Exogenous lipoid pneumonia. Clinical and radiological manifestations.

Lipoid pneumonia results from the pulmonary accumulation of endogenous or exogenous lipids. Host tissue reactions to the inhaled substances differ according to their chemical characteristics. Symptoms can vary significantly among individuals, ranging from asymptomatic to severe, life-threatening disease. Acute, sometimes fatal, cases can occur, but the disease is usually indolent. Possible complications include superinfection by nontuberculous mycobacteria, pulmonary fibrosis, respiratory insufficiency, cor pulmonale, and hypercalcemia. The radiological findings are nonspecific, and the disease presents with variable patterns and distribution. For this reason, lipoid pneumonia may mimic many other diseases. The diagnosis of exogenous lipoid pneumonia is based on a history of exposure to oil, characteristic radiological findings, and the presence of lipid-laden macrophages on sputum or BAL analysis. High-resolution computed tomography (HRCT) is the best imaging modality for the diagnosis of lipoid pneumonia. The most characteristic CT finding in LP is the presence of negative attenuation values within areas of consolidation. There are currently no studies in the literature that define the best therapeutic option. However, there is a consensus that the key measure is identifying and discontinuing exposure to the offending agent. Treatment in patients without clinical symptoms remains controversial, but in patients with diffuse pulmonary damage, aggressive therapies have been reported. They include whole lung lavage, systemic corticosteroids, and thoracoscopy with surgical debridement.