B淋巴细胞增生性疑难病例中IgH基因克隆性重排的分析

目的 探讨IgH基因克隆性重排对B淋巴细胞增生性疑难病变的辅助诊断价值.方法 检测77例B淋巴细胞增生性疑难病例中IgH基因的克隆性重排情况,均采用BIOMED-2系统IgH克隆性试剂盒中FR1、FR2、FR3三组家族引物进行PCR及聚丙烯酰胺凝胶电泳,硝酸银染色后观察,并对照最终病理诊断进行分析.结果 77例病变的最终病理诊断:B淋巴细胞反应性增生12例,不能排除B淋巴细胞不典型增生或淋巴瘤20例,B细胞性淋巴瘤45例.三组中FR1、FR2和FR3至少有一个为阳性的比值分别为2/12、11/20(55%)和36/45(80%).B细胞性淋巴瘤中,FR1、FR2和FR3的阳性率分别为60%(27/45)、60%(27/45)、56%(25/45),其类型有边缘区B细胞性淋巴瘤20例(其中黏膜相关淋巴组织型结外边缘区淋巴瘤18例,结内边缘区淋巴瘤2例),弥漫性大B细胞淋巴瘤7例,滤泡性淋巴瘤7例,套细胞性淋巴瘤1例,Burkitt淋巴瘤1例,浆细胞瘤4例,不能分型5例.FR1、FR2和FR3三者检测均为阴性但仍诊断为淋巴瘤9例(20%),其中1例后来出现肝脏B细胞淋巴瘤.对IgH基因重排阳性的B淋巴细胞反应性增生和不典型增生14例的随访结果,4例重新取活检后诊断为B细胞性淋巴瘤,其中3例IgH基因重排检测为阳性.结论 联合检测IgH基因FR1、FR2和FR3克隆性重排对B淋巴细胞增生性疑难病变诊断有重要的辅助价值;对形态改变和免疫表型诊断淋巴瘤依据不足而基因重排阳性者,重取活检或随访有一定价值;对阴性病例有必要补充IgH基因重排及IgK和IgL基因重排的检测以提高检测敏感性.     

Immunohistochemistry and gene rearrangement studies in the diagnosis of malignant lymphomas: a comparison of 152 cases.

One hundred fifty-two cases (155 specimens) of lymphoproliferative disorders were studied by immunohistochemistry and gene rearrangement analysis. Ninety-five of 96 B-cell lymphomas (99%) showed genotypic B-cell monoclonality. Of these, five cases had rearranged T-cell receptor (TCR) beta chain gene in addition to immunoglobulin heavy chain (IgH) and kappa light chain (Ig-K), one case had rearranged IgH and TCR-gamma chain but not Ig-K or TCR-beta, and two cases had only Ig-K rearrangement. One exceptional case in the B-cell lymphoma group had unrearranged, germline genotypes. In contrast, only 10 of 19 (53%) phenotypic T-cell lymphomas had rearranged TCR-beta, eight with concurrent TCR-gamma rearrangement. Of the remaining nine cases, six had germline configuration, two had rearranged Ig-K only, and one had both IgH and Ig-K rearrangement. This last case was reclassified as T-cell predominant, B-cell lymphoma. Thirteen of 16 cases of Hodgkin's disease had germline configuration; three cases had rearranged IgH and Ig-K, of which two were lymphocyte predominant with light chain monoclonality and one was a recurrence. Among 21 reactive lesions, 17 had germline configuration and four had rearranged IgH and Ig-K genes. Of these four cases, two were orbital lesions, one was a partially involved lymph node, and one developed a nodular lymphoma 9 months later. Our results indicate that almost all B-cell lymphomas have IgH and/or Ig-K rearrangement. In contrast, peripheral T-cell lymphomas have greater genotypic heterogeneity, and germline patterns for TCR genes are not uncommon. Reactive lesions and Hodgkin's disease tend to retain germline configuration, and any exception is often associated with an unusual clinical setting and/or histology. Genotypic analysis is thus most indicated in B-cell lymphomas with equivocal immunohistochemistry findings, T-cell lymphomas, and atypical cases of Hodgkin's disease and reactive lesions.     

BIOMED-2引物系统检测急性淋巴细胞白血病患者免疫球蛋白基因重排

目的 探讨BIOMED-2引物系统检测成人急性淋巴细胞白血病(ALL)患者Ig基因重排的敏感性,分析Ig基因重排方式、各胚系基因的利用频率等.方法 采用BIOMED-2引物系统扩增29例成人ALL患者Ig重链(IgH)和Ig轻链(IgL)重排基因.将PCR产物直接测序,使用IMGT/V-QUEST等生物信息资源分析B细胞-ALL(B-ALL)患者IgH和IgL基因重排类型、胚系基因片段利用及体细胞突变情况.结果 24例B-ALL患者中IgH完全重排阳性率为70.8%,不完全重排为12.5%,IgK VH-JH重排为29.2%,IgK删失元件(IgK-Kde)重排为25.0%,未检测出IgL阳性重排.所有B-ALL患者Ig基因重排检出率可达100%.5例T细胞-ALL(T-ALL)患者1例检测到IgH不完全重排阳性,2例IgK VH-JH重排阳性,2例未检测出Ig基因重排.B-ALL中IgH重排优先利用的V、D、J家族分别为VH3和VH4、DH3和JH6.5例IgK重排中4例利用了 Vκ1家族.重排基因中发生替代突变的基因占23.5%.替代突变零星散布于Ig基因全长,互补决定区中替代突变与静寂突变的比例<1.结论 BIOMED-2引物系统可以检测出绝大多数B-ALL患者的Ig基因重排,国内的临床检测资料亦然.这是一种有效的检测工具,为定量分析微小残留病(MRD)水平提供了基础资料.     

BIOMED-2聚合酶链反应Ig基因重排对成熟非霍奇金B细胞淋巴瘤诊断的价值

目的 探讨BIOMED-2聚合酶链反应(PCR)在成熟非霍奇金B细胞淋巴瘤(B-NHL)诊断中的价值.方法 收集成熟B-NHL组织标本72例,其中弥漫性大B细胞淋巴瘤37例,黏膜相关淋巴组织结外边缘区淋巴瘤35例为研究对象,并以反应性增生病变25例作为对照.提取以上组织的DNA,并以PCR来检测其完整性和可扩增性,选取质量合格的DNA.85.6%(83/97)的样品DNA长度>300 bp,其中60例成熟B-NHL和23例反应性增生可用于BIOMED-2 PCR检测免疫球蛋白重链(IgH)和kappa轻链(IgK)基因重排的克隆性.结果 利用BIOMED-2 PCR检测的60例成熟B-NHL中,57例存在Ig基因的克隆性重排,其检测敏感性为95%,23例反应性增生病例中未出现Ig基因的克隆性重排,其检测特异性为100%.结论 BIOMED-2 PCR适用于石蜡包埋组织.该方法具有很高的敏感性和特异性,对成熟B-NHL诊断的辅助价值很高.     

Tissue microarray-based screening for chromosomal breakpoints affecting the T-cell receptor gene loci in mature T-cell lymphomas

The pathogenesis of mature T-cell non-Hodgkin lymphomas (T-NHLs) is poorly understood. Analogous to B-cell lymphomas, in which the immunoglobulin (IgH) receptor loci are frequently targeted by chromosomal translocations, the T-cell receptor (TCR) gene loci are affected by translocations in a subset of precursor T-cell malignancies. In a large-scale analysis of 245 paraffin-embedded mature T-NHLs, arranged in a tissue microarray format and using improved FISH assays for the detection of breakpoints in the TCRalpha/delta, TCRbeta, and TCRgamma loci, we provide evidence that mature T-NHLs other than T-cell prolymphocytic leukaemia (T-PLL) also occasionally show a chromosomal rearrangement that involves the TCRalpha/delta locus. In particular, one peripheral T-cell lymphoma (not otherwise specified, NOS) with the morphological variant of Lennert lymphoma displayed a chromosomal translocation t(14;19) involving the TCRalpha/delta and the BCL3 loci. A second case, an angio-immunoblastic T-cell lymphoma (AILT), carried an inv(14)(q11q32) affecting the TCRalpha/delta and IgH loci. FISH signal constellations as well as concomitant comparative genomic hybridization (CGH) data were also suggestive of the occurrence of an isochromosome 7, previously described to be pathognomonic for hepatosplenic T-cell lymphomas, in rare cases of enteropathy-type T-cell lymphoma.     

儿童散发性伯基特淋巴瘤的分子遗传学特征分析

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.     

IgH, TCR-gamma, and TCR-beta gene rearrangement in 80 B- and T-cell non-Hodgkin's lymphomas: study of the association between proliferation and the so-called "aberrant" patterns.

The current study analyzes the rearrangement pattern of immunoglobulin H (IgH), T-cell receptor (TCR)-gamma, and TCR-beta genes in a group of 80 non-Hodgkin's lymphomas (NHL) of different histologic subtypes (43 B-cell and 37 T-cell types). The sensitivity and specificity provided by polymerase chain reaction amplification of these loci are evaluated. The association between the proliferation index and the presence of the so-called "aberrant" or "dual" rearrangements is also considered. Ninety-one percent of B-cell NHL showed IgH gene monoclonality, and 21% also exhibited a monoclonal pattern in one of the TCR genes. Among T-cell NHL, the sensitivity of the study was 65% for the TCR-gamma gene and 46% for the TCR-beta gene. The total sensitivity was 76%, amplifying both loci. IgH gene aberrant rearrangements were observed in 16% of T-cell neoplasms. A substantial percentage of dual rearrangements were detected in precursor and mature B- and T-cell NHL. B-cell NHL showed a tendency toward higher values of proliferation when aberrant rearrangements were present; however, this trend was not significant. Furthermore, in the case of T-cell NHL there was a significant negative association between these two variables.     

Rearrangement of the T-cell receptor delta chain gene in T-cell lymphomas with a mature phenotype.

The configuration of the T-cell receptor (TCR) delta chain gene was assessed using restriction fragment analysis and the Southern blot technique in 39 T-cell lymphomas with a mature immunophenotype. The TCR delta gene was rearranged in four lymphomas although the gamma/delta TCR was not expressed in two cases studied. The TCR delta gene was the only TCR gene rearranged in two cases. Each lymphoma with TCR delta gene rearrangement had an aberrant T-cell immunophenotype and three cases were of the large cell anaplastic type. The TCR delta gene was deleted in 22 cases and was in the germline configuration in 13 lymphomas. Deletion of the TCR delta gene was characteristic of mycosis fungoides, adult T-cell leukemia/lymphoma (human T cell leukemia-lymphoma virus positive), and Lennert's lymphoma, and was not identified in angiocentric lymphomas. In eight cases with TCR delta deletion, however, a large number of polyclonal (presumably reactive) T cells were present and, in these lymphomas, the authors could not determine if TCR delta gene deletion occurred in the polyclonal T cells, the neoplastic cells, or both cell populations. The authors conclude that the TCR delta gene is usually deleted in mature T-cell lymphomas, as would be expected in alpha/beta TCR T cells. However, TCR delta gene rearrangement is detectable in approximately 10% of cases. Analysis of this locus may be useful diagnostically, as it occasionally may be the only molecular marker of clonality in mature T-cell lymphomas T-cell receptor delta chain gene rearrangement also is found most often in lymphomas of the large cell anaplastic type.     

BIOMED-2系统引物用于检测T细胞淋巴瘤石蜡样本T细胞受体γ基因重排的研究

目的 了解BIOMED-2系统T细胞受体(TCR)γ引物组合对T细胞淋巴瘤的常规石蜡包埋组织样本中TCR基因重排的检出情况及其实用性.方法 用酚/氯仿法提取55例各种组织类型的T细胞淋巴瘤石蜡包埋组织样本的DNA并通过扩增看家基因β-globin检测其质量,利用BIOMED-2系统TCR-γ引物组合和TCR-γ基因通用型引物(TVG/TJX)对55例进行TCR基因重排检测,比较二者的检出率并进行统计学分析.结果 BIOMED-2系统TCR-γ引物组合和TCRγ基因通用型引物(TVG/TJX)的TCR基因重排检出率分别为76.4%和60.0%,前者高于后者,二者的差异无统计学意义(P>0.05).结论 BIOMED-2系统TCRγ引物组合适用于本组T细胞淋巴瘤石蜡包埋组织样本的TCR基因重排检测.     

皮下脂膜炎样T细胞淋巴瘤的免疫表型、基因重排检测及其在诊断中的意义

目的 探讨免疫表型和基因重排检测在皮下脂膜炎样T细胞淋巴瘤(SPTL)的诊断和鉴别诊断中的意义.方法 参照2005年世界卫生组织-欧洲癌症研究与治疗组织(WHO-EORTC)皮肤淋巴瘤分类标准收集20例SPTL.采用10种抗原标记进行免疫表型检测,运用PCR技术检测TCRγ、IgH基因重排,并用EB病毒编码的小RNA1/2(EBER1/2)原位杂交检测EB病毒感染.结果 (1)本组病例中男9例、女11例,平均年龄29.5岁;(2)所有病例的瘤细胞均表达1个或多个T细胞分化抗原(CD2、CD3或CD45RO),18/19病例表达BF1,18/20病例表达CD8,20/20、16/20病例分别表达细胞毒颗粒相关蛋白TIA-1、颗粒酶B,瘤细胞不表达CD4、CD20和CD56;(3)16/20病例检出TcRγ基因重排,未检出IgH基因重排;(4)5/20病例EBERl/2原位杂交阳性.结论 SPTL的瘤细胞具有克隆性TCR基因重排,综合临床病理、免疫表型及基因重排检测有助于本病确诊.     

Gene rearrangements in T-cell lymphoblastic lymphoma

This study presents an examination of the Ig heavy chain (IgH) and T-cell receptor gamma (TCRγ) genes in a series of 39 CD3-positive T-cell acute lymphoblastic leukaemia (ALL) cases with and without co-expression of CD79a; 30/39 cases had a rearrangement of the TCRγ genes and two of these 30 cases also demonstrated an IgH rearrangement. No cases had solely an IgH rearrangement. The conclusion of the study is that lymphoblastic lymphoma cases that are positive for CD3 are of T-cell lineage, regardless of CD79a expression. Copyright © 1999 John Wiley & Sons, Ltd.     

滤泡型淋巴瘤中t(14;18)染色体易位的分析及其临床意义

目的探讨滤泡型淋巴瘤（FL）的分子遗传学特征及其在病理诊断中的意义。方法收集55例FL石蜡标本,对照组小B细胞淋巴瘤28例和反应性滤泡增生（RFH）10例,应用套式PCR技术检测FL中,免疫球蛋白重链基因（IgH）的克隆性重排;应用标准PCR技术检测55例FL中t（14;18）易位,以10例RFH做对照;采用双色荧光原位杂交（FISH）技术检测20例淋巴结FL中t（14;18）易位,以4例RFH作为对照;并与PCR检测结果进行比较。结果（1）55例FL中,结内49例,结外6例。男性33例,女性22例,男女比为1．5：1。发病年龄36—79岁（中位年龄57岁）;FL分级：FL1—3分别为25例、19例和11例。（2）55例中50例（90％）检出β-肌动蛋白（actin）,该50例中FR3A阳性24例（48％）,FR2阳性25例（50％）,其中15例（30％）呈FR3A和FR2双阳性,共34例（68％）IgH基因重排。对照组小B细胞淋巴瘤28例中,25例检出β—actin,其中FR3A阳性18例（64％）,FR2阳性17例（61％）,共24例（86％）可检测出克隆性IgH基因重排。4例RFH均未检出IgH基因重排。（3）在44例结内FL中检出15例（34％）t（14;18）易位,其中14例在MBR,1例在mcr。（4）20例中,有16例（80％）可检出t（14;18）易位。结论（1）IgH克隆性重排在FL中的检测率比其他小B淋巴细胞低。（2）FISH检测石蜡包埋组织中t（14;18）易位有助于FL的诊断。FISH比PCR的敏感性更好,操作简便,可用于检测石蜡包埋组织中的分子遗传学改变。     

The relationship between primary gastric B-cell lymphoma and immunoglobulin heavy chain (IgH) gene rearrangement--a histopathological study of primary gastric lymphomas

The aim of this study was to review our primary gastric lymphoma cases according to the new WHO classifications and to investigate the histopathological features of B-cell lymphomas. In addition, B-cell monoclonality was analyzed for immunoglobulin heavy chain (IgH) gene rearrangement using the polymerase chain reaction at the site of the lymphoma lesion, transitional lesion, and the non-lymphoma lesion. Specimens resected from 31 primary gastric lymphomas were examined. There were 28 cases (90.3%) of B-cell lymphoma and three cases (9.7%) of T-cell lymphoma. The B-cell lymphomas were classified as low-grade mucosa-associated lymphoid tissue (MALT) lymphoma (LGML) (9%), high-grade MALT lymphoma (HGML) (42%), and diffuse large B-cell lymphoma (DLBCL) (29%). Histopathologically, lymphoepithelial lesions (LEL) were higher in LGML (100%) than in DLBCL (22%), with statistical significance (p < 0.05). A monoclonal pattern of IgH rearrangement was detected in LGML (50.0%), HGML (60.0%), and DLBCL (80.6%), with a statistically significant difference between LGML and DLBCL (p < 0.01). The IgH monoclonal pattern may reflect the gross appearance of lymphoma or the lymphoma infiltration depth. Superficial spreading and shallow growth in LGML may correspond to an oligoclonal pattern, and mass-forming and deep invasive growth in DLBCL may correspond to a more monoclonal pattern.     

PCR analysis of immunoglobulin heavy chain (IgH) and TcR-gamma chain gene rearrangements in the diagnosis of lymphoproliferative disorders: results of a study of 525 cases.

This report summarizes a cumulative 4-year experience in polymerase chain reaction (PCR) analysis of immunoglobin heavy chain (IgH) and TcR-gamma chain gene rearrangements in 525 cases of lymphoproliferative disorders. Because the sensitivity of the PCR methodology was found to be tissue dependent, in the study of the presence of clonal cell population in tissues containing a small number of polyclonal lymphocytes, such as skin and gastrointestinal biopsy specimens, we used the multiple-PCR run approach. In this latter methodology, we repeat the PCR reaction from the same sample at least three times to confirm the reproducibility of the results. In the study of 273 cases of B- or T-cell lymphomas with characteristic immunomorphological and clinical features, a clonal IgH or TcR-gamma chain gene rearrangement was detected in approximately 80% of cases. A clonal rearrangement involving both IgH and TcR-gamma chain genes was found in 10% of cases of both B-cell and T-cell lymphomas. The study of 167 cases of nonneoplastic lymphoid tissue samples showed the presence of clonally rearranged cell populations for IgH or TcR-gamma genes in 3 and 9% of cases, respectively. We also applied PCR for the study of 85 cases of lymphoproliferations with no definite diagnosis (i.e., benign versus malignant) after immunomorphological analysis. In 65 cases (76%), the correlation of immunomorphological features with the presence (48 cases) or the absence (17 cases) of clonal lymphoid cell populations led to a definite diagnosis. In almost all these cases, the final diagnosis was found to be in agreement with the clinical course. In the 20 remaining cases (24%), no definite diagnosis could be made. We also assessed the value of PCR in detecting bcl-2/J(H) gene rearrangement as an additional clonal marker in the diagnosis of follicular lymphoma. Bcl-2/J(H) rearrangement and/or IgH gene rearrangement was found in approximately 85% (71/85) of follicular lymphoma cases studied.     

Analysis of immunoglobulin heavy chain genes rearrangement by PCR from paraffin-embedded tissue in B-cell lymphomes in Tunisia

OBJECTIVE: To study the lymphoid clonality on Tunisian B-cell lymphomas cases by polymerase chain reaction (PCR)-based techniques using DNA from paraffin-embedded tissues. MATERIAL AND METHODS: Here we conducted a retrospective PCR clonality study on 73 cases of B-cell lymphomas and 12 reactive lymphoid tissues. The quality of DNA extracted was tested by beta-globin PCR. Consensus primers directed at the FRIII-VH and FRII-VH regions of the immunoglobulin heavy chain (IgH) gene were used to detect clonality. RESULTS: The results showed that 52 of 73 (71%) B-cell lymphomas exhibited good quality of amplifiable DNA. Clonality was found in 77% of cases using the set of primers FRIIIa/LJH/VLJH and in 65.5% using the set of primers FRIIa/LJH/VLJH. Lymphomas derived from pregerminal centre showed a high rate detection of clonal IgH gene rearrangement (100%) compared to other group of tumors derived from germinal centre or postgerminal centre (74.5%). None of the polyclonal controls gave a clonal pattern. CONCLUSION: This is the first large series of PCR clonality study of IgH gene rearrangements on B-cell lymphoma from Tunisia. Our results were similar to other reports in terms of sensitivity and specificity of these techniques and confirm the interest of that PCR for detecting clonal IgH gene rearrangements in lymphoma.     

Detection of T-cell receptor-gamma gene rearrangement in lymphoproliferative disorders by temperature gradient gel electrophoresis

OBJECTIVE: Polymerase chain reaction amplification of DNA for T-cell receptor (TCR) gene rearrangement analysis is helpful in the evaluation of T-cell lymphoproliferative disorders. Detection of polymerase chain reaction products is limited by the poor resolution of bands analyzed by agarose or polyacrylamide gel electrophoresis. To improve the detection of a clonal T-cell population, we used temperature gradient gel electrophoresis (TGGE) as an alternative method for analysis of TCR gene rearrangement. DESIGN: One hundred eighteen archival DNA samples were randomly selected based on previous Southern blot analysis results. Samples included 58 T-cell neoplasms with positivity for TCR beta gene rearrangement, 22 cases of reactive hyperplasia with germline pattern for both TCR beta and J(H), and 38 patients with B-cell lymphoma. MOLT-16, a T-cell lymphoblastic cell line, was used for the sensitivity assay. Polymerase chain reaction was performed using GC-clamped multiplex primers to amplify the TCR gamma locus and was analyzed by TGGE. The range of temperature gradients was empirically determined for optimal resolution of bands. RESULTS: The sensitivity of TGGE was 0.1% when DNA from the MOLT-16 cell line was serially diluted with DNA from reactive lymphoid tissue. Fifty-four (93%) of 58 T-cell neoplasms with TCR beta gene rearrangements showed rearrangement patterns by TCR gamma TGGE, and only 1 of 60 samples (reactive or B-cell lymphomas) showed evidence of gene rearrangement by TGGE. Patients with T-cell neoplasm and involvement of multiple sites showed an identical migration pattern by TGGE analysis. CONCLUSION: We demonstrate that TGGE is an effective method for analysis of TCR gene rearrangement in the evaluation of nodal and extranodal lymphoid lesions.     

T-cell/histiocyte-rich large B-cell lymphoma is a disseminated aggressive neoplasm: differential diagnosis from Hodgkin's lymphoma

AIMS: An accurate diagnosis of T-cell/histiocyte-rich large B-cell lymphoma needs to take into consideration those forms of Hodgkin's lymphoma also characterized by a predominance of small lymphocytes and histiocytes, i.e. nodular lymphocyte predominance Hodgkin's lymphoma and lymphocyte-rich classical Hodgkin's lymphoma. We have studied the clinical, phenotypic and genetic features of a series of 12 cases of T-cell/histiocyte-rich large B-cell lymphoma along with 18 cases of Hodgkin's lymphoma for comparative purposes. METHODS AND RESULTS: Of the Hodgkin's lymphoma cases, there were 11 lymphocyte predominance type and seven classic type. T-cell/histiocyte-rich large B-cell lymphomas presented usually in advanced stages (III or IV in 11/12 cases), frequently with 'B' symptoms (6/9 cases), and followed a more aggressive course than Hodgkin's lymphoma (4/8 patients died due to the tumour in T-cell/histiocyte-rich large B-cell lymphoma versus 0/15 in Hodgkin's lymphoma). T-cell/histiocyte-rich large B-cell lymphoma cases showed diffuse effacement of the nodal architecture by a proliferation of scattered large atypical B-cells obscured by a background of small T-lymphocytes (more CD8+, TIA1+ than CD57+). Five cases showed also a prominent histiocytic component. The large B-cells expressed CD45 and often EMA (6/10 cases). On the other hand, CD 30, CD15 and latent infection by Epstein-Barr virus (EBV) were generally lacking. bc l6 and CD10 were, respectively, detected in 6/6 and 1/5 cases. Conventional polymerase chain reaction (PCR) showed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements in all T-cell/histiocyte-rich large B-cell lymphomas studied (5/5), but did not detect any case with t(14;18) involving the major breakpoint region (0/4). CONCLUSIONS: The differential diagnosis of T-cell/histiocyte-rich large B-cell lymphoma from Hodgkin's lymphoma is facilitated by the integration of different immunophenotypic, molecular and clinical findings. T-cell/histiocyte-rich large B-cell lymphoma is a monoclonal neoplasm of bc l6+ B-cells with a phenotypic profile similar to lymphocyte predominance Hodgkin's lymphoma, suggesting a germinal centre origin and a possible relation to this disease. Therefore, in order to distinguish it from lymphocyte predominance Hodgkin's lymphoma, characterization of the reactive background, IgH gene rearrangement studies by conventional PCR and clinical features are more useful. In contrast, T-cell/histiocyte-rich large B-cell lymphoma can be distinguished from classical Hodgkin's lymphoma thanks to the presence of monoclonal IgH rearrangement and the CD 30-CD15-CD45+EMA+ immunophenotypic profile of the neoplastic cells in T-cell/histiocyte-rich large B-cell lymphoma.     

Quality assessment in diagnostic molecular pathology: experience from a German-Austrian-Swiss multicenter trial

In order to assess the current technical standard of diagnostic molecular pathology, we have conducted a multicenter trial with 34 participating pathology laboratories in Germany, Austria and Switzerland. Formalin-fixed, paraffin-embedded tissue blocks were selected from 15 cases, comprising 4 B-cell non-Hodgkin’s lymphomas, 4 T-cell non-Hodgkin lymphomas, 4 cases with lymphadenitis, 2 cases with confirmed tuberculosis and 1 case of sarcoidosis. All participating laboratories received one 10-μm section from each of the 15 cases to detect clonality using immunoglobulin heavy chain (IgH) gene or T-cell receptor (TCR)-γ gene rearrangement analysis in 12 and mycobacterial DNA in 3 cases. In addition, participants had to answer technical questions about the application of internal quality controls and performance of fragment length or sequence analysis. Correct results were reported in 80% and 90% for IgH and TCR-γ gene rearrangement analysis, respectively, and in 83% for mycobacterial DNA analysis. No significant differences in the quality of results were obvious when the individual techniques used for molecular analysis were compared. However, when two independent techniques were used by the same laboratory, a higher rate of correct results was obtained for IgH and TCR rearrangement analysis. In conclusion, this study demonstrates a high technical standard of molecular diagnostic adjuncts among the participating laboratories. Regular multicenter trials with a greater number of participating laboratories working in this field will be indispensable to ensure a continuing or increasing standard in diagnostic molecular pathology. Received: 3 February 2000 / Accepted: 17 February 2000     

High frequency of EBV association and 30-bp deletion in the LMP-1 gene in CD56 lymphomas of the upper aerodigestive tract

Natural killer (NK)/T-cell lymphomas are frequently associated with Epstein-Barr virus (EBV), and usually lack TCR gene rearrangement. Studies from Asia have reported frequent deletion in the LMP-1 gene in EBV-associated nasopharyngeal carcinoma (NPC). The present study aims to investigate LMP-1 and TCRgamma gene status in upper aerodigestive tract lymphomas. A total of 43 cases were classified into T-, B-, and NK/T-cell tumors based on the phenotype expressions of CD3(+)/CD20(-)/CD56(-), CD3(-)/CD20(+)/CD56(-), and CD3(+)/CD20(-)/CD56(+), respectively. The presence of EBV in the tumor was confirmed by EBV early RNA-in situ hybridization. LMP-1 gene deletion and TCR gamma gene rearrangement were analyzed by polymerase chain reaction on paraffin-embedded tissues. There were 20 NK/T-, eight T-, and 15 B-cell phenotype lymphomas in the present series, and EBV was detected in 19 (95%), two (25%), and three (20%) cases in the respective groups. All EBV+ cases carried 30-bp deletion in the LMP-1 gene, and two of the NK/T-cell cases were infected by both the wild type and deleted strains. Five (25%) of the NK/T-cell phenotype lymphomas showed rearranged TCR gamma gene. The present study revealed a high frequency of EBV association, and a high frequency of 30-bp deletion in the LMP-1 gene in the virus in the present series of lymphoma. The NK/T-phenotype lymphomas are comprised of both NK-cell and cytotoxic T-lymphocyte-derived tumors.     

Lymph nodes in gastric B-cell lymphoma: pattern of involvement and early histological changes

AIMS: This study aims to analyse the histological pattern of nodal involvement in gastric B-cell lymphoma and to detect early involvement of the lymph nodes. METHODS AND RESULTS: Histological findings of 37 resected primary gastric lymphomas with 1313 regional lymph nodes were analysed. The primary tumour was classified into four groups: MALT lymphoma, MALT lymphoma with a minor large B-cell lymphoma (<20%), large B-cell lymphoma with MALT lymphoma, and large B-cell lymphoma without MALT lymphoma. Histological patterns of nodal involvement were divided into sinusoidal, subsinusoidal/marginal, follicular, and diffuse patterns. Semi-nested polymerase chain reaction (PCR) analysis for IgH gene rearrangement was performed. Nodal involvement was found in 2/13 (15%) MALT lymphomas, 5/6 (83%) MALT lymphomas with a minor large B-cell lymphoma, 9/12 (75%) large B-cell lymphomas with MALT lymphoma, and 6/6 (100%) large B-cell lymphomas without MALT lymphoma. The MALT lymphoma and MALT lymphoma with a minor large B-cell lymphoma showed a predominantly sinusoidal and subsinusoidal pattern, whereas diffuse pattern predominated in large B-cell lymphomas without MALT lymphoma and large B-cell lymphomas with MALT lymphoma. The follicular pattern was least common, being observed in 10.2% of large B-cell lymphomas without MALT lymphoma and large B-cell lymphomas with MALT lymphoma. Sinusoidal obliteration with permeation of small monocytoid cells into subsinusoidal zone is a characteristic finding suggesting early nodal involvement of MALT lymphoma. CONCLUSIONS: Histological patterns of nodal involvement in gastric B-cell lymphoma vary according to the histological grade. Immunostaining for CD20 with or without PCR analysis for IgH gene rearrangement would be a useful ancillary method to confirm lymphomatous involvement.