Differential Diagnosis of Malignant and Cirrhotic Ascites-With Special Emphasis on the Value of Ascitic Cholesterol Determination

Abstract

To determine the value of ascitic cholesterol and other parameters in differentiating malignant ascites from cirrhotic ascites, we measured ascitic cholesterol, triglyceride, total protein, albumin, lactate dehydrogenase (LDH), gammaglutamyl-transferase (GGT), uric acid, carcinoembryonic antigen (CEA) titer, blood cell counts, serous cholesterol, triglyceride, protein, albumin, LDH, serum-ascites albumin gradient, ascites/serum protein ratio and ascites/serum LDH ratio in 38 patients with malignant ascites, in 50 patients with cirrhotic ascites and in 25 ascitic patients with hepatocellular carcinoma (HCC). We found that there were no differences in the ascitic fluid analysis between cirrhotic ascites and HCC groups. The following parameters had significantly higher values in the malignant ascites group than in the cirrhotic ascites group (mean±S. D., p＜0.05): ascitic cholesterol (68.9±48.7 vs. 8.9±8.6mg/dl), ascitic triglyceride (39.3±42.3 vs. 18.2±18.1mg/dl), ascitic albumin (1.6±0.7 vs. 0.4±0.3g/dl), ascitic protein (2.8±1.3 vs. 1.1±0.8g/dl), ascitic LDH (647±1051 vs. 81±128IU/l), ascitic GGT (49±48 vs. 12±15IU/l), ascites/serum protein ratio (0.4±0.2 vs. 0.1 ±0.2), ascites/serum LDH ratio (1.6±2.1 vs. 0.2±0.4), ascitic CEA (53±45 vs. 3±2 ng/ml). The serum-ascites albumin gradient was lower in the malignant ascites group than in the cirrhotic ascites group (1.2±05 vs. 1.9±0.4g/dl). With regard to the best cutoff value for diagnostic accuracy, only ascitic cholesterol ＞28mg/dl, ascitic albumin ＞1.0g/dl, ascitic LDH＞100IU/l, serum-ascites albumin gradient ＜1.4g/dl and asciric CEA ＞5ng/ml achieved a diagnostic accuracy ＞80%. Among these 5 parameters, ascitic fluid cholesterol level was most reliable (sensitivity 82%, specificity 94%, diagnostic accuracy 89%) in discriminating malignant from cirrhotic ascites, and should be considered as a supplemental test of ascitic fluid.