Characteristics of cellular composition in malignant pericardial effusion and its association with the clinical course of carcinomatous pericarditis.

To date, the cellular composition of malignant pericardial effusion (MPE) and its association with the clinical course of carcinomatous pericarditis remain unclear. We aimed to determine the MPE cellular composition and its association with carcinomatous pericarditis. Forty-four cases indicated for pericardial drainage due to symptomatic carcinomatous pericarditis were retrospectively reviewed; the blood cell count and composition of MPE were examined. The most dominant cells in MPE were neutrophils. The appearance ratio of an atypical cell in cytologically positive MPE was 95.5%. Low neutrophil and high lymphocyte counts were significantly associated with good effusion failure-free survival at 1 month. The survival after pericardial drainage was significantly shorter when the neutrophil/lymphocyte ratio was 3.5 or more (P = 0.041). Patients whose performance status improved due to drainage had significantly high leukocyte counts in MPE (P = 0.02). Prediction of the course of drainage through basic examination of MPE cellular composition might be beneficial in clinical practice.