Lipoid Pneumonia

Excerpt

Lipoid pneumonia is a rare, underrecognized pulmonary disorder characterized by parenchymal inflammation caused by lipid accumulation in the distal airways and alveoli, impairing gas exchange. The term “lipoid pneumonia” was first introduced by Laughlin in 1925.

The condition is broadly classified into 2 types. Exogenous lipoid pneumonia (ELP) results from aspiration or inhalation of lipid-containing substances, such as mineral oils and vaping products. Endogenous lipoid pneumonia (EnLP), also known as cholesterol pneumonia, arises from internal lipid accumulation due to airway obstruction, cellular necrosis, or metabolic dysfunction. Both forms exhibit nonspecific clinical and radiologic features that overlap with infectious pneumonia, malignancy, and diffuse parenchymal lung diseases, complicating diagnosis. A thorough clinical history, combined with characteristic radiographic and histopathologic findings, often provides essential diagnostic clues.

Heightened clinical awareness is increasingly important given the rising incidence of ELP associated with electronic cigarette (e-cigarette) and tetrahydrocannabinol (THC) oil use among adolescents and young adults, as well as aspiration-related ELP in vulnerable populations, including infants, older adults, and individuals with neuromuscular or esophageal disorders. Despite growing relevance, lipoid pneumonia remains poorly understood, with limited research resulting from frequent underreporting and misdiagnosis. This activity focuses on the etiology, clinical manifestations, evaluation, and treatment of this condition.