A Case of Exogenous Lipoid Pneumonia: A Malignancy Mimicker

Abstract

SESSION TITLE: Sarcoidosis and Cystic Lung Disease SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Exogenous lipoid pneumonia (ELP) is an uncommon form of aspiration pneumonia caused by aspiration of a fat-containing material. While rare, an early and correct diagnosis is important to decrease morbidity. We describe a case of ELP due to mineral oil aspiration CASE PRESENTATION: A 57-year-old male with history of gastric bypass surgery presented with incidental findings of lung infiltrates on abdominal CT. CT was done to assess for possible malignancy due to significant constitutional symptoms of weight loss, bone pain, muscle weakness, and recurrent falls. He chewed tobacco for 40 years and denied any respiratory symptoms. Vital signs and chest examination were unremarkable. Chest CT showed patchy bilateral centrilobular ground-glass opacities with lingular consolidation, that of fat density (-61 HU) on mediastinal views. Pulmonary testing and rheumatologic serologies were unrevealing. Bronchoalveolar lavage showed predominantly neutrophilic alveolitis (88%) with negative cytology and cultures. Transbronchial biopsy showed patchy foamy alveolar macrophage accumulation. Although the diagnosis was apparent, due to ongoing concerns for an underlying malignancy, he underwent a surgical lung biopsy that confirmed ELP. In retrospect, he reported ingesting mineral oil at bedtime for constipation DISCUSSION: The history of gastric bypass surgery and the timing of ingestion increased his risk for aspiration. ELP is often silent and chronic as oils do not provoke a strong swallow or cough reflex. Diagnosis is often delayed due to nonspecific clinical presentation and often with minimal respiratory symptoms disproportionate to the radiological findings. However, ELP can be suggested by characteristic ground-glass opacities and consolidation that is of fat attenuation in the right clinical context (i.e. exposure). A bronchoscopy can aid diagnosis with findings of lipid laden macrophages. Spontaneous resolution is expected in most with cessation of exposure. Other therapies include corticosteroids and whole lung lavage CONCLUSIONS: Exposure history is essential to facilitate a timely diagnosis of ELP. CT findings can range from ground-glass to consolidation, but it is important to view the consolidation in mediastinal windows. Bronchoscopy in the right clinical and radiographic context can help confirm the diagnosis and potentially avoid additional invasive procedures Reference #1: Marchiori E, Zanetti G, Mano CM, Hochhegger B. Exogenous lipoid pneumonia. Clinical and radiological manifestations. Respir Med 2011;105(5):659-666 DISCLOSURE: The following authors have nothing to disclose: Ali Zaied, Jack Leventhal No Product/Research Disclosure Information