中枢神经系统 ( CNS)是髓外白血病最多发生部位 ,我院自 1991年以来共收治 110例 ,有 CNS浸润的 34例 ,现分析如下。1　临床资料1.1　诊断标准 :参照血液病诊断及疗效标准 [1]。 1有中枢神经系统症状和体征 ;2脑脊液的改变 :压力增高 0 .0 2 k Pa( 2 0 0 mm H2 O)。白细胞计数 Central nervous system (CNS) is the site of extramedullary leukemia most occurred in our hospital since 1991 were treated 110 cases, 34 cases of CNS infiltration, are analyzed as follows. 1 clinical data 1.1 diagnostic criteria: reference blood disease diagnosis and efficacy standards [1]. 1 has central nervous system symptoms and signs; 2 cerebrospinal fluid changes: pressure increased 0. 0 2 k Pa (200 mm H2 O). White blood cell count