Runyon B A
J Clin Gastroenterol. 1994 Mar;18(2):94-8. doi: 10.1097/00004836-199403000-00002.
A large number of ascitic fluid tests, e.g., fibronectin and cholesterol, 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 proteins 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 ascites, pancreatitis ascites, etc. usually have values in the malignancy range, i.e., false-positive results. This can lead to an extensive search for a nonexistent tumor, with confusion and anxiety for patient and physician. The cytology is the single best test to order when peritoneal carcinomatosis is suspected; its sensitivity approaches 100%. However, 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 ascitic fluid specimens into portal-hypertension-related and non-portal-hypertension-related categories. An elevated serum alpha-fetoprotein test can be useful in raising suspicion of hepatocellular carcinoma. Careful analysis of ascitic fluid, without measurement of "humoral tests of malignancy," combined with information obtained from the history and physical examination, usually lead to an accurate diagnosis of the cause of ascites.
大量腹水检查，如纤维连接蛋白和胆固醇，已被提出有助于检测作为腹水病因的恶性肿瘤。不幸的是，这些“恶性肿瘤体液检查”并不具有特异性。尽管在腹膜癌患者中这些蛋白质或蛋白结合物质的腹水浓度往往相当高，而在肝硬化腹水患者中则较低，但问题在于结核性腹膜炎、心源性腹水、胰腺炎腹水等患者的检查结果通常处于恶性肿瘤范围内，即出现假阳性结果。这可能导致对不存在的肿瘤进行广泛检查，给患者和医生带来困惑与焦虑。当怀疑有腹膜癌时，细胞学检查是唯一最好的检查项目；其敏感性接近100%。然而，腹膜癌只是肿瘤导致腹水的几种机制之一。不能期望单一检查就能检测出作为这些不同腹水形成机制病因的肿瘤。血清 - 腹水白蛋白梯度有助于将腹水标本分为与门静脉高压相关和与非门静脉高压相关的类别。血清甲胎蛋白检测升高有助于提高对肝细胞癌的怀疑。在不进行“恶性肿瘤体液检查”测量的情况下，仔细分析腹水，并结合病史和体格检查所获得的信息，通常能准确诊断腹水的病因。
