Serum—ascites albumin concentration gradient and ascites fibronectin in the diagnosis of malignant ascites

Background. The differential diagnosis between malignant and nonmalignant ascites by using laboratory parameters has not been completely achieved so far. Methods. The authors studied serum‐ascites albumin concentration gradients ([albumin]_a — [albumin]_a), ascites fibronectin and various parameters in 149 consecutive patients with ascites (including Group 1: 22 patients with intraabdominal malignant lesions; Group 2: 81 patients with chronic liver disease; and Group 3: 46 patients with hepatocellular carcinoma [HCC]). Results. The concentrations of fibronectin, albumin, protein, lactate dehydrogenase, and carcinoembryonic antigen in ascites were significantly higher in Group 1 than in Group 2 (P < 0.001). By contrast, the [albumin]_a— [albumin]_a was significantly lower in Group 1 than in Group 2 (P < 0.001). None of these parameters was useful in differentiating the ascites of chronic liver disease from that of HCC. In this study, to differentiate malignant ascites from the ascites caused by liver diseases, [albumin]_a — [albumin]_a (< 1.5 g/dl) and the fibronectin level in the ascites (> 100 μ/ml) provided diagnostic accuracy (96.8% and 95.9%, respectively) as precise as those of the levels of albumin (> 1.6 g/dl), protein (> 2.5 g/dl), and lactate dehydrogenase (> 60 U/1; 97.9%, 96.7%, and 94.8%, respectively) in ascites. These results were better than that of carcinoembryonic antigen level (> 1.5 ng/ml, 80.9%). Conclusions. The authors concluded that [albumin]_a — [albumin]_a offered the best method to survey malignant ascites because of its sensitivity (100%).