[Cryptogenic organizing pneumonia versus secondary organizing pneumonia]

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.

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.

A retrospective study of 68Ga-FAPI PET/CT in differentiating the nature of pulmonary lesions

Purpose

This study aimed to investigate the characteristics of various pulmonary lesions as revealed by 68Ga-FAPI PET/CT and to determine the utility of 68Ga-FAPI PET/CT in distinguishing the nature of these pulmonary lesions.

Methods

A retrospective analysis was conducted on 99 patients with pulmonary lesions, who were categorized into three distinct groups: primary lung tumors (G1), metastatic lung tumors (G2), and benign lesions (G3). Each participant underwent a 68Ga-FAPI PET/CT scan. Among these groups, variables such as the Tumor/Background Ratio (TBR), Maximum Standardized Uptake Value (SUVmax), and the true positive rate of the lesions were compared. Furthermore, the FAPI uptake in nodular-like pulmonary lesions (d<3cm) and those with irregular borders was evaluated across the groups. A correlation analysis sought to understand the relationship between FAPI uptake in primary and pulmonary metastatic lesions.

Results

The study's participants were composed of 52 males and 47 females, with an average age of 56.8 ± 13.2 years. A higher uptake and detection rate for pulmonary lesions were exhibited by Group G1 compared to the other groups (SUVmax [G1 vs. G2 vs. G3: 9.1 ± 4.1 vs. 6.1 ± 4.1 vs. 5.3 ± 5.8], P<0.05; TBR [G1 vs. G2 vs. G3: 6.2 ± 2.4 vs. 4.1 ± 2.2 vs. 3.2 ± 2.7], P<0.01; true positive rate 95.1% vs. 88% vs. 75.6%]. In nodular-like lung lesions smaller than 3 cm, G1 showed a significantly higher FAPI uptake compared to G2 and G3 (SUVmax [G1 vs. G2 vs. G3: 8.8 ± 4.3 vs. 5.2 ± 3.2 vs. 4.9 ± 6.1], P<0.01; TBR [G1 vs. G2 vs. G3: 5.7 ± 2.7 vs. 3.7 ± 2.1 vs. 3.3 ± 4.4], P<0.05). Both G1 and G2 demonstrated significantly elevated FAPI agent activity in irregular-bordered pulmonary lesions when compared to G3 (SUVmax [G1 vs. G2 vs. G3: 10.9 ± 3.3 vs. 8.5 ± 2.7 vs. 4.6 ± 2.7], P<0.01; TBR [G1 vs. G2 vs. G3: 7.2 ± 2.1 vs. 6.4 ± 1.3 vs. 3.2 ± 2.4], P<0.01). A positive correlation was identified between the level of 68Ga-FAPI uptake in primary lesions and the uptake in pulmonary metastatic lesions within G2 (r=0.856, P<0.05).

Conclusion

68Ga-FAPI PET/CT imaging proves to be of significant value in the evaluation of pulmonary lesions, offering distinctive insights into their nature.

The Hidden Pandemic of COVID-19-Induced Organizing Pneumonia

Since the beginning of the COVID-19 pandemic, clinical, radiological, and histopathological studies have provided evidence that organizing pneumonia is a possible consequence of the SARS-CoV2 infection. This post-COVID-19 organizing pneumonia (PCOP) causes persisting dyspnea, impaired pulmonary function, and produces radiological abnormalities for at least 5 weeks after onset of symptoms. While most patients with PCOP recover within a year after acute COVID-19, 5-25% of cases need specialized treatment. However, despite substantial resources allocated worldwide to finding a solution to this problem, there are no approved treatments for PCOP. Oral corticosteroids produce a therapeutic response in a majority of such PCOP patients, but their application is limited by the anticipated high-relapse frequency and the risk of severe adverse effects. Herein, we conduct a systematic comparison of the epidemiology, pathogenesis, and clinical presentation of the organizing pneumonias caused by COVID-19 as well as other viral infections. We also use the clinical efficacy of corticosteroids in other postinfection OPs (PIOPs) to predict the therapeutic response in the treatment of PCOP. Finally, we discuss the potential application of a candidate anti-inflammatory and antifibrotic therapy for the treatment of PCOP based on the analysis of the latest clinical trials data.

ALK-positive lung adenocarcinoma in a patient with rheumatoid arthritis with long-term treatment for organizing pneumonia: A case report

RATIONALE

Rheumatoid arthritis (RA) causes inflammation in various organs including the lungs. Pulmonary manifestations include inflammation of the pleura, vasculature, airway, and parenchyma, including interstitial lung disease (ILD). RA-organizing pneumonia (OP) is the third most common cause of RA-ILD. Cases of OP coexisting/complicated with lung cancer have been reported. Therefore, lung cancer can represent a diagnostic challenge, especially in patients with underlying pulmonary diseases including OP.

PATIENT CONCERNS

An 81-year-old woman with a 12-year history of RA-OP underwent multiple transbronchial lung biopsies (TBLBs), all of which resulted in no malignant findings. She was treated with prednisolone (PSL) depending on the deteriorated infiltrations. At admission, chest computed tomography (CT) images showed exacerbation of left S8 consolidation on chest CT. Additionally, her RA activity was exacerbated, and PSL dose was increased to 30 mg/day, which resulted in improved dyspnea and consolidation. Accordingly, PSL dose was gradually decreased. However, 6 months later, when PSL dose was 11 mg/d, due to a worsening of consolidation and the joint symptoms of RA, PSL dose was increased to 20 mg/d and tacrolimus 2 mg/d was administered. 3 months after the increase in PSL dose, dyspnea improved and PSL dose was reduced to 15 mg/d; however, she was admitted to our hospital because of low back pain.

DIAGNOSIS

Spinal magnetic resonance imaging showed bone metastases in the third and fifth lumbar vertebrae, and lung cancer was suspected as the primary tumor on CT.

INTERVENTIONS

TBLB was performed on the left B8 infiltrate, which showed no evidence of malignancy in the previous TBLB.

OUTCOMES

Pathological examination of TBLB on the left B8 revealed an adenocarcinoma that was positive for anaplastic lymphoma kinase.

LESSONS

Physicians should be aware of the development of lung cancer in regions with OP, even after a partial response to corticosteroid therapy.

The many faces of cryptogenic organizing pneumonia (COP)

Organizing pneumonia (OP) is interstitial pneumonia with an acute or subacute clinical course and a histological pattern compatible with acute lung injury. It usually arises after a recent infection of the peripheral bronchial system, whereby is called secondary OP. However, often OP arises with no recognizable cause for which it is called cryptogenic organizing pneumonia (COP). From a radiological standpoint, COP exhibits different imaging appearances and this review makes radiologists and clinicians familiar with the entire spectrum of expected disease findings. Successful interpretation of imaging is pertinent for a rapid diagnosis of COP and knowledge of the entire spectrum of imaging findings in COP is mandatory.

WFUMB Technological Review: How to Perform Contrast-Enhanced Ultrasound of the Lung

The use of ultrasound has revolutionized the evaluation of pulmonary complaints and pathology. Historically, most lung ultrasound uses described are limited to B-mode, M-mode and occasionally color Doppler. However, the use of contrast can significantly expand the diagnostic capabilities of lung ultrasound. Ultrasound contrast enables significant expansion of therapeutic and intervention capabilities. We provide a detailed description of contrast administration, phases and uses in lung ultrasound. Additionally provided are example contrast use cases and illustrative examples of contrast use in a wide range of lung ultrasound applications including pneumonia, atelectasis, pulmonary embolism and neoplasms. Clinical practice examples will help providers incorporate contrast use into their lung ultrasound practice.

Perfusion Patterns of Peripheral Organizing Pneumonia (POP) Using Contrast-Enhanced Ultrasound (CEUS) and Their Correlation with Immunohistochemically Detected Vascularization Patterns

Purpose: To describe the perfusion patterns of peripheral organizing pneumonia (POP) by contrast-enhanced ultrasound (CEUS) and their correlation with vascularization patterns (VPs) represented by immunohistochemical CD34 endothelial staining. Methods: From October 2006 until December 2020, 38 consecutive patients with histologically confirmed POPs were standardized-examined by CEUS. The time to enhancement (TE; classified as an early pulmonary-arterial [PA] pattern of enhancement vs. delayed bronchial-arterial [BA] pattern of enhancement), the extent of enhancement (EE; classified as marked or reduced), the homogeneity of enhancement (HE; classified as homogeneous or inhomogeneous), and the decrease of enhancement (DE; classified as rapid washout [<120s] or late washout [≥120s]) were evaluated retrospectively. Furthermore, tissue samples from the study patients were immunohistochemically stained with CD34 antibody. The presence of avascular areas (AAs) and the VPs were evaluated in all tissue samples. Results: The majority of POPs showed a BA pattern of enhancement (71.1%), an isoechoic marked enhancement (76.3%), and an inhomogeneous enhancement (81.6%). A rapid DE was observed in 50.0% of cases. On CD34 staining, all POPs had a chaotic VP, indicating BA neoangiogenesis. AAs (abscess, necrosis, hemorrhage) were identified in (41.9%) cases with an inhomogeneous enhancement on CEUS. Conclusion: On CEUS, POPs predominantly revealed a marked inhomogeneous BA pattern of enhancement with a rapid washout in 50% of cases. Furthermore, we demonstrated that the presence of a PA pattern of enhancement, found in 28.9% of POPs, did not exclude a BA neoangiogenesis as an important feature of chronic inflammatory and malignant processes.