomography showed a patchy consolidation and ground-glass attenuation in the both lungs, consistent with acute interstitial pneumonia. Transbronchial lung cryobiopsy revealed organizing pneumonia with marked intra-alveolar fibrin, and pathologically diagnosed as acute fibrinous organizing pneumonia (AFOP). Other causative diseases such as dermatomyositis was clinically ruled out, and COVID-19 vaccine-induced AFOP was diagnosed. Physician should check the history of COVID-19 vaccination when encountering a case of AFOP with an unknown cause.

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.

Concordance between transbronchial lung cryobiopsy and surgical lung biopsy in patients with idiopathic multicentric Castleman disease: A report of four cases.

BACKGROUND: Idiopathic multicentric Castleman disease (iMCD) is a rare polyclonal lymphoproliferative disease often associated with pulmonary involvement. Recently, transbronchial lung cryobiopsy (TBLC) has been reported to be useful for the diagnosis of diffuse interstitial lung disease. However, there have been no reports of pathological assessment of TBLC for iMCD. METHOD: To clarify the efficacy of TBLC in the diagnosis of iMCD, we retrospectively reviewed four iMCD patients who had undergone both TBLC and surgical lung biopsy (SLB). RESULTS: The median age was 44 years; 2 males and 2 females. Two or three TBLC specimens were taken from each patient. All patients had no complications other than minimal bleeding. The size of the TBLC specimens was approximately 5-6 × 3-4 mm, and the alveolar region, and centrilobular and perilobular areas were adequately sampled. As with SLB, the extent of lung lesions and inflammatory cell infiltration could be sufficiently evaluated by TBLC. The presence of lymphoid follicles could also be assessed by TBLC; however, the germinal centers with lymphoid follicles were difficult to evaluate. The TBLC specimens could also be evaluated for immunostaining, especially IgG4 immunostaining, to rule out IgG4-related lung disease. Pulmonary pathological grading showed a high concordance rate between major pathological findings of TBLC and SLB. The pathologist's confidence level of TBLC for the diagnosis of iMCD was high in all cases. CONCLUSIONS: TBLC exhibits a high concordance rate with SLB in the pathological evaluation of iMCD, which may be useful for the diagnosis of iMCD.

High prevalence of upper lung field pulmonary fibrosis radiologically consistent with pleuroparenchymal fibroelastosis in patients with round atelectasis.

BACKGROUND: Upper-lung field pulmonary fibrosis (upper-PF), radiologically consistent with pleuroparenchymal fibroelastosis (PPFE), was reported to develop in patients with a history of asbestos exposure and tuberculous pleurisy, indicating that chronic pleuritis is correlated with upper-PF development. Round atelectasis reportedly emerges after chronic pleuritis. This study aimed to clarify the association between round atelectasis and upper-PF. METHODS: We examined the radiological reports of all consecutive patients with round atelectasis between 2006 and 2018 and investigated the incidence of upper-PF development. RESULTS: Among 85 patients with round atelectasis, 21 patients (24.7%) were confirmed to finally develop upper-PF lesions. Upper-PF was diagnosed after round atelectasis recognition in more than half of the patients (13/21, 61.9%), whereas upper-PF and round atelectasis were simultaneously detected in the remaining 8 patients. At the time of round atelectasis detection, almost all patients (19/21, 90.5%) had diffuse pleural thickening and round atelectasis was commonly observed in non-upper lobes of 19 patients (90.5%). Fourteen patients had round atelectasis in unilateral lung, and the remaining 7 patients had round atelectasis in bilateral lungs. Among all 14 patients with unilateral round atelectasis, upper-PF developed on the same (n = 11) or both sides (n = 3). Thus, upper-PF emerged on the same side where round atelectasis was present (14/14, 100%). The autopsy of one patient revealed a thickened parietal-visceral pleura suggestive of chronic pleuritis. Subpleural fibroelastosis was also observed. CONCLUSIONS: Upper-PF occasionally develops on the same side of round atelectasis. Upper-PF may develop as a sequela of chronic pleuritis.

Successful tepotinib treatment of adenocarcinoma with MET exon 14 skipping and discordant results between Oncomine Dx target test and ArcherMET: A case report.

Patients with non-small cell lung cancer (NSCLC) are often positive for oncogenic driver mutations, such as EGFR, ALK, BRAF, RET and MET exon 14 skipping mutations (METex14 skipping). Recently, METex14 skipping has become a functional biomarker for NSCLC with the approval of MET kinase inhibitors. Tepotinib is an oral MET kinase inhibitor. Its overall response rate is 46%, and the median duration of the response is 11.1 months. In Japan, companion diagnostics for tepotinib are limited with the ArcherMET and AmoyDx test, but not with Oncomine Dx target test. The present study reports the case of a 60-year-old male patient with lung adenocarcinoma harboring METex14 skipping, which was positive on Oncomine DxTT, but not on ArcherMET. In his sample used for Oncomine DxTT, the read count of MET(13)-MET(15) products was only 46. He was treated with various chemotherapeutic agents, but developed cardiac tamponade due to the progression of the disease of mediastinal lymph node metastases. Tepotinib was administered following pericardial drainage, resulting in an immediate response in all lesions. The majority of the discordant samples between Oncomine DxTT and ArcherMET had read counts <800, and the patient described herein had only 46. Therefore, the results of the present study indicate that the use of tepotinib should be considered even in patients whose METex14 skipping results were negative with ArcherMET, yet positive on Oncomine DxTT, particularly relatively with low lead counts.

Radiological and Pathological Features of Cyst Formation in Idiopathic Multicentric Castleman Disease.

INTRODUCTION: Idiopathic multicentric Castleman disease (MCD) has been reported to form lung cysts at a relatively high rate. However, the radiological and pathological features of cystic formation in MCD are unclear. METHODS: To clarify these questions, we retrospectively investigated the radiological and pathological findings of cysts in MCD patients. Eight consecutive patients who underwent surgical lung biopsies in our center from 2000 to 2019 were included. RESULTS: The median age was 44.5 years, with three males and five females. On the initial computed tomography, cyst formation was found in seven patients (87.5%). All of the cysts were multiple, round, and thin walled, accompanying ground-glass attenuation (GGA) around cysts. In six patients (75%), cysts increased during their clinical courses, and the new cysts had emerged from GGA, although GGA was improved by treatment. In all four cases, whose pulmonary cysts could be pathologically evaluated, a marked plasma cell infiltration around the cyst wall, and loss of elastic fibers of the alveolar wall were observed. CONCLUSIONS: Pulmonary cysts emerged in the area of GGA pathologically consistent with plasma cell infiltration. Cysts in MCD may be formed by the loss of elastic fibers due to marked plasma cell infiltration and may be considered irreversible changes.

Cumulative Incidence of Thromboembolism and Prognostic Impact of Stroke in BRAF V600E-mutant Non-small-cell Lung Cancer.

BACKGROUND/AIM: Cancer and ischemic stroke are closely associated. Thromboembolism susceptibility in lung cancer may differ depending on oncogenic alterations. However, the clinical characteristics of thromboembolism in patients with BRAF-mutant non-small-cell lung cancer remain unknown. Thus, this study aimed to evaluate the cumulative incidence of thromboembolism in this population and describe such cases in detail. PATIENTS AND METHODS: We retrospectively investigated consecutive patients with BRAF V600E-mutant non-small-cell lung cancer. Cumulative incidence was calculated using a competing risk analysis. RESULTS: Of 10 patients with BRAF-V600E mutant lung cancer, five developed a total of seven thromboembolic events, showing a 1-year cumulative incidence of 43% (95% confidence interval=11-72%). These events consisted of four cancer-related stroke (CRS) events and three venous events including deep vein thrombosis or pulmonary embolism. Of note, most of the early thrombotic events were CRS. Two patients with CRS had multiple brain infarctions during anticancer drug therapy, characterized by high D-dimer levels, resulting in short-term mortality (13 and 22 days after stroke onset). CONCLUSION: A substantial proportion of patients with BRAF V600E-mutant lung cancer experienced thromboembolism during their disease course. CRS of undetermined source may predict a worse prognosis in this population.

A distinctive cytomorphological feature of interstitial pneumonia-related lung adenocarcinoma: The potential issues and solutions in practical diagnosis.

BACKGROUND: The cytological features of interstitial pneumonia (IP)-related lung adenocarcinoma (LADC) have not been clearly described. This study aimed to describe its cytomorphological features, uncover potential problems in practical cytological diagnosis, and provide possible solutions. METHODS: Bronchial brushing cytology samples from 40 IP-related LADC cases (the IP group) and 110 control cases (LADC unrelated to IP; the non-IP group) were analyzed. All patients underwent surgery after brushing cytology, and their histopathological subtypes were determined. The authors reviewed the cytological features and focused particularly on cytoplasmic mucin production. RESULTS: In the IP group, neoplastic cells with cytoplasmic mucin were detected at a significantly higher frequency (44.4% [8 of 18] vs. 6.3% [4 of 64]), and most of them were invasive mucinous adenocarcinomas (IMAs). Twenty-two of the 40 LADC cases in the IP group failed to be judged as "malignant/positive" (thus, they were judged to be "equivocal and/or negative"). The frequency of equivocal and/or negative judgments was 55.0% (22 of 40) in the IP group and 41.8% (46 of 110) in the non-IP group. The cytological diagnosis of IMA was difficult because it showed only slight nuclear atypia. Therefore, the authors examined the immunocytochemical expression of hepatocyte nuclear factor 4α (HNF4α), a diagnostic marker for IMA. As a result, four of the six cases that were judged to be equivocal in the IP group showed positive signals and could be retrospectively judged as malignant/positive. CONCLUSIONS: The cytological diagnosis of IP-related LADC may be more difficult because of the larger proportion of IMA. Immunocytochemistry for HNF4α can be used to improve diagnostic confidence in IP-related LADC.

Incidence of acute exacerbation in patients with interstitial lung disease after COVID-19 vaccination.

Acute exacerbations due to COVID-19 vaccination in patients with interstitial lung disease (ILD) have been reported, but their incidence is unknown. We investigated the incidence of exacerbations of ILD and respiratory symptoms due to the mRNA COVID-19 vaccines. A questionnaire survey was conducted on adverse reactions to the mRNA COVID-19 vaccination in 545 patients with ILD attending our hospital and retrospectively examined whether the eligible patients actually developed acute exacerbations of ILD induced by the vaccine. Of the 545 patients, 17 (3.1%) patients were aware of the exacerbation of respiratory symptoms, and four (0.7%) patients developed an acute ILD exacerbation after vaccination. Of the four patients who experienced exacerbations, two had collagen vascular disease-associated ILD, one had nonspecific interstitial pneumonia, another had unclassifiable idiopathic pneumonia, and none had idiopathic pulmonary fibrosis. Four patients were treated using steroid pulse therapy with a steroid taper, and two of the four also received intravenous cyclophosphamide pulse therapy. Tacrolimus was started in one patient with myositis-associated interstitial lung disease. Eventually, all patients exhibited improvement with immunosuppressive treatment and were discharged. COVID-19 vaccination for patients with ILD should be noted for developing acute exacerbations of ILD with low incidence, although manageable with early diagnosis and treatment.