EDITORIAL - MALIGNANCY-RELATED ASCITES AND ASCITIC FLUID HUMORAL TESTS OF MALIGNANCY

A large number of ascitic fluid tests, e.g., fibronectin and cholester ol, have been proposed as helpful in detecting malignancy as the cause of ascites. Unfortunately, these ''humoral tests of malignancy'' are nonspecific. Although the ascitic fluid concentrations of these protei ns or protein-bound substances tend to be quite high in patients with peritoneal carcinomatosis and low in the setting of cirrhotic ascites, the problem is that patients with tuberculous peritonitis, cardiac as cites, pancreatitis ascites, etc. usually have values in the malignanc y range, ie., false-positive results. This can lead to an extensive se arch for a nonexistent tumor, with confusion and anxiety for patient a nd physician. The cytology is the single best test to order when perit oneal carcinomatosis is suspected; its sensitivity approaches 100%. Ho wever, peritoneal carcinomatosis is only one of several mechanisms by which tumors can cause ascites. No one test can be expected to detect tumors as the cause of these diverse mechanisms of ascites formation. The serum-ascites albumin gradient is a helpful test in classifying as citic fluid specimens into portal-hypertension-related and non-portal- hypertension-related categories. An elevated serum cr-fetoprotein test can be useful in raising suspicion of hepatocellular carcinoma. Caref ul analysis of ascitic fluid, without measurement of ''humoral tests o f malignancy,'' combined with information obtained from the history an d physical examination, usually lead to an accurate diagnosis of the c ause of ascites.