Cytopathologic analysis of pericardial effusions in 116 cases: Implications for poor prognosis in lung cancer patients with positive interpretations

BACKGROUND: Few studies have evaluated the cytology of pericardial effusions. The aim of this study is to investigate the etiologies of pericardial effusions and to establish the relationship between cytopathologic interpretations and outcome patterns among patients with pericardial effusions. METHODS: We identified 116 patients with pericardial effusions at a single institution over a 4-year period and carefully analyzed all available clinical documents, including clinical diagnoses, cytopathologic findings, and outcome patterns. RESULTS: The cohort was made up of 74 patients with malignancies, 39 with non-malignancy diseases, and 3 without available clinical diagnosis. Lung cancer was the most common malignancy (58 cases), followed by breast cancer (4 cases) and lymphoma/leukemia (4 cases). Among the 116 fluid samples, 43 cases were diagnosed as malignant, 66 were diagnosed as benign, and seven were diagnosed as ambiguous. The nature of the hemorrhage was an important feature of cytopathology-positive effusions. Patients with detectable malignant cells in pericardial effusions have a significantly poorer prognosis than those without malignant cells. CONCLUSIONS: Lung cancer is the most common cause of large quantities of pericardial effusions. The present findings suggest that cytopathologic evaluation is valuable to predict the prognosis of cancer patients with pericardial effusions. Diagn. Cytopathol. 2017;45:287-293.