Algorithmic Approach to the Diagnosis of Organizing Pneumonia: A Correlation of Clinical, Radiologic, and Pathologic Features

Acute Pulmonary Injury: An Imaging and Clinical Review

Acute pulmonary injury can occur in response to any number of inciting factors. The body's response to these insults is much less diverse and usually categorizable as one of several patterns of disease defined by histopathology, with corresponding patterns on chest CT. Common patterns of acute injury include diffuse alveolar damage, organizing pneumonia, acute eosinophilic pneumonia, and hypersensitivity pneumonitis. The ultimate clinical diagnosis is multidisciplinary, requiring a detailed history and relevant laboratory investigations from referring clinicians, identification of injury patterns on imaging by radiologists, and sometimes tissue evaluation by pathologists. In this review, several clinical diagnoses will be explored, grouped by imaging pattern, with a representative clinical presentation, a review of the current literature, and a discussion of typical imaging findings. Additional information on terminology and disambiguation will be provided to assist with comprehension and standardization of descriptions. The focus will be on the acute phase of illness from presentation to diagnosis; treatment methods and chronic sequela of acute disease are beyond the scope of this review.

The bronchoalveolar lavage fluid CD44 as a marker for pulmonary fibrosis in diffuse parenchymal lung diseases

Introduction

Diffuse parenchymal lung diseases (DPLD) cover heterogeneous types of lung disorders. Among many pathological phenotypes, pulmonary fibrosis is the most devastating and represents a characteristic sign of idiopathic pulmonary fibrosis (IPF). Despite a poor prognosis brought by pulmonary fibrosis, there are no specific diagnostic biomarkers for the initial development of this fatal condition. The major hallmark of lung fibrosis is uncontrolled activation of lung fibroblasts to myofibroblasts associated with extracellular matrix deposition and the loss of both lung structure and function.

Methods

Here, we used this peculiar feature in order to identify specific biomarkers of pulmonary fibrosis in bronchoalveolar lavage fluids (BALF). The primary MRC-5 human fibroblasts were activated with BALF collected from patients with clinically diagnosed lung fibrosis; the activated fibroblasts were then washed rigorously, and further incubated to allow secretion. Afterwards, the secretomes were analysed by mass spectrometry.

Results

In this way, the CD44 protein was identified; consequently, BALF of all DPLD patients were positively tested for the presence of CD44 by ELISA. Finally, biochemical and biophysical characterizations revealed an exosomal origin of CD44. Receiver operating characteristics curve analysis confirmed CD44 in BALF as a specific and reliable biomarker of IPF and other types of DPLD accompanied with pulmonary fibrosis.

Mycobacterium goodii pulmonary disease with organizing pneumonia: A case report and review of literature

Mycobacterium goodii, a rapidly growing non-tuberculous mycobacterium, rarely causes pulmonary diseases. A patient was admitted to our hospital with a fever and cough. Chest radiography revealed consolidation in the right middle lung. As he had previously been treated for organizing pneumonia (OP), he was diagnosed with OP recurrence and administered systemic corticosteroids. Although initial improvement was observed, the pulmonary consolidations worsened. Transbronchial lung cryobiopsy revealed an OP pattern. M. goodii was identified in sputum acid-fast bacilli cultures. The patient was diagnosed with M. goodii pulmonary disease and secondary OP. Although intravenous imipenem-cilastatin, amikacin, and ciprofloxacin led to initial improvement in pulmonary consolidations, the consolidations re-worsened. Systemic corticosteroids were initiated, resulting in improvement in the consolidations. The dose of systemic corticosteroids was tapered; oral antimycobacterial therapy was continued. M. goodii can cause pulmonary disease and induce OP; antimycobacterial therapy and systemic corticosteroids can be effective.

Secondary organizing pneumonia after infection

This editorial explores the clinical implications of organizing pneumonia (OP) secondary to pulmonary tuberculosis, as presented in a recent case report. OP is a rare condition characterized by inflammation in the alveoli, which spreads to alveolar ducts and terminal bronchioles, usually after lung injuries caused by infections or other factors. OP is classified into cryptogenic (idiopathic) and secondary forms, the latter arising after infections, connective tissue diseases, tumors, or treatments like drugs and radiotherapy. Secondary OP may be triggered by infections caused by bacteria, viruses, fungi, mycobacteria, or parasites. Key diagnostic features include subacute onset of nonspecific respiratory symptoms such as dry cough, chest pain, and exertional dyspnea. Imaging with computed tomography scans typically reveals three patterns: (1) Bilateral subpleural consolidation; (2) Nodular consolidation; and (3) A reticular pattern. Bronchoscopy with bronchoalveolar lavage helps exclude other causes. Standard treatment consists of corticosteroid therapy tapered over 6 months to 12 months. This editorial highlights clinical and diagnostic strategies to ensure timely and effective patient care.

Ocrelizumab-associated cryptogenic organizing pneumonia in multiple sclerosis: Two case reports and comprehensive literature review

BACKGROUND

Cryptogenic organizing pneumonia (COP) is an interstitial lung disease, with causes including anti-CD20 antibodies. Ocrelizumab is a humanized monoclonal antibody against CD20 approved for use in relapsing-remitting or primary progressive multiple sclerosis (MS), with no conclusive data regarding pulmonary toxicity.

CASES

We describe two cases of COP associated with ocrelizumab use in multiple sclerosis patients.

CONCLUSIONS

We suggest considering COP whenever respiratory symptoms arise in MS patients receiving ocrelizumab therapy. COP diagnosis requires clinical and radiological exclusion of alternative diagnoses such as opportunistic infections, autoimmunity, drugs, and neoplasms. Appropriate steroid therapy has an excellent clinical response rate.

Correlation between CT-based phenotypes and serum biomarker in interstitial lung diseases

BACKGROUND

The quantitative analysis of computed tomography (CT) and Krebs von den Lungen-6 (KL-6) serum level has gained importance in the diagnosis, monitoring, and prognostication of interstitial lung disease (ILD). However, the associations between quantitative analysis of CT and serum KL-6 level remain poorly understood.

METHODS

In this retrospective observational study conducted at tertiary hospital between June 2020 and March 2022, quantitative analysis of CT was performed using the deep learning-based method including reticulation, ground glass opacity (GGO), honeycombing, and consolidation. We investigated the associations between CT-based phenotypes and serum KL-6 measured within three months of the CT scan. Furthermore, we evaluated the performance of the combined CT-based phenotypes and KL-6 levels in predicting hospitalizations due to respiratory reasons of ILD patients.

RESULTS

A total of 131 ILD patients (104 males) with a median age of 67 years were included in this study. Reticulation, GGO, honeycombing, and consolidation extents showed a positive correlation with KL-6 levels. [Reticulation, correlation coefficient (r) = 0.567, p < 0.001; GGO, r = 0.355, p < 0.001; honeycombing, r = 0.174, p = 0.046; and consolidation, r = 0.446, p < 0.001]. Additionally, the area under the ROC of the combined reticulation and KL-6 for hospitalizations due to respiratory reasons was 0.810 (p < 0.001).

CONCLUSIONS

Quantitative analysis of CT features and serum KL-6 levels ascertained a positive correlation between the two. In addition, the combination of reticulation and KL-6 shows potential for predicting hospitalizations of ILD patients due to respiratory causes. The combination of reticulation, focusing on phenotypic change in lung parenchyma, and KL-6, as an indicator of lung injury extent, could be helpful for monitoring and predicting the prognosis of various types of ILD.

Immune checkpoint inhibitor therapy‑related pneumonitis: How, when and why to diagnose and manage (Review)

Immune checkpoint inhibitor (ICI) therapy has revolutionized cancer treatment by enhancing the immune response against tumor cells. However, their influence on immune pathways can lead to immune-related adverse events such as pneumonitis, necessitating rapid diagnosis and management to prevent severe complications. These adverse events arise from the activation of the immune system by immunotherapeutic drugs, leading to immune-mediated inflammation and tissue damage in various organs and tissues throughout the body. The present review article discusses the pathophysiology, clinical presentation, diagnostic modalities and management strategies for ICI-related pneumonitis, emphasizing early recognition and tailored interventions. Future research endeavors should focus on elucidating the underlying mechanisms of pneumonitis and identifying predictive biomarkers to guide personalized treatment strategies in this evolving field of oncology.

Clinical utility of bedside Contrast-Enhanced Ultrasound (CEUS) in the diagnosis of pneumonia in elderly patients: Comparison with clinical, -radiological and ultrasound diagnosis

AIMS

to measure the clinical impact of contrast-enhanced ultrasound (CEUS) in the diagnosis of -community-acquired pneumonia (CAP), compared to clinical, radiological and ultrasound diagnosis.

METHODS

84 patients (47/37 males/females, mean age:78,57±11,7 Y) with clinical suspicion of pneumonia and with ultrasound findings of peripheral lung lesions, were investigated with CEUS for a better characterization. Final diagnosis of 65 cap was obtained with complete disappearance of symptoms and pulmonary nodule(s); 19 neoplasms: 16 patients performed histologically with bronchoscopy; 3 refused (non-invasive diagnosis with basal CT-scan and positron emission tomography (PET) with fluorodeoxyglucose (FDG)). Sensitivity, specificity, overall diagnostic accuracy (ODA) (and corresponding AUROC) of clinical-data (CD), chest X-ray(CXR), Lung-ultrasound(LUS), CEUS were calculated with SPSS 26.0 software.

RESULTS

Final diagnosis: 65 CAP, and 19 chest cancers. 9/65 (13%) patients died, of these 7/9 with older age and heart disease as comorbidity. CD: True-Positive (TP):23, True-negative (TN): 17; False-Positive (FP):2; False-negative (FN):42 (sens:35,4% spec:89,5% ODA10%: PPV:92%, NPV:28,8%) (AUROC±SEauc:0,46±0,076); CXR: TP: 36, TN:14; FP:5, FN:29; (sens: 55,4%; spec: 73,7%; ODA: 32%; PPV:87,5%, NPV:32,66%) (AUROC±SEauc:0,645±0,068). US: TP:59; TN: 14; FP:5, FN:6 (sens: 90,8%, spec: 73,7%, ODA: 84,9%, PPV:92,2%, NPV:70%) (AUROC±SEauc:0,9417±0,024); CEUS: TP: 63; TN: 19; FP:0; FN:2 (sens: 96,9%; spec: 100% ODA: 97,5%; PPV: 100%, NPV:90,5%) (AUROC±SEauc:0,98±0,01).

CONCLUSIONS

Clinical-data and chest X-RAYS are insufficient to obtain a correct diagnosis of CAP in elderly population; US demonstrated a good accuracy to establish CAP, but with a relatively low specificity; in these cases, CEUS is able to give a correct characterization, allowing you to save the need for a chest contrast-enhanced-CT (CECT).

Cryptogenic organizing pneumonia caused by solanine: A case report

RATIONALE

Cryptogenic organizing pneumonia (COP) is a type of pneumonia with unknown cause, presenting with symptoms like dyspnea, fever, and cough. Solanine poisoning can cause symptoms like increased heart rate, rapid breathing, sore throat, diarrhea, vomiting, and fever, but there are no known cases of it causing COP.

PATIENT CONCERNS

A 43-year-old man had a dry cough, worse at night, with phlegm and chest tightness after eating sprouted potatoes. No history of surgeries or family medical issues.

DIAGNOSIS

Laboratory tests and metagenomic next-generation sequencing of bronchoalveolar lavage fluid from the bilateral lower lobes did not yield a definitive pathogen. Further evaluation included testing for vasculitis-associated antibodies and rheumatologic immune markers for myositis spectra to rule out connective tissue disease-associated interstitial lung disease as the etiology of organizing pneumonia. As a result, the final diagnosis was determined to be COP.

INTERVENTIONS

The patient received glucocorticoid therapy and oxygen therapy, and responded well to the treatment.

OUTCOMES

On the 10th day of hospitalization, the patient was discharged with success. A follow-up chest CT conducted over a month later revealed that the lesions in both lungs had essentially resolved, with only minor residual fibrotic changes present.

LESSONS

Regularly monitoring disease progression is crucial for patients with solanine poisoning who have pulmonary symptoms. Promptly conducting chest CT scans and bronchoscopy is advised to check for any infections. It is also important to rule out pneumonia related to connective tissue disease-associated interstitial lung disease and provide appropriate treatment promptly.

Organizing pneumonia secondary to pulmonary tuberculosis: A case report

BACKGROUND

Organizing pneumonia secondary to pulmonary tuberculosis is rare. Moreover, the temporal boundary between pulmonary tuberculosis and secondary organizing pneumonia has not been defined. We report a case of secondary organizing pneumonia associated with pulmonary tuberculosis occurring after nine months of antituberculosis treatment.

CASE SUMMARY

A 54 years old man, previously diagnosed with pulmonary tuberculosis and tuberculous pleurisy, underwent nine months of antituberculosis treatment. Follow-up lung computed tomography revealed multiple new subpleural ground-glass opacities in both lungs, and a lung biopsy confirmed organizing pneumonia. Treatment continued with anti-tuberculosis agents and hormone therapy, and subsequent dynamic pulmonary computed tomography exams demonstrated improvement in lesion absorption. No disease recurrence was observed after corticosteroid therapy discontinuation.

CONCLUSION

When treating patients with active pulmonary tuberculosis, if an increase in lesions is observed during anti-tuberculosis treatment, it is necessary to consider the possibility of tuberculosis-related secondary organizing pneumonia, timely lung biopsy is essential for early intervention.

Solitary Pure Ground-glass Opacity Suspected of Being the Initial Presentation of Nonfibrotic Hypersensitivity Pneumonitis

We herein report a rare case of hypersensitivity pneumonitis (HP) that was initially demonstrated as solitary pure ground-glass opacity (GGO) on chest computed tomography (CT). A 51-year-old woman with a history of breast cancer underwent follow-up CT, which revealed solitary pure GGO. The patient developed exertional dyspnea after two years, and CT revealed diffuse centrilobular nodules in addition to GGO, which had increased in size. An antigen avoidance test was performed to diagnose HP, leading to the resolution of CT abnormalities, including the GGO. Our findings suggested that nonfibrotic HP can present as solitary pure GGO.

How I diagnose and treat organizing pneumonia in hematopoietic cell transplant recipients

ABSTRACT

Organizing pneumonia (OP) is a known noninfectious pulmonary complication following allogeneic hematopoietic cell transplant (HCT) and represents a significant risk factor for nonrelapse mortality in HCT recipients. Unlike bronchiolitis obliterans syndrome, it is not universally acknowledged as a distinctive pulmonary manifestation of chronic graft-versus-host disease (cGVHD) and, therefore, its diagnostic criteria and management approach are lacking. Given its shared similar clinical features and radiological and histologic findings to OP in the non-HCT population, the diagnostic approach and treatment strategy for OP in HCT recipients is largely adapted from the non-HCT population. In this article, we aim to enhance the understanding of OP within the context of cGVHD following HCT and distinguish its clinical features and treatment strategy from non-HCT counterparts, thereby reinforcing its recognition as a pulmonary manifestation of graft-versus-host disease. We will propose the diagnostic criteria and outline our approach in diagnosis and treatment strategy, highlighting the potential challenges that may arise in each process. Finally, we will discuss knowledge gaps in this field and identify the area of need for future research.

Cryptogenic Organizing Pneumonia Is Associated With Increased Mortality Risk in Hospitalizations for Systemic Lupus Erythematosus (SLE): A National Inpatient Sample Analysis

Background This study analyzed the incidence, characteristics, and mortality risk associated with cryptogenic organizing pneumonia (COP) among hospitalizations for systemic lupus erythematosus (SLE) with lung involvement. Methods Adult hospitalizations from the 2016-2020 nationwide inpatient sample were analyzed using relevant International Classification of Diseases (ICD)-10 codes for SLE with lung involvement (M32.13) and COP (J84.116). We compared baseline characteristics of individuals with SLE and COP to those of other lung involvements using Chi-square tests for categorical variables and the Wilcoxon rank sum test for continuous variables. A Cox proportional hazards model was used to assess the risk of developing COP in the pooled cohort of SLE patients. The impact of COP on SLE mortality was assessed using multivariate logistic regression adjusting for illness severity, baseline risk of mortality at admission, and patient- and hospital-level covariates. Results Of 40,356 admissions for SLE, 3,175 (7.9%) were due to lung involvement, with COP identified in 570 cases (17.9%). Compared with other lung involvement in SLE, individuals with COP were significantly older (mean age: 65 vs. 44.3 years; p<0.001), mostly female (515; 90.4% vs. 2,305 males; 88.5%; p=0.572), had a greater baseline risk of mortality [diagnosis-related groups (DRG) major or extreme likelihood of dying: 360; 63.1% vs. 1,133; 43.5%; p<0.001], and had a higher prevalence of peripheral vascular disease (25; 4.4% vs. 39; 1.5%; p<0.001), and lower prevalence of lymphocytopenia (45; 7.9% vs. 359; 13.8%; p=0.001), and hypothyroidism (44; 7.8% vs. 357; 13.7%; p=0.001). Predictors of COP included female sex [adjusted hazard ratio (AHR): 1.46; 95% confidence interval (CI): 1.12-2.96; p=0.022]; hospitalizations occurring in the third quarter of the year (AHR: 1.37; 95% CI: 1.05-2.23; p=0.038); hospital stays of six days or longer (AHR: 1.71; 95% CI: 1.06-2.77; p=0.029); undergoing five or more procedures during the same hospitalization (AHR: 1.56; 95% CI: 1.26-3.56; p=0.041); coexisting lymphocytopenia (AHR: 1.92; 95% CI: 1.16-3.19; p=0.011); need for mechanical ventilation (AHR: 1.60; 95% CI: 1.48-3.93; p=0.049), presence of another autoimmune disorder (AHR: 1.37; 95% CI: 1.15-4.29; p=0.040), and being hospitalized at private, investor-owned hospitals (AHR: 2.62; 95% CI: 1.03-6.64; p=0.043). Mortality in SLE with lung involvement was correlated with age ≥ 60 years [hazard ratio (HR) (95% CI) 1.16 (1.05-1.56); p=0.012], coexisting lupus nephritis [HR (95% CI), 2.44 (2.04-3.49); p=0.031], cancer [HR (95% CI), 3.49 (2.19-5.79); p<0.001], liver disease [HR (95% CI), 9.82 (4.79-12.57); p<0.001]; immune deficiency [HR (95% CI), 2.22 (2.02-3.11); p=0.031], hypothyroidism [HR (95% CI), 4.67 (1.47-7.75); p=0.009], and high blood pressure [HR (95% CI), 3.15 (2.83-4.51); p<0.001]. In the multivariable analysis, COP remained significantly associated with an increased risk of mortality [AHR (95% CI), 1.43 (1.16-2.74); p=0.031]. The incidence of COP did not significantly impact hospitalization costs ($US 94,772 ± 14,759 vs. 95,982 ± 32,625; p=0.954) or length of stay (mean length of hospital stay: 8.3 vs.6.8 days; p=0.147). Conclusion Cryptogenic organizing pneumonia was associated with 1% of all hospitalizations for SLE and 18% of cases involving lung complications in SLE. The presence of COP significantly increased the risk of mortality in SLE patients with lung involvement.

Ocrelizumab-induced organizing pneumonia in multiple sclerosis: case report and literature review

Patients with relapsing-remitting multiple sclerosis should be offered disease-modifying therapies as part of their management. Recommended options include integrin antagonist therapy including natalizumab as well as anti-CD20 monoclonal antibodies like, ocrelizumab, rituximab, ofatumumab, and ublituximab. These therapies reduce relapse rates and slow brain lesion accumulation. Disease-modifying therapies selection may depend on patient preferences, potential fetal harm, and specific drug risks, requiring continuous monitoring via tracking clinical relapses and new MRI brain lesions. Natalizumab carries a risk of progressive multifocal leukoencephalopathy, particularly in anti-JCV antibody-positive patients, necessitating regular monitoring. Ocrelizumab, rituximab, and ublituximab are associated with an increased risk of infections (especially respiratory and skin infections), infusion reactions, and hypogammaglobulinemia. Ocrelizumab additionally poses a heightened risk of immune-mediated colitis and breast cancer, and it is contraindicated for patients with active hepatitis B due to the risk of viral reactivation. Ublituximab has been noted to be linked to potential fetal harm. We report the case of a 42-year-old male with relapsing-remitting multiple sclerosis on ocrelizumab who developed persistent fever and shortness of breath, two weeks after his last ocrelizumab dose. Despite antibiotic treatment for suspected pneumonia, his symptoms persisted. A chest CT scan revealed multifocal ground-glass opacities suggestive of organizing pneumonia, likely secondary to ocrelizumab. The patient's condition improved with high-dose corticosteroids, underscoring the importance of vigilance for extremely rare ocrelizumab-associated pulmonary side effects and the need for prompt, appropriate intervention.

Ferroptosis-Associated Extracellular Matrix Remodeling in Radiation-Induced Lung Fibrosis Progression

Background: Radiation-induced lung fibrosis (RILF) is a life-threatening complication of thoracic radiotherapy. Ferroptosis, a recently discovered type of cell death, is believed to contribute to RILF, though the associated mechanisms are unknown. This study aimed to investigate the potential mechanism of ferroptosis in RILF and examine the contribution of different cell types to ferroptosis during RILF progression. Methods: Histopathological changes in RILF lung tissue were assessed through H&E and Masson staining. IHC staining investigated ferroptosis markers (GPX4, ACSL4, NCOA4). Ferroptosis-related genes (FRG) and pathway scores were derived from RILF transcriptome microarray data. The sc-RNAseq analysis detected FRG score dynamics across cell types, validated by IF staining for PDGFR-α and ACSL4. Results: ACSL4 and NCOA4 protein levels were significantly higher and GPX4 lower in IR than control. FRG scores were positively correlated with fibrosis-related pathway scores in the RILF transcriptome data. FRG and ECM scores were concurrently upregulated in myofibroblasts. Enhanced co-staining of PDGFR-α and ACSL4 were observed in the fibrotic areas of RILF lungs. Conclusions: Our research indicated that in RILF, fibroblasts undergoing ferroptosis may release increased levels of ECM, potentially accelerating the progression of lung fibrosis. This finding presents ferroptosis as a potential therapeutic target in RILF.

A Diagnostic Dilemma: A Case of Complicated Pneumonia With Pyelonephritis and Subclinical Myocarditis

A 41-year-old woman presented with a 3.5-month history of fever, weakness, productive cough, and burning micturition along with generalized weakness and significant weight loss. Chest X-ray revealed bilateral infiltrates and bilateral pleural effusion, and the workup suggested community-acquired pneumonia (CAP). However, the course was complicated by persistent fevers, elevated inflammatory markers, elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), and pelvic fluid collection. Extensive investigations, including bronchoscopy and lung biopsy, failed to identify a specific pathogen. Pulmonary vasculitis and lymphoma were ruled out. Antibiotic and corticosteroid therapy resulted in clinical improvement. While the cause remains unknown, brucellosis and aspergillosis were considered but ruled out with advanced testing. The underlying etiology remains elusive, highlighting the diagnostic challenges in CAP with atypical presentations.

Cryptogenic organizing pneumonia: clinical outcomes of 60 consecutive cases

Background

Cryptogenic organizing pneumonia (COP) improves rapidly following corticosteroid treatment; however, relapse is common. Therefore, this retrospective observational study aimed to clarify the clinical outcomes of COP and identify the predictive factors for relapse.

Methods

The laboratory findings, pulmonary function test results, computed tomography (CT) findings, and clinical outcomes of 60 consecutive COP patients treated at our institution between 2007 and 2013 were retrospectively reviewed. The clinical characteristics of COP patients who did and did not show improvement were compared to identify the predictive factors for relapse in patients showing improvement.

Results

Forty-one patients showed improvement without relapsing (Group 1), whereas thirteen relapsed after showing improvement (Group 2). Six patients did not show any improvement (Group 3). The serum Krebs von den Lungen-6 (KL-6) levels in Group 3 were greater than those in Groups 1 and 2 (P=0.004). The incidence of traction bronchiectasis and reticular opacities in Group 3 was higher than that in Groups 1 and 2 (P=0.048 and P=0.006, respectively). The cut-off levels of C-reactive protein (CRP), blood neutrophil fraction (%neutrophils) and lymphocyte fraction (%lymphocytes) for predicting relapse were 6.84 mg/dL, 68.7% and 14.1% in Groups 1 and 2, respectively. The log-rank test revealed that high serum CRP levels (P<0.001), high %neutrophils (P=0.003) and low %lymphocytes (P=0.006) showed significant correlations with a shorter time to the first relapse episode.

Conclusions

Chest CT findings depicting pulmonary fibrosis and high serum KL-6 levels were correlated with the non-improvement of COP. Blood test results indicating inflammatory reactions were correlated with relapse in patients with COP showing improvement.

Relationship between idiopathic interstitial pneumonias (IIPs) and connective tissue disease-related interstitial lung disease (CTD-ILD): A narrative review

While idiopathic interstitial pneumonia (IIP) centering on idiopathic pulmonary fibrosis (IPF) is the most prevalent interstitial lung disease (ILD), especially in the older adult population, connective tissue disease (CTD)-related ILD is the second most prevalent ILD. The pathogenesis of IPF is primarily fibrosis, whereas that of other ILDs, particularly CTD-ILD, is mainly inflammation. Therefore, a precise diagnosis is crucial for selecting appropriate treatments, such as antifibrotic or immunosuppressive agents. In addition, some patients with IIP have CTD-related features, such as arthritis and skin eruption, but do not meet the criteria for any CTD, this is referred to as interstitial pneumonia with autoimmune features (IPAF). IPAF is closely associated with idiopathic nonspecific interstitial pneumonia (iNSIP) and cryptogenic organizing pneumonia (COP). Furthermore, patients with iNSIP or those with NSIP with OP overlap frequently develop polymyositis/dermatomyositis after the diagnosis of IIP. Acute exacerbation of ILD, the most common cause of death, occurs more frequently in patients with IPF than in those with other ILDs. Although acute exacerbation of CTD-ILD occurs at a low rate of incidence, patients with rheumatoid arthritis, microscopic polyangiitis, or systemic sclerosis experience more acute exacerbation of CTD-ILD than those with other CTD. In this review, the features of each IIP, focusing on CTD-related signatures, are summarized, and the pathogenesis and appropriate treatments to improve the prognoses of patients with various ILDs are discussed.

Detection of Feline Coronavirus in Bronchoalveolar Lavage Fluid from Cats with Atypical Lower Airway and Lung Disease: Suspicion of Virus-Associated Pneumonia or Pneumonitis

The premortem understanding of the role of feline coronavirus (FeCoV) in the lungs of cats is limited as viruses are seldom inspected in the bronchoalveolar lavage (BAL) specimens of small animal patients. This study retrospectively analyzed the prevalence of FeCoV in BAL samples from cats with atypical lower airway and lung disease, as well as the clinical characteristics, diagnostic findings, and follow-up information. Of 1162 clinical samples submitted for FeCoV RT-nPCR, 25 were BAL fluid. After excluding 1 case with chronic aspiration, FeCoV was found in 3/24 (13%) BAL specimens, with 2 having immunofluorescence staining confirming the presence of FeCoV within the cytoplasm of alveolar macrophages. The cats with FeCoV in BAL fluid more often had pulmonary nodular lesions (66% vs. 19%, p = 0.14) and multinucleated cells on cytology (100% vs. 48%, p = 0.22) compared to the cats without, but these differences did not reach statistical significance due to the small sample size. Three cats showed an initial positive response to the corticosteroid treatment based on the clinical signs and radiological findings, but the long-term prognosis varied. The clinical suspicion of FeCoV-associated pneumonia or pneumonitis was raised since no other pathogens were found after extensive investigations. Further studies are warranted to investigate the interaction between FeCoV and lung responses in cats.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

[A clinical-radiomics nomogram for differentiating focal organizing pneumonia and lung adenocarcinoma]

OBJECTIVE

To evaluate the performance of a clinical-radiomics model for differentiating focal organizing pneumonia (FOP) and lung adenocarcinoma (LUAD).

METHODS

We retrospectively analyzed the data of 60 patients with FOP confirmed by postoperative pathology at the First Medical Center of the Chinese PLA General Hospital from January, 2019 to December, 2022, who were matched with 120 LUAD patients using propensity score matching in a 1∶2 ratio. The independent risk factors for FOP were identified by logistic regression analysis of the patients' clinical data. The cohort was divided into a training set (144 patients) and a test set (36 patients) by random sampling. Python 3.7 was used for extracting 1835 features from CT image data of the patients. The radiographic features and clinical data were used to construct the model, whose performance was validated using ROC curves in both the training and test sets. The diagnostic efficacy of the model for FOP and LUAD was evaluated and a diagnostic nomogram was constructed.

RESULTS

Statistical analysis revealed that an history of was an independent risk factor for FOP (P=0.016), which was correlated with none of the hematological findings (P > 0.05). Feature extraction and dimensionality reduction in radiomics yielded 30 significant labels for distinguishing the two diseases. The top 3 most discriminative radiomics labels were GraylevelNonUniformity, SizeZoneNonUniformity and shape-Sphericity. The clinical-radiomics model achieved an AUC of 0.909 (95% CI: 0.855-0.963) in the training set and 0.901 (95% CI: 0.803-0.999) in the test set. The model showed a sensitivity of 85.4%, a specificity of 83.5%, and an accuracy of 84.0% in the training set, as compared with 94.7%, 70.6%, and 83.3% in the test set, respectively.

CONCLUSION

The clinical-radiomics nomogram model shows a good performance for differential diagnosis of FOP and LUAD and may help to minimize misdiagnosis-related overtreatment and improve the patients' outcomes.

A rare pulmonary manifestation of Crohn's disease: Acute fibrinous and organizing pneumonia presenting as multifocal nodules

Acute Fibrinous and Organizing Pneumonia (AFOP) is a rare pulmonary disease, and it has not been recorded in literature as a pulmonary manifestation of Crohn's disease. A 22-year-old individual with an extensive history of Crohn's disease presented to the hospital initially for hematochezia and diarrhea. Computed tomography of her abdomen and pelvis showed multiple pulmonary nodules bilaterally. The patient did not report cough, sputum production, or dyspnea. Autoimmune and infectious workup were overall unremarkable. A CT-guided percutaneous biopsy of a peripheral lung nodule was performed showing features consistent with AFOP. The patient was ultimately treated with a long taper of prednisone and Ustekinumab for Crohn's disease. Follow-up CT-chest showed interval reduction and improvement in lung nodules, which correlated with better control of the patient's Crohn's disease. Pulmonary manifestations of IBD are varied, including pleural disease, bronchiectasis, and organizing pneumonia. Bronchiolitis obliterans organizing pneumonia has been described more frequently in patients with ulcerative colitis compared to Crohn's. Pulmonary nodules are a rare manifestation of IBD and often tend to be granulomatous or necrobiotic. AFOP is a rare entity with no previously reported association with IBD. Secondary AFOP can be caused by autoimmune diseases, drug reactions, infections, or radiation. Treatment of AFOP is usually immunosuppression by glucocorticoids.

Fleischner Society: Glossary of Terms for Thoracic Imaging

Members of the Fleischner Society have compiled a glossary of terms for thoracic imaging that replaces previous glossaries published in 1984, 1996, and 2008, respectively. The impetus to update the previous version arose from multiple considerations. These include an awareness that new terms and concepts have emerged, others have become obsolete, and the usage of some terms has either changed or become inconsistent to a degree that warranted a new definition. This latest glossary is focused on terms of clinical importance and on those whose meaning may be perceived as vague or ambiguous. As with previous versions, the aim of the present glossary is to establish standardization of terminology for thoracic radiology and, thereby, to facilitate communications between radiologists and clinicians. Moreover, the present glossary aims to contribute to a more stringent use of terminology, increasingly required for structured reporting and accurate searches in large databases. Compared with the previous version, the number of images (chest radiography and CT) in the current version has substantially increased. The authors hope that this will enhance its educational and practical value. All definitions and images are hyperlinked throughout the text. Click on each figure callout to view corresponding image. © RSNA, 2024 Supplemental material is available for this article. See also the editorials by Bhalla and Powell in this issue.

Organizing pneumonia and COVID-19

Organizing pneumonia (OP) is an interstitial lung disease, and can be cryptogenic, if no cause is identified, or secondary to several conditions. COVID-19-induced persistent inflammation can be associated with interstitial lung disease. We present a review of literature of OP and COVID-19-induced OP with an illustrative case. A 38-year-old man was admitted with COVID-19 that required mechanical ventilation for 56 days. Initial chest computed tomography (CT) revealed diffuse bilateral ground-glass opacities in the lungs with consolidation areas involving 75 % of the parenchyma. After weaning from MV, the patient still required oxygen supplementation. A new chest CT scan also showed extensive diffuse areas of consolidation and ground-glass opacity. OP was hypothesized and 40 mg/day prednisone initiated and continued for six months with resolution of lung functional and image abnormalities. Organizing pneumonia should be included in the differential diagnosis of COVID-19 patients with respiratory symptoms after partial pulmonary recovery.

Eosinophilia with Lung Involvement in an Elderly Patient with a History of Chronic Obstructive Pulmonary Disease

Eosinophilia with pulmonary involvement is characterized by the presence of peripheral blood eosinophilia, typically >500 cells/mm3, nonspecific pulmonary symptoms, and radiographic evidence of pulmonary disease. Clinical, laboratory, and radiologic features can be overlapping in these diseases, thus, it is wise to approach eosinophilia with pulmonary involvement systematically to determine the diagnosis and provide definitive treatment for a better outcome. The authors present a case of idiopathic chronic eosinophilic pneumonia in a patient with a long history of chronic obstructive pulmonary disease (COPD) which was resolved by corticosteroid.

The tumor or inflammation? a case report on primary pulmonary choriocarcinoma

Choriocarcinoma is a rare malignant germ cell neoplasm with high invasiveness, the majority of which are pregnancy-related, and the female genital tract is the most prevalent site of the disease. Although early-stage choriocarcinoma typically metastasizes to the lungs, primary pulmonary choriocarcinoma is extremely rare. Primary pulmonary choriocarcinoma is difficult to diagnose, and it progresses rapidly. Combined with the difficulty of treatment, the prognosis of patients is generally poor. In this article, we retrospectively analyzed a case of female primary pulmonary choriocarcinoma, combined with a review of literature, to understand and describe the diagnostic and treatment progress of PPC.

CT Approach to Lung Injury

Diffuse alveolar damage (DAD), which represents the pathologic changes seen after acute lung injury, is caused by damage to all three layers of the alveolar wall and can ultimately result in alveolar collapse with loss of the normal pulmonary architecture. DAD has an acute phase that predominantly manifests as airspace disease at CT owing to filling of the alveoli with cells, plasma fluids, and hyaline membranes. DAD then evolves into a heterogeneous organizing phase, with mixed airspace and interstitial disease characterized by volume loss, architectural distortion, fibrosis, and parenchymal loss. Patients with DAD have a severe clinical course and typically require prolonged mechanical ventilation, which may result in ventilator-induced lung injury. In those patients who survive DAD, the lungs will remodel over time, but most will have residual findings at chest CT. Organizing pneumonia (OP) is a descriptive term for a histologic pattern characterized by intra-alveolar fibroblast plugs. The significance and pathogenesis of OP are controversial. Some authors regard it as part of a spectrum of acute lung injury, while others consider it a marker of acute or subacute lung injury. At CT, OP manifests with various forms of airspace disease that are most commonly bilateral and relatively homogeneous in appearance at individual time points. Patients with OP most often have a mild clinical course, although some may have residual findings at CT. In patients with DAD and OP, imaging findings can be combined with clinical information to suggest the diagnosis in many cases, with biopsy reserved for difficult cases with atypical findings or clinical manifestations. To best participate in the multidisciplinary approach to patients with lung injury, radiologists must not only recognize these entities but also describe them with consistent and meaningful terminology, examples of which are emphasized in the article. © RSNA, 2023 See the invited commentary by Kligerman et al in this issue. Quiz questions for this article are available in the supplemental material.

Tofacitinib treatment in anti-glycyl-tRNA synthetase antibody interstitial lung disease - A case report

Anti-aminoacyl-transfer-RNA synthetase syndrome (ASS) related interstitial lung disease (ILD) is rarely presented initially alongside acute respiratory distress syndrome (ARDS), which in and of itself is a severe condition with a high mortality rate. Additionally, rapidly progressive change is not a common feature in ASS. Numerous case reports have described the efficacy which tofacitinib has on rapidly progressive ILD (RP-ILD). However, none have mentioned the use of tofacitinib in patients with impaired renal function. Herein, a case of ASS involving ILD is reported with the initial presentation of RP-ILD to ARDS being complicated by acute renal failure with an initial complete response to tofacitinib. Patients experiencing unexplained rapidly progressive interstitial pneumonia should be examined thoroughly for the diagnosis of ASS. Furthermore, tofacitinib can also be considered as a choice of treatment even in patients with impaired renal function.

Organizing pneumonia

Organizing pneumonia is a nonspecific pathologic pattern of response to lung damage. It can be idiopathic, or it can occur secondary to various medical processes, most commonly infections, connective tissue disease, and pharmacological toxicity. Although there is no strict definition of the pattern of organising pneumonia as in other idiopathic interstitial pneumonias, the characteristic pattern of this disease could be considered to include patchy consolidations and ground-glass opacities in the peribronchial and subpleural areas of both lungs. Moreover, studies of the course of the disease show that these lesions respond to treatment with corticoids, migrate with or without treatment, and tend to recur when treatment is decreased or withdrawn. Other manifestations of organising pneumonia include nodules of different sizes and shapes, solitary masses, nodules with the reverse halo sign, a perilobular pattern, and parenchymal bands.

Diagnosis of Organizing Pneumonia with an Ultrathin Bronchoscope and Cone-Beam CT: A Case Report

Organizing pneumonia (OP) is a pulmonary disease histopathologically characterized by plugs of loose connective tissue in distal airways. The clinical and radiological presentations are not specific and they usually require a biopsy confirmation. This paper presents the case of a patient with a pulmonary opacity sampled with a combined technique of ultrathin bronchoscopy and cone-beam CT. A 64-year-old female, a former smoker, was admitted to the hospital of Reggio Emilia (Italy) for exertional dyspnea and a dry cough without a fever. The history of the patient included primary Sjögren Syndrome interstitial lung disease (pSS-ILD) characterized by a non-specific interstitial pneumonia (NSIP) radiological pattern; this condition was successfully treated up to 18 months before the new admission. The CT scan showed the appearance of a right lower lobe pulmonary opacity of an uncertain origin that required a histological exam for the diagnosis. The lung lesion was difficult to reach with traditional bronchoscopy and a percutaneous approach was excluded. Thus, cone-beam CT, augmented fluoroscopy and ultrathin bronchoscopy were chosen to collect a tissue sample. The histopathological exam was suggestive of OP, a condition occurring in 4-11% of primary Sjögren Syndrome cases. This case showed that, in the correct clinical and radiological context, even biopsies taken with small forceps can lead to a diagnosis of OP. Moreover, it underlined that the combination of multiple advanced technologies in the same procedure can help to reach difficult target lesions, providing proper samples for a histological diagnosis.

Can Ultrasound and Contrast-Enhanced Ultrasound Help Differentiate between Subpleural Focal Organizing Pneumonia and Primary Lung Malignancy?

Background: Subpleural focal organizing pneumonia (FOP) and primary lung malignancy (PLM) are usually confused. The aim of this study was to explore the value of ultrasound (US) and contrast-enhanced ultrasound (CEUS) in the differential diagnosis of FOP and PLM. Methods: A total of 23 patients (mean age: 64.57 ± 11.86 years) with FOP and 100 (mean age: 66.29 ± 11.05 years) with subpleural lesions diagnosed as PLM, confirmed by pathological diagnosis and clinical follow-up, were retrospectively enrolled. The largest lesion diameter, angle between the lesion border and thoracic wall, air bronchial sign, internal blood supply, blood supply form, and pleural effusion examined using conventional US were retrospectively analyzed. The indicators of CEUS included the arrival time of contrast agent in the lesion, lesion−lung arrival time difference, degree of enhancement, distribution uniformity of contrast medium, presence of non-enhancing region, and arterial filling mode in the lesion. A p < 0.05 was considered statistically significant. Results: Presence of air bronchial sign (odds ratio [OR] = 6.18, p = 0.025), acute angle between the lesion border and thoracic wall (OR = 7.124, p = 0.033), and homogeneous enhancement (OR = 35.26, p = 0.01) showed predictive value for the diagnosis of FOP. According to the results of the logistic regression analysis, the area under the receiver operating curve of the above features combined was 0.960, and the sensitivity and specificity were 95.0% and 82.6%, respectively. Conclusions: US combined with CEUS has the potential to differentiate between FOP and PLM.