A Rare Case of Non-Small-Cell Lung Carcinoma Complicated by Massive Pericardial Effusion and Cardiac Tamponade: A Case Report.

This case report presents a late middle-aged man with a right infra-hilar lung mass and pericardial effusion (PE). The patient was diagnosed with metastatic small-cell lung carcinoma, with metastases to the liver, pancreas, and cerebellum. The pericardial fluid cytology confirmed the presence of malignant cells most compatible with non-small-cell carcinoma. The patient received carbo/etoposide chemotherapy, and his treatment plan included adding atezolizumab and radiation therapy. Despite the excellent efficacy of immunotherapy, immune-related adverse events (IRAEs), including cardiac toxicity, were noted in some patients. PE related to immune checkpoint inhibitor (ICI) use is rare but potentially severe. This case highlights the importance of vigilant monitoring for cardiovascular symptoms during immunotherapy and the significance of pericardial fluid analysis in diagnosing malignant pericardial disease. Prompt diagnosis and appropriate treatment can lead to improved patient outcomes in cases of lung cancer-associated cardiac complications.