Vaping-associated lung injury with a miliary pattern of disease

SESSION TITLE: Medical Student/Resident Imaging Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: A miliary pattern depicting a diffuse micronodular lung disease was previously seen as a pathognomonic for the lymphohematogenous spread of Mycobacterium tuberculosis. We present a case of vaping-associated lung injury with a novel pattern of diffuse, ill-defined centrilobular miliary micronodules with a tree-in-bud distribution, related to the development of small airway disease. CASE PRESENTATION: A 55-year-old male with a history of asthma presented with shortness of breath and cough for 1 month. He endorsed excessive vaping-use of about 100 mL of flavored nicotine per week utilizing a tank device. He was tachypneic and hypoxemic, with neutrophil-predominant leukocytosis and elevated CRP 152. Chest CT showed diffusely-distributed, ill-defined centrilobular micronodular opacifications (<4mm) with a tree-in-bud pattern, subpleural sparing, and interlobular septal thickening. Infectious disease work-up was negative, aside from one positive sputum culture of Mycobacterium Chlelonae Complex. On day 10, a transbronchial biopsy was performed, which was complicated by severe bronchospasms, bleeding and hypercapnic respiratory failure requiring prolonged intubation. Biopsy showed focal interstitial inflammation and patchy non-specific pneumonitis, with no airway fragments for investigation. He was empirically treated with broad-septum antibiotics, RIPE therapy, and Ambisome without significant improvement. The patient was then started on corticosteroid therapy. A repeat CT showed a mild decrease in the micronodular opacities, and a concern for the development of early bronchiectasis. On day 35, the patient was discharged. DISCUSSION: Our case report presents a patient with acute hypercapnic respiratory failure, presenting with a miliary pattern of disease. As an extensive workup showed no clear causes of disease, we believe that our patient’s excessive use of flavored e-cigarettes led to the development of his respiratory failure. Flavoring agents, such as diacetyl, have previously been seen as occupational exposures leading to the development of “popcorn lung” or crytogenic organizing pneumonia (COP). The presence of diffuse micronodular pattern is a rare radiographic pattern that has only been reported in a few cases of COP. Our findings of ill-defined centrilobular micronodules in a tree-in-bud pattern in a steroid-responsive patient can help support our diagnosis of vaping-associated bronchiolitis. CONCLUSIONS: We present a case of severe bronchiolar disease due to vaping with evidence of early bronchiectasis and hypercapnic respiratory failure. Our findings are distinct from the cases of alveolar damage presented in the recent outbreak, and represent an alternative complication that can arise from vaping. Early identification and treatment of differing radiographic patterns of vaping-associated lung injury is imperative for prevention of disease progression. Reference #1: Oikonomou, A., & Prassopoulos, P. (2013). Mimics in chest disease: interstitial opacities. Insights into imaging, 4(1), 9-27. Reference #2: Landman, S. T., Dhaliwal, I., Mackenzie, C. A., Martinu, T., Steele, A., & Bosma, K. J. (2019). Life-threatening bronchiolitis related to electronic cigarette use in a Canadian youth. CMAJ, 191(48), E1321-E1331. Reference #3: Kewcharoen, J., Poonsombudlert, K., Sathirareuangchai, S., Sae-Ow, W., La, H., & Sriratanaviriyakul, N. (2020). Cryptogenic Organizing Pneumonia with a Rare Radiographic Presentation of a Diffuse Micronodular Pattern Mimicking Miliary Lung Infiltration: A Case Report and Review of the Literature. Case Reports in Pulmonology, 2020. DISCLOSURES: No relevant relationships by Patrick Baghdasaryan, source=Web Response No relevant relationships by Richard Castriotta, source=Web Response No relevant relationships by Madlena Nalbandian, source=Web Response