Different pathways to lung cancer diagnosis in a real-life setting.

BACKGROUND: Most lung cancers are diagnosed at an advanced stage and therefore have a poor prognosis. One major challenge is to choose the most adapted sampling technique to obtain a rapid pathological diagnosis so as to start treatment as early as possible. A growing number of techniques have been developed in recent years. This study sought to assess the diagnostic efficiency of each, along with the respective duration of the diagnostic pathways. METHODS: This retrospective, bicentric, observational study enrolled patients with inoperable lung cancer (stage III or IV) diagnosed in 2018-2019. Diagnostic efficiency was assessed based on the different examinations performed to achieve a precise diagnosis (pathology, immunohistochemistry, and/or molecular biology). The time between the first medical contact and treatment initiation was also assessed. RESULTS: Overall, 625 patients were included (median age 67 years; men 67 %; adenocarcinoma 55 %). The most frequent examinations were bronchial endoscopy (n = 469, 75 %), followed by metastasis biopsy (n = 137, 21.9 %) and guided transthoracic core-needle biopsy (TCNB) (n = 116, 18.6 %). 372 patients had only one procedure (59.5 %), mainly bronchial endoscopy (n = 217, 34.7 %) and metastasis biopsy (n = 71, 11 %). The most efficient examination was thoracic surgery (surgical pleural biopsy, (n = 32, 100 %); mediastinoscopy (n = 26, 96.3 %); surgical pulmonary biopsy (n = 14, 93.3 %). The second most efficient examination was metastasis biopsy (n = 126, 94 %) followed by guided TCNB (n = 108, 93.1 %). The median time from first medical contact to first examination was 4 days (interquartile range 25 %-75 % 1-8). The median time from first medical contact to pathological result was 17 days (10-34). The median time from first medical contact to treatment start was 48 days (30-69). CONCLUSIONS: In order to make an accurate and rapid diagnosis of lung cancer, it is crucial to choose the most appropriate technique. Bronchial endoscopy remains the first-line examination for central lesions, as it is efficient and easily accessible. Guided TCNB and metastasis biopsy are the preferred techniques for peripheral lesions. The choice of the diagnostic technique should be part of a multidisciplinary approach and a dedicated pathway to optimize initial management.

A comparative study of two automated solutions for cross-sectional skeletal muscle measurement from abdominal computed tomography images.

BACKGROUND: Measurement of cross-sectional muscle area (CSMA) at the mid third lumbar vertebra (L3) level from computed tomography (CT) images is becoming one of the reference methods for sarcopenia diagnosis. However, manual skeletal muscle segmentation is tedious and is thus restricted to research. Automated solutions are required for use in clinical practice. PURPOSE: The aim of this study was to compare the reliability of two automated solutions for the measurement of CSMA. METHODS: We conducted a retrospective analysis of CT images in our hospital database. We included consecutive individuals hospitalized at the Grenoble University Hospital in France between January and May 2018 with abdominal CT images and sagittal reconstruction. We used two types of software to automatically segment skeletal muscle: ABACS, a module of the SliceOmatic software solution "ABACS-SliceOmatic," and a deep learning-based solution called "AutoMATiCA." Manual segmentation was performed by a medical expert to generate reference data using "SliceOmatic." The Dice similarity coefficient (DSC) was used to measure overlap between the results of the manual and the automated segmentations. The DSC value for each method was compared with the Mann-Whitney U test. RESULTS: A total of 676 hospitalized individuals was retrospectively included (365 males [53.8%] and 312 females [46.2%]). The median DSC for SliceOmatic vs AutoMATiCA (0.969 [5th percentile: 0.909]) was greater than the median DSC for SliceOmatic vs. ABACS-SliceOmatic (0.949 [5th percentile: 0.836]) (p < 0.001). CONCLUSIONS: AutoMATiCA, which used artificial intelligence, was more reliable than ABACS-SliceOmatic for skeletal muscle segmentation at the L3 level in a cohort of hospitalized individuals. The next step is to develop and validate a neural network that can identify L3 slices, which is currently a fastidious process.

Computed Tomography Registration-Derived Regional Ventilation Indices Compared to Global Lung Function Parameters in Patients With COPD.

CT registration-derived indices provide data on regional lung functional changes in COPD. However, because unlike spirometry which involves dynamic maximal breathing maneuvers, CT-based functional parameters are assessed between two static breath-holds, it is not clear how regional and global lung function parameters relate to each other. We assessed the relationship between CT-density change (dHU), specific volume change (dsV), and regional lung tissue deformation (J) with global spirometric and plethysmographic parameters, gas exchange, exercise capacity, dyspnoea, and disease stage in a prospective cohort study in 102 COPD patients. There were positive correlations of dHU, dsV, and J with spirometric variables, DLCO and gas exchange, 6-min walking distance, and negative correlations with plethysmographic lung volumes and indices of trapping and lung distension as well as GOLD stage. Stepwise regression identified FEV1/FVC (standardized ß = 0.429, p < 0.0001), RV/TLC (ß = -0.37, p < 0.0001), and BMI (ß = 0.27, p=<0.001) as the strongest predictors of CT intensity-based metrics dHU, with similar findings for dsV, while FEV1/FVC (ß = 0.32, p=<0.001) and RV/TLC (ß = -0.48, p=<0.0001) were identified as those for J. These data suggest that regional lung function is related to two major pathophysiological processes involved in global lung function deterioration in COPD: chronic airflow obstruction and gas trapping, with an additional contribution of nutritional status, which in turn determines respiratory muscle strength. Our data confirm previous findings in the literature, suggesting the potential of CT image-based regional lung function metrics as the biomarkers of disease severity and provide mechanistic insight into the interpretation of regional lung function indices in patients with COPD.

NUT carcinoma of the lung.

NUT carcinoma of the thorax is a rare and very aggressive tumor, whose definition is based on the demonstration of a nuclear protein in testis (NUTM1; also known as NUT) gene fusion on 15q14 with different partners from the bromodomain-containing proteins gene family. This fusion results in an activation of MYC oncoprotein responsible for the tumor's aggressivity. NUT carcinoma arises preferentially in young adults, presenting a large thoracic mass frequently associated with lymph nodes, bone or pleural metastases. At histology, this tumor is often poorly differentiated, mainly composed of sheets of small cells with scant cytoplasm, a round nucleus with a central nucleolus. Focal areas of squamous differentiation can be observed. Mitoses and necrosis are frequent, as well as neutrophilic infiltrate. The diagnosis is based on the detection of NUT protein expression by immunohistochemistry using the rabbit monoclonal antibody C52B1 in more than 50% of the tumor nuclei. This technique offers 87% sensitivity and nearly 100% specificity with reference to FISH or RT-PCR, which confirm the NUTM1 rearrangement. The differential diagnoses include basaloid carcinoma of the lung, small cell carcinoma, thymic carcinoma (basaloid variant), SMARCA4_deficient thoracic sarcoma, other NUTM1 rearranged undifferentiated tumors, small round cell tumors, non-Hodgkin lymphoma/leukemia, and melanoma. The prognosis of NUT carcinoma remains very poor, with a median survival of 6.7 months, and 1- and 2-year overall survival rates of 30% and 19%, respectively. NUT carcinoma is often refractory to conventional chemotherapy, but ifosfamide-based regimens or BET inhibitors could represent promising therapies.

Nasal High Flow at 25 L/min or Expiratory Resistive Load Do Not Improve Regional Lung Function in Patients With COPD: A Functional CT Imaging Study.

BACKGROUND: Nasal high flow (NHF) is a non-invasive breathing therapy that is based on the delivery via a large-caliber nasal cannula of heated and humidified air at flow rates that exceed peak inspiratory flow. It is thought that positive airway pressure generated by NHF can help reduce gas trapping and improve regional lung ventilation. There are no data to confirm this hypothesis at flow rates applicable in stable chronic obstructive pulmonary disease (COPD) patients. METHODS: In this study, we used non-rigid registration of computed tomography (CT) images acquired at maximal expiration and inspiration to compute regional lung attenuation changes (ΔHU), and lung displacement (LD), indices of regional lung ventilation. Parametric response maps (Galban et al., 2012) were also computed in each experimental condition. Eight COPD patients were assessed at baseline (BL) and after 5 min of NHF and expiratory resistive loading (ERL). RESULTS: ΔHU was: BL (median, IQR): 85 (67.2, 102.8); NHF: 90.7 (57.4, 97.6); ERL: 74.6 (46.4, 89.6) HU (p = 0.531); and LD: 27.8 (22.3, 39.3); 17.6 (15.4, 27.9); and 20.4 (16.6, 23.6) mm (p = 0.120) in the 3 conditions, respectively. No significant difference in trapping was observed. Respiratory rate significantly decreased with both treatments [BL: 17.3 (16.4, 18.9); NHF: 13.7; ERL: 11.4 (9.6, 13.2) bpm; and p < 0.001]. CONCLUSION: Neither NHF at 25 L/min nor ERL significantly improved the regional lung ventilation of stable COPD patients with gas trapping, based on functional lung CT imaging. Further study including more subjects is needed to assess the potential effect of NHF on regional lung function at higher flow rates. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov/under, identifier NCT03821311.

Collagenase-Induced Patellar Tendinopathy with Neovascularization: First Results towards a Piglet Model of Musculoskeletal Embolization.

BACKGROUND: Therapeutic strategies targeting neovessels responsible for musculoskeletal chronic pain have emerged, including neovessels embolization. Our study aimed to develop a large animal model of patellar tendinopathy with neovascularization. METHODS: Nine 3-month-old male piglets (18 patellar tendons) received percutaneous injections of increasing doses of collagenase (0 to 50 mg) at day 0 (D0). Tendinopathy was evaluated by ultrasound (D7 and D14). Neovascularization was evaluated visually and on angiographies. Bonar score was used for histological analysis (D14). Correlations were evaluated using Spearman's rank (Rs) test. RESULTS: Research protocol was well tolerated. All tendons were enlarged with a median increase of 31.58% [25-40.28] at D7 (p = 0.244) at D7 and 57.52% [48.41-91.45] at D14 (p = 0.065). Tendons with collagenase injection had more hypoechoic changes, with one tendon rupture (p = 0.012). Neovascularization was reported above 5 mg collagenase (p < 0.01) at D7 and D14 with dose-related neovessels induction (Rs = 0.8, p < 0.001). The Bonar score increased above 5 mg collagenase, correlated with the dose (Rs = 0.666, p = 0.003). CONCLUSIONS: The study shows the feasibility, safety and reproducibility of this new large animal model of patellar tendinopathy with neovascularization after collagenase injection. It will allow studying new treatments on direct embolization of neovessels by endovascular approach.

Imaging features and differential diagnoses of non-neoplastic diffuse mediastinal diseases.

Acute or chronic non-neoplastic diffuse mediastinal diseases have multiple causes, degrees of severity, and a wide range of management. Some situations require emergency care while others do not need specific treatment. Although the diagnosis may be suspected on chest X-ray, it is mainly based on CT. A delayed recognition is not uncommonly observed. Some findings may prompt the radiologist to look for specific associated injuries or lesions.This pictorial review will successively describe the various non-neoplastic causes of diffuse mediastinal diseases with their typical findings and major differentials.First, pneumomediastinum that can be provoked by extra- or intra-thoracic triggers requires the knowledge of patient's history or recent occurrences. Absence of any usual etiological factor should raise suspicion of cocaine inhalation in young individuals.Next, acute mediastinitis may be related to post-operative complications, esophageal perforation, or contiguous spread of odontogenic or retropharyngeal infections. The former diagnosis is not an easy task in the early stage, owing to the similarities of imaging findings with those of normal post-operative appearance during the first 2-3 weeks.Finally, fibrosing mediastinitis that is linked to an excessive fibrotic reaction in the mediastinum with variable compromise of mediastinal structures, in particular vascular and airway ones. Differential diagnosis includes tumoral and inflammatory infiltrations of the mediastinum.

Percutaneous CT-guided biopsy of lytic bone lesions in patients clinically suspected of lung cancer: Diagnostic performances for pathological diagnosis and molecular testing.

OBJECTIVES: Bone is a common location for lung cancer metastasis. Clinicians are often reluctant to biopsy bone metastases, as they are known to require a decalcification process that damages nucleic acids, which makes it incompatible with molecular testing. We performed this study to assess the diagnostic performance of histopathology and molecular testing of computed tomography (CT)-guided percutaneous bone biopsies of lytic bone lesions during the initial assessment or during the progression of lung cancer. MATERIALS AND METHODS: This retrospective study included all patients suspected of having or known to have primary lung cancer and CT-guided percutaneous bone biopsies of lytic bone from January 2010 to June 2017. The main judgment criterion was the diagnostic performance of the pathological analysis. Secondary endpoints were the diagnostic performance of molecular testing and incidence of complications. RESULTS: Fifty patients were included. The yield of CT-guided percutaneous bone biopsies for pathological analysis was 100 %, allowing for a diagnosis of certainty in all cases. The percentage of tumor cells in samples was higher than the 20 % threshold in 83.9 % of cases. The yield of molecular analysis was 94.6 %. A mutation was found in 60 % of cases; most frequently in KRAS (Kirsten rat sarcoma viral oncogene homolog) (28.6 %) and EGFR (epidermal growth factor receptor) (14.3 %). The complication rate was 2 %, i.e. a minor undrained pneumothorax. CONCLUSION: CT-guided percutaneous biopsies of lytic bone is associated with a very low complication rate and high diagnostic performance for histopathology and mutation testing.

Development and Validation of a Deep Learning-Based Automated Detection Algorithm for Major Thoracic Diseases on Chest Radiographs.

Importance: Interpretation of chest radiographs is a challenging task prone to errors, requiring expert readers. An automated system that can accurately classify chest radiographs may help streamline the clinical workflow. Objectives: To develop a deep learning-based algorithm that can classify normal and abnormal results from chest radiographs with major thoracic diseases including pulmonary malignant neoplasm, active tuberculosis, pneumonia, and pneumothorax and to validate the algorithm's performance using independent data sets. Design, Setting, and Participants: This diagnostic study developed a deep learning-based algorithm using single-center data collected between November 1, 2016, and January 31, 2017. The algorithm was externally validated with multicenter data collected between May 1 and July 31, 2018. A total of 54 221 chest radiographs with normal findings from 47 917 individuals (21 556 men and 26 361 women; mean [SD] age, 51 [16] years) and 35 613 chest radiographs with abnormal findings from 14 102 individuals (8373 men and 5729 women; mean [SD] age, 62 [15] years) were used to develop the algorithm. A total of 486 chest radiographs with normal results and 529 with abnormal results (1 from each participant; 628 men and 387 women; mean [SD] age, 53 [18] years) from 5 institutions were used for external validation. Fifteen physicians, including nonradiology physicians, board-certified radiologists, and thoracic radiologists, participated in observer performance testing. Data were analyzed in August 2018. Exposures: Deep learning-based algorithm. Main Outcomes and Measures: Image-wise classification performances measured by area under the receiver operating characteristic curve; lesion-wise localization performances measured by area under the alternative free-response receiver operating characteristic curve. Results: The algorithm demonstrated a median (range) area under the curve of 0.979 (0.973-1.000) for image-wise classification and 0.972 (0.923-0.985) for lesion-wise localization; the algorithm demonstrated significantly higher performance than all 3 physician groups in both image-wise classification (0.983 vs 0.814-0.932; all P < .005) and lesion-wise localization (0.985 vs 0.781-0.907; all P < .001). Significant improvements in both image-wise classification (0.814-0.932 to 0.904-0.958; all P < .005) and lesion-wise localization (0.781-0.907 to 0.873-0.938; all P < .001) were observed in all 3 physician groups with assistance of the algorithm. Conclusions and Relevance: The algorithm consistently outperformed physicians, including thoracic radiologists, in the discrimination of chest radiographs with major thoracic diseases, demonstrating its potential to improve the quality and efficiency of clinical practice.

Partial response of pulmonary adenocarcinoma with symptomatic brain metastasis to nivolumab plus high-dose oral corticosteroid: a case report.

BACKGROUND: Nivolumab, a monoclonal antibody targeting the programmed death-1 receptor, is indicated in locally advanced or metastatic non-small cell lung cancer, with progression after platinum-based chemotherapy. Up-to-now, few data are available concerning brain activity of this treatment and concomitant use of corticosteroids. CASE PRESENTATION: A 64-year-old caucasian man with a pulmonary adenocarcinoma associated with brain metastases received four courses of nivolumab in concomitance with a high dose of corticosteroids for his neurologic symptoms. He experienced a partial response in his brain and chest with an improvement in his general condition. Nivolumab was effective in shrinking symptomatic brain metastases, and metastases at other sites, in a patient with non-small cell lung cancer and first-line chemotherapy failure. The effect of nivolumab was obtained despite concomitant high-dose corticosteroid therapy. Combined nivolumab and high-dose corticosteroid therapy did not induce unexpected adverse events. CONCLUSION: Nivolumab and concomitant high-dose corticosteroid therapy was found to be efficient and well tolerated.

Acquired pulmonary artery pseudoaneurysms: a pictorial review.

Pulmonary artery pseudoaneurysms (PAPs) are uncommon but potentially lethal. They may be incidentally discovered on imaging, or following massive haemoptysis if they rupture, with high risk of mortality. The most frequent causes of PAP are trauma and infectious disease. Vasculitis, in particular Behçet's disease, neoplasm, congenital disease and pulmonary hypertension are rarer causes of PAP. A PAP can be suspected from chest X-ray and contrast CT, but requires confirmation by CT angiography. Arteriography is no longer performed for diagnostic purposes, but can be useful in preparing endovascular occlusion of the PAP. In rare cases, surgery is necessary. The aim of this pictorial review was to illustrate the most common causes of acquired PAPs.

Comparison of the effects of model-based iterative reconstruction and filtered back projection algorithms on software measurements in pulmonary subsolid nodules.

OBJECTIVES: To evaluate the differences between filtered back projection (FBP) and model-based iterative reconstruction (MBIR) algorithms on semi-automatic measurements in subsolid nodules (SSNs). METHODS: Unenhanced CT scans of 73 SSNs obtained using the same protocol and reconstructed with both FBP and MBIR algorithms were evaluated by two radiologists. Diameter, mean attenuation, mass and volume of whole nodules and their solid components were measured. Intra- and interobserver variability and differences between FBP and MBIR were then evaluated using Bland-Altman method and Wilcoxon tests. RESULTS: Longest diameter, volume and mass of nodules and those of their solid components were significantly higher using MBIR (p < 0.05) with mean differences of 1.1% (limits of agreement, -6.4 to 8.5%), 3.2% (-20.9 to 27.3%) and 2.9% (-16.9 to 22.7%) and 3.2% (-20.5 to 27%), 6.3% (-51.9 to 64.6%), 6.6% (-50.1 to 63.3%), respectively. The limits of agreement between FBP and MBIR were within the range of intra- and interobserver variability for both algorithms with respect to the diameter, volume and mass of nodules and their solid components. There were no significant differences in intra- or interobserver variability between FBP and MBIR (p > 0.05). CONCLUSION: Semi-automatic measurements of SSNs significantly differed between FBP and MBIR; however, the differences were within the range of measurement variability. KEY POINTS: • Intra- and interobserver reproducibility of measurements did not differ between FBP and MBIR. • Differences in SSNs' semi-automatic measurement induced by reconstruction algorithms were not clinically significant. • Semi-automatic measurement may be conducted regardless of reconstruction algorithm. • SSNs' semi-automated classification agreement (pure vs. part-solid) did not significantly differ between algorithms.

The effect of late-phase contrast enhancement on semi-automatic software measurements of CT attenuation and volume of part-solid nodules in lung adenocarcinomas.

OBJECTIVES: To evaluate the differences in semi-automatic measurements of CT attenuation and volume of part-solid nodules (PSNs) between unenhanced and enhanced CT scans. MATERIALS AND METHODS: CT scans including unenhanced and enhanced phases (slice thickness 0.625 and 1.25mm, respectively) for 53 adenocarcinomas presenting as PSNs in 50 patients were retrospectively evaluated. For each nodule, semi-automatic segmentation provided the diameter, mean attenuation, mass, and volume of a whole nodule and its solid component. Interscan variability and statistical significance of the differences in those measures according to the adenocarcinoma category were evaluated by one reader. RESULTS: All parameters except for the mean attenuation of the solid components, were significantly increased on enhanced CT (p<0.05). For the whole nodule, the mean relative differences were as follows: the longest diameter, 1.4% (limits of agreement, -6.2-9.1); volume, 2.4% (-26.7-31.4); mass, 7.0% (-11.3-25.2); mean attenuation, 2.7% (-5.6-11). For the nodule's solid component, those differences were as follow: the longest diameter, 6.9% (-34.4-48.2); volume, 17.9% (-77.8-113.7); mass, 18.8% (-77.8-115.4). The differences of measures between the unenhanced and enhanced CT were not significantly different between two groups of adenocarcinoma in situ/minimally invasive adenocarcinomas and invasive adenocarcinomas (p>0.05). CONCLUSIONS: As most volumetric and attenuation measurements changed significantly after contrast enhancement, care should be taken in comparing unenhanced and enhanced CT in the evaluation of PSNs.

Immune biomarkers PD-1/PD-L1 and TLR3 in malignant pleural mesotheliomas.

Malignant pleural mesothelioma (MPM) is an aggressive tumor with no effective therapy. However PD-L1/PD-1 immunity checkpoint therapies gave encouraging results; TLR3 is a programmed death factor, which triggering up-regulates PD-L1. As PD-1/PD-L1 blocking antibodies could restore antitumor immune responses alone or in combination with TLR3 agonists, we investigated PD-L1/PD-1 and TLR3 expressions in MPM to select patients for immunotherapy. Sixty-eight pleural surgical specimens, including 58 MPM (epithelioid, n = 34; biphasic, n = 11; sarcomatoid, n = 13) and 10 benign lesions, were studied. PD-L1 expression was assessed using E1L3N and SP142 clones in tumor cells (TCs) and in tumor-infiltrating lymphocytes (TILs) (positivity threshold of 1%), and compared with overall survival. PD-1, CD3 and CD8 expression by TILs, and TLR3 expression by TCs were analyzed concomitantly. PD-L1 was more expressed by sarcomatoid subtype than by other MPM (62% versus 23% and 9% for E1L3N; 38% versus 11% for SP142) (P = .01 and .04, respectively). Specificity and sensitivity of E1L3N and SP142 were of 53% and 98%, and 90% and 86%, respectively. PD-L1 expression by TILs and TCs correlated for SP142 (P = .023), and PD-L1 SP142 expression by TCs was associated with shorter overall survival (P = .016). TLR3 was expressed in most MPM, but weakly in sarcomatoid MPM. We confirm by comparing two commercially available antibodies that PD-L1 expression is higher in sarcomatoid MPM and correlates with a shorter survival. Whereas TLR3 agonists could be tested in MPM expressing TLR3, the sarcomatoid subtype could benefit from anti-PD-L1/PD-1 therapies alone or in combination.

Serum potassium concentration predicts brain hypoxia on CT after avalanche-induced cardiac arrest.

BACKGROUND: Brain anoxia after complete avalanche burial and cardiac arrest (CA) may occur despite adequate on-site triage. PURPOSE: To investigate clinical and biological parameters associated with brain hypoxia in a cohort of avalanche victims with whole body computed tomographic (CT) scan. METHODS: Retrospective study of patients with CA and whole body CT scan following complete avalanche burial admitted in a level-I trauma center. MAIN FINDINGS: Out of 19 buried patients with whole body CT scan, eight patients had refractory CA and 11 patients had pre-hospital return of spontaneous circulation. Six patients survived at hospital discharge and only two had good neurologic outcome. Twelve patients had signs of brain hypoxia on initial CT scan, defined as brain edema, loss of gray/white matter differentiation and/or hypodensity of basal ganglia. No clinical pre-hospital parameter was associated with brain anoxia. Serum potassium concentration at admission was higher in patients with brain anoxia as compared to patients with normal CT scan: 5.5 (4.1-7.2) mmol/L versus 3.3 (3.0-4.2) mmol/L, respectively (P<.01). A threshold of 4.35 mmol/L serum potassium had 100% specificity to predict brain anoxia on brain CT scan. CONCLUSIONS: Serum potassium concentration had good predictive value for brain anoxia after complete avalanche burial. This finding further supports the use of serum potassium concentration for extracorporeal life support insertion at hospital admission in this context.

Focal pleural thickening mimicking pleural plaques on chest computed tomography: tips and tricks.

Diagnosis of pleural plaques (PPs) is commonly straightforward, especially when a typical appearance is observed in a context of previous asbestos exposure. Nevertheless, numerous causes of focal pleural thickening may be seen in routine practice. They may be related to normal structures, functional pleural thickening, previous tuberculosis, pleural metastasis, silicosis or other rarer conditions. An application of a rigorous technical approach as well as a familiarity with loco-regional anatomy and the knowledge of typical aspects of PP are required. Indeed, false-positive or false-negative results may engender psychological and medico-legal consequences or can delay diagnosis of malignant pleural involvement. Correct recognition of PPs is crucial, as they may also be an independent risk factor for mortality from lung cancer in asbestos-exposed workers particularly in either smokers or former/ex-smokers. Finally, the presence of PP(s) may help in considering asbestosis as a cause of interstitial lung disease predominating in the subpleural area of the lower lobes. The aim of this pictorial essay is to provide a brief reminder of the normal anatomy of the pleura and its surroundings as well as the various aspects of PPs. Afterwards, the common pitfalls encountered in PP diagnosis will be emphasized and practical clues to differentiate actual plaque and pseudoplaque will be concisely described.

Usual interstitial pneumonia end-stage features from explants with radiologic and pathological correlations.

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia, with typical high-resolution computed tomography (HRCT) features and histologic pattern of usual interstitial pneumonia (UIP); its main differential diagnosis is fibrotic nonspecific interstitial pneumonia (F-NSIP). Usual interstitial pneumonia was mainly described from lung biopsies, and little is known on explants. Twenty-two UIP/IPF explants were analyzed histologically and compared with previous open lung biopsies (OLBs; n = 11) and HRCT (n = 19), when available. Temporospatial heterogeneity and subpleural and paraseptal fibrosis were similarly found in UIP/IPF explants and OLB (91%-95%). Fibroblastic foci were found in 82% of OLBs and 100% of explants, with a higher mean score in explants (P = .023). Honeycombing was present in 64% of OLBs and 95% of explants, with a higher mean score in explants (P = .005). Almost 60% of UIP/IPF explants showed NSIP areas and 41% peribronchiolar fibrosis; inflammation, bronchiolar metaplasia, and vascular changes were more frequent in UIP/IPF explants; and Desquamative Interstitial Pneumonia (DIP)-like areas were not common (18%-27%). Numerous large airspace enlargements with fibrosis were frequent in UIP/IPF explants (59%). On HRCT, honeycombing was observed in 95% of the cases and ground-glass opacities in 53%, correlating with NSIP areas or acute exacerbation at histology. Six patients had combined IPF and emphysema. Lesions were more severe in UIP/IPF explants, reflecting the worsening of the disease. Usual interstitial pneumonia/IPF explants more frequently presented with confounding lesions such as NSIP areas, peribronchiolar fibrosis, and airspace enlargements with fibrosis sometimes associated with emphysema.