凋亡抑制基因bcl-2在弥漫性大B细胞淋巴瘤中的表达及其临床意义

目的 探讨凋亡抑制基因bcl-2在弥漫性大B细胞淋巴瘤(DLBCL)不同免疫亚型中的表达,以及bcl-2蛋白表达对患者生存期的影响.方法 应用免疫组织化学(EliVision plus和PV-9002法)对214例DLBCL进行CD10、bcl-6、MUM-1、bcl-2及NF-κB检测,采用Hans免疫分型方法将DL...     

MUM1蛋白在弥漫性大B细胞淋巴瘤中的表达及意义

目的 探讨弥漫大B细胞淋巴瘤(diffuse large B-cell lymphoma,DLBCL)中活化的B细胞相关蛋白MUM1的表达与临床病理特征之间的关系.方法 利用组织微阵列免疫组化检测60例DLBCL石蜡包埋组织中MUM1、bcl-6和CD10的表达.结果 60例DLBCL被分为两种抗原表达表型:一种为活化的B细胞表型(A型)表达MUM1;另一种为生发中心B细胞表型(B型),表达CD10和(或)bcl-6但不表达MUM1.60例DLBCL中61.67%为A型,31.67%为B型,其中59.25%中心母细胞型,3/4免疫母细胞型,2/2间变性大B细胞型均为A型.A型在结外和结内DLBCL中分别占61.76%和61.54%,而在胃肠道DLBCL中的比例(47%)显著低于在其他结外DLBCL中的比例(80%,P=0.079).在MUM-1( )/bcl-6( )/CD10( /-)的病例中,75.00%(12/16)为结外DLBCL,高于在MUM-1( )/bcl-6(-)/CD10(-)病例中的比例43.75%(7/16),但差异没有显著性(P=0.149).结论 A型(表达MUM1)在DLBCL中的比例较高,提示MUM1表达很可能与DLBCL组织学变异有关,联合检测CD10和bcl-6,可协助DLBCL分型诊断.     

弥漫大B细胞淋巴瘤免疫表型分型与预后的关系

目的 探讨弥漫大B细胞淋巴瘤（DLBCL）的免疫表型之生发中心B细胞样（GCB）和非GCB两个亚型的特征及其与DLBCL预后的关系。方法 根据肿瘤细胞免疫组织化学EnVision法标记CD10、bc1-6、MUM-1的表达情况,将133例DLBCL分为GCB和非GCB两个亚型。对以下指标的5年总生存率（OS）及5年无进展生存率（PFS）进行了比较：（1）CD10、bc1-6和MUM-1的阳性和阴性病例;（2）GCB亚型与非GCB亚型;（3）不同国际预后指数（IPI）分组中GCB亚型与非GCB亚型的关系。结果 133例DLBCL中,44例（33．1％）CD10阳性,48例（34．6％）bc1-6阳性,60例（45．1％）MUM-1阳性。CD10阳性DLBCL患者的5年OS及PFS均明显高于CD10阴性患者（P=0．041和0．031）;bc1-6阳性DLBCL患者的PFS明显高于bc1-6阴性患者（P=0．044）,MUM．1阳性DLBCL患者的5年0s及PFS均明显低于MUM-1阴性患者（P=0．031和0．028）。GCB型54例（40．6％）,非GCB型79例（59．4％）。GCB型5年OS及PFS均明显高于非GCB型（P=0．004和0．003）。国际预后指数（IPI）0-1分组及2-5分组中,GCB型5年OS及PFS均明显高于非GCB型（IP10-1分组P=0．019和0．014,2-5分组P=0．006和0．009）,其中IPI2-5分组中的非GCB预后最差。结论 DLBCL亚型及其与IPI联合分析可以作为预测患者预后的有效指标。     

弥漫性大B细胞淋巴瘤3q27染色体状态和不同亚型与预后的关系

目的 从蛋白和基因水平研究弥漫性大B细胞淋巴瘤(DLBCL)的3q27染色体状态和不同亚型与预后的关系.方法 应用免疫组织化学EnVision法对有随访资料的73例DLBCL进行CD3、CD10、CD20、bcl-6、MUM-1标记,根据Hans的分类方法分为生发中心B细胞型(GCB型)和非生发中心B细胞型(non-GCB型),其中54例应用荧光原位杂交(FISH)技术检测bcl-6基因所在的3q27染色体的断裂和扩增情况.结果 73例DLBCL患者GCB型16例(21.9%),non-GCB型57例(78.1%).54例DLBCL患者中3q27染色体断裂11例(20.4%),扩增14例(25.9%).5年总体生存率GCB型(78%)高于non-GCB型(40%),差异有统计学意义(P=0.011).bcl-6阳性表达较阴性者预后好(P=0.041);3q27断裂阳性组病例总体生存率低于3q27断裂阴性组.结论 DLBCL的GCB型比non-GCB型预后好.bcl-6蛋白表达有助于DLBCL的预后判断,3q27染色体断裂阳性病例总体生存率低于3q27断裂阴性组.目前仍有必要区分DLBCL的B细胞的起源.     

儿童腹腔非霍奇金B细胞淋巴瘤的临床病理及免疫表型分析

目的 探讨儿童腹腔原发性非霍奇金B细胞淋巴瘤的临床病理、免疫表型与EBER特征及其病理诊断和鉴别诊断.方法 按WHO(2008年)淋巴瘤分类标准分析74例儿童腹腔原发性非霍奇金B细胞淋巴瘤的临床病理资料,制备组织芯片,进行免疫组织化学SP法染色,EBER原位杂交和c-myc基因荧光原位杂交,观察CD20、CD79a、CD3、CD10、bcl-6、MUM1、bcl-2、CD43、CD38和Ki-67蛋白的表达和EBER表达特征,并区分伯基特淋巴瘤(BL)、弥漫性大B细胞淋巴瘤(DLBCL)和介于BL和DLBCL之间的不能分类的B细胞淋巴瘤(DLBCL/BL)病理类型,在DLBCL中再区分其生发中心B细胞型(GCB)和非生发中心B细胞型(non-GCB)的分化特征.结果 儿童腹腔非霍奇金B细胞淋巴瘤中BL为65例(87.8%),DLBCL为4例(5.4%),DLBCL/BL为5例(6.8%).临床以腹痛、腹部包块、肠梗阻及肠套叠为主要发病症状.BL免疫组织化学表达CD20(65例)、CD79a(65例)、CD10(63例)、bcl-6(62例)、MUM1(15例)、CD43(46例)和CD38(63例);不表达CD3、bcl-2;27例(41.6%)EBER阳性;54例(93.0%)c-myc基因位点断裂.DLBCL免疫组织化学表达CD20(4例)、CD79a(4例)、CD10(3例)、bcl-6(2例)、MUM1(2例)、bcl-2(3例)、CD43(2例)、CD38(2例);不表达CD3;其中2例GCB,2例non-GCB;EBER阴性;1例c-myc基因位点断裂.DLBCL/BL免疫组织化学表达CD20(5例)、CD79a(5例)、CD10(5例)、bcl-6(4例)、MUM1(3例)、CD43(5例)、CD38(3例),不表达CD3和bcl-2;4例EBER阴性;3例c-myc基因位点断裂.结论 儿童腹腔非霍奇金B细胞淋巴瘤具有侵袭性生长的特点,以BL为主要病理类型.临床以腹痛、腹部包块、肠梗阻及肠套叠为主要发病症状,主要累及回盲部肠组织及周围系膜淋巴结,病理形态、免疫表型、EBER、c-myc基因的检测对BL、DLBC及DLBCL/BL淋巴瘤的诊断和鉴别诊断有重要作用.     

EBV阳性弥漫大B细胞淋巴瘤18例临床病理分析

目的观察EBV阳性弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)的临床病理特点并探索可能的预后相关因素。方法回顾性分析2012年～2017年间福建医科大学附属协和医院诊断的18例EBV阳性DLBCL病例临床特点、病理形态、免疫表型及EBER原位杂交等相关资料,并随访患者,采用Kaplan-Meier法进行生存分析。结果EBV阳性DLBCL仅占EBV感染状态明确DLBCL病例的3. 7%(18/483);发病年龄33～79岁,中位发病年龄69岁;男女比为2. 6∶1; 50岁以下的患者仅4例(22%,4/18);发病部位以淋巴结病变为主;临床上多数患者血常规表现为贫血、白细胞减少或血小板减低,血乳酸脱氢酶水平明显增加; 9例血清EBV DNA载量明显升高(64. 3%,9/14);肿瘤细胞形态以多形性为主(88. 9%,16/18)。免疫表型非生发中心起源型(non-germinal center origin subtype,non-GCB型)稍多(55. 5%,10/18),多数病例表达CD30(62. 5%,10/16);患者随访2～47个月,8例死亡,7例存活,3例失访,中位生存时间为16个月;发病部位的不同与患者生存时间的长短有一定的关系(P=0. 022)。结论 EBV阳性DLBCL是一类以老年男性为主、淋巴结病变多见的高侵袭性淋巴瘤,病理以多形性型及non-GCB免疫表型为主,总体病死率高,仅发生淋巴结病变的患者预后相对更差。     

T细胞淋巴瘤1和CD44蛋白在Burkitt淋巴瘤中的表达及其诊断价值

目的 探讨T细胞淋巴瘤1(TCL1)和CD44蛋白在Burkitt淋巴瘤中的表达及其诊断价值.方法 在石蜡包埋的实验组25例Burkitt淋巴瘤和对照组25例非特指弥漫性大B细胞淋巴瘤(DLBCL)中采用免疫组织化学EnVision法检测CD44、TCLl以及CD10、bel-2、bcl-6、c-myc、Ki-67等常用抗体表达情况.结果 Burkitt淋巴瘤中瘤细胞96%(24例)呈TCL1阳性,仅4%(1例)CD44阳性;88%(22例)CD10阳性、92%(23例)bcl-6和c-myc阳性,仅4%(1例)bcl-2阳性;Ki-67增殖指数为95%～100%.非特指DLBCL中仅16%(4例)TCL1弱阳性,84%(21例)CD44阳性、32%(8例)CD10阳性、72%(18例)bcl-6和bcl-2阳性、c-myc均阴性,Ki-67增殖指数40%～90%.结论 当形态和免疫表型不典型时,TCL1和CD44两种蛋白的检测有助于提高Burkitt淋巴瘤的确诊率及其与DLBCL的鉴别诊断.     

原发性骨非霍奇金淋巴瘤临床病理预后和病因学分析

目的探讨原发性骨非霍奇金淋巴瘤（PNHLB）的临床病理特征、预后指标及病因学。方法复习17例PNHLB患者的临床资料,同时进行免疫组织化学EnVision法检测免疫标志物、原位杂交检测EBER及PCR检测bcl-2／JH基因重排,并对血清LDH、治疗、国际预后指数（IPI）、免疫标志物与预后的关系进行分析。结果17例PNHLB以弥漫性大B细胞淋巴瘤为主（94．1％）,患者的5年生存率为68．8％,IPI高危类、bcl-2过表达对预后不利（2者的P值分别为0．031和0．028）,治疗方式和CD10、MUM-1、bcl-6的表达对预后的判断差异无统计学意义（P〉0．05）。8例人类B-珠蛋白基因扩增阳性的骨DLBCL患者中1例Bcl-2／JH基因重排扩增阳性。EBER原位杂交仅1例阳性。结论PNHLB预后较好,IPI及免疫组织化学检测bcl-2过表达是判断预后的指标。EB病毒与病因无相关性。     

原发性中枢神经系统弥漫性大B细胞淋巴瘤主要为活化B细胞亚型

目的 对原发性中枢神经系统弥漫性大B细胞淋巴瘤分型,并探讨其组织起源和预后相关意义.方法 应用免疫组织化学EnVision二步法,检测CD10、bcl-6、MUM-1、CD138和FOXP1在47例原发性中枢神经系统弥漫性大B细胞淋巴瘤中的表达情况.结果 CD10、bcl-6、MUM-1、CD138和FOXPI表达率分别为6.4%、53.2%、91.5%、0和93.6%.47例中有43例(91.5%)为活化B细胞表型:21例(44.7%)为活化的生发中心亚型,22例(46.8%)为活化的非生发中心亚型.该分型及FOXP1的表达与预后无明显相关性(P=0.279和P=0.154).结论 原发性中枢神经系统弥漫性大B细胞淋巴瘤绝大多数为活化B细胞亚型,是系统性弥漫性大B细胞淋巴瘤中一种相对同质性的亚型,推测其组织起源是生发中心末期至后生发中心早期的B细胞.     

弥漫性大B细胞淋巴瘤各分子亚型中的bcl-6基因重排与蛋白表达的临床意义

目的 探讨弥漫性大B细胞淋巴瘤(DLBCL)各分子亚型中的bel-6基因重排、蛋白表达情况及其临床病理意义.方法 运用组织芯片技术,通过荧光原位杂交(FISH)技术对149例DLBCL组织中bcl-6基因重排进行检测,应用免疫组织化学技术(EnVision法)检测bcl-6以及细胞增殖指标Ki-67、细胞周期蛋白(cyclin)D3、p27Kill及Geminin等蛋白表达水平;结合临床病理资料,分析它们之间的相关性.结果 149例DLBCL可被分成3个分子亚型,其中4J0例为生发中心B细胞样(GCB样)亚型,75例为活化的非生发中心B细胞样(ABC样)亚型,34例为Type 3亚型.有118例成功进行了FISH检测,33例可检测到bcl-6基因重排,阳性率为28.0%.其中35.5%(22/62)的ABC样亚型DLBCL呈现bcl-6基因重排;较GCB样亚型(6/31,19.4%)和Type 3亚型(5/25,20.0%)的bcl-6基因重排高(P=0.160).在绝大部分(26/33,78.8%)有bcl-6基因重排的DLBCL中,伴随有bcl-6蛋白的过度表达,明显高于无bcl-6基因重排的病例(53/84,62.4%,P=0.088).有bcl-6基因重排的DLBCL中,24例(24/33,72.7%)cyclin D3呈现高水平表达,明显高于bcl-6基因无易位DLBCL组中的cyclin D3表达(37/81,45.7%,P=0.009).在33例bcl-6基因易位的DLBCL中,29例(87.9%)为Ann Arbor Ⅲ-Ⅳ期,较bcl-6基因无易位高者(65/85,76.5%,P=0.167).单变量Cox风险比模型分析发现,bcl-6基因重排与患者的生存率呈负相关,是一个危险因子,相对危险度(RR)为1.842.结论 bcl-6基因重排导致的bcl-6蛋白表达上调参与了部分DLBCL的发病过程,并可能成为DLBCL的ABC样亚型的一个分子标志.     

Follicular origin of a subset of CD5+ diffuse large B-cell lymphomas

Most follicular lymphomas (FLs) have a phenotype consistent with the origin from CD5-, CD10+, bcl-6+ follicular center cells and can progress to diffuse large B-cell lymphoma (DLBCL). CD5 is expressed in about 10% of DLBCLs, showing prognostic value, whereas expression is rare in FL. We present 6 cases with coexisting features of CD5+ FL and CD5+ DLBCL, supporting a follicular origin for some CD5+ DLBCLs. The follicular areas showed a meshwork of CD21+ follicular dendritic cells that were lacking in the DLBCL areas. All cases showed a clonal CD19+, CD20+, CD5+, and CD10+ population in both follicular and diffuse areas. Molecularly, 4 of 6 cases demonstrated immunoglobulin heavy chain rearrangements and 1 case, a bcl-2/immunoglobulin heavy chain gene rearrangement. Somatic hypermutations were high in all 4 cases, in keeping with their germinal center origin. Four of five patients died of disease within 42 months, consistent with the proposed prognostic value of CD5 expression in DLBCL. Our data describe an aggressive variant of CD5+ FL suggesting the follicular origin of some CD5+ DLBCLs.     

Expression of transmembrane adaptor protein PAG/Cbp in diffuse large B-cell lymphoma: immunohistochemical study of 73 cases

PAG/Cbp is a transmembrane adaptor protein involved in proximal immune signaling. It is expressed in reactive germinal centers (GC) of secondary lymphatic follicles and related malignant lymphomas. We studied PAG/Cbp expression in GC-like and non-GC-like diffuse large B-cell lymphoma (DLBCL) subtypes. Seventy-three cases of DLBCL identified among 155 malignant lymphomas were classified as GC-like DLBCL (CD10+ or CD10-, bcl-6+, and MUM1-) and non-GC-like DLBCL (CD10-, MUM1+ or CD10-, bcl-6+, MUM1+). PAG/Cbp was detected by monoclonal antibody MEM-255 following routine immunohistochemical procedures. Thirty-five of 40 GC-like DLBCLs (88%) and 20 of 33 non-GC-like DLBCL cases (61%) expressed PAG/Cbp. Four of 12 bcl-6-negative non-GC-like DLBCL cases (33%) were PAG/Cbp positive, and only 4 of 20 bcl-6-positive non-GC-like DLBCL cases (25%) were PAG/CBP negative. All 37 FL and all 5 Burkitt's lymphomas (BL) expressed PAG/Cbp, whereas all 6 mantle cell lymphomas (MCL) and 4 of 5 chronic lymphocytic leukemias (CLL/SLL) were PAG/Cbp negative. PAG/Cbp is a reliable GC marker. Its expression correlates with GC-like DLBC phenotype in a significant majority of cases. It is typically absent in MCL and SLL/CLL.     

弥漫性大B细胞淋巴瘤基因表达谱的初步研究

目的探讨弥漫性大B细胞淋巴瘤（DLBCL）不同免疫表型组的基因表达谱状况。方法根据CD10、bcl-6和MUM1的表达状况对156例DLBCL进行分组：CD10^＋和（或）bcl-6^＋、MUM1-（第1组）;CD10^＋和（或）bcl-6^＋、MUM1^＋（第2组）;CD10^-和bcl-6^-、MUM1^＋（第3组）。从各组中各选择3例共（9例）临床分期为Ⅳ期的病例标本,另取3例正常扁桃体组织作为对照,采用Affymetrix U133 plus2．0寡核苷酸芯片研究12例样本的基因表达谱。结果通过unsupervised等级聚类分析,12例样本被分成了4组,分别命名为A、B、C、D组。经与免疫表型分组结果对照显示两种分组结果完全一致：A、B、C组分别对应第1、2、3组,D组对应正常对照组。在DLBCL病例组中（A、B、C组）有81个基因显著表达下调,有86个基因显著表达上调。而其中的一个组（B组）虽然具有混合性生发中心B细胞样（GCB,A组）和活化的外周血B细胞样（ABC,C组）DLBCL的免疫表型,但在聚类分析中发现其基因表达谱与A组和C组均不同,有45个基因表达上调,并且有27个特异性表达基因。结论初步结果显示,DLBCL全基因组表达谱在分子水平上有不同的亚群,且可能通过免疫表型来区分。还提示基因表达谱B组DLBCL可能存在除细胞起源以外的不同异质性因素,而这种因素可能与DLBCL的发病机制相关。     

CD10 antigen expression correlates with the t(14;18)(q32;q21) major breakpoint region in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a common morphologic term for a biologically diverse group of lymphomas. The chromosome translocation, t(14;18)(q32;q21), and its associated bcl-2 gene rearrangement are generally associated with follicular lymphomas. Some investigators, however, proposed that the presence of the t(14;18) in DLBCL suggests a possible follicle center cell origin and might correlate with a higher relapse rate after therapy. The CD10 antigen is expressed in a majority of follicular lymphomas but is also seen occasionally in DLBCLs. In this study, we examined 26 DLBCLs for CD10 expression by flow cytometric analysis and tested them for the t(14;18)(q32;q21) major breakpoint region by a polymerase chain reaction-based method. bcl-2 protein expression was analyzed by an immunoperoxidase method. Of the 26 DLBCLs, 9 (35%) were CD10 positive. bcl-2 protein was expressed in 7 (78%) of 9 CD10-positive cases and in 9 (53%) of 17 CD10-negative cases (P = .4). The t(14; 18) translocation was present in 6 (67%) of 9 CD10-positive cases but in only 2 (17%) of 12 CD10-negative cases (P = .03). Five cases did not yield amplifiable DNA for analysis. In summary, no difference in bcl-2 protein expression was seen in CD10-positive versus CD10-negative DLBCLs, but CD10-positive DLBCLs were significantly more likely than CD10-negative DLBCLs to harbor the t(14;18) translocation. This suggests that CD10 might be a marker of follicle center cell origin in DLBCL.     

De novo CD5 positive diffuse large B-cell lymphomas with bone marrow involvement in Korean

In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lymphoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immunoglobulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.     

MUM-1/IRF4在滤泡性淋巴瘤中的表达及意义

目的 检测MUM-1/IRF4在滤泡性淋巴瘤中的表达,并探讨其在滤泡性淋巴瘤中表达的生物学意义.方法 应用组织芯片和免疫组织化学SP法检测98例滤泡性淋巴瘤中MUM-1/IRF4及CD10、bcl-6、bcl-2、Ki-67的表达,对MUM-1/IRF4在不同级别滤泡性淋巴瘤中的表达及与其他几个相关蛋白标志物表达的关系进行统计学分析.结果 (1)MUM-1/IRF4在滤泡性淋巴瘤中的表达率为39.8%(39/98),CD10为62.2%(61/98),bcl-6为80.6%(79/98),bcl-2为87.8%(86/98),Ki-67高表达(≥25%)的阳性率为50.0%(49/98);(2)MUM-1/IRF4主要在高级别滤泡性淋巴瘤中表达,与分级(r=0.628,P=0.000)和Ki-67(r=0.473,P=0.000)的表达呈正相关;(3)MUM-1/IRF4与CD10的表达呈负相关(r=-0.597,P=0.000),与bcl-6和bcl-2的表达无相关性.结论 MUM-1/IRF4在高级别滤泡性淋巴瘤中显著性高表达,MUM-1/IRF4阳性病例肿瘤细胞增殖活性高,提示其进展快,预后差,MUM-1/IRF4强阳性有助于高级别滤泡性淋巴瘤的诊断.

Abstract：

Objective To study the expression of MUM-1/IRF4 and its significance in follicular lymphoma. Methods Ninety-eight cases of follicular lymphoma were enrolled into the study. They were graded according to the 2008 WHO criteria. The expression of MUM-1/IRF4 protein and other markers (CD10, bcl-6, bcl-2 and Ki-67) was studied using tissue microarray and immunohistochemistry. Results Amongst the 98 cases studied, there were 24 grade 1 cases, 30 grade 2 cases, 26 grade 3A cases and 18 were grade 3B cases. The rates of expression of MUM-1/IRF4, CD10, bcl-6, bcl-2 and Ki-67 ( ≥25% )were 39. 8% ( 39/98 ), 62.2% ( 61/98 ), 80. 6% ( 79/98 ), 87. 8% ( 86/98 ) and 50. 0% ( 49/98 ),respectively. MUM-1/IRF4 predominantly expressed in high-grade follicular lymphoma and showed a significantly positive correlation with lymphoma grade ( r = 0. 628, P = 0. 000 ) and Ki-67 index ( r = 0. 473,P = 0.000). MUM-1/IRF4 expression had a significantly negative correlation with CD10 expression (r = -0. 597, P = 0. 000), but no correlation with bcl-6 and bcl-2 expression. Conclusions MUM-1/IRF4 expression is significantly higher in high-grade follicular lymphoma, indicating that these cases have a high proliferative activity, more aggressive behavior and poorer prognosis. MUM-1/IRF4, when strongly expressed, is another helpful marker for the diagnosis of high-grade follicular lymphoma.     

Homogeneous immunophenotype and paucity of secondary genomic aberrations are distinctive features of endemic but not of sporadic Burkitt's lymphoma and diffuse large B-cell lymphoma with MYC rearrangement

The present study has compared immunohistological marker expression profiles and genomic imbalances in seven African endemic Burkitt's lymphomas (eBLs) with those in ten European B-cell lymphomas with MYC rearrangement as shown by fluorescence in situ hybridization (FISH) analysis. eBLs showed a typical histomorphology and a homogeneous immuno-profile: CD10+, CD38+, CD77+, bcl-2-, and IgM+. Epstein-Barr virus (EBV) DNA was present in all cases. On comparative genomic hybridization (CGH), only three out of six eBLs showed imbalances (median number of imbalances = 2), with gains on chromosome 17 in two eBLs. The European lymphomas were all highly proliferating, with a Ki-67 index of at least 90%, and included seven with morphology typical of sporadic Burkitt's lymphoma (sBL) and three immunoblastic diffuse large B-cell lymphomas with MYC rearrangement (MYCre+DLBCL). In contrast to eBL, the immuno-profiles of the European lymphomas were less homogeneous and inconsistent for CD10, CD38, CD77, IgM and bcl-2 expression. EBV DNA was not detected. In five of seven sBLs, CGH showed a higher number of imbalances (median = 6), with recurrent gains on chromosome 1q (3/7) and losses on 12q and 17p (2/7), whereas all three MYCre+DLBCLs had fewer imbalances (median = 4), with gains on 17q in two of three lymphomas. It is concluded that eBL has a homogeneous immunohistology and few secondary genomic aberrations, whereas MYC-rearranged and highly proliferating European B-cell lymphomas are a heterogeneous group that includes sBL and a subgroup of diffuse large B-cell lymphomas.     

Coexpression of Bcl-6 and CD10 in diffuse large B-cell lymphomas: significance of Bcl-6 expression patterns in identifying germinal center B-cell lymphoma

Most follicular lymphomas (FLs) transform to diffuse lymphoma eventually, comprising a significant proportion of diffuse large B-cell lymphoma (DLBCL). Judging by bcl-2 rearrangement (bcl-2R), one third of DLBCLs are believed to be of FL derivation in the Western population. However, bcl-2R is not specific and is not detectable in every case of FL. In East Asia, FL is uncommon but DLBCL is not. The proportion of tumors of FL origin in DLBCL is not known in this region. The coexpression of Bcl-6 and CD10 proteins, a reliable marker to identify germinal center (GC) B-cell lymphoma including FL, was analyzed in primary nodal DLBCLs (n = 104) diagnosed at major hospitals in Seoul during a recent 2-year period, along with well-defined cases (n = 17) of nodal FL as controls. Bcl-2 protein expression (n = 77) was also studied along with bcl-2R (n = 64), by polymerase chain reaction. Formalin-fixed archival specimens were used in all these assays. The Bcl-6/CD10 coexpression was observed in 35 DLBCLs (34%) and 14 FLs (82%), and most of them showed a pattern of Bcl-6 expression similar to that of the GC. Bcl-2 expression or bcl-2R did not correlate with Bcl-6/CD10 coexpression. Histologically, compartmentalizing sclerosis was associated with a high rate of the coexpression (8 of 10). In conclusion, to detect GC B-cell lymphoma in routine biopsy specimens, a pattern of Bcl-6 staining similar to the GC must be identified. Bcl-6+/CD10+ GC B-cell lymphomas thus defined comprised one third of primary nodal DLBCLs in Korea. The incidence rate is similar to that in the West. The reasons for the discrepancy between the incidence of GC B-cell lymphoma and the paucity of the follicular pattern in East Asian subjects warrant further studies.