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Background To evaluate the chest CT appearance of patients with a clinicopathologic diagnosis of hypersensitivity pneumonia. Methods IRB approval was obtained for a retrospective review of patients with a preoperative CT scan, a surgical pathology report from a transbronchial biopsy or wedge resection consistent with hypersensitivity pneumonitis, and a pulmonary consultation, which also supported the diagnosis. The pathology report was evaluated for granulomas, airway-centered fibrosis, microscopic honeycombing, and fibroblast foci. The medical records were reviewed for any known antigen exposure. Patients were separated into two groups; those with and without a known antigen exposure. The CT scans were assessed for distribution of fibrosis: upper lobe or lower lobe predominance, airway-centered versus peripheral distribution, three-density pattern, and honeycombing. Results 264 pathology reports included the term chronic hypersensitivity pneumonitis (CHP). Thirty-eight of the patients had a pulmonologist who gave the patient a working diagnosis of CHP. The average age of these patients was 64 years, and 21/38 were women. Seventeen of the 38 patients had at least one antigen exposure described in the medical records. All the patients had fibrosis along the airways on chest CT. Both known antigen exposure and no known antigen patients had upper and lower lung-predominant fibrosis. There were more patients with hiatal hernias in the unknown antigen group. Honeycombing was an uncommon finding. Conclusion Airway-centered fibrosis was present on chest CT in all 38 patients with CHP (100%), with or without known antigen exposure.

The INBUILD trial investigated the efficacy and safety of nintedanib versus placebo in patients with progressive fibrosing interstitial lung diseases (ILDs) other than idiopathic pulmonary fibrosis (IPF). We aimed to establish the effects of nintedanib in subgroups based on ILD diagnosis., info:eu-repo/semantics/published

Objective To determine the prevalence of osteophyte induced lung fibrosis (OIF) and its relationship to osteophyte size, location, and surrounding fat. Methods 94 CT scans of the chest were reviewed, size of the largest osteophyte and the presence of fibrosis were recorded. Results Presence of fibrosis was higher among patient with large (> 10 mm) osteophytes compared to those with small (1–10 mm) osteophytes. Age and presence of periosteophyte fat were significantly associated with presence of fibrosis. Conclusions As the size of an osteophyte increases, there is a greater likelihood of lung fibrosis. Subpleural fat protects the lung from OIF.

Background Early recognition of patients with interstitial lung disease (ILD) who have an increased risk of developing acute exacerbation (AE) or preclinical AE may be clinically useful, since AE is associated with poor outcome and preventive measures would be of interest to ILD researchers. This study evaluated the relationship between elevated serum D-dimer level (≥0.4 mcg/mL) and subsequent AE or preclinical AE in patients with ILD. Methods This single-center, retrospective study was performed from October 2009 through September 2015 in patients with ILD who were ≥18 years old and had idiopathic pulmonary fibrosis, other idiopathic interstitial pneumonias, chronic hypersensitivity pneumonitis, ILD related to collagen tissue disease, or combined pulmonary fibrosis/emphysema. The primary outcome measure was AE development within three months from each D-dimer measurement. The secondary outcome measures were respiratory-related hospitalization, all-cause hospitalization, venous thromboembolism (VTE), and all-cause mortality within three months. Results A total of 263 patients (mean age, 64.1 years) with 374 D-dimer measurements (median, 0.44 mcg/mL) were included. The risk of developing AE was significantly higher in patients with elevated serum D-dimer level (adjusted odds ratio: 10.46; 95% CI: 1.24–88.11; p = 0.03). Patients with elevated serum D-dimer level had increased risk for respiratory-related hospitalization, all-cause hospitalization, VTE, and all-cause mortality. The other factors predictive for AE were home oxygen therapy, increased serum lactate dehydrogenase, decreased FVC, and decreased FEV1.0. Conclusions Elevated serum D-dimer is associated with the risk of developing AE. Serum D-dimer may be used as a prognostic marker to predict AE or recognize preclinical AE.

The assessment of both the pattern and activity of myocardial injury has important implications for the clinical management of patients with cardiovascular disease. Comprehensive evaluation of these has previously been challenging using a single imaging modality. Cardiac magnetic resonance (CMR)

Purpose To determine patterns of progression of probable Usual Interstitial Pneumonitis (UIP). Methods This HIPPA compliant, IRB-approved study draws patients from our Fibrosis Registry. All patients with a consensus diagnosis of Idiopathic Pulmonary Fibrosis (IPF) were included. Most recent CT scans and all earlier CT scans were reviewed to determine the fibrosis grade in each lobe based on probable UIP (pUIP) findings of ground glass opacities, traction bronchiolectasis and reticulations or UIP findings of subpleural basilar predominant fibrosis with honeycombing (HC) and absence of features that would suggest an alternative diagnosis. Results 103 patients with a working diagnosis of IPF are the focus of this report. Among the 68 with pUIP on the initial CT, 32 (47%) progressed; median time to progression was 51 months. The risk of HC progression, adjusted for gender, of patients with emphysema was 2.53 times higher than patients without emphysema (HR = 2.53, 95% CI: 1.06–6.02). Among the 35 with HC on the initial CT scan, 20 (57%) progressed to more advanced HC; median time to progression was 31 months. Increased pulmonary artery size was significantly associated with an elevated risk for more advanced HC progression (HR = 1.16, 95% CI: 1.04–1.31). Conclusion Ground glass opacities, traction bronchiolectasis and reticulations, a “Probable UIP Pattern” by ATS criteria progressed to UIP in 47% of patients on follow-up imaging.

Background Some interstitial lung diseases are associated with lung cancer. However, it is unclear whether asymptomatic interstitial lung abnormalities convey an independent risk. Objectives The goal of this study was to assess whether interstitial lung abnormalities are associated with an increased risk of lung cancer. Methods Data from all participants in the National Lung Cancer Trial were analyzed, except for subjects with preexisting interstitial lung disease or prevalent lung cancers. The primary analysis included those who underwent low-dose CT imaging; those undergoing chest radiography were included in a confirmatory analysis. Participants with evidence of reticular/reticulonodular opacities, honeycombing, fibrosis, or scarring were classified as having interstitial lung abnormalities. Lung cancer incidence and mortality in participants with and without interstitial lung abnormalities were compared by using Poisson and Cox regression, respectively. Results Of the 25,041 participants undergoing low-dose CT imaging included in the primary analysis, 20.2% had interstitial lung abnormalities. Participants with interstitial lung abnormalities had a higher incidence of lung cancer (incidence rate ratio, 1.61; 95% CI, 1.30-1.99). Interstitial lung abnormalities were associated with higher lung cancer incidence on adjusted analyses (incidence rate ratio, 1.33; 95% CI, 1.07-1.65). Lung cancer-specific mortality was also greater in participants with interstitial lung abnormalities. Similar findings were obtained in the analysis of participants undergoing chest radiography. Conclusions Asymptomatic interstitial lung abnormalities are an independent risk factor for lung cancer that can be incorporated into risk score models.

Megakaryocytes have been implicated in the micro-environmental abnormalities associated with fibrosis and hematopoietic failure in the bone marrow (BM) of primary myelofibrosis (PMF) patients, the Philadelphia-negative myeloproliferative neoplasm (MPN) associated with the poorest prognosis. To identify possible therapeutic targets for restoring BM functions in PMF, we compared the expression profiling of PMF BM with that of BM from essential thrombocytopenia (ET), a fibrosis-free MPN also associated with BM megakaryocyte hyperplasia. The signature of PMF BM was also compared with published signatures associated with liver and lung fibrosis. Gene set enrichment analysis (GSEA) identified distinctive differences between the expression profiles of PMF and ET. Notch, K-Ras, IL-8, and apoptosis pathways were altered the most in PMF as compared with controls. By contrast, cholesterol homeostasis, unfolded protein response, and hypoxia were the pathways found altered to the greatest degree in ET compared with control specimens. BM from PMF expressed a noncanonical transforming growth factor β (TGF-β) signature, which included activation of ID1, JUN, GADD45b, and genes with binding motifs for the JUN transcriptional complex AP1. By contrast, the expression of ID1 and GADD45b was not altered and there was a modest signal for JUN activation in ET. The similarities among PMF, liver fibrosis, and lung fibrosis were modest and included activation of integrin-α9 and tropomyosin-α1 between PMF and liver fibrosis, and of ectoderm–neural cortex protein 1 and FRAS1-related extracellular matrix protein 1 between PMF and lung fibrosis, but not TGF-β. These data identify TGF-β as a potential target for micro-environmental therapy in PMF.

Background. We encounter interstitial lung disease (ILD) patients with psoriasis. The aim of this case series was to examine clinical and radiographic characteristics of patients with concomitant psoriasis and ILD. Methods. This is a retrospective review of our institutional experience of ILD concomitant with psoriasis, from the database in the Advanced Lung/Interstitial Lung Disease Program at the Mount Sinai Hospital. Out of 447 ILD patients, we identified 21 (4.7%) with antecedent or concomitant diagnosis of psoriasis. Clinical, radiographic, pathological, and outcome data were abstracted from our medical records. Results. Median age was 66 years (range, 46–86) and 14 (66.7%) were male. Thirteen (61.9%) had not previously or concomitantly been exposed to immunosuppressive therapy directed against psoriasis. Two (9.5%) ultimately died. Clinical diagnosis of ILD included idiopathic pulmonary fibrosis, 11 (52.4%); nonspecific interstitial pneumonia (NSIP), 2 (9.5%); cryptogenic organizing pneumonia, 2 (9.5%); chronic hypersensitivity pneumonitis, 2 (9.5%); and the others, while radiographic diagnosis included usual interstitial pneumonia pattern, 9 (42.9%); NSIP pattern, 6 (28.6%); organizing pneumonia pattern, 4 (19.0%); hypersensitivity pneumonitis pattern, 2 (9.5%); and the others. Conclusions. We report 21 ILD cases with antecedent or concomitant diagnosis of psoriasis. Further prospective studies are required to determine the association between ILD and psoriasis.

The purposes of this study were to determine the prevalence of interstitial lung disease (ILD) in a cohort undergoing low-dose CT screening for lung cancer, to identify the CT patterns of fibrosis, and to determine prognostic factors of disease progression.The study drew from a database of 951 participants in a lung cancer screening program between 2010 and 2014. Three thoracic radiologists reviewed CT scans to identify the ILD findings, defined as traction bronchiectasis, ground-glass opacities with traction bronchiectasis, reticulations with traction bronchiectasis, and honeycombing. Evidence of ILD was considered present if at least two of three reviewing radiologists agreed. Age, smoking history, and CT evidence of emphysema were also documented.Of the 951 participants, 63 (6.6%) had CT evidence of ILD, and 16 of the 63 (1.7% of the total cohort) had honeycombing. Significant univariate predictors of ILD were male sex (p = 0.003), older age (p0.0001), higher number of pack-years of cigarette smoking (p = 0.0003), and greater severity of emphysema (p = 0.004), but only age and male sex remained significant in the multivariate analysis. The most common pattern of ILD was peripheral fibrosis without honeycombing involving multiple lobes. The presence of honeycombing was significantly associated with progression of fibrosis score (p = 0.0001) and extent of fibrosis (p = 0.005).A potential added benefit of CT screening is earlier diagnosis of ILD in older smokers, who are at increased risk. Radiologists should recognize the earliest findings of ILD and understand the importance of early recognition.

Acute exacerbation of interstitial lung disease (ILD) is associated with a poor prognosis and high mortality. Numerous studies have documented acute exacerbation in idiopathic pulmonary fibrosis (IPF), but less is known about these events in other ILDs that may present a progressive-fibrosing phenotype. We propose defining acute exacerbation as an acute, clinically significant respiratory deterioration, typically less than 1 month in duration, together with computerised tomography imaging showing new bilateral glass opacity and/or consolidation superimposed on a background pattern consistent with fibrosing ILDs. Drawing on observations in IPF, it is suspected that epithelial injury or proliferation and autoimmunity are risk factors for acute exacerbation in ILDs that may present a progressive-fibrosing phenotype, but further studies are required. Current acute exacerbation management strategies are based on recommendations in IPF, but no randomised controlled trials of acute exacerbation management have been performed. Although there are no formal strategies to prevent the development of acute exacerbation, possible approaches include antifibrotic drugs (such as nintedanib and pirfenidone), and minimising exposure to infection, airborne irritants and pollutants. This review discusses the current knowledge of acute exacerbation of ILDs that may present a progressive-fibrosing phenotype and acknowledges limitations of the data available., SCOPUS: re.j, info:eu-repo/semantics/published

Objectives The purpose of this study was to explore the diagnostic usefulness of hybrid cardiac magnetic resonance (CMR) and positron emission tomography (PET) using 18 F-fluorodeoxyglucose (FDG) for active cardiac sarcoidosis. Background Active cardiac sarcoidosis (aCS) is underdiagnosed and has a high mortality. Methods Patients with clinical suspicion of aCS underwent hybrid CMR/PET with late gadolinium enhancement (LGE) and FDG to assess the pattern of injury and disease activity, respectively. Patients were categorized visually as magnetic resonance (MR)+PET+ (characteristic LGE aligning exactly with increased FDG uptake), MR+PET− (characteristic LGE but no increased FDG), MR−PET− (neither characteristic LGE nor increased FDG), and MR−PET+ (increased FDG uptake in absence of characteristic LGE) and further characterized as aCS+ (MR+PET+) or aCS− (MR+PET−, MR−PET−, MR−PET+). FDG uptake was quantified using maximum target-to-normal-myocardium ratio and the net uptake rate ( K i ) from dynamic Patlak analysis. Receiver-operating characteristic methods were used to identify imaging biomarkers for aCS. FDG PET was assessed using computed tomography/PET in 19 control subjects with healthy myocardium. Results A total of 25 patients (12 males; 54.9 ± 9.8 years of age) were recruited prospectively; 8 were MR+PET+, suggestive of aCS; 1 was MR+PET−, consistent with inactive cardiac sarcoidosis; and 8 were MR−PET−, with no imaging evidence of cardiac sarcoidosis. Eight patients were MR−PET+ (6 with global myocardial FDG uptake, 2 with focal-on-diffuse uptake); they demonstrated distinct K i values and hyperintense maximum standardized uptake value compared with MR+PET+ patients. Similar hyperintense patterns of global (n = 9) and focal-on-diffuse (n = 2) FDG uptake were also observed in control patients, suggesting physiological myocardial uptake. Maximum target-to-normal-myocardium ratio values were higher in the aCS+ group (p Conclusions CMR/PET imaging holds major promise for the diagnosis of aCS, providing incremental information about both the pattern of injury and disease activity in a single scan. (In Vivo Molecular Imaging [MRI] of Atherothrombotic Lesions; NCT01418313)

Background The provision of effective palliative care is of great importance to patients awaiting lung transplantation. Although the prospect of lung transplantation provides hope to patients and their families, these patients are usually very symptomatic from their underlying disease. Methods An e-mail questionnaire was sent to members of the American College of Chest Physicians' Transplant NetWork and the Pulmonary Council of the International Society for Heart and Lung Transplantation (ISHLT). The survey included questions about barriers to providing palliative care, the availability of palliative care services, and recommended strategies to improve palliative care for lung transplant candidates. Results The 158 respondents represented approximately 65% of transplant programs in the ISHLT registry. Respondents were in practice a mean of 11.3 (± 9) years, 70% were pulmonologists, 17% were surgeons, and 13% were other care providers. Barriers were classified into domains including patient factors, family factors, physician factors, and institutional/transplant program/lung allocation system factors. Significant patient/family barriers included unrealistic patient/family expectations about survival, unwillingness to plan end-of-life care, concerns about abandonment or inappropriate care after enrollment in a palliative care program, and family disagreements about care goals. For institutional/program/allocation system barriers, only the requirement for weight loss or gain to meet program-specific BMI requirements was identified. Significant physician barriers included competing time demands and the seemingly contradictory goals of transplant vs palliative care. Strategies recommended to improve palliative care included routine advance care planning for patients awaiting transplantation, access to palliative care specialists, training of transplant physicians in symptom management, and regular meetings among transplant physicians, nurses, patients, and families. Conclusions Physicians providing care to lung transplant candidates reported considerable barriers to the delivery and acceptance of palliative care and identified specific strategies to improve palliative care for lung transplant candidates.

Cardiac positron emission tomography (PET) imaging suffers from image blurring due to the constant motion of the heart that can impact interpretation. Hybrid PET/magnetic resonance (MR) has the potential to use radiation-free MR imaging to correct for the effects of cardio-respiratory motion in the PET data, improving qualitative and quantitative PET imaging in the heart. The purpose of this study was (i) to implement a MR image-based motion-corrected PET/MR method and (ii) to perform a proof-of-concept study of quantitative myocardial PET data in patients. The proposed method takes reconstructions of respiratory and cardiac gated PET data and applies spatial transformations to a single reference frame before averaging to form a single motion-corrected PET (MC-PET) image. Motion vector fields (MVFs) describing the transformations were derived from affine or non-rigid registration of respiratory and cardiac gated MR data. Eight patients with suspected cardiac sarcoidosis underwent cardiac PET/MR imaging after injection of 5 MBq kg-1 of 18F-fluorodeoxyglucose (18F-FDG). Myocardial regions affected by motion were identified by expert readers within which target-to-background ratios (TBR) and contrast-to-noise ratios (CNR) were measured on non-MC-non-gated, MC-PET, and double respiratory and cardiac gated PET images. Paired t-tests were used to determine statistical differences in quantitative uptake-measures between the different types of PET images. MC-PET images showed less blurring compared to non-MC-non-gated PET and tracer activity qualitatively aligned better with the underlying myocardial anatomy when fused with MR. TBR and CNR were significantly greater for MC-PET (2.8 ± 0.9; 21 ± 22) compared to non-MC-non-gated PET (2.4 ± 0.9, p = 0.0001; 15 ± 13, p = 0.02), while TBR was lower and CNR greater compared to double-gated PET (3.2 ± 0.9, p = 0.04; 6 ± 3, p = 0.004). This study demonstrated in a patient cohort that motion-corrected (MC) cardiac PET/MR is feasible using a retrospective MR image-based method and that improvement in TBR and CNR are achievable. MC PET/MR holds promise for improving interpretation and quantification in cardiac PET imaging.

Context After the collapse of the World Trade Center (WTC) on 11 September 2001, a dense cloud of dust containing high levels of airborne pollutants covered Manhattan and parts of Brooklyn, New York. Between 60,000 and 70,000 responders were exposed. Many reported adverse health effects. Case presentation In this report we describe clinical, pathologic, and mineralogic findings in seven previously healthy responders who were exposed to WTC dust on either 11 September or 12 September 2001, who developed severe respiratory impairment or unexplained radiologic findings and underwent video-assisted thoracoscopic surgical lung biopsy procedures at Mount Sinai Medical Center. WTC dust samples were also examined. We found that three of the seven responders had severe or moderate restrictive disease clinically. Histopathology showed interstitial lung disease consistent with small airways disease, bronchiolocentric parenchymal disease, and nonnecrotizing granulomatous condition. Tissue mineralogic analyses showed variable amounts of sheets of aluminum and magnesium silicates, chrysotile asbestos, calcium phosphate, and calcium sulfate. Small shards of glass containing mostly silica and magnesium were also found. Carbon nanotubes (CNT) of various sizes and lengths were noted. CNT were also identified in four of seven WTC dust samples. Discussion These findings confirm the previously reported association between WTC dust exposure and bronchiolar and interstitial lung disease. Long-term monitoring of responders will be needed to elucidate the full extent of this problem. The finding of CNT in both WTC dust and lung tissues is unexpected and requires further study.

Sarcoidosis-associated pulmonary hypertension (SAPH) is a common problem in patients with persistent dyspneic sarcoidosis. The objective of this study was to determine the effect of bosentan therapy on pulmonary arterial hemodynamics in patients with SAPH.This 16-week study was a double-blind, placebo-controlled trial of either bosentan or placebo in patients with SAPH confirmed by right-sided heart catheterization. Patients were enrolled from multiple academic centers specializing in sarcoidosis care. They were stable on sarcoidosis therapy and were receiving no therapy for pulmonary hypertension. The cohort was randomized two to one to receive bosentan at a maximal dose of 125 mg or placebo bid for 16 weeks. Pulmonary function studies, 6-min walk test, and right-sided heart hemodynamics, including pulmonary artery mean pressure and pulmonary vascular resistance (PVR), were performed before and after 16 weeks of therapy.Thirty-five patients completed 16 weeks of therapy (23 treated with bosentan, 12 with placebo). For those treated with bosentan, repeat hemodynamic studies at 16 weeks demonstrated a significant mean±SD fall in PA mean pressure (-4±6.6 mm Hg, P=.0105) and PVR (-1.7±2.75 Wood units, P=.0104). For the patients treated with placebo, there was no significant change in either PA mean pressure (1±3.7 mm Hg, P.05) or PVR (0.1±1.42 Wood units, P.05). There was no significant change in 6-min walk distance for either group. Two patients treated with bosentan required an increase of supplemental oxygen by2 L after 16 weeks of therapy.This study demonstrated that bosentan significantly improved pulmonary hemodynamics in patients with SAPH.ClinicalTrials.gov; No: NCT00581607; URL: www.clinicaltrials.gov.

Idiopathic pleuroparenchymal fibroelastosis is a rare recently described entity likely to be under- and misdiagnosed, as awareness of this entity is not yet widespread. We report two cases that show the need to include this disease in the differential diagnosis of patients with predominantly pleural and subpleural fibrotic processes. The condition is a fibrotic thickening of the pleura and subpleural parenchyma due to elastic fiber proliferation predominantly in the upper lobes. Performing elastic fiber stains routinely in patients with fibrosis of this distribution may, therefore, aid in establishing the diagnosis and differentiating it from usual interstitial pneumonia/idiopathic pulmonary fibrosis. These patients may be prone to the development of secondary spontaneous pneumothoraces and persistent postoperative bronchopleural fistulae. Continued study of newly diagnosed cases may uncover shared characteristics or features helpful in generating an etiologic hypothesis. Only with better understanding of this disease can we hope in the future to be able to offer treatments other than supportive care and ultimately lung transplantation, which are the only therapeutic options available today.

To date, no management approach has proven to be efficacious for the treatment of idiopathic pulmonary fibrosis (IPF). Consequently, therapeutic options remain controversial and confusing for many clinicians. We sought to formally review available evidence on treatment options for IPF and to have a diverse panel of physicians rate the "appropriateness," "inappropriateness," or "uncertainty" of some of the available therapeutic options.The RAND/UCLA Appropriateness Method was used to review and rate multiple clinical scenarios for the treatment of IPF. The panel was composed of nine physicians from geographically diverse areas who received a systematic review on the risks and benefits of commonly used treatments for IPF as background.A total of 324 clinical scenarios were rated: 25% as appropriate; 39%, uncertain; and 36%, inappropriate. The panel disagreed about 12% of the therapy indications in the final ratings, falling from 26% in the first-round ratings.Key themes emerged from the consensus process. Lacking evidence for a definitive therapy, it was considered most appropriate to enroll eligible patients in clinical trials and refer eligible patients for transplant evaluation. For patients without access to clinical trials, the committee was not unanimous regarding treatment recommendations. It was considered inappropriate for patients with a confident diagnosis of IPF to be treated with corticosteroids as the sole agent: corticosteroids should be used in conjunction with azathioprine. With progressive disease despite such combination use, there was agreement for the use of interferon gamma-1b in patients unwilling or unable to participate in available clinical trials.

Study objective To differentiate the clinical, radiographic, and physiologic profile in patients with sarcoidosis with and without pulmonary hypertension. Design Retrospective survey. Setting Tertiary care center. Patients One hundred six patients with sarcoidosis were classified by two-dimensional echocardiography into two groups: group 1, 54 patients with pulmonary hypertension; group 2, 52 patients without pulmonary hypertension. Interventions Patients underwent two-dimensional and Doppler echocardiography, chest radiography (CXR), pulmonary function testing, and arterial oxygen saturation determination, and the test results were compared between the two groups. Statistical analysis was performed using independent-sample t test and χ 2 test, as appropriate; p Results Predicted spirometric values and lung diffusing capacity were significantly lower in patients in group 1 compared to patients in group 2: FVC, 54% vs 64% (p = 0.0065), FEV 1 , 47% vs 61% (p = 0.0005), forced expiratory flow, midexpiratory phase, 35% vs 52% (p = 0.0363), and single-breath diffusing capacity of the lung for carbon monoxide (D lco sb), 39% vs 54% (p = 0.0001). Sixty percent of patients in group 1 had radiographic Scadding stage 4 sarcoidosis, while no radiographic stage predominated in group 2. Arterial oxygen saturation, need for oxygen supplementation, and degree of desaturation after exercise did not differ between groups. Conclusions The presence of pulmonary hypertension in patients with sarcoidosis is associated with higher prevalence of stage 4 sarcoidosis by CXR and lower predicted spirometric and D lco sb measurements.

Eleven patients with localized lymphoid nodules of the lung (LLN) were seen at the Mount Sinai Hospital from 1962-1981. The diagnosis of pseudolymphoma was made in six instances based on the following criteria: (1) solitary or multiple nodules discovered on chest roentgenograms composed of cytologically benign lymphoid cells (small lymphocytes); (2) polymorphic character of the infiltrate, including plasma cells, histiocytes and monocytes; and (3) presence of germinal centers in the lesion. Five lesions were classified as lymphomas and exhibited: (1) solitary or multiple nodules composed of atypical lymphoid cells; (2) absence of germinal centers; (3) lack of mediastinal lymph node involvement. Bronchial and/or pleural infiltration by lymphoid cells was present in lymphomas as well as in pseudolymphomas. Five lesions were studied with immunofluorescent techniques for the presence of intracytoplasmic immunoglobulins and in one pseudolymphoma, lymphocyte marker studies were performed. The procedures were not useful in separating benign from malignant lesions. All patients underwent surgery; three with lymphoma and one with pseudolymphoma received adjuvant chemotherapy. Patients were followed post surgically for up to 13 years. None of the six patients with pseudolymphoma died as a result of their lesions but two had either recurrences or developed extrapulmonary lymphoid lesions. All five lymphoma patients did well. Only one died while on chemotherapy with invasive pulmonary aspergillosis but no tumor. One-hundred and sixty-seven reported cases from the literature are analyzed. Pulmonary pseudolymphomas do not necessarily follow a benign course and malignant lymphomas limited to the lungs do not usually undergo progressive disease. Present pathologic criteria do not allow prediction of recurrence or progression of disease and are not acceptable for determining the advocacy of chemotherapy in patients with LLN.