胸腔积液临床上分为渗出液和漏出液。渗出液中最常见的两种类型 -结核性和恶性胸腔积液 ,因缺乏特异性的检验指标 ,若无组织学证据 ,诊断上有时非常棘手[1] 。作者发现检测胸腔积液中的心钠素 (ANP)水平 ,可以提高对良性和恶性胸腔积液的鉴别诊断 ,现报道如下。1　资料与方法1 Pleural effusion is clinically divided into exudate and leakage of fluid. Two of the most common types of exudate - tuberculous and malignant pleural effusion, because of the lack of specific test indicators, if no histological evidence, the diagnosis is sometimes very tricky [1]. The authors found that the detection of pleural effusion in the level of atrial natriuretic peptide (ANP), can improve the differential diagnosis of benign and malignant pleural effusion, are reported below. 1 Materials and Methods 1