A lung mass: Not the usual suspect, but not above suspicion.

Lipoid pneumonia is an entity that is not commonly thought of when faced with opacities on the chest radiograph. The radiological changes of lipoid pneumonia can mimic pneumonia or malignancy. Due to this mimicry, it is commonly missed and alternative diagnoses should always be considered and ruled out when suspecting lipoid pneumonia. Although majority of lipoid pneumonias occur due to exogenous ingestion of oil, endogenous factors such as bronchial obstruction and pulmonary alveolar proteinosis can also result in this condition. The emphasis of this case is on the approach to and treatment of lipoid pneumonia, including its association with malignancy.