小B细胞恶性淋巴瘤形态学和免疫组织化学研究

目的：探讨各种小B细胞恶性淋巴瘤的形态学、免疫表型特征及其鉴别诊断。方法：对15例小淋巴细胞性淋巴瘤（SLL）、3例淋巴浆细胞性淋巴瘤（LPL）、36例滤泡性淋巴瘤（FL）、25例套细胞淋巴瘤（MCL）、7例淋巴结边缘区B细胞淋巴瘤（MZL）和30例黏膜相关淋巴细胞型结外边缘区B细胞淋巴瘤（MALT－MZL）的石蜡切片进行HE形态学观察和CD5、CD10、CD23和cyclinD1等抗体的免疫组织化学分析。结果：各种小B细胞恶性淋巴瘤在组成细胞和组织结构上各具特征；免疫表型：SLL表达CD5（82％）和CD23（80％），FL表达CD10（87％），MCL表达cyclinD1（84％）和CD5（80％），MZL／MALT－MZL和LPL均不表达CD5、CD10、CD23和cyclinD1。结论：各种小B细胞恶性淋巴瘤均是独立疾病，各具形态学和免疫表型特征，结合HE形态学观察和CD5、CD10、CD23、cyclinD1等免疫组化分析有助于正确诊断和鉴别诊断。     

血液系统肿瘤患者外周血细胞IgH基因和TCRγ基因的检测及意义

检测各种血液系统肿瘤患者外周血细胞免疫球蛋白重链基因 (IgH )和T细胞受体γ基因 (TCRγ )克隆性重排并探讨其意义。通过多聚酶链式反应 (PCR )方法检测 32例非霍奇金淋巴瘤 (NHL )、 18例急性髓性白血病 (AML )、 2 4例多发性骨髓瘤 (MM )、 8例急性淋巴细胞白血病 (ALL )及 6例慢性淋巴细胞白血病 (CLL )患者外周血细胞IgH及TCRγ克隆性基因重排。结果表明 ,NHL、AML、MM、ALL及CLL患者中IgH克隆性重排率分别为 37 5 0 %、 2 2 2 2 %、 83 33%、 12 5 0 %和 16 6 7% ;TCRγ基因克隆性重排率分别为 6 2 5 0 %、 5 0 0 0 %、 5 4 17%、 5 0 0 0 %及 5 0 0 0 %。在B型、T型NHL中 ,IgH克隆性重排率分别为 31 5 8%及 6 6 6 7% ;TCRγ克隆性重排率分别为 47 37%及 6 6 6 7%。AML中IgH克隆性重排阳性者的初治完全缓解率(CR ) (5 0 0 0 % )与IgH重排阴性的初治CR率 (5 0 0 0 % )无显著差异 (P >0 0 5 )。TCRγ克隆性重排阳性者与阴性者的初治CR率 (均为 44 44 % )亦无显著差异 (P >0 0 5 )。IgH及TCRγ基因克隆性重排不具有细胞谱系的特异性 ,但通过检测外周血IgH、TCRγ克隆性基因重排对NHL有辅助诊断意义 ,并且可作为监测微小残留病壮 (MRD )的手段。     

霍奇金淋巴瘤侵犯骨髓的形态学及免疫表型分析

目的探讨霍奇金淋巴瘤侵犯骨髓的形态学、免疫表型特征及诊断与鉴别诊断要点。方法通过骨髓活检组织行HE、免疫组化Eli Vision两步法染色及EBER原位杂交,并结合临床资料进行分析。结果 10例经典型霍奇金淋巴瘤均可见由肿瘤性的大细胞(HRS细胞)及背景细胞和造血细胞形成的实体性或肉芽肿样结构;2例结节性淋巴细胞为主型霍奇金淋巴瘤可见由"爆米花"样细胞及背景细胞和造血细胞形成的实体瘤样结构。骨髓增生明显活跃者8例,造血组织三系增生减低者4例。有病态造血变化者8例表现为粒、红、巨三系分化及成熟异常,原始造血细胞增多。PET/CT示4例有骨质破坏,且伴骨髓纤维化及造血组织细胞三系减低的现象。免疫表型:2例结节性淋巴细胞为主霍奇金淋巴瘤CD20、BCL-6、OCT-2、CD45、EMA及BOB-1均阳性,而CD30、CD15均阴性;10例经典型霍奇金淋巴瘤CD30阳性,6例CD15阳性,9例Pax-5弱阳性,3例OCT-2阳性,3例CD20阳性。对8例混合细胞型经典型霍奇金淋巴瘤行EBER原位杂交检测,其中4例阳性。结论霍奇金淋巴瘤侵犯骨髓时,造血组织有病态造血的变化,尤其是粒细胞形态学的变化易与肿瘤性的大细胞混淆,在免疫表型上CD15亦阳性,需借助Pax-5加以鉴别,因为大多数肿瘤细胞Pax-5弱阳性,而粒细胞不表达Pax-5。骨髓活检可确诊霍奇金淋巴瘤骨髓浸润,对于无淋巴结侵犯或取材受限(如原发于呼吸道、纵隔等)的患者,在PET/CT引导下骨髓穿刺活检不仅可对其直接进行病理诊断,还有望提高淋巴瘤侵犯骨髓的检出率。     

富于PD-1阳性T细胞的滤泡间弥漫大B细胞淋巴瘤1例临床病理分析

目的探讨富于PD-1阳性T细胞的滤泡间弥漫大B细胞淋巴瘤(diffuse large B cell lymphoma,DLBCL)的临床病理学和免疫表型特征及鉴别诊断。方法应用HE和免疫组化染色、EBER原位杂交及基因克隆性重排技术检测1例罕见的富于PD-1阳性T细胞的滤泡间DLBCL,并复习相关文献。结果镜下见淋巴结内增生的淋巴滤泡散在分布,滤泡间区增宽明显伴多形性细胞浸润,包括异型的中心母细胞和免疫母细胞样大细胞、小淋巴样细胞、嗜酸性粒细胞和组织细胞。免疫表型:滤泡间区异型大细胞CD20、PAX5、MUM1一致强阳性表达,CD3、CD5、CD10、BCL-6、CD30和CD15均阴性,背景小淋巴样细胞多为PD-1阳性的T细胞。此外,EBER原位杂交阴性,免疫球蛋白基因重排示B细胞单克隆性增生,T细胞受体基因未见单克隆性重排。结论滤泡间DLBCL,特别是伴有PD-1阳性的T细胞背景,其诊断具有挑战性。认识DLBCL这一罕见生长方式很重要,需与包括反应性免疫母细胞增生性疾病、血管免疫母细胞性T细胞淋巴瘤、滤泡间霍奇金淋巴瘤和其它富于PD-1阳性T细胞的大B细胞淋巴瘤等类似病变鉴别。     

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.     

Castleman病的免疫表型和基因重排分析

目的 探讨Castleman病(Castleman's disease,CD)的临床病理特点,通过对其免疫组化及基因重排结果的分析以提高对该病的认识.方法 对12例Castleman病进行组织学、免疫组化和基因重排分析,着重探讨其免疫表型及克隆性基因重排的特点.结果 12例Castleman病患者中,男性4例,女性8例,年龄8～71岁.组织病理学分型:透明血管型(hyaline vascular type,HVCD)4例,浆细胞型(plasma cell type,PCCD)5例,混合型(mixed cell type,Mixed CD)3例.HVCD表现为淋巴滤泡生发中心与淋巴窦大部分消失,滤泡间小动脉增生伴透明变性,且插入滤泡中心内;外套层淋巴细胞层次显著增多并呈同心圆状排列.PCCD的小动脉的透明变性和外套层同心圆状改变不明显,淋巴窦尚存,滤泡间有大量成熟浆细胞增生.混合型则兼有上述两者的改变.免疫组化结果显示,无论HVCD或PCCD,滤泡内均有CD21和CD68阳性的滤泡树状突细胞(FDC)增生,滤泡套细胞层内CD57的限制性表达,以及滤泡间组织细胞与吞噬细胞的增生.此外,血管内皮抗原CD31、CD34均弥漫表达,HVCD滤泡内的CD31、CD34阳性血管密度高于PCCD;PCCD滤泡间有大量CD138阳性的浆细胞,而在HVCD中几乎不表达.基因重排结果:12例中8例为Ig与TCR基因重排阴性,有4例局限型Castleman病患者基因重排呈阳性反应,其中1例为IgL重排阳性,1例为IgH和IgK基因重排阳性,1例为TCRD与TCRG基因重排阳性,1例为IgH和TCRB基因重排均阳性.结论 除根据组织学特征之外,免疫组化染色有助于Castleman病的病理诊断和组织学分型,尤其对组织学特征不典型的病例可进行有效的鉴别诊断,免疫球蛋白基因和TCR基因重排分析可明确病变是否有克隆性增生或恶性转化.     

IgH、TCR-γ基因重排与免疫组化诊断非霍奇金淋巴瘤的价值

目的　探讨基因重排与免疫组化在诊断非霍奇金淋巴瘤(non Hodgkin’slymphoma,NHL)中的价值。方法　对131 例NHL的石蜡包埋组织进行免疫组化和基因重排检测。结果　60例B细胞NHL中51例IgH基因重排检测为阳性,阳性率 85%;50例T细胞NHL中38例TCR -γ基因重排检测为阳性,阳性率76%;HE形态学和免疫组化分型诊断率为84%(110 例),加用IgH和TCR -γ基因重排,分型诊断率达94.6%(124例),两分型诊断率差异有显著性(P<0.05)。6例巨大淋巴结 增生和3例血管免疫母细胞性淋巴结病IgH和TCR -γ基因重排检测均为阴性。基因重排与形态学和免疫组化结果不相符的 病例有7例。结论　联合运用免疫组化和基因重排技术,可提高NHL的分型诊断率。     

脾脏非霍奇金淋巴瘤临床病理学研究

目的 探讨脾脏非霍奇金淋巴瘤(SNHL)的形态学特点、免疫表型及鉴别诊断。方法 对39例SNHL进行形态学观察及免疫组化ABC法分析，使用抗体包括CD3、CD45RO、CD56、CD79α、CD20、CD68、Mac387、CD5、CD10、bcl—2、CD23、CD43、cyclinD1、IgM、IgD等。结果 39例SNHL中有B细胞淋巴瘤(BCL)24例，包括小淋巴细胞性淋巴瘤(SLL)4例，套细胞淋巴瘤(MCL)4例，滤泡性淋巴瘤(FL)5例，边缘区淋巴瘤(MZL)6例，弥漫大B细胞性淋巴瘤(DLBCL)5例，其中2例为大多叶核细胞淋巴瘤。T细胞淋巴瘤(TCL)11例，其中肝脾T细胞淋巴瘤2例，非特异性TCL9例。组织细胞性淋巴瘤4例。结论 脾脏淋巴瘤病理类型多样，掌握其形态学特征，熟悉各类型的免疫表型的异同点对诊断与鉴别诊断有重要意义。     

富于T细胞/组织细胞的B细胞淋巴瘤病理形态、免疫表型及鉴别诊断

目的 探讨富于T细胞／组织细胞的B细胞淋巴瘤（TCRBCL）的组织学特点、免疫表型及鉴别诊断。方法 根据WHO淋巴瘤新分类（2001）回顾性研究245例霍奇金淋巴瘤,发现8例TCRBCL;另有5例会诊病例及3例外检诊断病例,共16例;应用免疫组织化学SP方法检测瘤细胞及背景细胞的免疫表型,所用抗体包括CD20、CD79a、CD3、CD8、CD45RO、CDl0、bcl-6、CD21、CD35、CD57、T细胞限制性细胞内抗原（TIA）-1、CD15、CD30、上皮膜抗原（EMA）、细胞周期蛋白（cyclin）D1、CD68、潜伏膜抗原（LMP）-1;4例行原位杂交检测EBER;4例应用聚合酶链反应技术检测瘤细胞IgH基因重排。结果 16例TCRBCL,男8例,女8例,男女比为1：1。年龄10～68岁,平均年龄40．3岁,中位年龄46．5岁。主要表现为淋巴结肿大,伴发热及肝脾肿大。临床分期Ⅱ期3例,Ⅲ期10例,Ⅳ期3例。组织学上见少数非典型性大细胞散在分布于小淋巴细胞和组织细胞背景中。免疫组织化学显示大细胞呈CD20、CD79a、EMA阳性,CD15、CD30阴性;背景小淋巴细胞呈CD3、CD45RO阳性,其中CD8、TIA-1阳性细胞多于CD57阳性细胞;组织细胞呈CD68阳性。CD21、CD35均为阴性反应。所检测的4例均为EBER1／2阴性,4例行IgH基因重排检测均可见单克隆条带。结论 TCRBCL有着独特的组织学和免疫表型特征,诊断应结合形态学和免疫表型特征。鉴别诊断包括霍奇金淋巴瘤、反应性淋巴组织增生、淋巴瘤样肉芽肿病等。     

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.     

B-zone small lymphocytic lymphoma: a morphologic, immunophenotypic, and clinical study with comparison to "well-differentiated" lymphocytic disorders.

The pathologic, immunologic, and clinical features of five cases of B-zone small lymphocytic lymphoma (BZSLL), characterized by a nondestructive growth pattern with a selective and complete replacement of the B-zone areas of lymph nodes, were examined. These findings were compared with those of 13 cases of intermediate differentiated lymphoma/mantle zone lymphoma (ILL/MZL) and 20 cases of typical small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). B-zone SLL was characterized histologically by a deceptively benign pattern at a low magnification, the lymph node architecture being substantially preserved, in contrast to the ILL/MZL and SLL/CLL cases, in which complete effacement of the normal architecture usually could be observed. Moreover, in BZSLL the cellular population was rather uniform and lacked either a prolymphocytic component or the small-cleaved lymphoid cells often seen in SLL/CLL and ILL/MZL cases, respectively. The phenotypic profile of the BZSLL clonal cell population studied by the immunoperoxidase method and by single- and double-labeling flow cytometric analyses (SIg+, CD19+, CD20+, CD21+, CD22+, CD24+, CD35+, CD37+, CD74+, CD45+, CD45R+, MB2+, HLA-DR+, Leu-8+, CD9+/-, CDw75+/-, CD5-/+, CD23-/+, CD10-, FMC7-, PCA-1-, CD25-, CD38-, CD43-, CD3-) appeared to be fairly homogeneous and sufficiently distinct from that of ILL/MZL, based on the absence of FMC7 and CD38 molecules, and from that of SLL/CLL due to significantly stronger expression of SIgs (P less than .05), the higher reactivity with anti-CD9 and -CD22 antibodies (P less than .05), the lower reactivity with anti-CD5 and -CD23 antibodies (P less than .05), and the absence of CD25 determinants. Several clinical features of patients with BZSLL, including age group, advanced stage disease, and high frequency of bone marrow and peripheral blood involvement, were similar to those found in the other patients with ILL/MZL and SLL/CLL, but none of the BZSLL patients had an absolute lymphocyte count higher than 15.0 x 10(9)/L at presentation. Based on the architectural pattern, cytologic features, immunophenotypes, and hematologic findings, we conclude that BZSLL is an unusual variant of SLL that is primary in the lymph nodes and should be distinguished from ILL/MZL and CLL.     

Clonal evolution of B cells in transformation from low- to high-grade lymphoma

An outcome of low-grade B cell non-Hodgkins's lymphomas is the transformation to high-grade diffuse large B cell lymphomas (DLBL). To investigate the mechanisms of clonal evolution in the transformation to DLBL, we performed longitudinal molecular analyses of immunoglobulin (Ig), V(H)DJ(H) gene sequences expressed in cases of chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), and follicular lymphoma (FL) that transformed to DLBL. Among the neoplastic CLL and SLL cells and their respective high-grade transformants, there was no evidence for a clonotypic shift or acquired mutations in the expressed Ig V(H)DJ(H) gene segments, as further confirmed by a specific and sensitive PCR-single strand polymorphism analysis. In contrast, among the FL cells there was a high degree of intraclonal diversification with highly divergent V(H)DJ(H) gene sequences. Despite this intraclonal heterogeneity, the related DLBL expressed a collinear but unique V(H)DJ(H) gene sequence. The intraclonal genealogical tree for the FL case demonstrated that the DLBL emerged in association with unique V(H)DJ(H) gene mutational events. Among the intraclonal FL and related DLBL transformants, the nature and distribution of the Ig V(H)DJ(H) gene mutations were consistent with antigenic selection. Thus, clonal evolution in the transformation from low- to high-grade B cell lymphoma may involve distinct pathways which vary according to the cellular origin and the type of the progenitor B cell tumor.     

Diffuse large B cell lymphoma expressing the natural killer cell marker CD56

The expression of the natural killer (NK) cell antigen, CD56, in hematological malignancies is rare. However, there are several reports that some hematological malignancies, such as T/NK cell lymphoma, multiple myeloma (MM) and acute myeloid leukemia (AML), express this molecule. In B cell non-Hodgkin's lymphomas (NHL), however, very limited number of cases have been reported to express CD56 molecule. Although one study has recently described that half of microvillous B cell lymphoma (MVL), an uncommon subset of large cell lymphoma, expressed CD56, there have been no reports about most common type of B-NHL, diffuse large B cell lymphoma (DLBL) other than a mention of weak CD56 expression in one of 83 DLBL. We herein presented the first case of diffuse large B cell lymphoma expressing CD56 clearly. The immunophenotype determined by immunostaining and flow cytometric analysis was CD10+, CD19+, CD20+, CD45RO-, CD3- and CD56+. On immunohistochemical study, neither bcl-2 nor TIA-1 was positive for tumor cell. Monoclonal immunoglobulin heavy chain (IgH) gene rearrangement was detected, and the sequence analysis of the variable region of IgH (VH) suggested that this tumor was derived from antigen selected post germinal center B cell. Conventional combination chemotherapy (CHOP) was administered, and the patient has still been in complete remission for 10 months.     

CD5+ follicle center lymphoma. Immunophenotyping detects a unique subset of "floral" follicular lymphoma

The "floral" variant of follicle center lymphoma (FCL) may be confused with progressive transformation of germinal centers or lymphocyte predominance Hodgkin lymphoma. Immunohistochemistry and gene rearrangement studies are usually sufficient to differentiate among these entities. We present 11 cases of floral FCL that were evaluated at our institution by flow cytometry, immunohistochemistry, or both and by polymerase chain reaction-based molecular analysis. In 4 cases, the neoplastic B cells coexpressed CD5 antigens; 3 of these 4 cases also were CD10+, and all demonstrated rearrangement within the bcl-2 locus. These findings demonstrate that a subset of floral FCL is CD5+. Recognition of this immunophenotype is important to avoid misdiagnosis of nodular variants of small lymphocytic lymphoma and mantle cell lymphoma. Studies suggest that expression of CD5 by neoplastic germinal center cells might result from alterations of the follicular microenvironment and/or inappropriate B-cell responses to cytokine networks.     

Composite primary breast diffuse large B-cell lymphoma and T lymphoblastic leukemia/lymphoma: report of a case and review of literature

We reported a rare case of composite diffuse large B-cell lymphoma and T lymphoblastic leukemia/lymphoma (T-LBL) in a 46-year-old woman with progressive enlargement of the breast lump. The patient initially sought care at a local hospital with a single left breast lump without any other physical examination findings. Histopathological analysis of which revealed a diffuse infiltration of tumor cells that were rich in cytoplasm with vesicular chromatin and prominent nucleoli. Further analysis of immunohistochemistry showed a cluster of neoplastic cells which express B-cell markers: CD19, CD20 (weak), CD79a, PAX5 and BCL-2, but negative for T-cell markers such as CD2, CD3, CD5 and CD7. PET-CT showed evidence of lymphadenopathy and splenomegaly, which may indicate lymphoma infiltration. Then a biopsy of bone marrow showed typical features of T-LBL. The aberrant terminal deoxynucleotidyl transferase (TDT) and cCD3 positive T-cell population that lack surface CD10 and CD19 were identified by flow cytometric immunophenotyping. Polymerase chain reaction analysis of the T-cell receptor gamma gene and IgH gene revealed a clonal rearrangement and confirming T-cell clonality. Fluorescence in-situ hybridization (FISH) revealed a deletion of the P53 gene in these T-neoplastic cells may indicate a bad outcome of such disease. Neither the large B-cells nor T-cells were positive for Epstein-Barr virus encoded RNA.     

Immunohistochemical detection of ZAP-70 in 341 cases of non-Hodgkin and Hodgkin lymphoma.

Using immunohistochemical methods, we evaluated zeta-associated protein (ZAP)-70 expression in 341 cases of non-Hodgkin and Hodgkin lymphoma. In B-cell NHL, ZAP-70 was positive in five of six (83%) precursor B-lymphoblastic lymphoma, 11 of 37 (30%) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), five of 39 (13%) mantle cell lymphoma, one of 12 (8%) Burkitt lymphoma, and one of 12 (8%) nodal marginal zone B-cell lymphoma. In 22 cases of CLL/SLL, seven of nine (78%) with unmutated IgVH genes expressed ZAP-70, compared with one of 13 (8%) with mutated IgVH genes (P=0.0015 Fisher's exact test). ZAP-70 expression was not detected in diffuse large B-cell lymphoma (n=26), extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (n=24), follicular lymphoma (n=21), plasma cell myeloma/plasmacytoma (n=10), lymphoplasmacytic lymphoma (n=10), or splenic marginal zone lymphoma (n=6). In T/NK-cell NHL, ZAP-70 was positive in all extranodal natural killer (NK) / T-cell lymphoma, nasal-type (n=6) and enteropathy-type T-cell lymphoma (n=4), four of five (80%) subcutaneous panniculitis-like T-cell lymphoma, six of eight (75%) mycosis fungoides, three of five (60%) precursor T-lymphoblastic lymphoma, 10 of 17 (59%) peripheral T-cell lymphoma, two of four (50%) blastic NK-cell lymphoma, one of three (33%) T-cell prolymphocytic leukemia, 13 of 52 (25%) anaplastic large cell lymphoma, and one of six (17%) angioimmunoblastic T-cell lymphoma. Seven of 12 (58%) cutaneous CD30-positive lymphoproliferative disorders were also ZAP-70-positive. In Hodgkin lymphoma, ZAP-70 was negative in neoplastic cells in all cases tested. ZAP-70 staining in B-cell lymphomas and reactive T cells was predominantly nuclear with variable cytoplasmic staining. By contrast, ZAP-70 staining in T/NK-cell lymphomas was heterogeneous, and a shift from predominantly nuclear to predominantly cytoplasmic staining was observed, particularly in those neoplasms with high-grade morphology. In summary, ZAP-70 is expressed by many lymphoma types, correlates with immunoglobulin heavy-chain variable region gene mutational status in CLL/SLL, and can be detected reliably using immunohistochemical methods.     

Bcl-6 protein expression by follicle center lymphomas. A marker for differentiating follicle center lymphomas from other low-grade lymphoproliferative disorders.

Low-grade lymphoproliferative disorders are a heterogeneous group of lymphoid neoplasms with wide variation in histologic features, immunologic phenotype, and molecular abnormalities. Subclassification of these disorders with small lymphocytic proliferation may be difficult on the basis of morphologic findings alone. The bcl-6 gene, originally cloned from a tumor with 3q27 translocation, is commonly expressed in large cell lymphomas. In humans, bcl-6 encodes for a Krüppel-type zinc finger protein and is believed to be important in germinal center formation. Bcl-6 protein is expressed mainly by follicle center cells and a few interfollicular T lymphocytes. We analyzed Bcl-6 expression with immunologic methods in common low-grade lymphoproliferative disorders as an aid to differentiation of tumors with follicle center origin. We analyzed Bcl-6 staining of formalin-fixed paraffin-embedded tissue from 72 indolent lymphomas including 31 grade I and II follicle center lymphomas (FCL). 13 small lymphocytic lymphomas (SLL), 12 mantle cell lymphomas (MCL), and 16 marginal zone lymphomas (MZL) including lymphomas of mucosa-associated lymphoid tissue and spleen. All of 31 FCL were positive for Bcl-6 expression. One of 13 SLL and 1 of 12 MCL were positive, whereas none of 16 MZL were positive. Bcl-6 was also detected in 5 of 5 FCL and 1 of 3 MZL but in no SLL or MCL by Western blot analysis in 14 cases with lymphoid disorders. Our study demonstrates that Bcl-6 expression is common in low-grade FCL but is rare in other indolent B-cell lymphoid disorders, and may be a useful adjunct in classification of indolent lymphomas.     

Genotypic and phenotypic alterations in Epstein-Barr virus-associated lymphoma

AIMS: Epstein-Barr virus (EBV) is associated with numerous reactive and neoplastic lymphoproliferative disorders. In vitro, EBV infection can transform B-lymphocytes and induce phenotypic alterations. This study presents the clinicopathological features of four cases with malignant lymphoma, which showed phenotypic and/or genotypic alterations during the course of the disease. METHODS AND RESULTS: To determine the type of EBV genotype, we performed polymerase chain reaction (PCR) for lymphocyte-defined membrane antigen (LYDMA) of EBV, subtype A/B and latent membrane protein (LMP)-1 deletion. In addition, we analysed the terminal repeat (TR) band of EBV and receptor genes (T-cell receptor gene, TCR; immunoglobulin gene heavy chain, IgH) for EBV-infected cell clonality. Double staining of cell markers (B, T-lymphocytes; histiocytes), and in-situ hybridization (ISH) for EBV were performed using tissues obtained during the course of the disease. The first case showed genotypic and phenotypic alterations of T-cell type to B-cell type. The first TCR rearrangement and T-cell markers (CD3+, CD4+, CD8-) were lost and IgH rearrangement and B-cell markers (CD19+, CD20+) were identified. During the course of the disease, EBV-TR bands changed in size; however, the EBV genotype type B, LMP1 deletion type, and single LYDMA band remained the same. The initial T-cell lymphoma clone was considered to be different from the latter B-cell lymphoma clone. The second case showed phenotypic alterations. The first B-cell marker (CD19+, CD20+, CD68-) changed to histiocytic markers (CD19-, CD20-, CD68+). However, IgH rearrangement and EBV-TR bands remained the same throughout the course of the disease and EBV genotype type A, LMP1 deletion type, and single LYDMA band remained unchanged. The third case showed phenotypic alterations. The B-cell marker (CD20+) was lost; however, IgH rearrangement of PCR and EBV genotype remained the same. In the second and third cases, the initial lymphoma clones were considered to be same as the latter clones. The last case showed lineage alterations from Hodgkin's disease to natural killer (NK) cell leukaemia. However, EBV genotype did not change. The second case and Hodgkin's disease showed LMP expression, but the first and third cases showed no LMP, and EBNA2 was not detected in all cases. CONCLUSIONS: We report the genotypic and/or phenotypic alterations in four patients with EBV-associated lymphoma/leukaemia. However, EBV genotype did not change in all four. These findings suggest that EBV might induce the cell marker and lineage alteration in vivo, as in vitro.