同时发生myc和bcl-2/IgH或bcl-6易位的B细胞淋巴瘤临床病理特征

目的 观察同时发生myc和bcl-2/IgH或bcl-6易位的B细胞淋巴瘤(“双击”淋巴瘤)的临床病理学特点.方法 收集145例经活检诊断的侵袭性成熟B细胞淋巴瘤病例石蜡包埋组织,其中包括弥漫性大B细胞淋巴瘤(DLBCL) 129例,具有介于DLBCL和伯基特淋巴瘤(BL)之间特征无法分类的B细胞淋巴瘤(BCLU)5例,BL 7例和高级别滤泡淋巴瘤合并DLBCL4例,在组织芯片上进行myc、bcl-2/IgH和bcl-6系列探针的间期荧光原位杂交检测,记录基因易位情况、拷贝数变化和其他基因异常,同时收集病例的临床、病理学及随访资料.结果 共检测出同时发生myc和bcl-2或bcl-6基因易位(“双击”淋巴瘤)病例5例,检出率5/145(3.4％);其中myc伴bcl-2易位2例(原形态学诊断1例是DLBCL,1例是BCLU);myc伴bcl-6易位3例,均为DLBCL.Ki-67阳性指数60％ ～100％.另发现3例bcl-2伴bcl-6易位,均为DLBCL.其余DLBCL病例中出现单个基因易位或拷贝数增加的占51.2％ (66/129).随访资料显示,5例“双击”淋巴瘤患者中3例在诊断后2年内死亡,1例失访,1例随访36个月无病生存.结论 “双击”淋巴瘤属于罕见病例,主要根据基因检测手段来诊断,形态学上不完全等同于2008 WHO分类中的BCLU这一亚型,还可表现为其他的形态学谱系.大部分患者预后差.     

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.     

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.     

眼附属器淋巴组织增生性病变的临床病理和分子遗传学特征及其意义

目的 分析眼附属器淋巴组织增生性病变的临床病理特点,探讨其分子遗传学特征及其意义.方法 收集1995-2007年37例眼附属器淋巴组织增生性病变石蜡组织标本(其中5例为反应性增生性病变,32例为淋巴瘤),依据2001年WHO肿瘤分类标准对32例淋巴瘤标本重新诊断分类.采用IgH、MALT1、bcl-6、c-Mye、bcl-2、CCND1、bcl-10、FOXP1双色分离重排探针、IgH/bcl-2双色融合易位探针和18号染色体着丝粒探针,利用间期荧光原位杂交(FISH)的方法 检测眼附属器淋巴组织增生性病变的分子遗传学特点.结果 32例淋巴瘤均为非霍奇金B细胞淋巴瘤.其中,黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(MALT)淋巴瘤28例(87.5%),滤泡性淋巴瘤2例,弥漫性大B细胞淋巴瘤2例.60.7%(17/28)的眼附属器MALT淋巴瘤携带分子遗传学异常.其中,IgH基因断裂1例,但未找到与其发生相互易位的伙伴基因;基因3拷贝者16例,其中MALT1基因、bcl-6基因和c-Myc基因3拷贝的发生率分别为25%(7/28)、43%(12/28)和7%(2/28).16例基因3拷贝病例中,两种基因3拷贝合并存在者5例,其中bcl-6基因合并MALT1基因3拷贝者4例,bcl-6基因合并c-Myc基因3拷贝者1例.进一步研究显示,MALT1基因3拷贝者均存在18号染色体三体.2例滤泡性淋巴瘤都携带t(14;18)(q32;q21)/IgH-bcl-2.2例弥漫性大B细胞淋巴瘤均存在遗传学异常,1例表现为bcl-6基因3拷贝合并18号染色体三体,另1例表现为bcl-6基因3拷贝合并IgH和c-Myc基因双断裂.5例反应性淋巴组织增牛性标本均未见分子遗传学异常.结论 MALT淋巴瘤是眼附属器最常见的淋巴瘤类型;间期FISH有助于淋巴组织增生性病变的良恶性鉴别及淋巴瘤的分类;MALTI基因3拷贝者由18号染色体三体所致;18号染色体三体和bcl-6基因3拷贝(可能为3号染色体三体所致)是眼附属器MALT淋巴瘤常见的分子遗传学异常.     

应用细胞芯片荧光原位杂交技术检测弥漫性大B细胞淋巴瘤3q27重排

目的 研究3q27染色体断裂及bcl-6基因扩增与弥漫性大B细胞淋巴瘤(diffuse large B-cell lymphoma, DLBCL)与其分子分类及治疗效果、临床分期的关系.方法 用细胞芯片荧光原位杂交(fluorescence in situ hybridization,FISH)技术对60例DLBCL的标本进行3q27染色体断裂及bcl-6扩增检测;采用免疫组化S-P法在组织微阵列上同步观测CD20、CD10、bcl-6、MUM1的表达,进行生发中心样(germinat center Bcell-like,GCB)和非生发中心样(non-germinal center B-cell-like, non-GCB)分子分类;通过对临床病例的分析得出与治疗效果及临床分期的信息;统计分析以上各因素之间的关系.结果 在60例DLBCL中,GCB占48.3%(29/60),non-GCB占51.7%(31/60).FISH结果显示,3q27断裂阳性15例,bcl-6基因扩增阳性22例.存在3q27染色体断裂的15例中BCL-6蛋白表达阳性3例(20.0%),阴性12例(80.0%),与无3q27染色体断裂者相比其BCL-6蛋白表达率降低(P=0.017).在60例DLBCL中,bcl-6扩增22例,其中GCB 5例(22.7%),non-GCB 17例(77.3%),与无bcl-6扩增者相比差异有统计学意义(P=0.003).在36例经正规CHOP治疗的DLBCL中,bcl-6扩增15例,其治疗效果显效、部分有效、无效分别为4(26.7%)、4(26.7%)、7(46.7%),与无bcl-6扩增的病例比差异有统计学意义(P=0.016).bel-6扩增与BCL-6蛋白表达及I临床分期的关系差异无统计学.BCL-6蛋白表达阳性组、阴性组与治疗效果及临床分期关系差异无统计学意义.结论 存在bel-6基因断裂的病例,其BCL-6蛋白表达率低.存在bcl-6基因扩增的DLBCL多数为non-GCB,并且治疗效果差,临床分期较晚,可能与DLBCL晚期染色体呈多倍体增加的趋势有关.     

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.     

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.     

荧光原位杂交技术在淋巴瘤诊断中的价值

目的 探讨荧光原位杂交(FISH)检测在淋巴瘤诊断中的价值,为淋巴瘤的准确诊断提供依据.方法 以前瞻性非随机分组模式,采用三组IgH/bcl-2、IgH/CCNDl、API2/MALT1探针,对临床初诊为淋巴瘤的74例活检新鲜样本的瘤细胞进行FISH,检测其相应t(14;18)、t(11;14)及t(11;18)染色体易位,将检测结果与组织病理诊断进行比较评价.结果 74例中8例(10.8%)检测到染色体易位,分别为t(14;18)和t(11;14)各4例.62例组织病理诊断为淋巴瘤者中7例检测到染色体易位,分别为t(14;18)3例(组织病理诊断2例为滤泡性淋巴瘤、1例为结节硬化型霍奇金淋巴瘤);t(11;14)4例(组织病理诊断2例为套细胞淋巴瘤、1例滤泡性淋巴瘤,1例小淋巴细胞淋巴瘤).在组织病理未诊断为淋巴瘤的12例中,仅检测到1例t(14;18),而其组织形态显示为淋巴组织增生活跃,经FISH检测更正诊断为滤泡性淋巴瘤.25例弥漫性大B细胞淋巴瘤未检测到t(14;18).在其他有基因数目异常者56例(75.7%)中恶性病变52例(92.9%),与4例(7.1%)良性病变比较,病变性质与基因数目异常之间差异有统计学意义(P=0.011).结论 FISH技术检测淋巴瘤特异的遗传学异常对于复核组织病理诊断、鉴别其类型、亚型及病变的良、恶性有重要参考价值.     

不同部位黏膜相关淋巴组织结外边缘区B细胞淋巴瘤中染色体的异常及其意义

目的 探讨不同部位黏膜相关淋巴组织结外边缘区B细胞淋巴瘤(MALT淋巴瘤)中t(11;18)/APl2-MALT1、t(1;14)/IgH-bcl-10、t(14;18)/IgH-MALT1和其他遗传学异常的发生情况及其意义.方法 收集196例不同部位的MALT淋巴瘤,包括胃53例[其中9例有弥漫性大B细胞淋巴瘤(DLBCL)成分]、眼眶50例、涎腺20例、肺20例、肠17例、皮肤17例、肝脏8例、甲状腺5例和其他部位6例(包括舌根2例,胰腺、喉、声带和肾脏各1例),用荧光原位杂交(FISH)分别检测APl2-MALT1、bel-10、MALT1和IgH基因的异常.结果 在196例MALT淋巴瘤中,APl2-MALT1融合基因共检出25例(12.8%).但是在不同部位,阳性率差异有统计学意义(P=0.002):从高到低依次为肺(45.0%,9/20)、不伴DLBCL成分的胃MALT淋巴瘤(22.7%,10/44)、涎腺(15.0%,3/20)、肠2/17、眼眶2.0%(1/50).而在伴DLBCL成分的胃MALT淋巴瘤、皮肤、甲状腺、肝脏和其他散发部位均未发现APl2-MALT1融合基因.在196例中,1例肺MALT淋巴瘤同时显示IgH基因和MALT1基因异常,可能是t(14;18)/IgH-MALT1异常.3例(2例不伴DLBCL成分的胃和1例肺)同时显示IgH基因和bcl-10基因异常,可能是t(1;14)/IgH-bcl-10异常.此外,用MALT1基因探针检测中,6例(2例涎腺、2例肝脏、1例伴DLBCL成分的胃和1例甲状腺)可能为18号染色体3体;3例(2例胃和1例肠)为MALT1基因扩增.结论 在MALT淋巴瘤中特异性的染色体异常发生率较低,但在不同部位,这些异常发生率存在差异.该现象提示发生在不同部位的MALT淋巴瘤,尽管组织形态学特点类似,但可能具有不同的发病机制.     

睾丸原发性淋巴瘤17例临床病理分析

目的探讨睾丸原发性淋巴瘤(primary testicular lymphoma,PTL)的临床病理学特征。方法回顾性分析17例PTL的临床病理学特征。结果患者年龄37~81岁,中位年龄69岁;以睾丸无痛性肿大为主要临床表现;病变位于左侧6例,右侧10例,双侧1例;肿块最大径2~6 cm。组织学分型:17例PTL中16例(94%)为弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL),1例(6%)为结外NK/T细胞淋巴瘤(鼻型)。免疫表型提示16例DLBCL中14例为非生发中心B细胞样(non-germinal center B-cell-like,non-GCB)型,2例为生发中心B细胞样(germinal center B-cell-like,GCB)型;c-myc与BCL-2或BCL-6抗体共同阳性表达者(c-myc阳性率30%以上且BCL-2阳性率70%以上者)10例。对10例共表达病例行FISH检测,发现仅1例有MYC基因重排,未发现双重打击淋巴瘤(double-hit lymphoma,DHL)。EB病毒原位杂交检测除1例鼻型NK/T细胞淋巴瘤为阳性外均为阴性。Ann Arbor临床分期:Ⅰ+Ⅱ期15例(88%),Ⅲ+Ⅳ期2例(12%)。17例患者均行患侧睾丸根治性切除术,8例DLBCL患者行CHOP或R-CHOP方案化疗。结论 PTL发病率低,主要发生于老年人,最常见的组织学类型为DLBCL,以non-GCB型伴c-myc与BCL-2/BCL-6共表达为主,患者预后差。PTL中很少发现伴随MYC和BCL-2同时基因重排的DHL。PTL术前诊断困难,确诊需依靠病理组织学、免疫表型及分子病理学检查等。     

Comparative immunohistochemical analysis of pediatric Burkitt lymphoma and diffuse large B-cell lymphoma

Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) account for nearly all pediatric nonlymphoblastic B-cell lymphomas. Because clinical behavior, prognosis, and response to therapy might differ, diagnostic accuracy is important. Morphologic examination often is sufficient, but occasionally, diagnostic ancillary studies are required. In adults, immunophenotyping is useful; however, pediatric data are limited. We characterized the immunohistochemical expression of 6 proteins (c-myc, CD10, bcl-6, bcl-2, CD138, and MIB-1) in pediatric BL (33 cases) and DLBCL (20 cases) with classic morphologic features. Significant differences in c-myc (BL, 30/33 [91%] vs DLBCL, 5/20 [25%]; P < .0001), bcl-2 (BL, 1/25 [4%] vs DLBCL, 7/19 [37%]; P < .02), and mean MIB-1 (BL, 99% vs DLBCL, 56%; P < .0001) expression were observed. There were no significant differences for CD10 (100% expression in BL and DLBCL), bcl-6 (BL, 23/33 [70%] vs DLBCL, 15/20 [75%]), or CD138 (no expression). Thus, pediatric BL and DLBCL have distinctive immunohistochemical profiles, and staining for c-myc, MIB-1, and bcl-2 might be useful in morphologically difficult cases.     

Germinal center and activated b-cell profiles separate Burkitt lymphoma and diffuse large B-cell lymphoma in AIDS and non-AIDS cases

Morphologic features of Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) overlap. No single phenotypic marker or molecular abnormality is pathognomonic. We tested a panel of 8 germinal center (GC) and activated B-cell (ABC) markers for their ability to separate BL and DLBCL. We diagnosed 16 BL and 39 DLBCL cases from 21 patients with AIDS and 34 without AIDS based on traditional morphologic criteria, Ki-67 proliferative index, and c-myc rearrangement (fluorescence in situ hybridization). After immunohistochemically staining tissue microarrays of BL and DLBCL for markers of GC (bcl-6, CD10, cyclin H) and ABC (MUM1, CD138, PAK1, CD44, bcl-2), we scored each case for the percentage of positive cells. Hierarchical clustering yielded 2 major clusters significantly associated with morphologic diagnosis (P < .001). For comparison, we plotted the sum of the GC scores and ABC scores for each case as x and y data points. This revealed a high-GC/low-ABC group and a low-GC/high-ABC group that were associated significantly with morphologic diagnosis (P < .001). Protein expression of multiple GC and ABC markers can separate BL and DLBCL.     

T-cell/histiocyte-rich large B-cell lymphoma displays a heterogeneity similar to diffuse large B-cell lymphoma: a clinicopathologic, immunohistochemical, and molecular study of 30 cases.

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL), a proliferating peripheral B-cell neoplasm, is a morphologic variant of diffuse large B-cell lymphoma (DLBCL), which may be confused with Hodgkin's lymphoma, non-Hodgkin's lymphoma, and reactive lymphadenopathies. Though more recent studies suggested that it might be a distinct clinicopathologic entity and/or a heterogeneous entity with derivation from germinal center B cells, its histogenetic derivation remains controversial. The authors analyzed 30 cases of THRLBCL to further characterize the origin of the neoplastic cells using immunohistochemical and molecular studies for expression of Bcl-6, CD10, and CD138, as well as rearrangements of IgH/bcl-2 genes on paraffin-embedded tissue. Half of the cases (15/30) showed Bcl-6 expression and five cases (19%) showed CD10 expression, but none had CD138 expression (0/20). Only three cases showed coexpression of both Bcl-6 and CD10. Molecular studies performed in 21 cases detected rearrangement of immunoglobulin heavy gene in 18 cases, with none having detectable Bcl-2 gene rearrangement. These data indicate that similar to DLBCL, the cell origin of neoplastic cells in THRLBCL is composed of a heterogeneous group of proliferating peripheral B cells, with only some cases originating from germinal center B cells and others derived from heterogeneous origins. Lack of Bcl-2 gene rearrangements seems to argue against a possible progression from preexisting follicular lymphoma. Thus, the normal counterpart of the neoplastic cells cannot at this time be the sole basis for the subclassification of THRLBCL.     

Discordant bone marrow involvement in diffuse large B-cell lymphoma: comparative molecular analysis reveals a heterogeneous group of disorders

Discordant bone marrow (BM) involvement in patients with a diagnosis of large-cell non-Hodgkin's lymphoma (NHL) is characterized by marrow infiltrates predominantly composed of small lymphoid cell, cytologically compatible with low-grade NHL. Although this phenomenon is well described morphologically, molecular data concerning the relationship of the two lesions are lacking. The aim of the study was to investigate the clonal relationship of discordant lymphoma manifestations by using immunoglobulin heavy chain gene (IgH), as well as bcl-2 rearrangements, as molecular markers. IgH rearrangements were amplified by PCR with consensus primers directed against framework regions 3 or 2 (FR3 and FR2), followed by automated fragment length analysis and sequencing in selected cases. Rearrangements of the bcl-2 gene were identified with primers against the major breakpoint region. Small BM infiltrates were isolated by laser capture microdissection. In addition, immunohistochemistry was performed on paraffin sections using antibodies against CD3, CD10, CD20, bcl-2, bcl-6, p53, and the Ki67 antigen. Paraffin-embedded tissues of 21 cases diagnosed as diffuse large B-cell lymphoma (DLBCL) with discordant BM involvement and no previous history of low-grade B-cell NHL were analyzed. After review of immunohistochemical stains, 5 cases were excluded either as concordant BM infiltrates by large-cell lymphoma with abundant reactive T-cells (2 cases) or as benign, reactive lymphoid infiltrates (3 cases), as confirmed by a polyclonal pattern in the IgH analysis. Of the remaining 16 cases, a common clonal origin was confirmed in 8 cases by the presence of an identical clonal IgH rearrangement or bcl-2 rearrangement. In 4 cases, identification of distinct IgH or bcl-2 rearrangements gave evidence for the presence of two clonally unrelated neoplasms. The remaining 4 cases were not evaluable for technical reasons. Morphological, phenotypical, and molecular findings were compatible with a lymphoma of germinal center origin in the majority of cases. However, in 4 cases, flow cytometric analysis of the BM infiltrates revealed a B-cell chronic lymphocytic leukemia phenotype. Two of these cases were clonally related to the DLBCL and thus represented Richter's transformation. In summary, discordant BM infiltrates in DLBCL represent a heterogeneous group of disorders, encompassing cases with a clonally related, clinically occult small-cell component, as well as cases with two clonally distinct, unrelated B-cell neoplasms presenting synchronously at different locations.     

上海地区弥漫性大B细胞淋巴瘤的生发中心B细胞样型显著偏低

目的 探讨中国上海地区弥漫性大B细胞淋巴瘤(DLBCL)的生发中心B细胞(GCB)样型与非GCB样型的分布以及可能影响因素.方法 应用免疫组织化学EnVision法分析124例来自该院的原发DLBCL中CD10、bcl-6、MUMl、GCET1和FOXP15种蛋白的表达,采用Hans和Choi两种免疫表型分型法进行分型.其中118例应用荧光原位杂交技术检测t(14;18)和bcl-6基因重排情况.结果 使用Hans法对124例DLBCL进行分型,27例(22%)为GCB样型,97例(78%)为非GCB样型.使用Choi法进行分型显示34例(27%)为GCB样型,90例(73%)为非GCB样型(即ABe样型).GCB样型显著低于非GCB样型(P=0.0001).t(14;18)易位仅4例(3%),3例发生于GCB样型中.bcl-6基因重排阳性的病例为46例(39%),高发于GCB样型中.bcl-6基因重排与bcl-6蛋白表达没有明显相关性.结论 中国上海地区DLBCL的GCB样型显著低于非GCB样型,可能与其DLBCL的t(14;18)低水平发生有关.     

bcl-6基因5'非编码区突变与弥漫性大B细胞淋巴瘤生发中心亚型的相关性

目的 分析弥漫性大B细胞淋巴瘤(DLBCL)中bcl-6基因5'非编码区突变频率及与其生发中心B细胞(GCB)型的相关性.方法 对60例DLBCL行套式PCR检测t(14;l8)易位,并经免疫组织化学EnVision两步法进行GCB和非GCB分子分型.PCR扩增bcl-6主要突变区,测序检测突变位点.结果 60例中7例(11.7%)发生t(14;18)易位,为主要断裂点发生转位;联合免疫组织化学分析和t(14;18)易位检测,筛选出GCB型18例和非GCB型42例;5'非编码区总突变率为20.0%(12/60),GCB型突变率为7/18,非GCB型突变率为11.9%(5/42);+363和+469位点频繁发生突变.结论 DLBCL的bcl-65'非编码区发生突变频率较国外低,突变多发生于GCB型中.t(14;18)易位检测有助于DLBCL的分子分型.     

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.