Clinical utilization of artificial intelligence-based COVID-19 pneumonia quantification using chest computed tomography - a multicenter retrospective cohort study in Japan.

BACKGROUND: Computed tomography (CT) imaging and artificial intelligence (AI)-based analyses have aided in the diagnosis and prediction of the severity of COVID-19. However, the potential of AI-based CT quantification of pneumonia in assessing patients with COVID-19 has not yet been fully explored. This study aimed to investigate the potential of AI-based CT quantification of COVID-19 pneumonia to predict the critical outcomes and clinical characteristics of patients with residual lung lesions. METHODS: This retrospective cohort study included 1,200 hospitalized patients with COVID-19 from four hospitals. The incidence of critical outcomes (requiring the support of high-flow oxygen or invasive mechanical ventilation or death) and complications during hospitalization (bacterial infection, renal failure, heart failure, thromboembolism, and liver dysfunction) was compared between the groups of pneumonia with high/low-percentage lung lesions, based on AI-based CT quantification. Additionally, 198 patients underwent CT scans 3 months after admission to analyze prognostic factors for residual lung lesions. RESULTS: The pneumonia group with a high percentage of lung lesions (N = 400) had a higher incidence of critical outcomes and complications during hospitalization than the low percentage group (N = 800). Multivariable analysis demonstrated that AI-based CT quantification of pneumonia was independently associated with critical outcomes (adjusted odds ratio [aOR] 10.5, 95% confidence interval [CI] 5.59-19.7), as well as with oxygen requirement (aOR 6.35, 95% CI 4.60-8.76), IMV requirement (aOR 7.73, 95% CI 2.52-23.7), and mortality rate (aOR 6.46, 95% CI 1.87-22.3). Among patients with follow-up CT scans (N = 198), the multivariable analysis revealed that the pneumonia group with a high percentage of lung lesions on admission (aOR 4.74, 95% CI 2.36-9.52), older age (aOR 2.53, 95% CI 1.16-5.51), female sex (aOR 2.41, 95% CI 1.13-5.11), and medical history of hypertension (aOR 2.22, 95% CI 1.09-4.50) independently predicted persistent residual lung lesions. CONCLUSIONS: AI-based CT quantification of pneumonia provides valuable information beyond qualitative evaluation by physicians, enabling the prediction of critical outcomes and residual lung lesions in patients with COVID-19.

Exposure to Cigarette Smoke Enhances the Stemness of Alveolar Type 2 Cells.

Chronic exposure to cigarette smoke (CS) causes chronic inflammation, oxidative stress, and apoptosis of epithelial cells, which results in destruction of the lung matrix. However, the mechanism by which the lung fails to repair the CS-induced damage, thereby succumbing to emphysema, remains unclear. Alveolar type 2 (AT2) cells comprise the stem cells of the alveolar compartments and are responsible for repairing and maintaining lung tissues. In this study, we examined the effect of chronic CS on AT2 stem cells. Adult mice expressing GFP in their AT2 cells were exposed to CS for > 3 months. Histological assessment showed that CS not only induced emphysematous changes but also increased the number of AT2 cells compared with that of air-exposed lungs. Assessment of sorted GFP+/AT2 cells via the stem cell three-dimensional organoid/colony-forming assay revealed that the number and size of the colonies formed by the CS-exposed AT2 stem cells were significantly higher than those of air-exposed control AT2 cells. Although CS-exposed lungs had more apoptotic cells, examination of the surviving AT2 stem cells in two-dimensional in vitro culture revealed that they developed a higher ability to resist apoptosis. Microarray analysis of CS-exposed AT2 stem cells revealed the upregulation of genes related to circadian rhythm and inflammatory pathways. In conclusion, we provide evidence that AT2 stem cells respond to chronic CS exposure by activating their stem cell function, thereby proliferating and differentiating faster and becoming more resistant to apoptosis. Disturbances in expression levels of several circadian rhythm-related genes might be involved in these changes.

Impact of cataract on health-related quality of life in a longitudinal Japanese chronic obstructive pulmonary cohort.

Cigarette smoking increases the risk of developing both cataract and chronic obstructive pulmonary disease (COPD). The prevalence of cataract and the clinical characteristics of COPD patients with cataract were retrospectively investigated in a 2-year observational COPD cohort. We analyzed 395 patients with complete data on ophthalmologic evaluation (319 subjects with COPD and 76 subjects at risk of COPD). There was no difference in the prevalence of cataract between COPD patients and those at risk (47.0% vs. 42.1%, p = 0.44). Age ≥ 75 years, low body mass index, and hypertension were independently associated with cataract as a comorbidity in COPD. The incidence of exacerbation within 2 years was significantly higher in COPD patients with cataract than those without cataract (36.6% vs. 18.3%, p = 0.0019). COPD patients with cataract exhibited significantly higher COPD assessment test score compared to those without cataract (13.7 ± 8.9 vs. 11.5 ± 7.2, p = 0.0240). Overall St George's Respiratory Questionnaire score and each component were significantly worse in COPD patients with cataract compared to those without cataract. COPD patients with cataract exhibited poor health-related quality of life and frequent exacerbations. The association between cataract and exacerbations of COPD deserves further attention.

Pneumococcal Infection Aggravates Elastase-Induced Emphysema via Matrix Metalloproteinase 12 Overexpression.

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (COPD)--typically caused by bacterial or viral infection--is associated with poor prognosis and emphysema progression through unknown mechanisms. We aimed to elucidate the mechanisms responsible for the poor prognosis and emphysema progression associated with COPD exacerbation. METHODS: We established a mouse model mimicking acute human COPD exacerbation, wherein mice with elastase-induced emphysema were intranasally infected with Streptococcus pneumoniae. RESULTS: In mice with elastase-induced emphysema, infection with S. pneumoniae resulted in increased mortality, an increased number of inflammatory cells in bronchoalveolar lavage fluid (BALF), and increased matrix metalloproteinase 12 (MMP-12) production in the lungs, as well as enhanced emphysema progression. The increased MMP-12 production was mostly due to alveolar type II cells, alveolar macrophages, and lymphocytes that aggregated around vessels and bronchioles. Dexamethasone treatment suppressed the mortality rate and number of inflammatory cells in BALF but not emphysema progression, possibly owing to the failure of MMP-12 suppression in the lungs, whereas treatment with the MMP inhibitor ONO-4817 dramatically suppressed both mortality rate and emphysema progression. CONCLUSIONS: These results suggest that MMP-12 production during COPD exacerbation results in increased mortality and emphysema progression. Our study identifies MMP-12 as a target to prevent further aggravation of COPD.

[Bone turnover and bone structure in clinical animal models of COPD.]

The features of chronic obstructive pulmonary disease(COPD)are chronic inflammatory and emphysema changes in the lungs by long-term cigarette smoke(CS)exposure. Osteoporosis is an important systemic comorbidity of COPD. Severe emphysema and low body mass index(BMI)are independent risk factors for low bone mineral density in COPD patients. However the pathophysiologic mechanisms underlying emphysema and osteoporosis have not been fully elucidated. An established mouse model of CS-induced emphysema with decrease body weight and bone mineral density is important for investigating the cause of osteoporosis in COPD patients.

Evaluation of cigarette smoke-induced emphysema in mice using quantitative micro-computed tomography.

Chronic cigarette smoke (CS) exposure provokes variable changes in the lungs, and emphysema is an important feature of chronic obstructive pulmonary disease. The usefulness of micro-computed tomography (CT) to assess emphysema in different mouse models has been investigated, but few studies evaluated the dynamic structural changes in a CS-induced emphysema mouse model. A novel micro-CT technique with respiratory and cardiac gating has resulted in high-quality images that enable processing for further quantitative and qualitative analyses. Adult female C57BL/6J mice were repeatedly exposed to mainstream CS, and micro-CT scans were performed at 0, 4, 12, and 20 wk. Emphysema was also histologically quantified at each time point. Air-exposed mice and mice treated with intratracheal elastase served as controls and comparisons, respectively. End-expiratory lung volume, corresponding to functional residual volume, was defined as the calculated volume at the phase of end-expiration, and it evaluated air trapping. The end-expiratory lung volumes of CS-exposed mice were significantly larger than those of air controls at 12 and 20 wk, which was in line with alveolar enlargement and destruction by histological quantification. However, CS exposure neither increased low attenuation volume nor decreased the average lung CT value at any time point, unlike the elastase-instilled emphysema model. CS-exposed mice had rather higher average lung CT values at 4 and 12 wk. This is the first study characterizing a CS-induced emphysema model on micro-CT over time in mice. Moreover, these findings extend our understanding of the distinct pathophysiology of CS-induced emphysema in mice.

Polymorphism of LRP5 gene and emphysema severity are associated with osteoporosis in Japanese patients with or at risk for COPD.

BACKGROUND AND OBJECTIVE: Osteoporosis is an important systemic comorbidity of chronic obstructive pulmonary disease (COPD). However, neither its mechanisms nor its risk factors have been fully elucidated. With regard to genetic factors, low-density lipoprotein receptor-related protein 5 (LRP5) A1330V is known to be associated with osteoporosis in the general population, but the influence of this polymorphism in COPD is unknown. The aim of this study was to investigate the potential risk factors of COPD-related bone loss and fracture. METHODS: Keio University and affiliated hospitals have enrolled an observational cohort to investigate the management of COPD comorbidities. To assess risk factors for osteopenia and osteoporosis, bone mineral density (BMD) of the hip and lumbar spine, presence of vertebral fracture, quantitative data on emphysema and airway wall on computed tomography, as well as LRP5 genotype were analysed in patients with or at risk for COPD (n = 270). RESULTS: The percentage of subjects with osteoporosis (T-score ≤ -2.5), osteopenia (T-score between -1 and -2.5) and a normal BMD (T-score ≥ -1) was 15.2%, 35.9% and 48.9%, respectively. T-score was significantly decreased in subjects with LRP5 TT genotype (n = 15) compared with that in those with CC/CT genotype (n = 255) (-1.83 vs. -0.98, P = 0.0167). On multivariate logistic regression analysis, female gender (odds ratio (OR) 10.4; P < 0.0001), severe emphysema (OR 2.3; P = 0.013) and LRP5 TT genotype (OR 3.7; P = 0.031) independently increased the risk of osteopenia/osteoporosis. CONCLUSIONS: This study confirmed the complex pathophysiology of COPD-related osteoporosis, including the influence of gender, clinical phenotype and genetic factors.

Analysis of comorbid factors that increase the COPD assessment test scores.

BACKGROUND: The chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) is a concise health status measure for COPD. COPD patients have a variety of comorbidities, but little is known about their impact on quality of life. This study was designed to investigate comorbid factors that may contribute to high CAT scores. METHODS: An observational study at Keio University and affiliated hospitals enrolled 336 COPD patients and 67 non-COPD subjects. Health status was assessed by the CAT, the St. Georges Respiratory Questionnaire (SGRQ), and all components of the Medical Outcomes Study Short-Form 36-Item (SF-36) version 2, which is a generic measure of health. Comorbidities were identified based on patients' reports, physicians' records, and questionnaires, including the Frequency Scale for the Symptoms of Gastro-esophageal reflux disease (GERD) and the Hospital Anxiety and Depression Scale. Dual X-ray absorptiometry measurements of bone mineral density were performed. RESULTS: The CAT showed moderate-good correlations with the SGRQ and all components of the SF-36. The presence of GERD, depression, arrhythmia, and anxiety was significantly associated with a high CAT score in the COPD patients. CONCLUSIONS: Symptomatic COPD patients have a high prevalence of comorbidities. A high CAT score should alert the clinician to a higher likelihood of certain comorbidities such as GERD and depression, because these diseases may co-exist unrecognized. TRIAL REGISTRATION: Clinical trial registered with UMIN (UMIN000003470).

Lung volume measurement using chest CT in COVID-19 patients: a cohort study in Japan.

OBJECTIVE: This study aimed to investigate the utility of CT quantification of lung volume for predicting critical outcomes in COVID-19 patients. METHODS: This retrospective cohort study included 1200 hospitalised patients with COVID-19 from 4 hospitals. Lung fields were extracted using artificial intelligence-based segmentation, and the percentage of the predicted (%pred) total lung volume (TLC (%pred)) was calculated. The incidence of critical outcomes and posthospitalisation complications was compared between patients with low and high CT lung volumes classified based on the median percentage of predicted TLCct (n=600 for each). Prognostic factors for residual lung volume loss were investigated in 208 patients with COVID-19 via a follow-up CT after 3 months. RESULTS: The incidence of critical outcomes was higher in the low TLCct (%pred) group than in the high TLCct (%pred) group (14.2% vs 3.3%, p<0.0001). Multivariable analysis of previously reported factors (age, sex, body mass index and comorbidities) demonstrated that CT-derived lung volume was significantly associated with critical outcomes. The low TLCct (%pred) group exhibited a higher incidence of bacterial infection, heart failure, thromboembolism, liver dysfunction and renal dysfunction than the high TLCct (%pred) group. TLCct (%pred) at 3 months was similarly divided into two groups at the median (71.8%). Among patients with follow-up CT scans, lung volumes showed a recovery trend from the time of admission to 3 months but remained lower in critical cases at 3 months. CONCLUSION: Lower CT lung volume was associated with critical outcomes, posthospitalisation complications and slower improvement of clinical conditions in COVID-19 patients.

CT-derived vertebral bone mineral density is a useful biomarker to predict COVID-19 outcome.

The low vertebral bone computed tomography (CT) Hounsfield unit values measured on CT scans reflect low bone mineral density (BMD) and are known as diagnostic indicators for osteoporosis. The potential prognostic significance of low BMD defined by vertebral bone CT values for the coronavirus disease 2019 (COVID-19) remains unclear. This study aimed to assess the impact of BMD on the clinical outcome in Japanese patients with COVID-19 and evaluate the association between BMD and critical outcomes, such as high-flow nasal cannula, non-invasive and invasive positive pressure ventilation, extracorporeal membrane oxygenation, or death. We examined the effects of COVID-19 severity on the change of BMD over time. This multicenter retrospective cohort study enrolled 1132 inpatients with COVID-19 from the Japan COVID-19 Task Force database between February 2020 and September 2022. The bone CT values of the 4th, 7th, and 10th thoracic vertebrae were measured from chest CT images. The average of these values was defined as BMD. Furthermore, a comparative analysis was conducted between the BMD on admission and its value 3 months later. The low BMD group had a higher proportion of critical outcomes than did the high BMD group. In a subanalysis stratifying patients by epidemic wave according to onset time, critical outcomes were higher in the low BMD group in the 1st-4th waves. Multivariable logistic analysis of previously reported factors associated with COVID-19 severity revealed that low BMD, chronic kidney disease, and diabetes were independently associated with critical outcomes. At 3 months post-infection, patients with oxygen demand during hospitalization showed markedly decreased BMD than did those on admission. Low BMD in patients with COVID-19 may help predict severe disease after the disease onset. BMD may decrease over time in patients with severe COVID-19, and the impact on sequelae symptoms should be investigated in the future.

Integrated assessment of computed tomography density in pectoralis and erector spinae muscles as a prognostic biomarker for coronavirus disease 2019.

BACKGROUND ＆ AIMS: Muscle quantification using chest computed tomography (CT) is a useful prognostic biomarker for coronavirus disease 2019 (COVID-19). However, no studies have evaluated the clinical course through comprehensive assessment of the pectoralis and erector spinae muscles. Therefore, we compared the impact of the areas and densities of these muscles on COVID-19 infection outcome. METHODS: This multicenter retrospective cohort study was conducted by the COVID-19 Task Force. A total of 1410 patients with COVID-19 were included, and data on the area and density of the pectoralis and erector spinae muscles on chest CT were collected. The impact of each muscle parameter on the clinical outcome of COVID-19 was stratified according to sex. The primary outcome was the percentage of patients with severe disease, including those requiring oxygen supplementation and those who died. Additionally, 167 patients were followed up for changes in muscle parameters at three months and for the clinical characteristics in case of reduced CT density. RESULTS: For both muscles, low density rather than muscle area was associated with COVID-19 severity. Regardless of sex, lower erector spinae muscle density was associated with more severe disease than pectoralis muscle density. The muscles were divided into two groups using the receiver operating characteristic curve of CT density, and the population was classified into four (Group A: high CT density for both muscles, Group B: low CT density for pectoralis and high for erector spinae muscle. Group C: high CT density for pectoralis and low for erector spinae muscle, Group D: low CT density for both muscles). In univariate analysis, Group D patients exhibited worse outcomes than Group A (OR: 2.96, 95% CI: 2.03-4.34 in men; OR: 3.02, 95% CI: 2.66-10.4 in women). Multivariate analysis revealed that men in Group D had a significantly more severe prognosis than those in Group A (OR: 1.82, 95% CI: 1.16-2.87). Moreover, Group D patients tended to have the highest incidence of other complications due to secondary infections and acute kidney injury during the clinical course. Longitudinal analysis of both muscle densities over three months revealed that patients with decreased muscle density over time were more likely to have severe cases than those who did not. CONCLUSIONS: Muscle density, rather than muscle area, predicts the clinical outcomes of COVID-19. Integrated assessment of pectoralis and erector spinae muscle densities demonstrated higher accuracy in predicting the clinical course of COVID-19 than individual assessments.

Epicardial adipose tissue measured from analysis of adipose tissue area using chest CT imaging is the best potential predictor of COVID-19 severity.

BACKGROUND: Computed tomography (CT) imaging is widely used for diagnosing and determining the severity of coronavirus disease 2019 (COVID-19). Chest CT imaging can be used to calculate the epicardial adipose tissue (EAT) and upper abdominal visceral adipose tissue (Abd-VAT) areas. The EAT is the main source of inflammatory cytokines involved in chest inflammatory diseases; thus, the EAT area might be a more useful severity predictor than the Abd-VAT area for COVID-19. However, to the best of our knowledge, there are no large-scale reports that sufficiently consider this issue. In addition, there are no reports on the characteristics of patients with normal body mass index (BMI) and high adipose tissue. AIM: The purpose of this study was to analyze whether the EAT area, among various adipose tissues, was the most associated factor with COVID-19 severity. Using a multicenter COVID-19 patient database, we analyzed the associations of chest subcutaneous, chest visceral, abdominal subcutaneous, and Abd-VAT areas with COVID-19 outcomes. In addition, the clinical significance of central obesity, commonly disregarded by BMI, was examined. METHODS: This retrospective cohort study evaluated patients with COVID-19 aged ≥18 years In Japan. Data including from chest CT images collected between February 2020 and October 2022 in four hospitals of the Japan COVID-19 Task Force were analyzed. Patient characteristics and COVID-19 severity were compared according to the adipose tissue areas (chest and abdominal subcutaneous adipose tissue [Chest-SAT and Abd-SAT], EAT, and Abd-VAT) calculated from chest CT images. RESULTS: We included 1077 patients in the analysis. Patients with risk factors of severe COVID-19 such as old age, male sex, and comorbidities had significantly higher areas of EAT and Abd-VAT. High EAT area but not high Abd-VAT area was significantly associated with COVID-19 severity (adjusted odds ratio (aOR): 2.66, 95 % confidence interval [CI]: 1.19-5.93). There was no strong correlation between BMI and VAT. Patients with high VAT area accounted for 40.7 % of the non-obesity population (BMI < 25 kg/m2). High EAT area was also significantly associated with COVID-19 severity in the non-obesity population (aOR: 2.50, 95 % CI: 1.17-5.34). CONCLUSIONS: Our study indicated that VAT is significantly associated with COVID-19 severity and that EAT is the best potential predictor for risk stratification in COVID-19 among adipose tissue areas. Body composition assessment using EAT is an appropriate marker for identifying obesity patients overlooked by BMI. Considering the next pandemic of the global health crisis, our findings open new avenues for implementing appropriate body composition assessments based on CT imaging.

Differential impacts between fat mass index and fat-free mass index on patients with COPD.

BACKGROUND: Differences in the clinical impacts of fat mass index (FMI) and fat-free mass index (FFMI) remain unclear in patients with chronic obstructive pulmonary disease (COPD). We hypothesized that FMI and FFMI have different impacts on 1) emphysema and 2) pulmonary function and health-related quality of life of COPD patients. METHODS: Patients with COPD (n = 228), enrolled in a multicenter prospective 3-year cohort were classified into four groups based on baseline median FMI and FFMI values. Emphysema assessed as the ratio of low attenuation area to total lung volume (LAA%) on computed tomography, pulmonary function, and health-related quality of life assessed using the St. George's Respiratory Questionnaire (SGRQ) were compared. RESULTS: The four groups had statistically significant differences in LAA%, pulmonary function, and SGRQ scores. The Low FMI Low FFMI group exhibited the highest LAA%, lowest pulmonary function, and worst SGRQ scores among the four groups. In addition, these differences were consistent over 3 years. Multivariate analysis showed that low FMI was associated with high LAA%, low inspiratory capacity/total lung capacity (IC/TLC), and carbon monoxide transfer coefficient (KCO). In contrast, low FFMI was associated with these factors as well as worse SGRQ scores. CONCLUSION: FMI and FFMI have different effects on the clinical manifestations of COPD. Both low fat and muscle mass contributed to severe emphysema, whereas only low muscle mass contributed to worse health-related quality of life in patients with COPD.

Propensity-Score Matched Analysis of the Effectiveness of Baricitinib in Patients With Coronavirus Disease 2019 (COVID-19) Using Nationwide Real-World Data: An Observational Matched Cohort Study From the Japan COVID-19 Task Force.

Background: To determine the effectiveness of baricitinib in patients with coronavirus disease 2019 (COVID-19), investigate whether baricitinib prevents the need for invasive mechanical ventilation and identify patient subgroups that would benefit from baricitinib. Methods: This observational matched-cohort study was conducted by the Japan COVID-19 Task Force, a nationwide multicenter consortium. Patients with COVID-19 aged ≥18 years were identified from 70 hospitals in Japan. Among patients with confirmed COVID-19 from February 2020 to September 2021, those receiving baricitinib were propensity-score matched with controls. Results: Among 3309 patients, 144 propensity score-matched pairs were identified. Thirteen (9.0%) patients in the baricitinib group and 27 (18.8%) in the control group required invasive mechanical ventilation during the disease course (odds ratio, 0.43). Although the baricitinib group had more severe disease, there were no significant differences in the intensive care unit admission rates (odds ratio, 1.16) and mortality rates (odds ratio, 0.74) between groups. In subgroup analyses, baricitinib was associated with a significant reduction in the need for invasive mechanical ventilation in patients requiring oxygen support (odds ratio, 0.28), with rapid shadow spread on chest radiography (odds ratio, 0.11), or treated with remdesivir (odds ratio, 0.27), systemic corticosteroids (odds ratio, 0.31), or anticoagulants (odds ratio, 0.17). Conclusions: Baricitinib is effective at preventing the need for invasive mechanical ventilation in patients with COVID-19.

Characteristics of chronic obstructive pulmonary disease patients with robust progression of emphysematous change.

Emphysema is a major pathological change in chronic obstructive pulmonary disease (COPD). However, the annual changes in the progression of emphysematous have not been investigated. We aimed to determine possible baseline predicting factors of the change in emphysematous progression in a subgroup of COPD patients who demonstrated rapid progression. In this observational study, we analyzed patients with COPD who were followed up by computed tomography (CT) at least two times over a 3-year period (n = 217). We divided the annual change in the low attenuation area percentage (LAA%) into quartiles and defined a rapid progression group (n = 54) and a non-progression group (n = 163). Predictors of future changes in emphysematous progression differed from predictors of high LAA% at baseline. On multivariate logistic regression analysis, low blood eosinophilic count (odds ratio [OR], 3.22; P = 0.04) and having osteoporosis (OR, 2.13; P = 0.03) were related to rapid changes in emphysematous progression. There was no difference in baseline nutritional parameters, but nutritional parameters deteriorated in parallel with changes in emphysematous progression. Herein, we clarified the predictors of changes in emphysematous progression and concomitant deterioration of nutritional status in COPD patients.

Tracheal granular cell tumour presenting with throat discomfort.

Granular cell tumours (GCTs) are a rare form of neoplasm found throughout the body. Tracheobronchial involvement is less common. We describe a case of tracheal GCT in a 37-year-old Japanese woman presenting with throat discomfort. A tracheal tumour was found during laryngoscopy for undefined throat discomfort. Bronchoscopy demonstrated a white sub-epithelial solitary nodule on the tracheal wall, and pathological examination of the biopsy samples confirmed GCT. No therapeutic procedures were performed, and the tumour is currently under strict observation. Throat discomfort is a rare presentation of tracheal tumours, but an early inspection using laryngoscopy and bronchoscopy may be helpful in determining an accurate diagnosis.

Pattern of FDG-PET uptake in lipoid pneumonia simulating lung cancer.

Lipoid pneumonia presents with a variety of lung abnormalities, particularly mass forming lesions that mimic lung cancers. While 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) is expected to discriminate both diseases, some previous reports showed pseudo-positive FDG uptake in lipoid pneumonia. Here, we report a case of pathologically proven chronic lipoid pneumonia in a 78-year-old Japanese man. Computed tomography (CT) showed multi-lobar mass-forming lesions with a fat-density. PET confirmed the spotty accumulation of FDG in the corresponding fat-density area on CT, suggesting lipoid pneumonia. We reviewed the literature and discussed the FDG uptake patterns in lipoid pneumonia.

Pulmonary sclerosing pneumocytoma demonstrating intratumoral hematoma.

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign neoplasm of the lung that shows a slow growing pattern. Corresponding contrast-enhancements on chest computed tomography (CT) vary widely in both patterns and degrees. However, gross intratumoral radiolucencies, attributable to cyst formation, necrosis, or intratumoral hematoma, were rarely reported in PSP cases. We herein report on a case involving a 61-year-old Japanese women with PSP demonstrating CT-defined intratumoral radiolucency. A chest CT scan revealed a solitary and well-circumscribed nodule that showed a substantial growth over a 7-year period. The tumor was composed of a solid portion visualized with contrast-enhancement and a central radiolucency on a chest CT scan. A positron emission tomography scan revealed high uptake of fluorodeoxyglucose on the solid portion of the tumor, but the radiolucent portion showed negative uptake. The examination of a tumor specimen obtained by a percutaneous core needle biopsy aided in determining a pathological diagnosis of PSP, and the patient subsequently received a right lower lobectomy of the lung. The portion of central radiolucency on the CT scan corresponding to the surgical specimen was pathologically proven to be gross hematoma.

A Histologically Complete Response to Immunotherapy Using Pembrolizumab in a Patient with Giant Cell Carcinoma of the Lung: An Additional Report and Literature Review.

We previously reported a case of giant cell carcinoma in the lung, in which the use of antiprogrammed death 1 (PD-1) immunotherapy resulted in substantial tumor reduction. In the present study, we describe an additional clinical course. A 69-year-old woman was diagnosed with giant cell carcinoma of the lung in clinical stage IVB (T2bN0M1c, BRA). The tumor expressed programmed death ligand 1 (PD-L1) in a high proportion. The patient received stereotactic radiotherapy for two sites of small brain metastases, followed by immunotherapy using anti-PD-1 antibodies (pembrolizumab). The treatment exerted a substantial tumor reduction through four cycles. However, treatment was withdrawn due to renal dysfunction. The primary lung tumor continued to regress for an additional four months without any further therapy, resulting in a clinical stage of T1aN0M0. Salvage thoracic surgery was then performed to remove the tumor residue in the lung. Microscopic examination of the sample revealed no residual cancer. The patient was free from recurrence at 16 months post surgery. We then comprehensively reviewed lung sarcomatoid carcinoma cases in the literature, in which anti-PD-1 antibodies were implemented. The current literature and our own findings suggest sarcomatoid carcinomas express high levels of tumoral PD-L1 and can be effectively treated with anti-PD-1 antibodies.

Predictive and modifying factors of bone mineral density decline in patients with COPD.

RATIONALE: Various determinants of osteoporosis have been previously identified. However, only a few longitudinal studies have examined related factors. We aimed to investigate factors predicting and modifying rapid decline of bone mineral density in patients with chronic obstructive pulmonary disease. METHODS: We analyzed patients with chronic obstructive pulmonary disease whose bone mineral density were measured at least three times over three years (n = 111). We divided annual per cent changes of bone mineral density in different body parts into tertiles. Rapid decliners (n = 33) were defined as those with the largest decline in at least two parts; all other participants were defined as non-rapid decliners (n = 78). RESULTS: At enrollment, bone mineral density did not differ between the two groups. However, rapid decliners had a significantly greater rate of new vertebral fractures over 3 years compared with non-rapid decliners. On multivariate logistic regression analysis, age, moderate to severe emphysema, no daily exercise habits, and anemia increased the likelihood of rapid decliners. Furthermore, patients who newly started and continued bisphosphonate exhibited higher annual per cent changes of bone mineral density than did those without bisphosphonate use. CONCLUSIONS: A rapid decline in bone mineral density correlates to a higher likelihood of vertebral fracture. We clarified the predictors of bone mineral density decline and demonstrated that bisphosphonate use might modify bone mineral density in patients with chronic obstructive pulmonary disease.