Clinical course and risk factors for development and progression of interstitial lung disease in primary Sjögren's syndrome.

This single-center, retrospective study aimed to investigate the course and prognostic factors of patients with primary Sjögren syndrome-associated interstitial lung disease (pSS-ILD). We included 120 pSS patients who underwent at least two high-resolution computed tomography (HRCT) scans between 2013 and 2021. Clinical symptoms, laboratory data, HRCT findings, and pulmonary function test results were collected. Two thoracic radiologists reviewed the HRCT findings. In patients with pSS without ILD at baseline (n = 81), no development of ILD was found on follow-up (median, 2.8 years). In patients with pSS-ILD (n = 39), total disease extent, extent of coarse reticulation, and traction bronchiectasis increased on HRCT, whereas the extent of ground glass opacity (GGO) decreased at follow-up (median, 3.2 years) (each p < 0.001). In progressive group of pSS-ILD (48.7%), the extent of coarse reticulation and coarseness score of fibrosis were increased at follow-up (p < 0.05). Usual interstitial pneumonia pattern on CT (OR, 15.237) and follow-up duration (OR, 1.403) were independent risk factors for disease progression in patients with pSS-ILD. In both progressive and non-progressive pSS-ILD, GGO decreased, whereas the extent of fibrosis increased even after treatment with glucocorticoid and/or immunosuppressants. In conclusion, progression occurred in approximately half of the pSS-ILD patients with slow gradual deterioration. Our study identified a definite group of progressive pSS-ILD who did not respond to current anti-inflammatory treatment.

Application of 18 F-fluorodeoxyglucose PET/CT radiomic features and machine learning to predict early recurrence of non-small cell lung cancer after curative-intent therapy.

OBJECTIVE: To predict the recurrence of non-small cell lung cancer (NSCLC) within 2 years after curative-intent treatment using a machine-learning approach with PET/CT-based radiomics. PATIENTS AND METHODS: A total of 77 NSCLC patients who underwent pretreatment 18 F-fluorodeoxyglucose PET/CT were retrospectively analyzed. Five clinical features (age, sex, tumor stage, tumor histology, and smoking status) and 48 radiomic features extracted from primary tumors on PET were used for binary classifications. These were ranked, and a subset of useful features was selected based on Gini coefficient scores in terms of associations with relapsed status. Areas under the receiver operating characteristics curves (AUC) were yielded by six machine-learning algorithms (support vector machine, random forest, neural network, naive Bayes, logistic regression, and gradient boosting). Model performances were compared and validated via random sampling. RESULTS: A PET/CT-based radiomic model was developed and validated for predicting the recurrence of NSCLC during the first 2 years after curation. The most important features were SD and variance of standardized uptake value, followed by low-intensity short-zone emphasis and high-intensity zone emphasis. The naive Bayes model with the 15 best-ranked features displayed the best performance (AUC: 0.816). Prediction models using the five best PET-derived features outperformed those using five clinical variables. CONCLUSION: The machine learning model using PET-derived radiomic features showed good performance for predicting the recurrence of NSCLC during the first 2 years after a curative intent therapy. PET/CT-based radiomic features may help clinicians improve the risk stratification of relapsed NSCLC.

Risk factors for heel pressure injury in cardiovascular intensive care unit patients.

This study analyzed the risk factors for heel pressure injury in cardiovascular intensive care unit patients with the aim of laying the groundwork for preventive nursing interventions. We conducted a retrospective case-control study of 92 patients who were admitted to the cardiovascular surgical or medical intensive care unit of a university hospital in South Korea between January and December 2017. Of these patients, 31 and 61 were included to the heel pressure injury group and the non-heel pressure injury group, respectively. Data on their demographic, disease-related, and intensive care unit treatment characteristics, as well as the degree of pressure injury, were collected from the hospital's electronic medical records using a standardized form. Cardiac surgery (P < .001), operation time (P = .001), use of a mechanical ventilator (P < .001), use of vasoconstrictors (P < .001), use of sedative drugs (P < .001), and extracorporeal membrane oxygenation treatment (P < .001) were identified as significant risk factors for heel pressure injury. A total of 22 patients (71%) from the heel pressure injury group developed deep tissue injury, and 16 patients (51.6%) who received extracorporeal membrane oxygenation treatment developed heel pressure injury.

Diagnostic Value of Bone SPECT/CT Using 99mTc-Methylene Diphosphonate in Patients with Unspecified Chest Wall Pain.

PURPOSE: We investigated the diagnostic performance of single photon emission computed tomography (SPECT)/computed tomography (CT) as a combination of functional and anatomic imaging, in patients with unspecified chest wall pain. METHODS: Fifty-two patients with unspecified chest wall pain and no history of recent major traumatic events or cardiac disease were included. The number and location of radioactive chest wall lesions were evaluated on both planar images and SPECT/CT. The clinical diagnosis was made based on all of the clinical and imaging data and follow-up information. RESULTS: Chest wall diseases were diagnosed in 42 patients (80.8 %). SPECT/CT showed abnormal findings in 35 (67.3 %) patients with positive predictive value (PPV) of 97.1 %. SPECT/CT revealed 56 % more lesions than planar bone scan (P = 0.002) and most of the abnormal radioactive lesions (94.6 %) showed combined morphological changes on the matched CT component. When comparing between age subgroups (< 60 y vs. ≥ 60 y), the prevalence of chest wall disease and diagnosis rate of fracture was significantly higher in the older age group. On SPECT/CT, the older age group showed higher frequency of having abnormal finding (95.8 % vs. 42.9 %, P < 0.001) and significantly more lesions were detected (a total of 189 vs. 32, P = 0.003). CONCLUSION: SPECT/CT showed good diagnostic performance and proved to have higher sensitivity, detecting 56 % more lesions than planar bone scan. A negative result could be helpful for excluding pathologic chest wall disease. SPECT/CT might be recommended for integration in to the diagnostic workup in patients with unspecified chest wall pain, especially in patients ≥ 60 y of age, considering the high disease prevalence and the high frequency of positive results.

Necrotizing sarcoid granulomatosis simulating pulmonary malignancy: A case report.

RATIONALE: Necrotizing sarcoid granulomatosis (NSG) has recently been termed "sarcoidosis with NSG pattern" for the disease entity representing nodular sarcoidosis with granulomatous pulmonary angiitis. It is characterized by sarcoid-like granulomas, vasculitis, and a variable degree of necrosis. Its rarity and nonspecific clinical symptoms can easily lead to misdiagnosis or delayed diagnosis. PATIENT CONCERNS: We report a 67-year-old female with a biopsy-confirmed sarcoidosis with NSG pattern mimicking pulmonary malignancy on initial chest computed tomography scan. DIAGNOSES: Sarcoidosis with NSG pattern. INTERVENTIONS: The patient underwent video-assisted thoracoscopic surgery with a lung biopsy. No further treatment was performed after the lung biopsy. OUTCOMES: Follow-up imaging studies revealed spontaneous regression of the disease after 2 months. LESSONS: Awareness of this rare benign disease entity and overlapping radiologic manifestations with pulmonary malignancy or other granulomatous diseases can be helpful for making a precise diagnosis with a better differential diagnosis.

Tissue Adequacy and Safety of Percutaneous Transthoracic Needle Biopsy for Molecular Analysis in Non-Small Cell Lung Cancer: A Systematic Review and Meta-analysis.

OBJECTIVE: We conducted a systematic review and meta-analysis of the tissue adequacy and complication rates of percutaneous transthoracic needle biopsy (PTNB) for molecular analysis in patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: We performed a literature search of the OVID-MEDLINE and Embase databases to identify original studies on the tissue adequacy and complication rates of PTNB for molecular analysis in patients with NSCLC published between January 2005 and January 2020. Inverse variance and random-effects models were used to evaluate and acquire meta-analytic estimates of the outcomes. To explore heterogeneity across the studies, univariable and multivariable meta-regression analyses were performed. RESULTS: A total of 21 studies with 2232 biopsies (initial biopsy, 8 studies; rebiopsy after therapy, 13 studies) were included. The pooled rates of tissue adequacy and complications were 89.3% (95% confidence interval [CI]: 85.6%-92.6%; I² = 0.81) and 17.3% (95% CI: 12.1%-23.1%; I² = 0.89), respectively. These rates were 93.5% and 22.2% for the initial biopsies and 86.2% and 16.8% for the rebiopsies, respectively. Severe complications, including pneumothorax requiring chest tube placement and massive hemoptysis, occurred in 0.7% of the cases (95% CI: 0%-2.2%; I² = 0.67). Multivariable meta-regression analysis showed that the tissue adequacy rate was not significantly lower in studies on rebiopsies (p = 0.058). The complication rate was significantly higher in studies that preferentially included older adults (p = 0.001). CONCLUSION: PTNB demonstrated an average tissue adequacy rate of 89.3% for molecular analysis in patients with NSCLC, with a complication rate of 17.3%. PTNB is a generally safe and effective diagnostic procedure for obtaining tissue samples for molecular analysis in NSCLC. Rebiopsy may be performed actively with an acceptable risk of complications if clinically required.

Quantitative evaluation of computed tomography findings in patients with bronchial asthma: prediction of therapeutic response.

INTRODUCTION: To compare pretreatment quantitative CT parameters between patients with well-controlled and those with poorly controlled bronchial asthma after treatment. METHODS: We retrospectively reviewed 785 patients with clinical diagnosis of bronchial asthma from January 2009 to April 2015. Of these, 43 patients underwent high-resolution CT and pulmonary function tests at initial diagnosis. According to the Global Initiative for Asthma (GINA) 2015 guidelines, the patients were classified into two groups (well-controlled (GINA1), n = 18; poorly controlled (GINA2 and GINA3), n = 25). Quantitative measurements for airways (total cross-sectional area (TA), lumen area (LA), wall area (WA) and wall area percentage (WA%)), air trapping and emphysema were performed on initial pretreatment CT scans. We compared CT measurements for airways between well-controlled and poorly controlled groups and also compared those between ever-smokers and never-smokers. The significant quantitative CT parameters were evaluated with multiple regression analysis. RESULTS: The TA and the WA demonstrated significantly higher values in the poorly controlled than in the well-controlled patient group (TA in RB1 and LB1, each P < 0.05; WA in RB1 and RB8, each P < 0.05). Quantitative parameters for air trapping and emphysema did not show significant differences between the two patient groups. On multiple regression analysis, the TA and the WA were statistically significant in comparison of two patient groups with an adjustment for age, sex, body mass index and smoking history (each P < 0.05). Significantly higher values of the WA and the WA% were revealed in the asthmatics with smoking history comparing to non-smokers (P < 0.05). CONCLUSION: Most of the quantitative CT measurements did not correlate significantly with clinical outcomes in patients with bronchial asthma. And, further research that supplements the limitations of this study is needed to support and validate the association between CT parameters and therapeutic response. This can be justified by the fact that a trend of higher values in airway measurements on initial pretreatment HRCT scan in the poorly controlled than in the well-controlled patient group.

Prognostic Implications of CT Feature Analysis in Patients with COVID-19: a Nationwide Cohort Study.

BACKGROUND: Few studies have classified chest computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) and analyzed their correlations with prognosis. The present study aimed to evaluate retrospectively the clinical and chest CT findings of COVID-19 and to analyze CT findings and determine their relationships with clinical severity. METHODS: Chest CT and clinical features of 271 COVID-19 patients were assessed. The presence of CT findings and distribution of parenchymal abnormalities were evaluated, and CT patterns were classified as bronchopneumonia, organizing pneumonia (OP), or diffuse alveolar damage (DAD). Total extents were assessed using a visual scoring system and artificial intelligence software. Patients were allocated to two groups based on clinical outcomes, that is, to a severe group (requiring O2 therapy or mechanical ventilation, n = 55) or a mild group (not requiring O2 therapy or mechanical ventilation, n = 216). Clinical and CT features of these two groups were compared and univariate and multivariate logistic regression analyses were performed to identify independent prognostic factors. RESULTS: Age, lymphocyte count, levels of C-reactive protein, and procalcitonin were significantly different in the two groups. Forty-five of the 271 patients had normal chest CT findings. The most common CT findings among the remaining 226 patients were ground-glass opacity (98%), followed by consolidation (53%). CT findings were classified as OP (93%), DAD (4%), or bronchopneumonia (3%) and all nine patients with DAD pattern were included in the severe group. Uivariate and multivariate analyses showed an elevated procalcitonin (odds ratio [OR], 2.521; 95% confidence interval [CI], 1.001-6.303, P = 0.048), and higher visual CT scores (OR, 1.137; 95% CI, 1.042-1.236; P = 0.003) or higher total extent by AI measurement (OR, 1.048; 95% CI, 1.020-1.076; P < 0.001) were significantly associated with a severe clinical course. CONCLUSION: CT findings of COVID-19 pneumonia can be classified into OP, DAD, or bronchopneumonia patterns and all patients with DAD pattern were included in severe group. Elevated inflammatory markers and higher CT scores were found to be significant predictors of poor prognosis in patients with COVID-19 pneumonia.

Pulmonary toxicities of molecular targeted antineoplastic agents: a single-center 10-year experience.

BACKGROUND/AIMS: A better understanding of cancer cell biology has led to the discovery and development of several new targeted agents for cancer. These drugs are widely used in cancer treatment and have good toxicity profiles. However, some patients are extremely sensitive to these drugs and can develop severe toxicities. Among the toxicities, pulmonary complications are infrequent with most targeted therapies. This study aimed to identify the radiologic pulmonary complications in various targeted therapies and to analyze the characteristics of patients with pulmonary toxicity. METHODS: We retrospectively reviewed the medical records and chest image findings of 644 patients who were treated with targeted antineoplastic agents at Soonchunhyang University Hospital between May 2005 and September 2014. RESULTS: Of these 644 patients, 90 (14.0%) developed pulmonary complications as noted on chest computed tomography. Among these patients, 15 (2.3%) developed drug-related pulmonary toxicities. Treatment with targeted agents was discontinued in all patients, while 11 patients were simultaneously treated with glucocorticoids. Three patients died of drug-related pulmonary toxicity. CONCLUSION: During targeted therapy, clinicians should assess for pulmonary toxicities and symptoms that occur with dyspnea. If drug-induced pulmonary toxicities are suspected, imaging studies should be performed immediately, and the possibility of variable radiological patterns should be considered. Discontinuing the use of implicated causative agents and treatment with glucocorticoids resulted in an improvement in both symptoms and imaging findings, but some patients still experienced fatal pulmonary toxicities.

[Update in Diagnosis of Idiopathic Pulmonary Fibrosis and Interstitial Lung Abnormality]. / íŠ¹ë°œíì„¬ìœ ì¦ 진단의 ìµœì‹ ì§€ê²¬ê³¼ 간질성폐이상.

Idiopathic pulmonary fibrosis (IPF), based on the 2018 international clinical practice guidelines, can be diagnosed with a usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) and compatible clinical findings. Given that imaging is pivotal for IPF evaluation and diagnosis, more emphasis should be placed on the integration of clinical, radiological, and pathologic findings for multidisciplinary diagnosis. Interstitial lung abnormality (ILA), on the other hand, has a purely radiological definition based on the incidental identification of CT abnormalities. Taken together, differentiation between ILA and clinically significant interstitial lung disease (ILD) must be based on proper clinical evaluation. With this review, the recent updates in IPF diagnosis and the radiologic considerations for ILA can be well understood, which can be helpful for the proper diagnosis and management of patients with diffuse interstitial pulmonary fibrosis.

Early and Atypical Radiologic Presentations of Pulmonary Langerhans Cell Histiocytosis: A Report of Two Cases.

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, multi-systemic disease primarily affecting young male adults with a history of smoking. The two patients with PLCH in our report showed relatively early and atypical radiologic presentations at initial evaluation. On chest CT, PLCH presents variable radiologic features depending on the evolutional stage of the disease. Atypical CT features of PLCH may render precise radiologic diagnosis difficult and usually require lung biopsy for a confirmation of the diagnosis. Our case review is aimed at raising the awareness of radiologists on the atypical CT features of PLCH, to help make accurate radiologic diagnosis and prevent unnecessary and invasive diagnostic procedures.

Electronic Cigarette or Vaping Product Use-Associated Lung Injury: A Case Report.

Electronic cigarette (e-cigarette) or vaping product use-associated lung injury (EVALI) has emerged as a social issue as e-cigarette use is rapidly increasing worldwide and is related to many deaths in the United States. To our knowledge, this is the first case report of EVALI in South Korea of a 24-year-old man with acute respiratory symptoms and a history of e-cigarette use. Chest CT revealed diffuse bilateral ground-glass opacities with subpleural sparing, airspace consolidation, and centrilobular micronodules as typical patterns of EVALI with organizing pneumonia and diffuse alveolar damage. Infection was excluded with meticulous laboratory examinations, and the patients' illnesses were not attributed to other causes. EVALI was diagnosed by meeting the diagnostic criteria with consistent clinico-radiologic findings through a multidisciplinary approach. Radiologists should have good knowledge of EVALI radiologic findings and play a cardinal role in the proper diagnosis and management of EVALI.

Delayed Isolation of Active Pulmonary Tuberculosis in Hospitalized Patients: A Pivotal Role of Radiologic Evaluation.

OBJECTIVE. The purpose of this study was to determine factors related to delayed isolation of patients hospitalized with active pulmonary tuberculosis (TB). MATERIALS AND METHODS. A total of 130 immunocompetent hospitalized patients with active pulmonary TB who had positive sputum culture results from January 2015 to December 2017 were reviewed. Delayed isolation of pulmonary TB was defined as failure to initiate airborne isolation within the first 3 days of hospitalization. Clinical and microbiologic characteristics of the patients and radiologic features on chest radiography (n = 130) and chest CT (n = 118) were retrospectively reviewed. Findings were compared between patients with early isolation and those with delayed isolation. Univariate and multivariate analyses were performed to determine independent predictors of delayed isolation. RESULTS. Forty-four patients (34%) had delayed isolation after initial hospitalization. On univariate and multivariate analyses, atypical presentation of active pulmonary TB on CT (odds ratio, 7.203; 95% CI, 2.203-23.551; p = 0.001) and concurrent lung parenchymal diseases on CT (odds ratio, 14.605; 95% CI, 3.274-65.155; p < 0.001) were significant predictors of delayed isolation of patients with active pulmonary TB. CONCLUSION. Awareness of the factors related to delayed diagnosis of active pulmonary TB is important to avoid an unexpected in-hospital outbreak of TB and control the disease. Atypical presentation of active pulmonary TB and concurrent lung parenchymal diseases on CT are significant factors related to delayed isolation of hospitalized patients with active pulmonary TB.

Missed Lung Cancers on Chest Radiograph: An Illustrative Review of Common Blind Spots on Chest Radiograph with Emphasis on Various Radiologic Presentations of Lung Cancers.

Missed lung cancers on chest radiograph (CXR) may delay the diagnosis and affect the prognosis. CXR is the primary imaging modality to evaluate the lungs and mediastinum in daily practice. The purpose of this article is to review chest radiographs for common blind spots and highlight the importance of various radiologic presentations in primary lung cancer to avoid significant diagnostic errors on CXR.

Primary cardiac angiosarcoma with right atrial wall rupture: A case report.

RATIONALE: Cardiac angiosarcoma is the most common malignant tumor of the heart and a rare disease with rapid disease progression and poor prognosis. Cardiac wall rupture is an extremely rare complication. PATIENT CONCERNS: A 32-year-old woman presented with an acute onset of epigastric pain and chest discomfort at first time when she visited an emergency room. DIAGNOSES: A cardiac mass was identified on echocardiography and subsequently performed chest computed tomography and cardiac magnetic resonance imaging revealed the cardiac tumor at right atrium with right atrial wall rupture and hematogenous lung metastasis. Histopathologic diagnosis of metastatic angiosarcoma was done by open lung biopsy. INTERVENTIONS: The patient was treated with palliative chemotherapy for the primary cardiac tumor and hematogenous lung metastasis. OUTCOMES: The follow-up imaging studies revealed treatment response of the primary cardiac tumor and hematogenous lung metastasis. LESSONS: Clinical and radiologic evaluation of the cardiac angiosarcoma was well performed in our case with various diagnostic imaging modalities including echocardiography, chest computed tomography, cardiac magnetic resonance imaging, and fluorodeoxyglucose-positron emission tomography/computed tomography. This case report well demonstrates typical imaging findings of a rare cardiac tumor and emphasizes importance of early investigation for accurate diagnosis and proper management of the cardiac tumor.

Risk Factors for Delayed Isolation of Patients with Active Pulmonary Tuberculosis in an Acute-care Hospital.

The objective of the current study was to determine the factors associated with delayed isolation of pulmonary tuberculosis (TB). In this retrospective study, data of patients newly diagnosed with pulmonary TB from January 2015 through December 2017 at a referral hospital were reviewed. Delayed recognition of pulmonary TB was defined as failure to initiate airborne isolation within the first 3 days of admission. We analyzed the clinical, microbiological, and radiological factors associated with delayed isolation of pulmonary TB. A total of 134 patients with positive sputum acid-fast bacilli (AFB) cultures were analyzed, of which 44 (33%) were isolated within 3 days after admission. In multivariate logistic regression analysis, older age (p = 0.01), admission to departments other than Infectious Disease or Pulmonology (p = 0.005), and presence of malignancy (p = 0.02) were associated with delayed isolation. Patients with a radiologic diagnosis of active pulmonary TB were likely to be isolated early (p = 0.01). Better awareness of pulmonary TB among attending practitioners in hospital settings is required. Delay in isolation is associated with older age, malignancy, hospitalization to departments other than Infectious Disease or Pulmonology, and non-confident radiologic diagnosis of active pulmonary TB.

Mediastinal and retroperitoneal fibrosis as a manifestation of breast cancer metastasis: A case report and literature review.

RATIONALE: Mediastinal and retroperitoneal fibrosis as a manifestation of metastasis from malignancies is rare disease and particularly, cases of mediastinal fibrosis have been rarely reported. PATIENT CONCERNS: A 60-year-old woman presented with dyspnea and bilateral flank pain. The patient had no previous history of malignancy. DIAGNOSES: A contrast-enhanced chest computed tomography scan revealed a left breast mass and infiltrative soft tissue masses in the mediastinum and retroperitoneum, which showed high fluorodeoxyglucose uptake on positron emission tomography scan. The left breast mass was proven as a malignancy on biopsy and surgical excisional biopsy of the mediastinal mass revealed metastasis from the breast cancer on histopathologic examination. INTERVENTIONS: Our patient was treated with palliative hormone therapy for the primary breast cancer and metastasis with mediastinal and retroperitoneal fibrosis. OUTCOMES: Follow-up imaging studies showed improvement of the primary breast cancer and also metastasis. LESSONS: We report this rare case to emphasize that mediastinal and retroperitoneal fibrosis can be a presentation of metastasis from various primary malignancies. We expect that appropriate diagnosis and treatment for metastatic mediastinal and retroperitoneal fibrosis can have a beneficial effect on disease course and prognosis of the patient.

Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum: A Case Report and Literature Review.

Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor.

Early diagnosis based on clinical history and BALF for successful management of smoking-induced acute eosinophilic pneumonia without unnecessary antibiotic usage: a case report.

INTRODUCTION: Acute eosinophilic pneumonia (AEP) is a rapid onset and severe respiratory illness characterized by acute febrile respiratory insufficiency, eosinophilic infiltration in the lungs and unique findings on chest imaging. Difficulty in differentiating from other respiratory distress caused by community-acquired pneumonia may result in a delayed diagnosis or treatment with empirical antibiotics. CASE STUDY: Sixteen-year-old boy who developed AEP with marked eosinophilia in bronchoalveolar lavage fluid (BALF, 36.6%), decreased diffusion capacity of the lung for carbon monoxide (62%) and unique radiological findings. Although he initially denied tobacco use, on repeated thorough clinical history questioning, he eventually admitted beginning smoking 19 days before the onset of symptoms with gradually increasing frequency. RESULTS: His symptoms resolved quickly without use of antibiotics after cessation of tobacco and treatment with corticosteroids. CONCLUSION: Careful clinical history taking regarding tobacco use combined with early examination of BALF and recognition of unique radiological findings are critical for proper management of AEP.