Overlaps and uncertainties of smoking-related idiopathic interstitial pneumonias

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.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

The Application of Transbronchial Lung Cryobiopsy and Uniportal and Tubeless Video-Assisted Thoracic Surgery in the Multidisciplinary Diagnosis of Interstitial Lung disease-A Real-World Prospective Study

The application of transbronchial lung cryobiopsy (TBLC) and uniportal and tubeless video-assisted thoracic surgery (UT-VATS) in the multidisciplinary diagnosis of interstitial lung disease (ILD) has not been demonstrated in real-world clinical practice. This prospective study included 137 patients with no definitive diagnosis who were the subject of two multidisciplinary discussion (MDD) sessions. As indicated in the first MDD, 67 patients underwent UT-VATS and 70 underwent TBLC. The specificity of biopsy information and its contribution to final MDD diagnosis were evaluated in the second MDD. The post-operative complications and hospitalization costs associated with the two biopsy methods were compared. UT-VATS was favored for patients initially diagnosed with idiopathic pulmonary fibrosis (IPF), bronchiolitis-associated interstitial lung disease (RB-ILD)/desquamative interstitial pneumonia (DIP) and undefined idiopathic interstitial pneumonia (UIIP), while TBLC was preferred for pulmonary lymphangioleiomyomatosis (PLAM) and pulmonary alveolar proteinosis (PAP). The spirometry parameters were better in patients who underwent UT-VATS than those who underwent TBLC. UT-VATS provided more specific pathological results than TBLC (85.7 vs 73.7%, p = 0.06). In patients initially diagnosed with UIIP, pathological information from UT-VATS was more clinically useful than that obtained from TBLC, although both tests contributed similarly to cases initially diagnosed as interstitial pneumonia with auto-immune features (IPAF)/connective tissue disease-related ILD (CTD-ILD). The safety of UT-VATS was comparable with TBLC although TBLC was cheaper during hospitalization (US$4,855.7 vs US$3,590.9, p < 0.001). multidisciplinary discussion decisions about biopsies were driven by current knowledge of sampling and diagnosis capacity as well as potential risks of different biopsy methods. The current MDD considered UT-VATS more informative than TBLC in cases initially diagnosed as UIIP although they were equally valuable in patients initially diagnosed with IPAF/CTD-ILD.

CT findings of pulmonary cysts

Pulmonary cysts are thin-walled radiolucent lesions that may appear in a variety of uncommon disorders known as diffuse cystic lung diseases (DCLD) that essentially includes lymphangioleiomyomatosis (LAM), Langerhans cell histiocytosis (LCH), lymphocytic interstitial pneumonia (LIP), Pneumocystis jiroveci pneumonia (PJP), and Birt-Hogg-Dubé syndrome (BHDS). Moreover, they have been reported in several cases of coronavirus disease 2019 (COVID-19). The purpose of this review is to provide a practical approach for evaluating lung cysts when encountered on CT. We describe the imaging findings of DLCD emphasising their differences in terms of shape and distribution of the cysts, as well as their association with other findings such as nodules or ground-glass opacities, which may help in making a confident diagnosis. We also discuss the link between pulmonary cysts and COVID-19.

CA-125, CA-153, and CYFRA21-1 as clinical indicators in male lung cancer with ocular metastasis

Despite recent improvements in diagnosis and therapy, lung cancer remains the most common malignant tumor in males, with high morbidity and mortality. As the annual incidence continues to increase worldwide, the prognosis for male patients with lung cancer remains unsatisfactory. Interestingly, smoking is associated with lung cancer and ocular lesions by altering risk factors such as carbohydrate antigen (CA)-125, CA-153 and cytokeratin-19 fragment (CYFRA21-1). A diagnostic standard for serum biomarker levels of ocular metastasis (OM) in males with lung cancer is therefore urgently needed. In this retrospective analysis, we examined the relationship between smoking preference and OM in male patients with lung cancer to identify an independent prognostic factor or establish a quantitative indicated standard for OM using the clinical indexes from 2238 cases of male lung cancer. The combination of CA-125, CA-153 and CYFRA21-1 could help diagnose OM in male lung cancer patients. This finding might lead to more timely diagnosis and effective therapies.

Smoking Relapse Causing an Acute Exacerbation of Desquamative Interstitial Pneumonia with Pleural Effusions and Mediastinal Adenopathies

Desquamative interstitial pneumonia (DIP) is a rare interstitial pneumonia often caused by smoking. DIP is typically regarded as a chronic disease, but acute DIP exacerbations can occur, and some have resulted in death. Factors that can provoke a DIP exacerbation are not well described in the literature. We present a case of a 58-year-old male with DIP, who after being treated successfully with smoking cessation and steroids for 7 months, required hospitalization for acute hypoxemic respiratory failure. This acute episode was very likely an exacerbation of his DIP after a smoking relapse period of 6 weeks prior to this acute presentation. This report also highlights unique CT findings in a DIP case of pleural effusions and mediastinal adenopathies seen chronically and relapsing acutely. To the best of our knowledge, CT findings of pleural effusions and mediastinal adenopathies concurrently have not been described in a case of DIP in chronic or acute conditions.

[The respiratory effects of smoking]

A marked increase in the morbidity and mortality of a large number of broncho-pulmonary diseases has been documented in relation to smoking. The influence of tobacco smoking on various respiratory conditions. is discussed: incidence, severity or natural history modification of some respiratory illnesses: obstructive lung diseases (COPD, asthma), lung cancer, bacterial, viral respiratory infections, with the impact of smoking on tuberculosis. Finally, the relationship of tobacco with diffuse interstitial lung disease: protective role of smoking (controversial in sarcoidosis, real in hypersensitivity pneumonitis). The benefits of smoking cessation are described.