Chest computed tomography findings for a cohort of children with pulmonary Langerhans cell histiocytosis.

OBJECTIVE: This study was undertaken to describe the spectrum of lung computed-tomography (CT) findings in children with pulmonary Langerhans cell histiocytosis (PLCH) and to evaluate for this population the CT-scan nodule and cyst scores proposed by adult pulmonologists at diagnosis and during follow-up. METHODS: Among 175 children with PLCH identified in the French national population-based Langerhans cell histiocytosis cohort, 60 were retrospectively selected by the availability of CT for a central review by three pediatric radiologists. These 60 patients are representative of childhood PLCH for almost all clinical aspects, except a lower percentage of risk organ involvement (38% vs 54%; P = 0.05). RESULTS: The 60 children's chest CT scans (n = 218) were reviewed. At diagnosis, 63% of them had nodules, 53% had cysts, and 29% had both. The percentages of patients with nodules or cysts increased from diagnosis to peak disease activity, respectively, from 63% to 73% and from 53% to 66%. The costophrenic angle was involved in 71%. Patients with pneumothorax (25%) had a higher median cyst score. Alveolar consolidation was observed in 34%. Patients with low CT-scan nodule and cyst scores had no long-term pulmonary sequelae. CONCLUSIONS: Well-known characteristics of adult PLCH (nodules and cysts) were observed in children. The chest CT scores proposed by adult pulmonologists could easily be applied to childhood PLCH. Lesions in children, unlike those in adults, are frequently located near the costophrenic angles. Alveolar consolidation might be considered an atypical feature of childhood PLCH.

Prevalence and incidence of interstitial lung diseases in a multi-ethnic county of Greater Paris.

The objective of the study was to estimate the prevalence and incidence of interstitial lung diseases (ILDs) in Seine-Saint-Denis, a multi-ethnic county of Greater Paris, France.Patients with ILDs were identified between January and December 2012 by using several sources; all potentially involved medical specialists from public and private hospitals, community-based pulmonologists and general practitioners, and the Social Security system. Diagnoses were validated centrally by an expert multidisciplinary discussion.1170 ILD cases were reported (crude overall prevalence: 97.9/105 and incidence: 19.4/105/year). In the 848 reviewed cases, the most prevalent diagnoses were sarcoidosis (42.6%), connective tissue diseases associated ILDs (CTDs-ILDs) (16%), idiopathic pulmonary fibrosis (IPF) (11.6%), and occupational ILDs (5.0%), which corresponded to a crude prevalence of 30.2/105 for sarcoidosis, 12.1/105 for CTDs-ILDs and 8.2/105 for IPF. The prevalence of fibrotic idiopathic interstitial pneumonias, merging IPF, nonspecific interstitial pneumonia and cases registered with code J84.1 was 16.34/105 An adjusted multinomial model demonstrated an increased risk of sarcoidosis in North Africans and Afro-Caribbeans and of CTDs-ILDs in Afro-Caribbeans, compared to that in Europeans.This study, with a comprehensive recruitment and stringent diagnostic criteria, emphasises the importance of secondary ILDs, particularly CTDs-ILDs and the relatively low prevalence of IPF, and confirms that sarcoidosis is a rare disease in France.

Infectious Complications of Pulmonary Sarcoidosis.

In this review, the infectious complications observed in sarcoidosis are considered from a practical point of view to help the clinician not to overlook them in a difficult context, as pulmonary sarcoidosis makes the recognition of superinfections more difficult. An increased incidence of community-acquired pneumonia and of opportunistic pneumonia has been reported, especially in immunosuppressed patients. Pulmonary destructive lesions of advanced sarcoidosis increase the incidence of chronic pulmonary aspergillosis and infection by other agents. Screening and treatment of latent tuberculosis infection are crucial to prevent severe tuberculosis. Severity in COVID-19 appears to be increased by comorbidities rather than by sarcoidosis per se. The diagnosis of infectious complications can be challenging and should be considered as a potential differential diagnosis when the exacerbation of sarcoidosis is suspected. These complications not only increase the need for hospitalizations, but also increase the risk of death. This aspect must be carefully considered when assessing the overall health burden associated with sarcoidosis. The impact of immune dysregulation on infectious risk is unclear except in exceptional cases. In the absence of evidence-based studies on immunosuppressants in the specific context of pulmonary sarcoidosis, it is recommended to apply guidelines used in areas outside sarcoidosis. Preventive measures are essential, beginning with an appropriate use of immunosuppressants and the avoidance of unjustified treatments and doses. This approach should take into account the risk of tuberculosis, especially in highly endemic countries. Additionally, parallel emphasis should be placed on vaccinations, especially against COVID-19.

Differential diagnosis of pulmonary sarcoidosis: a review.

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

Progression of idiopathic pulmonary fibrosis: lessons from asymmetrical disease.

BACKGROUND: In idiopathic pulmonary fibrosis (IPF) the distribution and spatial-temporal progression of fibrotic changes may be influenced by general or locoregional conditions. From this perspective, patients with asymmetrical disease (AIPF) may be unique. METHODS: This retrospective study included 32 patients (26 men, mean ± SD age 69 ± 7 years) with AIPF, as defined by an asymmetry ratio (most affected--least affected fibrosis score)/(most affected + least affected fibrosis score) >0.2. The global fibrosis score was the average of the right and left scores. Patients with AIPF were compared with 64 matched controls with symmetrical IPF. RESULTS: Patients with AIPF did not differ from controls in global fibrosis score and forced vital capacity, but carbon monoxide transfer factor was less decreased (52 ± 19% vs 43 ± 13%, p=0.009). The rate of gastro-oesophageal reflux and acute exacerbations was significantly higher in patients with AIPF (62.5% vs 31.3%, p=0.006 and 46.9% vs 17.2%, p=0.004, respectively). In patients with AIPF the right side was more likely to be involved (62.5%); the median asymmetry ratio was 0.5 (range 0.24-1). Although the global fibrosis score worsened significantly in all 23 patients with AIPF with serial high-resolution CT scans (p<0.0001), pulmonary fibrosis remained asymmetrical in all except three. During follow-up, 15 patients with AIPF experienced 18 acute exacerbations. The first episode was virtually unilateral, occurring in the most affected lung in 10 patients (66.7%). Survival was similar between patients with AIPF and controls. CONCLUSION: AIPF may be related to locoregional factors including gastro-oesophageal reflux which may be responsible for both disease expansion and the occurrence of acute exacerbations.

High-resolution computed tomography to differentiate chronic diffuse interstitial lung diseases with predominant ground-glass pattern using logical analysis of data.

OBJECTIVES: We evaluated the performance of high-resolution computed tomography (HRCT) to differentiate chronic diffuse interstitial lung diseases (CDILD) with predominant ground-glass pattern by using logical analysis of data (LAD). METHODS: A total of 162 patients were classified into seven categories: sarcoidosis (n = 38), connective tissue disease (n = 32), hypersensitivity pneumonitis (n = 18), drug-induced lung disease (n = 15), alveolar proteinosis (n = 12), idiopathic non-specific interstitial pneumonia (n = 10) and miscellaneous (n = 37). First, 40 CT attributes were investigated by the LAD to build up patterns characterising a category. From the association of patterns, LAD determined models specific to each CDILD. Second, data were recomputed by adding eight clinical attributes to the analysis. The 20 x 5 cross-folding method was used for validation. RESULTS: Models could be individualised for sarcoidosis, hypersensitivity pneumonitis, connective tissue disease and alveolar proteinosis. An additional model was individualised for drug-induced lung disease by adding clinical data. No model was demonstrated for idiopathic non-specific interstitial pneumonia and the miscellaneous category. The results showed that HRCT had a good sensitivity (>or=64%) and specificity (>or=78%) and a high negative predictive value (>or=93%) for diseases with a model. Higher sensitivity (>or=78%) and specificity (>or=89%) were achieved by adding clinical data. CONCLUSION: The diagnostic performance of HRCT is high and can be increased by adding clinical data.

[Imaging of fibrosing interstitial pneumonias]. / Imagerie des pneumonies interstitielles fibrosantes.

The term fibrosing interstitial pneumonia covers several distinct entities, including usual interstitial pneumonia, non specific interstitial pneumonia acute interstitial pneumonia, desquamative interstitial pneumonia, and lymphoid interstitial pneumonia. Because of its very poor prognosis and different management, usual interstitial pneumonia, and particularly idiopathic forms (idiopathic pulmonary fibrosis), must be distinguished from other forms of interstitial pneumonia. The diagnosis of idiopathic pulmonary fibrosis is based on the CT or pathologic criteria of usual interstitial pneumonia, in the absence of asbestosis, chronic hypersensitive pneumonitis, and collagen vascular disease. In more than 50% of cases, idiopathic pulmonary fibrosis may be confidently diagnosed on the basis of CT findings, showing reticular opacities and honeycombing with a predominantly basal and subpleural distribution, without nodules, extensive consolidation or ground-glass opacities. Surgical biopsy may be necessary when these features are absent, given the overlap of CT findings between the different forms of interstitial pneumonia. In such cases, specific diagnosis of interstitial lung disease is based on a combination of clinical, radiological and histopathological findings.

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.

Pitfalls in diagnosis of infiltrative lung disease by CT.

The diagnosis of interstitial lung disease may be challenging, especially in atypical disease. Various factors must be considered when performing and reading a chest CT examination for interstitial lung disease, because each of them may represent a source of misinterpretation. Firstly, technical aspects must be mastered, including acquisition and reconstruction parameters as well as post-processing. Secondly, mistakes in interpretation related to the inaccurate description of predominant features, potentially leading to false-positive findings, as well as satisfaction of search must be avoided. In all cases, clinical context, coexisting chest abnormalities and previous examinations must be integrated into the analysis to suggest the most appropriate differential diagnosis.

Pulmonary cavitary sarcoidosis: clinico-radiologic characteristics and natural history of a rare form of sarcoidosis.

Pulmonary cavitary lesions in the absence of concomitant comorbidities are an uncommon and often confusing manifestation of sarcoidosis. We retrospectively reviewed the clinical and high-resolution computed tomography (HRCT) characteristics and the natural history of a series of 23 patients with pulmonary cavitary lesions found on HRCT extracted from a large cohort of patients with pulmonary sarcoidosis. The estimated prevalence of cavitary sarcoidosis was 2.2%. Cavitary lesions developed in patients with severe and active sarcoidosis (serum angiotensin-converting enzyme [SACE] > or =2 times the upper limit of normal range: 63.6%). Twelve (52.2%) patients had evidence of radiographic stage IV, 9 of whom (75%) had persistently increased SACE. As found on HRCT, cavitary lesions were multiple in 21 patients (91.3%), including 5 patients with 10 or more cavities. The size of cavitary lesions was variable, with a median diameter of 20 mm (range, 11-100 mm). Follow-up was available for 20 patients with a median follow-up of 6.25 years (range, 6 months to 15 years). Seven patients (35%) experienced some type of complication related to cavitary lesions, including 6 episodes of hemoptysis in 5 patients and aspergilloma occurrence in 3 patients. As seen on HRCT, the evolution of the number and size of cavitary lesions was variable, with a complete resolution of the largest cavitary lesion in only 5 patients (25%). During follow-up, wall thickening was always associated with a further infectious complication. In summary, cavitary lesions are rare in pulmonary sarcoidosis and usually occur in active and severe sarcoidosis. Their evolution is unpredictable, and complications are frequent.

High-resolution computed tomographic imaging of airways in sarcoidosis patients with airflow obstruction.

OBJECTIVE: To investigate airway involvement in patients with pulmonary sarcoidosis and airflow obstruction (AO) using high-resolution computed tomography. METHODS: Forty-two sarcoidosis patients with AO and 42 matched sarcoidosis patients without AO were retrospectively analyzed. High-resolution computed tomographic patterns of airway involvement were bronchial distortion, peribronchovascular thickening, small airway obstruction, and bronchial compression by enlarged lymph nodes. RESULTS: Interobserver agreement was good (kappa > 0.8). High-resolution computed tomographic patterns of airway involvement were found more frequently, scored higher, and were more often multiple (P < 0.05) in patients with AO than those without. Functional improvement under treatment was observed more frequently in patients with predominant peribronchovascular thickening compared with patients with predominant bronchial distortion (P < 0.03). CONCLUSIONS: In pulmonary sarcoidosis patients with AO, high-resolution computed tomography is a reliable tool to identify underlying airways involvements, which are often multiple, and enables prediction of the therapeutic response.

[Natural history of sarcoidosis]. / Histoire naturelle de la sarcoïdose.

The radiographical and clinical expression of sarcoidosis is highly variable according to the initial presentation, the organs involved and the course of the disease. An abnormal chest radiography is noticed in 90% cases. The radiographic staging makes possible an estimation of both the length of sarcoidosis and the probability of recovery. Extrathoracic localizations can appear at a variable time in the natural history of sarcoidosis, these are related to a short- or longstanding form of the disease and are influenced by the epidemiological context. An accurate knowledge of the natural history allows enhance the security of diagnosis, to plan the survey and to better interpret clinical events during evolution.

[Pulmonary imaging in ANCA-associated vasculitides]. / Imagerie pulmonaire dans les vascularites associées aux ANCA.

Imaging of ANCA-associated vasculitides principally shows nonsystematized alveolar opacities, predominantly central, that suggest alveolar hemorrhage, as well as uni- or multifocal alveolar opacities of variable interpretation, and nodules, including cavitary nodules. Other signs, observed more rarely on imaging, are interstitial lung diseases, tracheobronchial involvement, and pulmonary hypertension. The principal pulmonary signs of Wegener's granulomatosis are nodules and masses, sometimes cavitary, and areas of airspace consolidation that may or may not suggest diffuse alveolar hemorrhage. Except when the latter is present, the lesions correspond to necrotizing granulomatosis or organized pneumonia. The most frequent pulmonary signs of Churg-Strauss syndrome on computed tomography are ground glass areas or parenchymal consolidation in dispersed bands or with a predominantly subpleural distribution that expresses eosinophilic interstitial and alveolar infiltration. Alveolar hemorrhage is the most common expression of microscopic polyangiitis.

Sinonasal involvement in sarcoidosis: a case-control study of 20 patients.

We conducted a retrospective single-center study to describe the clinical features of sinonasal sarcoidosis (SNS) and to determine whether SNS is associated with a particular clinical phenotype of sarcoidosis. Twenty patients with histologically proven SNS (men/women, 7/13; mean age, 32 +/- 9 yr) were compared with control patients with sarcoid but without sinonasal (SN) involvement. Each patient was matched with 2 controls for the date of admittance in our institution. SN involvement occurred in the course of previously known sarcoidosis in 8 patients, whereas it preceded disease diagnosis in 12 patients. Among these 12 patients, 4 initially presented with strictly isolated SNS and 8 had other associated signs related to sarcoidosis. The most common symptoms were stuffiness (90%), anosmia (70%), and rhinorrhea (70%). Lupus pernio was frequent (50%). Local examination was constantly abnormal and showed hypertrophy (75%) and purplish coloring of the nasal mucosa with granulations (50%) on the septum and/or inferior turbinates. Computed tomography scans showed medial lytic lesions, mainly of the septum and/or the turbinates in about half the cases. All patients had negative antineutrophil cytoplasmic antibodies. Patients with SNS had significantly more frequent and severe involvement of vital organs than controls, had a longer history of sarcoidosis, and required systemic treatment more frequently (100% vs. 57.7%, p < 0.001) and for a longer time (78 +/- 42 mo vs. 29 +/- 18 mo, p < 0.0001). Corticosteroids maintenance dosage was high (10.5 +/- 6 mg daily) and mainly depended on SN involvement. Although rare, SN involvement is a severe and recalcitrant manifestation of sarcoidosis representing a therapeutic challenge.

Increased uptake of 111In-octreotide in idiopathic pulmonary fibrosis.

UNLABELLED: Idiopathic pulmonary fibrosis (IPF) is characterized by an uncontrolled accumulation and activation of lung fibroblasts. A modulation of fibroblast activation has been observed in various systems with octreotide, a synthetic somatostatin analog with strong affinity for the somatostatin receptor subtype 2 (sst2). One aim of our study was to evaluate the expression of somatostatin receptors in the lungs of patients with IPF. A second aim was to evaluate the relationship between 111In-octreotide uptake and the effect of pulmonary fibrosis as assessed by lung function tests and parameters and by radiologic findings. METHODS: We investigated 11 patients with IPF, 6 patients with pulmonary fibrosis associated with systemic sclerosis (SSc), and 19 patients with disease not of the lung (control patients). The expression of somatostatin receptors was evaluated in vivo using 111In-octreotide scintigraphy. We evaluated the relationship between 111In-octreotide uptake and the activity of pulmonary fibrosis as assessed by lung function tests, bronchoalveolar lavage (BAL) cellularity, and high-resolution CT (HRCT) of the chest. Planar images and thoracic SPECT (24 h) were performed after injection of 222 MBq of 111In-octreotide. Lung uptake was quantified using the lung-to-background ratio (L/B). In addition, the expression of sst2 was evaluated in vitro, in frozen lung-tissue samples using autoradiography, and in human cultures of lung fibroblasts using a ligand-binding assay. RESULTS: Compared with lung uptake in control patients (median L/B, 1.25; range, 1.14-1.49), lung uptake was increased in all 11 IPF patients (median L/B, 2.63; range, 1.59-3.13; P < 0.001) and in 4 of 6 SSc patients (median L/B, 1.68; range, 1.42-2.16). The L/B was lower in SSc patients than in IPF patients (P = 0.011). Increased uptake correlated with the alteration of lung function (carbon monoxide diffusing capacity [rho = -0.655; P = 0.038], diffusing capacity for carbon monoxide and alveolar volume ratio [rho = -0.627; P = 0.047], vital capacity [rho = -0.609; P = 0.054], and total lung capacity [rho = -0.598; P = 0.058]) and with the intensity of alveolitis (total BAL cellularity [rho = 0.756; P = 0.045], neutrophil counts [rho = 0.738; P = 0.05]), and HRCT fibrosis score (rho = 0.673; P = 0.007). Autoradiography suggested that vascular structures were a prominent binding site. Lung fibroblasts expressed somatostatin receptors in vitro as measured by binding assay. CONCLUSION: Our preliminary results identified an increased expression of sst2 in (mainly idiopathic) pulmonary fibrosis. Lung uptake correlates with the alteration of lung function and with the intensity of alveolitis.

[Interstitial lung disease in systemic sclerosis]. / Pneumopathie infiltrante diffuse de la sclérodermie systémique.

Interstitial lung diseases (ILD) associated with systemic sclerosis (SSc) are mainly encountered in patients with diffuse disease, although they may also be seen in patients with limited cutaneous SSc. ILD screening must be performed regularly, with high-resolution computed tomography and pulmonary function tests (TLCO). Up to 75% of patients with diffuse SSc develop a form of ILD. ILD remains stable in most patients and does not worsen. The nonspecific nature of SSc-associated ILD makes it different from idiopathic ILD and helps to explain its better prognosis. Nonetheless, ILD is one of the two leading causes of death in SSc patients. Treatment of SSc-associated ILD is not yet well codified. Antifibrotic treatments have not proved beneficial, and the efficacy of cyclophosphamide, which has been used to treat this condition for 15 years, has been shown to be very limited against SSc-associated ILD. A subgroup of patients with rapidly progressive ILD might benefit from intravenous cyclophosphamide pulses in association with 15 mg/d prednisone.

[Churg-Strauss syndrome and pulmonary fibrosis: an unusual association]. / Syndrome de Churg-Strauss et fibrose pulmonaire: une association exceptionnelle.

INTRODUCTION: Churg-Strauss syndrome (CSS) is characterized by asthma, hypereosinophilia, and vasculitis involving at least two extrapulmonary organs. CASE: We report a case of a patient with antineutrophilic cytoplasmic antibody-negative CSS who developed pulmonary interstitial fibrosis (PIF). DISCUSSION: The possible relations between CSS and PIF are discussed. Because this case report is the first to describe features of pulmonary fibrosis in a patient with CSS, we cannot know whether this association is causal or fortuitous.

Management of sarcoidosis in clinical practice.

Sarcoidosis is a systemic disease of unknown cause with very diverse presentation, outcome, severity and need for treatments. While some presentations may be very typical, for many patients, the presentation is nonspecific, with shared associations with other diseases at times being by far more frequent or misleading, which can be a cause of significant delay and often several consultations before a diagnosis of sarcoidosis can be confirmed. This is particularly the case when pulmonary manifestations are in the forefront. The diagnosis relies on three well-known criteria. In clinical practice, these criteria are not easily implemented, particularly by physicians without expertise in sarcoidosis, which can lead to a risk of either under- or over-diagnosis. Qualifying the presentation according to sarcoidosis diagnosis is essential. However, it is often not easy to classify the presentation as typical versus compatible or compatible versus inconsistent. Further investigations are needed before any other hypothesis is to be considered. It is important to detect events and to determine whether or not they are indicative of a flare of sarcoidosis. Eventually, treatment needs to be related to the correct indications. The evaluation of the efficacy and safety of treatments is crucial. To address such issues, we present five emblematic cases that illustrate this.

High-resolution computed tomography to differentiate chronic diffuse infiltrative lung diseases with chronic multifocal consolidation patterns using logical analysis of data.

BACKGROUND: Chronic lung consolidation has a limited number of differential diagnoses requiring distinct managements. The aim of the study was to investigate how logical analysis of data (LAD) can support their diagnosis at HRCT (high-resolution computed tomography). METHODS: One hundred twenty-four patients were retrospectively included and classified into 8 diagnosis categories: sarcoidosis (n=35), connective tissue disease (n=21), adenocarcinoma (n=17), lymphoma (n=13), cryptogenic organizing pneumonia (n=11), drug-induced lung disease (n=9), chronic eosinophilic pneumonia (n =7) and miscellaneous (n=11). First, we investigated the patterns and models (association of patterns characterizing a disease) built-up by the LAD from combinations of HRCT attributes (n=51). Second, data were recomputed by adding simple clinical attributes (n=14) to the analysis. Third, cluster analysis was performed to explain LAD failures. RESULTS: HRCT models reached a sensitivity >80% and a specificity >90% for adenocarcinoma and chronic eosinophilic pneumonia. The same thresholds were obtained for sarcoidosis, connective tissue disease, and drug-induced lung diseases when clinical attributes were added to HRCT. LAD failed to provide a satisfactory model for lymphoma and cryptogenic organizing pneumonia, with overlap between both diseases shown on cluster analysis. CONCLUSION: LAD provides relevant models that can be used as a diagnosis support for the radiologist. It highlights the need to add clinical data in the analysis due to frequent overlap between diseases at HRCT.

Endoluminal stenosis of proximal bronchi in sarcoidosis: bronchoscopy, function, and evolution.

AIM: Endoluminal stenosis of proximal bronchi (ESPB) is a potentially severe manifestation of sarcoidosis. Unusual clinical presentation and variable response to medical treatment require specific attention to diagnosis and follow-up. DESIGN: Of 2,500 patients with sarcoidosis seen at our institution, we retrospectively identified 18 patients with stage 1-3 sarcoidosis and ESPB. Clinical manifestations, endoscopic findings, pulmonary function tests, follow-up, and therapeutic response were assessed. RESULTS: Respiratory symptoms were present in 17 patients (94%): cough and dyspnea (89% each), wheezing (83%), and hemoptysis (11%). Generalized symptoms (67%) and extrapulmonary manifestations (72%) of sarcoidosis were frequent. Three bronchoscopic patterns were observed: single stenosis (n = 3), multiple stenoses (n = 12), or diffuse narrowing of the bronchial tree (n = 3). The two former groups accounted for 45 ESPBs located in the left upper lobe (44.5%), the right upper and middle lobes (15.5% each), and the left lower lobe (11%). ESPBs were due to mural thickening of bronchi (n = 16) or associated with extrinsic compression by lymphadenopathy (n = 2). Endobronchial biopsies uniformly confirmed the presence of granulomas. FEV(1)/FVC ratio was < 70% in 12 patients (66.7%), with a correlation between the decrease of FEV(1)/FVC ratio and the number of ESPBs (R(2) = 0.31; p = 0.02). Patients treated with oral corticosteroids (n = 12) or methotrexate (n = 1) within the first 3 months had a good prognosis, whereas patients in whom treatment was delayed by > 3 months (n = 4) or who did not receive any systemic treatment (n = 1) acquired fixed ESPB and persistent ventilatory defects. CONCLUSIONS: ESPB is a rare and serious complication of sarcoidosis. Its clinical hallmarks include multiple respiratory symptoms, multiorgan involvement, and generalized symptoms. Treatment has to be started early to avoid the development of fixed stenotic lesions and irreversible pulmonary function impairment.