COVID-19 Vaccine-Associated Pneumonitis in the Republic of Korea:A Nationwide Multicenter Survey

Background@#Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2. @*Methods@#In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies. @*Results@#From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients. @*Conclusion@#These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 1. Introduction / 결핵

Idiopathic interstitial pneumonia (IIP) is a histologically identifiable pulmonary disease without a known cause that usually infiltrates the lung interstitium. IIP is largely classified into idiopathic pulmonary fibrosis, idiopathic non-specific interstitial pneumonia, respiratory bronchiolitis-interstitial lung disease (ILD), cryptogenic organizing pneumonia, desquamative interstitial pneumonia, and acute interstitial pneumonia. Each of these diseases has a different prognosis and requires specific treatment, and a multidisciplinary approach that combines chest high-resolution computed tomography (HRCT), histological findings, and clinical findings is necessary for their diagnosis. Diagnosis of IIP is made based on clinical presentation, chest HRCT findings, results of pulmonary function tests, and histological findings. For histological diagnosis, video-assisted thoracoscopic biopsy and transbronchial lung biopsy are used. In order to identify ILD associated with connective tissue disease, autoimmune antibody tests may also be necessary. Many biomarkers associated with disease prognosis have been recently discovered, and future research on their clinical significance is necessary. The diagnosis of ILD is difficult because patterns of ILD are both complicated and variable. Therefore, as with other diseases, accurate history taking and meticulous physical examination are crucial.

A Rare Case of Adenosquamous Carcinoma Arising in the Background of IgG4-Related Lung Disease

IgG4-related disease is a systemic inflammatory disease and is known as IgG4-related lung disease (IgG4-RLD) when it involves the respiratory system. Primary lung cancer arising from a background of IgG4-RLD is very rare. Herein, we report a case of adenosquamous carcinoma arising from the background of IgG4-RLD and presenting as an interstitial lung disease pattern. A 66-year-old man underwent lobectomy under the impression of primary lung cancer. Grossly, the mass was ill-defined and gray-tan colored, and the background lung was fibrotic. Microscopically, tumor cells showed both squamous and glandular differentiation. Dense lymphoplasmacytic infiltration with fibrosis and obliterative phlebitis were seen in the background lung. IgG4 immunohistochemical stain showed diffuse positivity in infiltrating plasma cells. Primary lung adenosquamous carcinoma has not been reported in a background of IgG4-RLD. Due to the rarity of IgG4-RLD, physicians must follow patients with IgG4-RLD over long periods of time to accurately predict the risk of lung cancer.

Korean Guidelines for Diagnosis and Management of Interstitial Lung Diseases: Part 1. Introduction / 결핵및호흡기질환

Idiopathic interstitial pneumonia (IIP) is a histologically identifiable pulmonary disease without a known cause that usually infiltrates the lung interstitium. IIP is largely classified into idiopathic pulmonary fibrosis, idiopathic non-specific interstitial pneumonia, respiratory bronchiolitis-interstitial lung disease (ILD), cryptogenic organizing pneumonia, desquamative interstitial pneumonia, and acute interstitial pneumonia. Each of these diseases has a different prognosis and requires specific treatment, and a multidisciplinary approach that combines chest high-resolution computed tomography (HRCT), histological findings, and clinical findings is necessary for their diagnosis. Diagnosis of IIP is made based on clinical presentation, chest HRCT findings, results of pulmonary function tests, and histological findings. For histological diagnosis, video-assisted thoracoscopic biopsy and transbronchial lung biopsy are used. In order to identify ILD associated with connective tissue disease, autoimmune antibody tests may also be necessary. Many biomarkers associated with disease prognosis have been recently discovered, and future research on their clinical significance is necessary. The diagnosis of ILD is difficult because patterns of ILD are both complicated and variable. Therefore, as with other diseases, accurate history taking and meticulous physical examination are crucial.

Successful Treatment with Empirical Erlotinib in a Patient with Respiratory Failure Caused by Extensive Lung Adenocarcinoma / 대한구급학회지

We herein describe a 70-year-old woman who presented with respiratory failure due to extensive lung adenocarcinoma. Despite advanced disease, care in the intensive care unit with ventilator support was performed because she was a newly diagnosed patient and was considered to have the potential to recover after cancer treatment. Because prompt control of the cancer was needed to treat the respiratory failure, empirical treatment with an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was initiated before confirmation of EGFR-mutant adenocarcinoma, and the patient was successfully treated. Later, EGFR-mutant adenocarcinoma was confirmed.

Successful Treatment with Empirical Erlotinib in a Patient with Respiratory Failure Caused by Extensive Lung Adenocarcinoma / 대한중환자의학회지

We herein describe a 70-year-old woman who presented with respiratory failure due to extensive lung adenocarcinoma. Despite advanced disease, care in the intensive care unit with ventilator support was performed because she was a newly diagnosed patient and was considered to have the potential to recover after cancer treatment. Because prompt control of the cancer was needed to treat the respiratory failure, empirical treatment with an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was initiated before confirmation of EGFR-mutant adenocarcinoma, and the patient was successfully treated. Later, EGFR-mutant adenocarcinoma was confirmed.

Changes in the Flow-Volume Curve According to the Degree of Stenosis in Patients With Unilateral Main Bronchial Stenosis

OBJECTIVES: The shape of the flow-volume (F-V) curve is known to change to showing a prominent plateau as stenosis progresses in patients with tracheal stenosis. However, no study has evaluated changes in the F-V curve according to the degree of bronchial stenosis in patients with unilateral main bronchial stenosis. METHODS: We performed an analysis of F-V curves in 29 patients with unilateral bronchial stenosis with the aid of a graphic digitizer between January 2005 and December 2011. RESULTS: The primary diseases causing unilateral main bronchial stenosis were endobronchial tuberculosis (86%), followed by benign bronchial tumor (10%), and carcinoid (3%). All unilateral main bronchial stenoses were classified into one of five grades (I, 90% to near-complete obstruction without ipsilateral lung collapse). A monophasic F-V curve was observed in patients with grade I stenosis and biphasic curves were observed for grade II-IV stenosis. Both monophasic (81%) and biphasic shapes (18%) were observed in grade V stenosis. After standardization of the biphasic shape of the F-V curve, the breakpoints of the biphasic curve moved in the direction of high volume (x-axis) and low flow (y-axis) according to the progression of stenosis. CONCLUSION: In unilateral bronchial stenosis, a biphasic F-V curve appeared when bronchial stenosis was >25% and disappeared when obstruction was near complete. In addition, the breakpoint moved in the direction of high volume and low flow with the progression of stenosis.

Significance of Myositis Autoantibody in Patients with Idiopathic Interstitial Lung Disease

PURPOSE: Some patients with interstitial lung disease (ILD) related to connective tissue disease (CTD) have a delayed diagnosis of the underlying CTD when the ILD is categorized as idiopathic. In this study, we evaluated the frequency of myositis autoantibodies in patients diagnosed with idiopathic ILD and investigated the clinical significance stemming from the presence of the antibodies. MATERIALS AND METHODS: A total 32 patients diagnosed with idiopathic ILD were enrolled in this study. We analyzed a panel of 11 myositis autoantibody specificities in the patients using a line blot immunoassay. Then, we divided them into myositis autoantibody-positive and -negative groups and compared the clinical features and laboratory data between the two groups. RESULTS: Of the 32 idiopathic ILD patients, 12 patients had myositis autoantibodies encompassing 9 specificities, except for anti-Mi-2 and anti-PM-Scl 100 (12/32, 38%). Anti-synthetase autoantibodies including Jo-1, EJ, OJ, PL-7, and PL-12 were present in 7 patients (7/32, 22%). The group with myositis autoantibodies presented more frequently with the symptom of mechanic's hand and showed abnormal pulmonary function test results with low forced vital capacity, diffusing capacity for carbon monoxide, total lung capacity, and high lactate dehydrogenase values in blood when compared with the group without myositis antibodies. CONCLUSION: We strongly suggest that patients undergo an evaluation of myositis autoantibodies, if they are diagnosed with idiopathic ILD in the presence of clinical characteristics including mechanic's hand, arthralgia, and autoantibodies which are insufficient to make a diagnosis of a specific CTD category.

Clinical Value of Endobronchial Ultrasound Findings for Predicting Nodal Metastasis in Patients with Suspected Lymphadenopathy: A Prospective Study

We evaluated whether sonographic findings can provide additional diagnostic yield in endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), and can more accurately predict nodal metastasis than chest computed tomography (CT) or positron emission tomography (PET)/CT scans. EBUS-TBNA was performed in 146 prospectively recruited patients with suspected thoracic lymph node involvement on chest CT and PET/CT from June 2012 to January 2013. Diagnostic yields of EBUS finding categories as a prediction model for metastasis were evaluated and compared with findings of chest CT, PET/CT, and EBUS-TBNA. In total, 172 lymph nodes were included in the analysis: of them, 120 were malignant and 52 were benign. The following four EBUS findings were predictive of metastasis: nodal size > or =10 mm, round shape, heterogeneous echogenicity, and absence of central hilar structure. A single EBUS finding did not have sufficient diagnostic yield; however, when the lymph node had any one of the predictive factors on EBUS, the diagnostic yields for metastasis were higher than for chest CT and PET/CT, with a sensitivity of 99.1% and negative predictive value of 83.3%. When any one of predictive factors is observed on EBUS, subsequent TBNA should be considered, which may provide a higher diagnostic yield than chest CT or PET/CT.

The Clinical, Radiological, and Bronchoscopic Findings and Outcomes in Patients with Benign Tracheobronchial Tumors

PURPOSE: We evaluated the characteristics of and treatment outcomes in patients with benign tracheobronchial tumors. MATERIALS AND METHODS: We reviewed the records of patients with benign tracheobronchial tumors who underwent bronchoscopic intervention with mechanical removal and Nd: YAG laser cauterization, and evaluated the characteristics and treatment outcomes of 55 patients with hamartomas, leiomyomas, papillomas, typical carcinoids, or schwannomas seen between April 1999 and July 2012. RESULTS: The most common tumors were hamartoma (n=24), leiomyoma (n=16), papilloma (n=7), typical carcinoid (n=5), and schwannoma (n=3). Forty-one patients (75%) had symptoms. On chest computed tomography, 35 patients (64%) had round or ovoid lesions, accompanied by atelectasis (n=26, 47%) or obstructive pneumonia (n=17, 31%). Fatty components (n=9, 16%) and calcifications (n=7, 13%) were observed only in hamartomas, leiomyomas, and typical carcinoids. At bronchoscopy, the typical findings were categorized according to tumor shape, surface, color, and visible vessels. Fifty (91%) patients underwent complete resection. Forty patients (73%) achieved successful bronchoscopic removal defined as complete resection without complications or recurrence. Recurrences occurred in four papillomas, one leiomyoma, and one typical carcinoid. The proportions of tumor types (p=0.029) differed between the successful and unsuccessful removal groups, and a pedunculated base (p<0.001) and no spontaneous bleeding (p=0.037) were more frequent in the successful removal group. CONCLUSION: We described clinical, radiological, and typical bronchoscopic findings in patients with benign tracheobronchial tumors; these findings might help to differentiate such tumors. Bronchoscopic intervention was a useful treatment modality, and tumor type, pedunculated base, and vascularity may influence successful tumor removal.

A Case Report of IgG4-Related Disease Clinically Mimicking Pleural Mesothelioma / 결핵및호흡기질환

An immunoglobulin G4 (IgG4)-related disease is a recently emerging entity, and a few cases of IgG4-related disease in lung and pleura have been reported. Herein, we report the case of a 74-year-old man with IgG4-related disease of lung and pleura, clinically suspicious of malignant mesothelioma. Chest computed tomography showed diffuse nodular pleural thickening, and microscopic finding disclosed diffuse thickening of visceral pleura with infiltrations of many lymphoplasma cells with increased number of IgG4-positive plasma cells and a few multinucleated giant cells. It is important for pathologists and clinicians to recognize this rare entity and its histologic finding, because it can be confused with malignant tumors on the radiologic examination although it can be treated with steroid therapy.

A Case of Pulmonary Amyloidosis Mimicking Lymphangitic Lung Carcinomatosis / 대한내과학회지

Amyloidosis is defined by tissue deposits of amyloid, which cause both functional and structural damage to organs. Three histopathological types of pulmonary amyloidosis have been described: tracheobronchial, nodular parenchymal, and diffuse parenchymal or alveolar septal types. Diffuse alveolar septal involvement of the lung is a rare form of primary pulmonary amyloidosis, with radiological features similar to those of pulmonary edema, pulmonary fibrosis, and lymphangitic carcinomatosis. Therefore, it is always challenging to diagnose alveolar septal involvement of pulmonary amyloidosis. Here, we report a case of alveolar septal involvement of pulmonary amyloidosis mimicking lymphangitic carcinomatosis, which was diagnosed from a transbronchial lung biopsy.

Usual Interstitial Pneumonia with Lung Cancer: Clinicopathological Analysis of 43 Cases

BACKGROUND: Previous studies have suggested an association between usual interstitial pneumonia (UIP) and lung cancer (Ca). However, clinical and histological information is not enough to determine such an association, due to the low incidence and short survival time of patients with both conditions. METHODS: We retrospectively reviewed the clinical and histological records of Ca patients with UIP between January 1999 and August 2013 at the Samsung Medical Center, Seoul, Korea. We found 43 patients who had Ca with UIP (UIP-Ca). Previously reported data of eighty-four patients with UIP-only were included as a comparison group. RESULTS: Smoking is related to poor prognosis in patients with UIP-Ca, and the number of patients with a high smoking index of more than 30 pack-years significantly increased in UIP-Ca patients compared with UIP-only patients. There is no significant prognostic differentiation between UIP-Ca patients and UIP-only patients. Microscopically, UIP-Ca patients showed characteristically heterogeneous histological patterns and degrees of differentiation. There were many foci of squamous metaplasia or dysplasia at the peripheral area of squamous cell carcinomas. CONCLUSIONS: We report 43 cases of UIP-Ca. Our results suggest that smoking is related to cancer occurrence in UIP patients and poor prognosis in UIP-Ca patients.

Prognostic factors for bronchoscopic intervention in advanced lung or esophageal cancer patients with malignant airway obstruction

Bronchoscopic intervention can provide immediate relief from suffocation and an opportunity for additional treatment in patients with malignant airway obstruction. However, few studies have specifically identified prognostic factors affecting the survival of advanced lung or esophageal cancer patients receiving bronchoscopic intervention. We aimed to investigate prognostic factors influencing survival in these patients. We conducted retrospective study. The clinical parameters were retrospectively reviewed in 51 patients [lung cancer: n=35; esophageal cancer: n= 16] who underwent palliative bronchoscopic interventions due to malignant airway. Bronchoscopic interventions, such as mechanical removal [n = 26], stenting [n = 31], laser cauterization [n= 19], and ballooning [n= 16], were performed on intraluminal [n = 21, 41%], extrinsic [n = 8, 16%], and combined lesions [n = 22, 43%]. Tracheal invasion was found in 24 patients [47%] Successful palliation was achieved in 49 patients [96%]. After the intervention, additional anti-cancer treatment was followed in 24 patients [47%]. The median survival time and overall survival rate were 3.4 months and 4%. Survival was increased with selected conditions, including a treatment-naive status [hazard ratio [HR], 0.359; confidence interval [Cl], 0.158-0.815; P= 0.01], an intact proximal airway [HR, 0.265; Cl, 0.095-0.738; P= 0.01], and post-procedural additional treatment [HR, 0.330; Cl, 0.166-0.657; P<0.01]. Brochoscopic intervention could provide immediate relief and survival improvement in advanced lung or esophageal cancer patients with selected conditions such as a treatment-naive status, an intact proximal airway, and available post-procedural additional treatment

Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis

In patients with post-tuberculosis bronchial stenosis [PTBS], the severity of bronchial stenosis affects the restenosis rate after the silicone stent is removed. In PTBS patients with incomplete bronchial obstruction, who had a favorable prognosis, the timing of stent removal to ensure airway patency is not clear. We evaluated the time for silicone stent removal in patients with incomplete PTBS. A retrospective study examined PTBS patients who underwent stenting and removal of a silicone stent. Incomplete bronchial stenosis was defined as PTBS other than total bronchial obstruction, which had a luminal opening at the stenotic segment on bronchoscopic intervention. The duration of stenting was defined as the interval from stent insertion to removal. The study included 44 PTBS patients and the patients were grouped at intervals of 6 months according to the duration of stenting. Patients stented for more than 12 months had a significantly lower restenosis rate than those stented for less than 12 months [4% vs. 35%, P = 0.009]. Multiple logistic regression revealed an association between stenting for more than 12 months and a low restenosis rate [odds ratio 12.095; 95% confidence interval 1.097-133.377]. Moreover, no restenosis was observed in PTBS patients when the stent was placed more than 14 months previously. In patients with incomplete PTBS, stent placement for longer than 12 months reduced restenosis after stent removal

Bronchogenic Cyst Rupture and Pneumonia after Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A Case Report / 결핵및호흡기질환

We report a 54-year-old woman who presented with a well-defined, homogeneous, and non-enhancing mass in the retrobronchial region of the bronchus intermedius. The patient underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for histological confirmation. Serous fluid was aspirated by EBUS-TBNA. Cytological examination identified an acellular smear with negative microbiological cultures. The patient was finally diagnosed with bronchogenic cysts by chest computed tomography (CT) and EBUS-TBNA findings. However, 1 week after EBUS-TBNA, the patient developed bronchogenic cyst rupture and pneumonia. Empirical antibiotics were administered, and pneumonia from the bronchogenic cyst rupture had resolved on follow-up chest CT. To our knowledge, this is the first reported case of pneumonia from bronchogenic cyst rupture after EBUS-TBNA.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for the Diagnosis of Central Lung Parenchymal Lesions

PURPOSE: The purpose of this study was to evaluate the usefulness of convex probe endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for detecting malignancy in parenchymal pulmonary lesions located adjacent to the central airways. MATERIALS AND METHODS: We retrospectively reviewed the diagnostic performance of EBUS-TBNA in consecutive patients with high clinical suspicion of a centrally located primary lung cancer who had undergone EBUS-TBNA at the Samsung Medical Center between May 2009 and June 2011. RESULTS: Thirty-seven patients underwent EBUS-TBNA for intrapulmonary lesions adjacent to the central airways. Seven lesions were located adjacent to the trachea and 30 lesions were located adjacent to the bronchi. Cytologic and histologic samples obtained via EBUS-TBNA were diagnostic in 32 of 37 (86.4%) of patients. The final diagnosis was lung cancer in 30 patients (7 small cell lung cancer, 23 non-small cell lung cancer), lymphoma in one and malignant fibrous histiocytoma in one patient. The diagnostic sensitivity of EBUS-TBNA in detecting malignancy and detecting both malignancy and benignity was 91.4% and 86.5%, respectively. Two patients experienced minor complications. CONCLUSION: EBUS-TBNA is an effective and safe method for tissue diagnosis of parenchymal lesions that lie centrally close to the airways. EBUS-TBNA should be considered the procedure of choice for patients with centrally located lesions without endobronchial involvement.

Connective Tissue Disease-Associated Interstitial Lung Disease / 대한내과학회지

Interstitial lung disease (ILD) is the most common pulmonary manifestation of connective tissue disease (CTD). It may develop in the patients with preexisting connective tissue diseases or may be the initial lone manifestation of an underlying CTD. Since ILD causes a potentially substantial morbidity and mortality in the patients with CTD, close collaboration among pulmonologists, rheumatologists, radiologists and pathologists is very essential to optimize the diagnostic evaluation and treatment. Important information on the pattern and extent of the ILD can be obtained by chest HRCT imaging. In general, surgical lung biopsy is not recommended for CTD-associated ILD. All patients with CTD-associated ILD do not require pharmacologic treatment. The decision to treat CTD-associated ILD often depends on 1) whether the patient is clinically impaired by the ILD, 2) whether the ILD is progressive, and 3) what contraindications exist. Differential diagnosis from superimposed pneumonia and drug-induced ILD is quite important. Immunosuppressive therapy is the mainstay of treatment. Recent success of cyclophosphamide in the clinical trials of systemic sclerosis-associated ILD is promising.

Antifactor Xa Levels in Critically Ill Korean Patients Receiving Enoxaparin for Thromboprophylaxis: A Prospective Observational Study

The aim of this study was to investigate antifactor Xa (aFXa) levels after once daily dose of 40 mg of enoxaparin and to evaluate factors influencing aFXa levels among Korean intensive care unit (ICU) patients. This prospective observational study was conducted between August and December 2011 in medical ICUs at Samsung Medical Center. AFXa levels between 0.1 and 0.3 U/mL were considered to be effective for antithrombotic activity. Fifty-five patients were included. The median aFXa levels were 0.22 (IQR 0.17-0.26) at 4 hr, 0.06 (IQR 0.02-0.1) at 12 hr, and 0 U/mL (IQR 0-0.03) at 24 hr. The numbers of patients showing effective antithrombotic aFXa levels were 48 (87.3%), 18 (32.7%), and 0 (0%) at 4, 12 and 24 hr, respectively. At 12 hr, higher sequential organ failure assessment (SOFA) scores and hyperbilirubinemia were significantly associated with low aFXa levels (OR, 0.58; 95% CI, 0.36-0.93; P = 0.02 and 0.06; 0.003-0.87; 0.04, respectively). Once daily dose of 40 mg of enoxaparin is inadequate for maintaining effective antithrombotic aFXa levels, and the inadequacy is more salient for patients with high SOFA scores and hyperbilirubinemia.

Usefulness of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Diagnosis of Sarcoidosis

PURPOSE: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an accurate and minimally invasive technique used routinely for investigation of mediastinal and hilar lymphadenopathy. However, few studies have addressed its role in comparison to the traditional diagnostic approaches of transbronchial lung biopsy (TBLB), endobronchial biopsy (EBB), and bronchoalveolar lavage (BAL) in the diagnosis of sarcoidosis. We evaluated the usefulness of EBUS-TBNA in the diagnosis of sarcoidosis compared to TBLB, EBB, and BAL. MATERIALS AND METHODS: Consecutive patients with suspected sarcoidosis (stage I and II) on chest radiography and chest computed tomography were included. All 33 patients underwent EBUS-TBNA, TBLB, EBB, and BAL during the same session between July 2009 and June 2011. EBUS-TBNA was performed at 71 lymph node stations. RESULTS: Twenty-nine of 33 patients, were diagnosed with histologically proven sarcoidosis; two patients were compatible with a clinical diagnosis of sarcoidosis during follow-up; and two patients were diagnosed with metastatic carcinoma and reactive lymphadenopathy, respectively. Among 29 patients with histologically proven sarcoidosis in combination with EBUS-TBNA, TBLB, and EBB, only EBUS-TBNA and TBLB revealed noncaseating granuloma in 18 patients and one patient, respectively. The overall diagnostic sensitivities of EBUS-TBNA, TBLB, EBB, and BAL (CD4/CD8 > or =3.5) were 90%, 35%, 6%, and 71%, respectively (p<0.001). The combined diagnostic sensitivity of EBUS-TBNA, TBLB, and EBB was 94%. CONCLUSION: EBUS-TBNA was the most sensitive method for diagnosing stage I and II sarcoidosis compared with conventional bronchoscopic procedures. EBUS-TBNA should be considered first for the histopathologic diagnosis of stage I and II sarcoidosis.