[Lipoid pneumonia: simulating neoplastic lesions]

Introduction: Lipoid pneumonia is a pulmonary disease caused by the accumulation of lipids in the alveoli, the diagnosis of which can be a challenge due to its similarity with lung tumors. Objectives: Through the review of tomographic tests, histological studies and risk factors, we seek to improve diagnostic accuracy and facilitate an appropriate differentiation between this condition and tumoral lesions. Methodology: We analyzed five cases of patients with suspected neoplasms, evaluated using computerized tomography between 2022 and December 2024. Patients with oncological risk factors and a history of prolonged exposure to oils were selected. Results: The cases included four women and one man, with an average age of 78 years. Two patients had a history of cancer, and all were former smokers, although four of them had chronic exposure to oils. The CT scans revealed different patterns: consolidations, nodules, a mass and, in one case, cavitations with calcifications. Three patients underwent PET-CT, showing increased radiopharmaceutical uptake. Biopsies confirmed the presence of cells with intracytoplasmic vacuoles. Conclusions: Given that lipoid pneumonia can mimic primary or secondary tumors, it should be considered in patients with persistent pulmonary opacities, especially in older adults. The identification of lesions with fat attenuation and the review of history of exposure to lipids can improve diagnostic accuracy, avoiding unnecessary invasive procedures.