摘要目的 研究儿童散发性伯基特淋巴瘤(BL)的分子遗传学特征及其诊断和鉴别诊断.方法 对64例儿童BL和6例儿童弥漫性大B细胞淋巴瘤(DLBCL)进行免疫组织化学染色(SP法)和荧光原位杂交(FISH)技术检测c-myc、bcl-2、bcl-6、IgH、myc/lgH及bcl-2/IgH基因重排的情况.根据细胞起源分类分为生发中心组(GC组)、生发中心晚期组(late-GC组)、生发中心后组(post-GC组).结果 BL表达CD20(64例)、CD10(63例)、bcl-6(62例)、MUM1(15例)、bcl-2(0例).GC组49例(76.6%)、late-GC组14例(21.9%)、post-GC组1例(1.6%).c-myc基因断裂54例(93.1%);IgH基因断裂48例(82.8%);c-myc与IgH基因同时断裂并myc/IgH基因易位46例(85.2%);c-myc基因断裂、IgH和myc/IgH基因正常4例(7.4%);c-myc、IgH和myc/IgH基因均正常4例(7.4%);bcl-2基因正常61例(100%);bcl-6基因正常59例,1例断裂并扩增具有BL的病理形态和免疫表型特征,同时具有c-myc基因断裂,将病理诊断修改为介于DLBCL和BL之间的未分类的B细胞淋巴瘤(DLBCL/BL).6例DLBCL中c-myc基因断裂2例;2例bcl-6基因扩增,其中1例伴c-myc基因断裂;无bcl-2/IgH基因重排.结论 儿童散发性BL大多数来源于生发中心B细胞,c-myc基因的断裂是其主要分子遗传学改变.应用FISH进行多基因的检测,有助于提高儿童BL的诊断和鉴别诊断水平.

abstractsObjective To investigate the molecular genetic features and diagnostic aspects of sporadic Burkitt's lymphoma (BL) in children. Methods Tissue microarray was constructed to include 64 cases of pediatric BL and 6 cases of pediatric diffuse large B-cell lymphoma (DLBCL).Immunohistochemistry and fluorescence in-situ hybridization for c-myc, bcl-2, bcl-6, IgH, myc/IgH and bcl-2/IgH gene were performed. Cases of pediatric Burkitt's lymphomas were subclassified into three groups based on their cellular orgins: the germinal center (GC) group, the late-germinal center (late-GC) group and the post-germinal center (post-GC) group. Results Among 64 Burkitt's lymphomas studied,expression of CD20, CD10, bcl-6, bcl-2 and MUM1 by immunohistochemistry were 100% (64 cases),98.4% (63 cases), 96.9% (62 cases) , 0(0 cases) and 23.4% ( 15 cases), respectively. Various gene rearrangements were found involving the c-myc 93.1% (54/58 cases) and IgH 82.8% (48/58 cases).Detailed rearrangements are as follows: 46 cases (85.2% ) myc/IgH gene translocation along with c-myc and IgH gene rearrangement; 4 cases (7.4%) c-myc gene rearrangement without IgH and myc/IgH abnormality; 4 cases (7.4%) without c-myc, IgH or myc/IgH gene rearrangement. No case showed bcl-2 gene abnormality ( 100% ). Fifty nine cases showed normal bcl-6 gene status. One case had bcl-6 gene rearrangement and amplification with the pathologic and immunophenotypic characteristics of BL, leading to a revised pathological diagnosis of B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt's lymphoma(DLBCL/BL). Two cases showed c-myc gene rearrangement.Two cases showed bcl-6 gene amplification and 6 DLBCL cases had a normal status of bcl-2/IgH.Conclusions A majority of pediatric sporadic BL arise from the germinal center B cells, most of which have c-myc gene rearrangement. It is useful to distinguish BL and DLBCL by multiple genes detection.