ATP-induced fibrogenic pathway in circulating cells obtained by idiopathic pulmonary fibrotic (IPF) patients is not blocked by nintedanib and pirfenidone.

Idiopathic pulmonary fibrosis (IPF) is a severe disability due to progressive lung dysfunction. IPF has long been viewed as a non-immune form of pulmonary fibrosis, but nowadays it is accepted that a chronic inflammatory response can exacerbate fibrotic patterns. IL-1-like cytokines and ATP are highly detected in the lung and broncho-alveolar lavage fluid of IPF patients. Because ATP binds the purinergic receptor P2RX7 involved in the release of IL-1-like cytokines, we aimed to understand the role of P2RX7 in IPF. PBMCs from IPF patients were treated with nintedanib or pirfenidone in the presence of ATP. Under these conditions, PBMCs still released IL-1-like cytokines and the pro-fibrotic TGFß. Bulk and scRNAseq demonstrated that lung tissues of IPF patients had higher levels of P2RX7, especially on macrophages, which were correlated to T cell activity and inflammatory response with a TGFBI and IL-10 signature. A subcluster of macrophages in IPF lung tissues had 2055 genes that were not in common with the other subclusters, and that were involved in metabolic and PDGF, FGF and VEGF associated pathways. These data confirmed what observed on circulating cells that, although treated with anti-fibrotic agents, nintedanib or pirfenidone, they were still able to release IL-1 cytokines and the fibrogenic TGFß. In conclusion, these data imply that because nintedanib and pirfenidone do not block ATP-induced IL-1-like cytokines and TGFß induced during P2RX7 activation, it is plausible to consider P2RX7 on circulating cells and/or tissue biopsies as potential pharmacological tool for IPF patients.

Aspergilloma Coexisting With Idiopathic Pulmonary Fibrosis: A Rare Clinical Entity.

Aspergilloma also known as fungal ball or mycetoma, is a saprophytic mycotic infection caused by Aspergillus species which usually colonizes pre-existing cavitary or cystic lesions in the lung. Here, we have a rare case of idiopathic pulmonary fibrosis (IPF) with bilateral bronchiectasis complicated by aspergilloma. Although the existence of aspergilloma is common in pre-existing lung cavities, its coexistence in patients with IPF is a rarity, and the incidence of such cases in the literature remains sparse. Here is an interesting case report of aspergilloma co-existing with IPF. This article comprehensively analyzes the existing literature depicting similar associations and the possible etiology for the development of aspergilloma in patients with IPF.

Presentation and progression of MPO-ANCA interstitial lung disease.

The association between MPO-ANCA-associated vasculitis (AAV) and interstitial lung disease (ILD) has been well established. Pulmonary fibrosis may coexist with, follow, or even precede the diagnosis of AAV, and its presence adversely affects the prognosis. The optimal approach to investigating ANCA in patients with ILD remains a subject of ongoing debate. Here we aim to describe presentation and progression of MPO-ANCA ILD. We conducted a retrospective evaluation of a cohort of individuals diagnosed with MPO-ANCA ILD, with or without accompanying renal impairment, at the Immunology and Cell Therapy Unit, Careggi University Hospital, Florence, Italy, between June 2016 and June 2022. Clinical records, imaging studies, pathologic examinations, and laboratory test results were collected. Among the 14 patients identified with MPO-ANCA ILD, we observed a significant association between MPO-ANCA titers assessed at the time of ILD diagnosis and renal involvement. Renal impairment in these cases often manifested as subclinical or slowly progressive kidney damage. Interestingly, complement C3 deposits were consistently found in all renal biopsy specimens, thereby suggesting the potential for novel therapeutic targets in managing renal complications associated with MPO-ANCA ILD. The presentation of MPO-ANCA vasculitis as ILD can be the first and only clinical manifestation. MPO-ANCA levels at ILD diagnosis could warn on the progression to renal involvement in patients with MPO-ANCA ILD, hence caution is needed because renal disease can be subclinical or smoldering.

Evaluation of Interstitial Lung Diseases with Deep Learning Method of Two Major Computed Tomography Patterns.

BACKGROUND: Interstitial lung diseases (ILD) encompass various disorders characterized by inflammation and/or fibrosis in the lung interstitium. These conditions produce distinct patterns in High-Resolution Computed Tomography (HRCT). OBJECTIVE: We employ a deep learning method to diagnose the most commonly encountered patterns in ILD differentially. MATERIALS AND METHODS: Patients were categorized into usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), and normal lung parenchyma groups. VGG16 and VGG19 deep learning architectures were utilized. 85% of each pattern was used as training data for the artificial intelligence model. The models were then tasked with diagnosing the patterns in the test dataset without human intervention. Accuracy rates were calculated for both models. RESULTS: 1 The success of the VGG16 model in the test phase was 95.02% accuracy. 2 Using the same data, 98.05% accuracy results were obtained in the test phase of the VGG19 model. CONCLUSION: Deep Learning models showed high accuracy in distinguishing the two most common patterns of ILD.

A Rare Case of Spontaneous Pneumothorax Leading to Cerebral Air Embolism.

Cerebral arterial air embolism (CAE), a rare subtype of air embolism, carries a 21% mortality rate. We present a unique case involving a 69-year-old female with a history of usual interstitial pneumonia (UIP) who suffered a transient ischemic attack (TIA) due to CAE. Unlike typical cases, CAE in this instance resulted from spontaneous pneumothorax, not the more common iatrogenic causes. Adding complexity, an unexpected discovery emerged during evaluation: a patent foramen ovale, contributing to paradoxical embolism. This underscores the vital need to consider CAE as a differential diagnosis in UIP patients with neurological symptoms, highlighting its rarity and diagnostic challenges.

Factors influencing long-term outcomes in fibrotic interstitial lung disease (F-ILD) diagnosed through multidisciplinary discussion (MDD): a prospective cohort study.

BACKGROUND: The diagnostic process for fibrotic interstitial lung disease (F-ILD) is notably intricate, necessitating a multidisciplinary discussion to achieve consensus based on both clinical and radiological features. This study investigated the shared and distinctive long-term mortality predictors among the two primary phenotypes of F-ILD, namely idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated interstitial lung disease (CTD-ILD). METHODS: We included patients with F-ILD diagnosed from December 2018 to December 2019 and conducted follow-up assessments until February 2023. Age, gender, usual interstitial pneumonia (UIP) pattern, gender-age-physiology (GAP) score, modified Medical Research Council (mMRC) dyspnea score, antifibrotic agent use, pulmonary function test parameters, and six-minute walking test (6MWT) parameters were recorded at baseline and used as mortality predictors in a multivariate Cox regression model. RESULTS: We enrolled 104 ILD patients. The survival rate of non-IPF patients was more than twice that of IPF patients (78.9% vs. 34%, p < 0.001), and the survival rate of patients with a GAP score of 0-2 was more than twice that of patients with a score of > 2 (93.2% vs. 36.6%, p < 0.001). Older age, male gender, definite UIP pattern, higher GAP score, higher mMRC dyspnea score, lower forced expiratory volume in one second/forced vital capacity (FEV1/FVC), shorter 6MWT distance, and lower initial and final SpO2 were also associated with higher long-term mortality (p < 0.05). In multivariable analysis, only a GAP score of > 2 (hazard ratio [HR]:16.7; 95% confidence interval [CI] 3.28-85.14; p = 0.001) and definite UIP pattern (HR: 4.08; 95% CI 1.07-15.5; p = 0.039) were significantly associated with overall mortality. CONCLUSION: The long-term mortality rate of IPF patients was higher than that of CTD-ILD patients. The GAP score and UIP patterns were significant mortality predictors for both IPF and CTD-ILD patients.

Pictorial Review of Fibrotic Interstitial Lung Disease on High-Resolution CT Scan and Updated Classification.

TOPIC IMPORTANCE: Given the recently expanded approval of antifibrotics for various fibrotic interstitial lung diseases (ILDs), early and correct recognition of these diseases is imperative for physicians. Because high-resolution chest CT scan forms the backbone of diagnosis for ILD, this review will discuss evidence-based imaging findings of key fibrotic ILDs and an approach for differentiating these diseases. REVIEW FINDINGS: (1) Imaging findings of nonspecific interstitial pneumonia may evolve over time and become indistinguishable from usual interstitial pneumonia. Therefore, if remote imaging can be reviewed, this would increase the likelihood of an accurate imaging diagnosis, particularly if findings appear to represent a usual interstitial pneumonia pattern on the recent examination. (2) Given the difficulty and lack of objectivity in classifying patients with hypersensitivity pneumonitis into acute, subacute, and chronic categories and that prognosis depends primarily on presence or absence of fibrosis, the new set of guidelines released in 2020 categorizes patients with hypersensitivity pneumonitis as either nonfibrotic (purely inflammatory) or fibrotic (either purely fibrotic or mixed fibrotic/inflammatory) based on imaging and/or histologic findings, and the prior temporal terms are no longer used. (3) Interstitial lung abnormalities are incidental CT scan findings that may suggest early ILD in patients without clinical suspicion for ILD. Patients with high-risk features should undergo clinical evaluation for ILD and be actively monitored for disease progression. SUMMARY: Fibrotic ILD on high-resolution chest CT scan is a complex topic, but with use of an evidence-based analysis and algorithm as provided in this article, the probability of a correct imaging diagnosis increases.

Balancing Routine and Pandemic: The Synergy of India's Universal Immunization Program and COVID-19 Vaccination Program.

The COVID-19 pandemic posed substantial challenges to healthcare systems globally and severely disrupted essential health services, including routine immunization programs. In India, these disruptions were exacerbated due to the sudden emergence of the pandemic and lockdown measures, leading to mass migrations and a shortage of healthcare workers. Caregivers' concerns about routine immunization sessions further compounded the problem, resulting in a sharp increase in zero-dose children. This review paper examines India's strategies for conducting one of the world's largest COVID-19 vaccination programs while effectively restoring and perpetuating its Universal Immunization Program (UIP). The UIP played a pivotal role in sustaining immunization services during the pandemic, ultimately improving immunization coverage compared to pre-pandemic levels. India's accomplishments in this regard are highlighted through key performance indicators, the reach of immunization services, a reduction in zero-dose children, and antigen-wise coverage. The paper also discusses the successful integration of COVID-19 vaccination within the UIP framework, underscoring the significance of existing infrastructure, technology, and capacity building. India's dedication to concurrently managing routine immunization and COVID-19 vaccination showcases the adaptability and resilience of its healthcare system. India's journey serves as a global example of efficient mass immunization during challenging times, emphasizing the importance of political will, healthcare infrastructure investment, skilled healthcare workforces, and comprehensive vaccination programs. In a world grappling with the dual challenge of COVID-19 and routine immunization, India's experience provides a roadmap for strengthening healthcare systems and promoting public health as the critical agenda in challenging times.

A Curious Case of Biopsy-Proven Usual Interstitial Pneumonia.

Usual interstitial pneumonia (UIP) refers to a combination of radiologic and histologic findings, which include patchy interstitial fibrosis with fibroblastic foci and dense acellular collagen that causes architectural distortion due to scarring and honeycomb change with alternating areas of normal lungs. The UIP pattern is not a synonymous term with idiopathic pulmonary fibrosis (IPF). IPF is diagnosed when an etiologic workup has been performed, deemed to be unrevealing, with a radiologic or histologic UIP pattern. While the 2018 American Thoracic Society (ATS)/European Respiratory Society (ERS) guideline categories of UIP help eliminate the need for surgical lung biopsy (SLB) in two categories, i.e., "definite UIP" and "probable UIP," when characterizing a patient in the other categories, clinicians should wary about prolonging SLB in patients to determine the fibrosis pattern. Changes in the treatment and overall prognosis of patients can occur due to SLB confirming a UIP pattern on histology. Here, we report the case of a patient with an indeterminate UIP pattern on high-resolution computed tomography (HRCT) with histopathologic diagnosis of UIP on SLB. With no underlying identifiable cause for the UIP pattern, the patient was diagnosed and managed as IPF, ultimately requiring lung transplantation. This case highlights the importance of pursuing surgical lung biopsy in patients with indeterminate UIP on HRCT scanning to facilitate prompt treatment and guide further management.

Up-regulation by overexpression of c-MET in fibroblastic foci of usual interstitial pneumonia.

Background: Usual interstitial pneumonia (UIP) is the radiologic and histologic hallmark of idiopathic pulmonary fibrosis (IPF) and the commonest histologic pattern of other progressive fibrosing interstitial lung diseases (e.g., fibrotic hypersensitivity pneumonia). Analogous to lung cancer, activation of epithelial-to-mesenchymal transition (EMT) is one of the main molecular pathways recently identified by transcriptomic studies in IPF. Fibroblastic foci (FF) are considered the active/trigger component of UIP pattern. The proto-oncogene C-MET is a key gene among molecules promoting EMT against which several inhibitors are currently available or promising in ongoing studies on lung cancer. Methods: Twenty surgical cases of diffuse fibrosing interstitial lung diseases (fILD) with UIP pattern and FF-rich (17 IPF and 3 patients with fibrotic hypersensitivity pneumonia, fHP) were retrospectively selected. FF were manually microdissected and analysed for c-MET gene alterations (FISH amplification and gene hot-spot mutations Sanger sequencing) and tested with a c-MET companion diagnostic antibody (clone SP44 metmab) by immunohistochemistry. Results: FF are characterized by upregulation of c-MET as shown by overexpression of the protein in 80% of cases, while no gene amplification by FISH or mutations were detected. C-MET upregulation of FF was observed either in IPF and fHP, with a tropism for the epithelial cell component only. Conclusion: Upregulation of c-MET in FF of ILD with UIP pattern further confirms the key role of the proto-oncogene c-MET in its pathogenesis, possibly representing an interesting and easily-detectable molecular target for selective therapy using specific inhibitors in future clinical trials, similar to lung cancer. It is reasonable to speculate that molecular alterations in FF can also be detected in FF by transbronchial cryobiopsy.

Radiographic grading system for usual interstitial pneumonia correlates with mortality and may serve as a surrogate endpoint in clinical trials.

PURPOSE: Usual interstitial pneumonia (UIP)/ idiopathic pulmonary fibrosis (IFP) is a relentlessly progressive lung disease with outcomes similar to cancer. We have previously established a radiologic grading system for UIP and demonstrated that it correlates with pulmonary function tests; here we test the hypothesis that it correlates with mortality. Validating a correlation with mortality will demonstrate the utility of this system for monitoring progression over time clinically and in trials of anti-fibrotic agents. METHODS: We searched the radiology record system "Catalyst" to identify cases and reviewed each case to confirm the diagnosis. 94 patients met the inclusion criteria for further assessment. Chest CT grade was determined by consensus of two cardiothoracic radiologists. Data was analyzed to identify the interval between chest CT and death. This interval was correlated with CT grade using Spearman correlation analysis. RESULTS: For all cases, chest CT grade and mortality demonstrated a positive correlation of rs = 0.37732, 2-tailed p = 0.00018. We also employed subgroup analysis; for the subgroup with intervals less than or equal to 100 days, there was a positive correlation, rs = 0.48339, 2-tailed p = 0.03602; for the subgroup with an interval greater than 100 days between imaging and death there was a positive correlation, rs = 0.302, 2-tailed p = 0.00846. CONCLUSION: These data support use of this system for monitoring clinical progression and as a surrogate endpoint for clinical trials. Future work building upon the data presented here will evaluate its utility in clinical trials and develop automated grading.

Clinical and Prognostic Significance of p-ANCA Positivity in Idiopathic Pulmonary Fibrosis: A Retrospective Observational Study.

Perinuclear Anti Neutrophil Cytoplasmic Antibody (p-ANCA) is a serological marker of Microscopic Polyangiitis (MPA), a vasculitis associated with lung involvement potentially mimicking Idiopathic Pulmonary Fibrosis (IPF). In this study, we evaluated the role of p-ANCA in predicting clinical evolution and prognosis in a cohort of IPF patients. In this observational, retrospective, case-control study, we compared 18 patients with an IPF diagnosis and p-ANCA positivity with 36 patients with seronegative IPF, matched for age and sex. IPF patients with and without p-ANCA showed similar lung function decline during the follow-up, but IPF p-ANCA+ showed better survival. Half of IPF p-ANCA+ patients were classified as MPA for the development of renal involvement (55%) or skin signs (45%). The progression towards MPA was associated with high levels of Rheumatoid Factor (RF) at baseline. In conclusion, p-ANCA, mainly when associated with RF, could predict the evolution of Usual Interstitial Pneumonia (UIP) towards a definite vasculitis in patients, with a better prognosis compared with IPF. In this view, ANCA testing should be included in the diagnostic workup of UIP patients.

Histologic Analysis of Idiopathic Pulmonary Fibrosis by Morphometric and Fractal Analysis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic lung disorder, ultimately leading to respiratory failure and death. Despite great research advances in understanding the mechanisms underlying the disease, its diagnosis, and its treatment, IPF still remains idiopathic without known biological or histological markers able to predict disease progression or response to treatment. The histologic hallmark of IPF is usual interstitial pneumonia (UIP), with its intricate architectural distortion and temporal inhomogeneity. We hypothesize that normal lung alveolar architecture can be compared to fractals, such as the Pythagoras tree with its fractal dimension (Df), and every pathological insult, distorting the normal lung structure, could result in Df variations. In this study, we aimed to assess the UIP histologic fractal dimension in relationship to other morphometric parameters in newly diagnosed IPF patients and its possible role in the prognostic stratification of the disease. Clinical data and lung tissue specimens were obtained from twelve patients with IPF, twelve patients with non-specific interstitial pneumonia (NSIP), and age-matched "healthy" control lung tissue from patients undergoing lung surgery for other causes. Histology and histomorphometry were performed to evaluate Df and lacunarity measures, using the box counting method on the FracLac ImageJ plugin. The results showed that Df was significantly higher in IPF patients compared to controls and fibrotic NSIP patients, indicating greater architectural distortion in IPF. Additionally, high Df values were associated with higher fibroblastic foci density and worse prognostic outcomes in IPF, suggesting that Df may serve as a potential novel prognostic marker for IPF. The scalability of Df measurements was demonstrated through repeated measurements on smaller portions from the same surgical biopsies, which were selected to mimic a cryobiopsy. Our study provides further evidence to support the use of fractal morphometry as a tool for quantifying and determining lung tissue remodeling in IPF, and we demonstrated a significant correlation between histological and radiological Df in UIP pattern, as well as a significant association between Df and FF density. Furthermore, our study demonstrates the scalability and self-similarity of Df measurements across different biopsy types, including surgical and smaller specimens.

Diffuse idiopathic skeletal hyperostosis as a cause for dysphagia in a patient with ankylosing spondylitis.

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by ankylosing spinal alterations which are often asymptomatic but may typically cause back pain and spinal stiffness. Presence of DISH may complicate spinal trauma and lead to unstable fractures requiring surgical intervention. Treatment options include physical activity, symptomatic treatment, local heat application, and optimization of metabolic comorbidities. CASE: A multimorbid older patient was admitted to the gastroenterological ward for the investigation of progressive dysphagia and weight loss. Gastroscopy revealed a dorsal impression of the esophagus at 25 cm from the incisor. Clinical work-up including computed tomography (CT) and magnetic resonance imaging (MRI) ruled out malignancy but showed ankylosing spondylophytes and non-recent fractures of vertebrae C5-C7, compatible with DISH of the cervicothoracic spine as a cause for the esophageal impression. Notably, imaging diagnostics showed ankylosing spine alterations extending to the lumbar spine and both sacroiliac joints, suggestive of ankylosing spondylitis (AS). Typical imaging characteristics, a history of psoriasis, and positive HLA*B27 status supported the diagnosis of underlying AS in this patient with dysphagia as an unusual primary symptom of DISH. Additionally, pulmonary alterations compatible with a usual interstitial pneumonia (UIP)-like pattern were seen on lung CT. CONCLUSION: Overlaps among AS, DISH and pulmonary abnormalities including UIP have been described previously; however, they represent unexpected findings in this older patient. This case underlines the importance of interdisciplinary collaboration and consideration of DISH as a differential diagnosis in patients with atypical symptoms.

Interstitial Lung Disease and Pulmonary Damage in Primary Sjögren's Syndrome: A Systematic Review and Meta-Analysis.

BACKGROUND: Pulmonary lung involvement is the most common extra-glandular manifestation in patients with primary Sjögren's syndrome (pSS), leading to a worsening of the patient's prognosis. To date, different studies have assessed the prevalence of pulmonary involvement and interstitial lung disease (ILD) in pSS patients with different results. METHODS: We performed a systematic literature review and meta-analysis on ILD pooled prevalence in pSS according to the PRISMA and MOOSE guidelines. Furthermore, we explored the pooled prevalence of the two main presentations of pSS-ILD, nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP). RESULTS: We analysed the pSS-ILD prevalence in 30 studies including 8255 pSS patients. The pSS-ILD pooled prevalence was 23% (95% CI: 16-30). For NSIP, we found a pooled prevalence of 52% (CI 41-64), and for UIP we found a pooled prevalence of 44% (CI: 32-55). Regarding the meta-regression analysis, male gender, DLco value, country, and HRCT seem to contribute to the ILD presence. CONCLUSIONS: At least 20% of pSS patients have a comorbid ILD, usually NSIP. Male gender and alteration in DLco value may be considered the most important independent factors supporting an active search of lung complications during the clinical history of pSS patients.

A silent march-Post covid fibrosis in asymptomatics - A cause for concern?

We report a case series of patients presenting with undiagnosed pulmonary fibrosis as a primary manifestation. On evaluation, after excluding other causes, the fibrosis was attributed to asymptomatic or mild COVID illness in the past. This case series serves to highlight the difficulties posed to clinicians while evaluating pulmonary fibrosis in the post-COVID era, more so in mild to asymptomatic COVID-19. The intriguing possibility of fibrosis setting even in mild to asymptomatic COVID is discussed.

Immune checkpoint inhibitor-related pneumonitis with atypical radiologic features in a patient with anti-aminoacyl-tRNA synthetase antibody.

A man with non-small-cell lung cancer who was negative for anti-nuclear antibodies was admitted for dyspnea after immune checkpoint inhibitor (ICI) administration. Computed tomography (CT) showed complexed radiologic features, including subpleural and basal predominant reticular shadow with cystic structures and peribronchovascular consolidation. Although we treated him with high-dose steroid under a diagnosis of ICI-related pneumonitis, he developed acute exacerbation of pneumonitis with progressive fibrosis and volume loss. A re-evaluation identified anti-aminoacyl-tRNA synthetase antibody in the serum collected before ICI administration. This case highlights the importance of re-evaluating pre-existing autoimmune disorders in patients who develop ICI-related pneumonitis with atypical radiologic features.

Plasma extracellular vesicle proteins as promising noninvasive biomarkers for diagnosis of idiopathic pulmonary fibrosis.

High-resolution computed tomography (HRCT) imaging is critical for diagnostic evaluation of Idiopathic Pulmonary Fibrosis (IPF). However, several other interstitial lung diseases (ILDs) often exhibit radiologic pattern similar to IPF on HRCT making the diagnosis of the disease difficult. Therefore, biomarkers that distinguish IPF from other ILDs can be a valuable aid in diagnosis. Using mass spectrometry, we performed proteomic analysis of plasma extracellular vesicles (EVs) in patients diagnosed with IPF, chronic hypersensitivity pneumonitis, nonspecific interstitial pneumonitis, and healthy subjects. A five-protein signature was identified by lasso regression and was validated in an independent cohort using ELISA. The five-protein signature derived from mass spectrometry data showed an area under the receiver operating characteristic curve of 0.915 (95%CI: 0.819-1.011) and 0.958 (95%CI: 0.882-1.034) for differentiating IPF from other ILDs and from healthy subjects, respectively. Stepwise backwards elimination yielded a model with 3 and 2 proteins for discriminating IPF from other ILDs and healthy subjects, respectively, without compromising diagnostic accuracy. In summary, we discovered and validated EV protein biomarkers for differential diagnosis of IPF in independent cohorts. Interestingly, the biomarker panel could also distinguish IPF and healthy subjects with high accuracy. The biomarkers need to be evaluated in large prospective cohorts to establish their clinical utility.

Isolated congenital interruption of the right interlobar pulmonary artery with unilateral interstitial lung abnormality.

We report a case of an isolated congenital interruption of the right interlobar pulmonary artery with unilateral interstitial lung abnormality. 3D-CT with enhancement showed absent right interlobar pulmonary artery without any other abnormalities of the pulmonary artery and an enlarged inferior phrenic artery. High-resolution CT demonstrated ground-glass opacities, reticular changes, and small cysts in the right middle and lower lobes, which were compatible with interstitial lung abnormality. The patient was diagnosed with an isolated congenital interruption of the right interlobar pulmonary artery since chronic pulmonary thromboembolism, structural heart disease, systemic congenital disease, and systemic vasculitis were ruled out.