Evaluation of alpha-fetoprotein assay in ascitic fluid for the diagnosis of hepatocellular carcinoma.

Ascites and hepatocellular carcinoma are frequently associated. We evaluated the usefulness of alpha-fetoprotein assay in ascitic fluid versus the serum assay, for the diagnosis of hepatocellular carcinoma, in 125 patients with peritoneal effusions (31 patients with hepatocellular carcinoma, 14 with extra-hepatic malignancies and 80 with a benign effusion). Albumin and total protein were also assayed and cytological analysis of the ascitic fluid performed. Alpha-fetoprotein appeared to be lower in ascitic fluid than in serum. For a diagnostic specificity of 95%, the thresholds were 18.9 microg/l in serum and 4 microg/l in ascitic fluid and the diagnostic sensitivity of alpha-fetoprotein was identical in serum and ascitic fluid (67.7%). Various ratios between alpha-fetoprotein and albumin or total protein did not enhance the diagnostic performance. Thus alpha-fetoprotein concentration in ascitic fluid reflected the serum concentration and proved to be of similar value for the diagnosis of hepatocellular carcinoma, providing that the appropriate thresholds are considered.