儿童侵袭性成熟B细胞淋巴瘤的临床病理学及分子遗传学特点

 目的　分析总结中国儿童各类型侵袭性成熟B细胞淋巴瘤的临床病理学及分子遗传学特点，为其诊断的标准化提供依据。方法　收集97例儿童侵袭性成熟B细胞淋巴瘤石蜡包埋组织标本，包括伯基特淋巴瘤（BL）81例、弥漫大B 细胞淋巴瘤（DLBCL）8例、介于BL和DLBCL间的不能分类的B细胞淋巴瘤（BL／DLBCL）8例，利用免疫组织化学技术和间期荧光原位杂交（FISH）技术检测其免疫表型和分子遗传学特征。结果　BL的bcl-2和MUM1的阳性率分别为3 %（2／66）和17 %（12／71），DLBCL分别为50 %（4／8）和63 %（5／8），BL／DLBCL分别为 50 %（4／8）和63 %（5／8）。BL、DLBCL 和BL／DLBCL 的Ki-67平均值分别为（93±4.4）%、（83±14.3）%和（80±11.5）%。BL、DLBCL 和BL／DLBCL 的c-myc 基因易位的比例分别为98 %（79／81）、38 %（3／8）和50 %（4／8）。38 %（3／8）的DLBCL和25 %（2／8）的BL／DLBCL 存在bcl-6基因的多拷贝，BL与DLBCL 之间、BL与BL／DLBCL之间bcl-2、MUM1和 Ki-67平均值的差异及c-myc基因易位和bcl-6基因多拷贝的差异均有统计学意义（均P＜0.05）。结论　儿童侵袭性成熟B细胞淋巴瘤的诊断和分型需要综合分析形态学、免疫表型和分子遗传学特征。儿童BL／DLBCL 可能是DLBCL 的一个亚型。CD+10、bcl-6+、bcl-2-、Ki-67＞90 %、伴有IGH／c-myc重排、不伴有bcl-2和bcl-6重排时，支持BL的诊断；bcl-2+、Ki-67 为50 %～90 %，同时伴有bcl-6基因的多拷贝时，支持 DLBCL或BL／DLBCL 的诊断。

Clinicopathologic and molecular genetics features of mature aggressive B-cell lymphomas in pediatrics

Objective To investigate the immunophenotype and molecular genetics of mature aggressive B-cell lymphomas in Chinese pediatric patients and provide the criteris for the diagnosis of them. Methods We collected 97 paraffin-embeded tissue samples of pediatric cases of mature aggressive B-cell lymphomas including 81 Burkitt lymphoma （BL） cases, 8 diffuse large B cell lymphoma （DLBCL） cases and 8 unclassifiable B cell lymphoma with featares intermediate between BL and DLBCL （BL/DLBCL） cases. The immunophenotype and genetic features of them were detected by immunohistochemistry and interphase FISH. Results The expression of bcl-2 3 %（2/66） in BL, 50 % （4/8） in DLBCL, 50 % （4/8） in BIJDLBCL], MUM1 17 % （12/71） in BL, 63 % （5/8） in DLBCL, 63 % （5/8） in BL/DLBCL] and mean Ki-67 proliferation index （93±4.4）% in BL, （83±14.3）% in DLBCL, （80±11.5）% in BL/DLBCL] were significantly different between BL and DLBCL and between BL and BL/DLBCL. The frequency of c-myc rearrangement 98 % （79/81） in BL, 38 % （3/8） in DLBCL, 50 % （4/8） in BIJDLBCL] and an extra copy of bcl-6 0 % in BL, 38 % （3/8） in DLBCL, 25 % （2/8） in BIJDLBCL] were also significantly different between BL and DLBCL and between BL and BL/DLBCL. Conclusion Diagnosis of the mature aggressive B cell lymphomas in pediatrics should be based on the comprehensive review and integration of morphologic, immunohistochemical and molecular genetic features. BL/DLBCL is more likely a subgroup of the DLBCL in pediatric population. The expression of CDI0 and bcl-6 but not bcl-2, a high Ki-67 PI （〉90 %） and a c-myc rearrangement but not bcl-2 or bcl-6 rearrangement are the features of BL. Regardless of the expression of CD10 and bcl-6, positive staining for bcl- 2, Ki-67 PI below 90 % and an extra copy of the bcl-6 favor a diagnosis of DLBCL or BL/DLBCL.