Lipid Pneumonia Presents as Lung Cancer in Breast Cancer Survivor: A Rare Case Study

In a remarkable case from a recent medical study, doctors have successfully diagnosed and treated a rare condition known as exogenous lipid pneumonia (ELP) that closely resembled lung cancer in a middle-aged woman. This unusual presentation highlights the importance of accurate diagnosis in differentiating between lipid pneumonia and malignancies.

Lipid pneumonia is a rare lung inflammation caused by the accumulation of fatty substances. It is classified into two types: exogenous and endogenous, with exogenous lipid pneumonia resulting from the inhalation or aspiration of fats. The specific pathogenesis of ELP is still unclear, and only a few case reports exist.

The case described involved a 49-year-old woman who worked as a waitress and had a history of left breast cancer. After undergoing a left modified radical mastectomy at 38, she received chemotherapy and regional radiotherapy. Initially, her chest radiography appeared normal, and she had no reported history of oil ingestion.

Seven years later, the patient experienced general malaise. Chest X-rays revealed increased infiltration in the left lung field, and a CT scan showed regional ground-glass opacity (GGO) in the left lower lung. Over the next year, she developed a dry cough and chest discomfort, with follow-up scans indicating an increase in the size of the GGO. Given these findings, malignancy, specifically lobar bronchioloalveolar carcinoma, was suspected.

To investigate further, she underwent a thoracoscopic lobectomy of the left lower lung. Pathological examination of the removed tissue revealed chronic inflammatory cell infiltration and alveolar spaces filled with CD163+ foamy histiocytes and proteinaceous exudates, confirming the diagnosis of lipid pneumonia.

One year after the surgery, the patient was asymptomatic and underwent a chest CT scan as part of her postoperative surveillance. This scan revealed new areas of mixed consolidation and GGO in the right middle lung. Ongoing monitoring and an optimal postoperative surveillance strategy are planned for her care.

This case highlights the importance of considering ELP in patients with a history of lung abnormalities, especially when previous malignancies or treatments may contribute to lung complications. Continued research and documentation of such cases will enhance understanding of ELP and inform better management strategies for affected individuals.

"We share our experience managing a rare case of exogenous lipid pneumonia that initially presented as lung cancer. The condition was successfully diagnosed and treated through thoracoscopic lobectomy. In specific clinical situations, CT-guided or transbronchial biopsy may be valuable pre-operative diagnostic tools. Notably, the patient had received cyclophosphamide, an antineoplastic agent, seven years earlier, suggesting a potential link to the development of ELP," Jiun-Chang Wu, Department of Medicine, MacKay Medical College, New Taipei, Taiwan, and colleagues wrote.

"This case highlights the need for further research to establish effective management guidelines for ELP moving forward," they concluded.

Reference:

Wu JC, Chen TY, Wen-Chien H, Lee JJ, Chen CH. Lipid Pneumonia Mimicking Lung Cancer in a Middle-Age Woman. Ann Thorac Cardiovasc Surg. 2024;30(1):24-00117. doi: 10.5761/atcs.cr.24-00117. PMID: 39477502; PMCID: PMC11524679.