Background <p>Focal cystic air space is a rare manifestation of lipoid pneumonia. In this study, we conduct an analysis and synthesis of the characteristics of two cases initially suspected to be cystic lung cancer, but subsequently diagnosed as lipoid pneumonia, with the aim of enhancing differential diagnostic capabilities and minimizing the risk of misdiagnosis.</p> Case presentation <p>Both patients were found to have ground-glass nodules upon physical examination. Chest CT scans revealed cavitary lesions in the lungs with surrounding ground-glass opacities, consistent with LUNG-RADS category 4A, not excluding cystic lung cancer. Later, surgical intervention was performed, and the pathological examination showed features consistent with lipoid pneumonia.</p> Conclusions <p>Lipoid pneumonia can present as ground-glass nodules and has certain similarities with cystic lung cancer in imaging manifestations. Clinicians should obtain a detailed exposure history, including the use of nasal oils or lip balms, to avoid misdiagnosis and ensure appropriate management. </p>