SESSION TITLE: Miscellaneous Case Report Posters II
SESSION TYPE: Affiliate Case Report Poster
PRESENTED ON: Tuesday, October 29, 2013 at 01:30 PM - 02:30 PM
INTRODUCTION: Incidental pulmonary masses particularly in a smoker raise concern for lung cancer. However, careful history may reveal clues to other unusual diagnoses. We present one such case, where biopsy of a lesion suspicious for lung cancer revealed lipoid pneumonia.
CASE PRESENTATION: A 62 year old asymptomatic woman with a history of COPD and anorexia/bulimia presented with pulmonary masses found incidentally on chest x-ray. Her medications included Advair and albuterol inhalers. She had a 46 pack-year history of smoking with no tuberculosis exposure or recent travel. Examination and laboratory tests were unremarkable. Chest CT scan demonstrated spiculated masses in the right middle and left lower lobes (Figure 1). PET scan showed FDG avidity within these lesions. Pathology from a CT-guided biopsy of the left lung mass showed benign lung tissue with lipid-laden macrophages and lipogranulomas (Figure 2). A diagnosis of exogenous lipoid pneumonia was made. It was later revealed that the patient had used mineral oil laxative for many years to lose weight. Management was supportive. She remains asymptomatic.
DISCUSSION: Exogenous lipoid pneumonia results from accumulation of lipids in the alveoli due to aspiration of mineral oil, animal fat or vegetable oil. The pathophysiology of lipoid pneumonia resulting from animal fat aspiration is an inflammatory reaction in the alveoli leading to necrosis. Mineral and vegetable oils induce a foreign body reaction to form granulomas, resulting in a mass-like appearance on imaging. Symptoms include cough, fever and dyspnea. Chronic cases may be asymptomatic. Commonest radiographic findings are ground glass opacities or consolidation. The characteristic CT appearance of chronic exogenous lipoid pneumonia is a fat containing mass. Differential diagnoses include fat containing lesions, such as hamartomas and metastasis from chondrosarcomas and liposarcomas. Presence of lipid-laden macrophages on bronchoalveolar lavage or lipogranulomas and lipid filled alveoli on histopathology are diagnostic. Treatment is usually supportive. Success with steroids has been reported in acute cases.
CONCLUSIONS: Accidental or deliberate ingestion of mineral oil may lead to aspiration and development of acute or chronic exogenous lipoid pneumonia. Diligent history taking may help identify the inciting agent. The presence of a mass on imaging, particularly in a smoker, is concerning for malignancy. Therefore awareness of this condition from the history is important and may help reassure patients even before tissue diagnosis is made. Cessation of exposure to the inciting agent and supportive care remain the mainstay of treatment.
Reference #1: Baron SE et al. Radiological and clinical findings in acute and chronic exogenous lipoid pneumonia. J of thoracic imaging 18.4(2003):217-224.
Reference #2: Betancourt S et al. Lipoid pneumonia: spectrum of clinical and radiologic manifestations. American Journal of Roentgenology 194.1(2010):103-109.
DISCLOSURE: The following authors have nothing to disclose: Satish Kalanjeri, Anu Suri, Hangjun Wang, Diane Stover
No Product/Research Disclosure Information