儿童系统性EB病毒阳性T细胞淋巴组织增殖性疾病的临床病理观察

目的 探讨儿童系统性EB病毒阳性T细胞淋巴组织增殖性疾病(CSEBV+T-LPD)的临床病理特征、诊断及鉴别诊断要点.方法 经过HE染色观察并采用免疫组织化学、原位杂交技术,结合临床资料,对30例CSEBV+T-LPD病例进行回顾性研究,并进行随访.结果 (1)CSEBV+T-LPD,男19例,女11例,中位年龄9岁;起病至确诊的时间平均14个月;主要临床表现有发热(96.7%),淋巴结增大(83.3%),肝脾肿大(66.7%),常见皮肤损害包括蚊虫叮咬超敏反应(13.3%)和皮疹(20.0%);20例随访患者中6例死亡,4例发展为淋巴瘤.(2)组织病理特点:淋巴结表现为T区扩大,淋巴滤泡缩小、减少甚至消失;病变主要为中小淋巴细胞以及多少不等的组织细胞,大细胞散在其中,轻至中度异型;21例淋巴结的间质及小血管增多,11例包膜增厚;另外,肝、脾和皮肤主要表现为轻至中度异形淋巴细胞浸润;3例可见噬血细胞现象.(3)免疫表型特点:病变中的中小淋巴细胞表达CD3、粒酶B和T细胞胞质内抗原(TIA-1);8例检测病例中7例表达CD8,1例主要表达CIM,也表达CD8;15例检测了CD56,2例阳性并已进展为NK/T细胞淋巴瘤,其余13例阴性.(4)30例均检测出EB病毒编码的小RNA(EBER)阳性细胞,数量5～500个/HPF;EBER在各种淋巴细胞中均阳性,9例以中至大淋巴细胞阳性为主,其余主要是中小淋巴细胞阳性;主要分布在T区,也见于套区、初级滤泡和生发中心内.结论 中国存在CSEBV+T-LPD;主要发生于儿童和青少年,病程为亚急性或慢性伴反复发热;此病为系统性病变,主要累及淋巴结和肝脾,也可累及皮肤,淋巴结以T区扩大和轻中度异形淋巴细胞浸润为主要形式;EB病毒感染的细胞毒性T细胞构成病变主体;是一种危及生命的疾病,患者往往死于严重并发症或进展为恶性淋巴瘤;应综合考虑临床、病理、免疫表形和EB病毒感染4方面信息以获得准确诊断.     

儿童系统性EB病毒阳性T细胞淋巴组织增殖性疾病的临床病理观察

目的 探讨儿童系统性EB病毒阳性T细胞淋巴组织增殖性疾病(CSEBV+T-LPD)的临床病理特征、诊断及鉴别诊断要点.方法 经过HE染色观察并采用免疫组织化学、原位杂交技术,结合临床资料,对30例CSEBV+T-LPD病例进行回顾性研究,并进行随访.结果 (1)CSEBV+T-LPD,男19例,女11例,中位年龄9岁;起病至确诊的时间平均14个月;主要临床表现有发热(96.7%),淋巴结增大(83.3%),肝脾肿大(66.7%),常见皮肤损害包括蚊虫叮咬超敏反应(13.3%)和皮疹(20.0%);20例随访患者中6例死亡,4例发展为淋巴瘤.(2)组织病理特点:淋巴结表现为T区扩大,淋巴滤泡缩小、减少甚至消失;病变主要为中小淋巴细胞以及多少不等的组织细胞,大细胞散在其中,轻至中度异型;21例淋巴结的间质及小血管增多,11例包膜增厚;另外,肝、脾和皮肤主要表现为轻至中度异形淋巴细胞浸润;3例可见噬血细胞现象.(3)免疫表型特点:病变中的中小淋巴细胞表达CD3、粒酶B和T细胞胞质内抗原(TIA-1);8例检测病例中7例表达CD8,1例主要表达CIM,也表达CD8;15例检测了CD56,2例阳性并已进展为NK/T细胞淋巴瘤,其余13例阴性.(4)30例均检测出EB病毒编码的小RNA(EBER)阳性细胞,数量5～500个/HPF;EBER在各种淋巴细胞中均阳性,9例以中至大淋巴细胞阳性为主,其余主要是中小淋巴细胞阳性;主要分布在T区,也见于套区、初级滤泡和生发中心内.结论 中国存在CSEBV+T-LPD;主要发生于儿童和青少年,病程为亚急性或慢性伴反复发热;此病为系统性病变,主要累及淋巴结和肝脾,也可累及皮肤,淋巴结以T区扩大和轻中度异形淋巴细胞浸润为主要形式;EB病毒感染的细胞毒性T细胞构成病变主体;是一种危及生命的疾病,患者往往死于严重并发症或进展为恶性淋巴瘤;应综合考虑临床、病理、免疫表形和EB病毒感染4方面信息以获得准确诊断.     

传染性单核细胞增多症的临床病理学特征及免疫表型分型

目的探讨传染性单核细胞增多症临床病理特征、免疫表型及EBV原位感染的特点,以提高对该病的认识和诊断水平。方法收集患者临床资料、各项实验室检查、淋巴结活检病理数据,采用免疫组化EliVision两步法和EBER原位杂交双重标记检测9例传染性单核细胞增多症,并进行文献复习。结果 9例患者平均年龄22岁,起病急,病程短,发热、肝脾及颈部淋巴结肿大,多数EBV CAV-IgM抗体阳性,EBV-DNA载量均增高,多数白细胞总数增高,肝功能异常;外周血淋巴细胞比例明显增高,异型淋巴细胞比例均大于10%。外周血免疫表型为高表达全T细胞标记及CD8,而CD4表达明显减低甚至不表达,CD4~+/CD8~+比值倒置。淋巴结结构有不同程度破坏,呈斑驳状,可见B细胞分化谱,无包膜增厚及间质纤维增生;病变以CD3阳性的淋巴细胞为主,CD20及CD30阳性的活化淋巴样母细胞及免疫母细胞散在分布,强弱不等;EBER原位杂交阳性的部位主要在T区。结论传染性单核细胞增多症是EBV引起的自限性淋巴组织增生性疾病,临床、病理工作中需综合考虑各方面的信息才能减少误诊,做出正确诊断。     

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。     

淋巴瘤样丘疹病临床病理分析

目的 探讨淋巴瘤样丘疹病(LyP)的临床病理特征、免疫表型及预后.方法 分析13例LyP的临床病理资料,用LSAB法、EliVision法行T淋巴细胞、B淋巴细胞、活化淋巴细胞和细胞毒性等12种免疫组织化学标记,原位杂交检测EB病毒.结果 13例LyP中男6例,女7例,平均年龄26.4岁,皮损多表现为四肢、躯干无症状的多发性丘疹、结节.组织学分型:A型6例,B型1例,c型6例,主要在真皮与皮下脂肪组织内浸润,主要浸润方式分别为楔形、带状及片状、结节状.13例中8例有瘤细胞亲表皮现象;1例B型无大瘤细胞,余12例的大瘤细胞均表达CD30.13例瘤细胞均表达2～3个T细胞标记(CD3、CD5或CD45RO)及1～3个细胞毒性标记[T细胞胞质内抗原(TIA)-1、粒酶B或穿孔素];13例均表达CD4、4例表达CD8、1例表达CD15、1例表达CD20(局灶阳性),均不表达间变性淋巴瘤激酶(ALK)-1.亲表皮之瘤细胞多为CD3~+、CD4~+、CD8~-表型.13例中1例EBER1/2原位杂交阳性.获随访的12例均存活.结论 LyP有独特的临床病理表现和免疫表型,预后较好.A型和C型中亲表皮的瘤细胞均为核扭曲、深染,似覃样霉菌病细胞,推测其与CD30~+大瘤细胞可能来源于不同的克隆群体有关.EB病毒与LyP可能无明确的相关性.     

进行性转化生发中心样滤泡T细胞淋巴瘤14例临床病理学分析

目的探讨进行性转化生发中心样滤泡T细胞淋巴瘤(PTGC样FTCL)的临床病理学特征。方法收集首都医科大学附属北京友谊医院病理科2017年1月至2022年1月14例PTGC样FTCL, 分析其临床特征、病理形态、免疫表型及EB病毒感染状态。对10例行T细胞受体基因检测, 对8例行免疫球蛋白(Ig)基因克隆性检测。结果 (1)患者男性10例, 女性4例, 男女比为5∶2, 发病年龄32～70岁, 中位年龄61岁, 起病时均有淋巴结肿大, 按Ann Arbor系统分期, Ⅰ～Ⅱ期7例, Ⅲ～Ⅳ期7例, 有B症状者7例, 脾肿大者4例, 伴皮疹及皮肤瘙痒者2例。10例获得原单位病理报告, 3例诊断为小B细胞淋巴瘤, 3例诊断为经典霍奇金淋巴瘤, 2例诊断为不除外血管免疫母细胞性T细胞淋巴瘤(AITL), 1例诊断为EB病毒相关淋巴组织增生性病变, 1例诊断为外周T细胞淋巴瘤(PTCL)伴多量B细胞反应。(2)形态学显示由形态成熟的小淋巴细胞构成的深染大结节, 结节内可见散在及灶状分布的异型瘤细胞, 胞质淡染或透明。2例在深染结节内见增生的生发中心。5例在结节内还见到散在霍奇金(HRS)样大细胞...     

原发性皮肤间变性大细胞淋巴瘤临床病理分析

目的 探讨原发性皮肤间变性大细胞淋巴瘤(C-ALCL)的临床病理特征、免疫表型及预后.方法 分析8例C-ALCL的临床病理资料,复习HE切片,进行T淋巴细胞、B淋巴细胞、活化淋巴细胞和细胞毒性等16种标记的免疫组织化学染色,原位杂交检测EB病毒.结果 8例中男3例,女5例,中位年龄49.5岁.临床上以皮肤无症状的单个红色结节、肿块为主要表现,组织学上肿瘤细胞在真皮与皮下脂肪内大片状、弥漫性浸润.瘤细胞以大细胞为主,异形性明显.8例C-ALCL的瘤细胞CD30阳性细胞数均大于75%.瘤细胞均表达1～3个T细胞标记(CD3、CD5或CD45RO)及1～3个细胞毒性标记[T细胞内抗原(TIA)-1、颗粒酶B或穿孔素].表达白细胞共同抗原(LCA)为8例、CIM为5例、CD8为1例、间变性淋巴瘤激酶(ALK)-1为1例、上皮细胞膜抗原(EMA)为3例,均不表达CD15、CD20、CK和HMB45.EBER 1/2原位杂交均为阴性.获随访的6例中5例存活,1例死亡(死因不详).结论 C-ALCL有独特的临床病理表现和免疫表型,预后较好.EB病毒与C-ALCL可能无明确的相关性.     

传染性单核细胞增生症淋巴结病病理诊断与鉴别诊断

目的 探讨传染性单核细胞增生症淋巴结病的病理形态学特点及诊断与鉴别诊断要点.方法 收集3例传染性单核细胞增生症淋巴结病(均为会诊病例:1例原单位诊断为间变性大细胞淋巴瘤,1例诊断为经典型霍奇金淋巴瘤,另1例未能定性),观察和分析其临床、病理组织学和免疫表型,并对病变淋巴结做EB病毒原位杂交检测.结果 3例患者中男性2例,女性1例,平均年龄15岁,平均病程16天;3例患者均表现为颈部淋巴结肿大,1例伴有低热及咽部疼痛.术后均未予特殊治疗,随访时间分别为5、9、18个月,无1例复发.镜检、免疫表型及EBV检测:淋巴结基本结构不同程度破坏,滤泡外免疫母细胞样大细胞增生,其大多数CD3、CD45RO、CD43、CD30均(+),CD15、EMA和ALK1(-),3例EBER均(+).结论 传染性单核细胞增生症淋巴结病的副皮质区有较多免疫母细胞增生,易过诊,但其临床特征、病理特点和免疫表型与大细胞淋巴瘤不同;结合EBV检测有助于其诊断.     

传染性单核细胞增多症患儿DNT细胞的变化及意义

目的探讨传染性单核细胞增多症(IM)患儿外周血DNT细胞和其他T淋巴细胞亚群的变化特点及其临床意义。方法应用流式细胞技术对53例生长发育正常的IM患儿外周血DNT细胞及其他T淋巴细胞亚群进行检测。结果 DNT细胞(CD3+CD4-CD8-)明显高于对照组(P0.001),Th细胞(CD3~+CD4~+)明显低于对照组(P0.001),Ts细胞(CD3+CD8+)明显高于对照组(P0.001)。结论 EB病毒感染的IM患儿外周血DNT细胞增多,免疫功能失调,与该病的发生发展关系密切,为IM患儿免疫治疗提供了理论依据。     

解读2008年恶性淋巴瘤WHO分类——T细胞和NK细胞淋巴瘤

1 T淋巴母细胞性白血病/淋巴瘤(T-lymphoblastic leukemia/lymphoma,T-ALL/LBL) 第4版分类中T-ALL/LBL的临床特点和形态学没有变化,免疫表型中强调除TdT外,证实前体T淋巴母细胞最特异性标记是CD99、CD34和CD1α.     

Characterization of the expanded T cell population in infectious mononucleosis: apoptosis, expression of apoptosis-related genes, and Epstein-Barr virus (EBV) status

Infectious mononucleosis (IM), a manifestation of primary infection with EBV, is characterized by a massive expansion of the T cell population. In this study we examined this expanded T cell population regarding its EBV status, its proliferative and apoptotic activity, and its expression of apoptosis-related genes. Whereas previous studies were performed on ex vivo cultures or on peripheral blood, our investigations included in vivo analysis of IM tonsillectomy specimens (14 cases) by in situ hybridization for viral RNA (EBERs) combined with immunohistochemistry (IHC; CD3, CD45RO, CD20, CD79a, Ki-67, Bcl-2, Bax, Fas, FasL) and the TUNEL method. Of the EBER+ cells 50-70% showed expression of the B cell markers CD20/CD79a. The remainder of the EBER+ cells expressed neither B nor T cell antigens. No co-expression of EBERs and T cell antigens was detected in any of the specimens. In accordance with a high rate of apoptosis (up to 2.37%) within the expanded T cell population, Bcl-2 expression was drastically reduced and FasL expression remarkably increased. The levels of Bax and Fas expression showed no or moderate up-regulation. In conclusion, the massive expansion of IM T cells is not caused by EBV infection of these cells but merely represents an intense immune reaction. Through altered expression of Bcl-2/Bax and Fas/FasL, the activated T cells are subject to enhanced apoptosis while residing within the lymphoid tissue, which eventually allows the efficient silencing of this potentially damaging T cell response.     

Prevalence of EBV RNA in sinonasal and Waldeyer's ring lymphomas.

A high incidence of a T cell phenotype of sinonasal lymphomas in other Asian countries has been associated with a high incidence of Epstein Barr virus (EBV) infection. We analyzed 13 sinonasal and 18 Waldeyer''s ring lymphomas for the prevalence of EBV encoded RNA (EBER) using a sensitive and specific in situ hybridization. In addition, we examined the relationship of histologic findings and immunophenotype as well as the location of the lymphomas to the presence of EBV. The EBER was detected in each of 12 sinonasal lymphomas with a T cell immunophenotype. One B cell sinonasal lymphoma was EBER negative. Four of 18 Waldeyer''s ring lymphomas were positive for EBER, including two T cell lymphomas. Two of 16 B cell Waldeyer''s ring lymphomas were EBER positive. Morphologically, 11 of 20 diffuse large cell lymphomas, 2 diffuse mixed small and large cell lymphomas, 2 of 4 immunoblastic lymphomas and 1 lymphoplasmacytic lymphoma were EBER positive. Four follicular large cell lymphomas were EBER negative. A characteristic angiocentric or angiodestructive pattern was found in most T cell lymphomas and EBER positive cases. These findings indicate that EBV infection is more strongly associated with the T cell immunophenotype, angiocentric pattern and sinonasal location of the lymphoma.     

Expression of B7 (CD80) and CD40 antigens and the CD40 ligand in Hodgkin's disease is independent of latent Epstein-Barr virus infection

Aim-To examine the expression of CD40 and B7 (CD80) antigens and the CD40 ligand in Hodgkin's disease.Methods-Antigen and ligand expression was studied in 17 cases of Hodgkin's disease using immunohistochemistry. The study included 11 cases of Hodgkin's disease in which latent Epstein-Barr virus (EBV) infection could be demonstrated within tumour cells by in situ hybridisation for the EBV encoded early RNAs (EBERs).Results-In all cases, irrespective of EBV status, Reed-Sternberg cells and their variants (HRS cells) showed strong expression of both B7 and CD40 antigens. CD40 ligand expression was not shown in HRS cells but was confined to a subset of small lymphocytes some of which were seen to be in intimate contact with HRS cells.Paraffin wax sections from a further 60 cases of Hodgkin's disease were examined for CD40 and EBER expression alone. The CD40 antigen was identified in HRS cells in all of these cases irrespective of EBER expression.Conclusions-As CD40 and B7 expression are features of professional antigen presenting cells, these results provide further evidence that HRS cells may have antigen presenting properties and that this may contribute to the characteristic recruitment and activation of non-malignant lymphocytes which is a feature of Hodgkin's disease. The ability of HRS cells to activate T(h) cells may in turn contribute to their own survival through the induction of the gp39/CD40 pathway.     

Epstein-Barr virus status and the histopathological changes of parotid gland lymphoid infiltrates in HIV-positive children

This study examined the EBV status and the morphology in parotid glands of a large cohort of HIV-positive pediatric patients. Nineteen children with vertically acquired HIV infection, ranging in age from three months to seven years and two months, were analyzed. Seventeen patients were assessed for serological evidence of EBV infection; nine showed evidence of past infection, one each re-activation and current infection and six did not have serological evidence of EBV. Immunohistochemistry and in situ hybridization for EBER 1 and 2 were performed on formalin-fixed, paraffin-embedded tissue. Fourteen of the 19 cases were classified as severe or established myoepithelial sialadenitis (MESA) and five were regarded as having mild MESA. The majority of intraepithelial lymphocytes were of B-cell lineage, while the pericystic infiltrate contained CD8-positive T-lymphocytes. p24 immunohistochemistry for HIV showed positive follicular dendritic cells, lymphoid cells and macrophages. Ten of 14 cases were positive for EBER 1 and 2. These included cases that were serologically negative for EBV. This study confirms that the morphology and immunophenotype of pediatric HIV-associated parotid lesions are similar to those seen in adults. Ten of 14 cases with evidence of EBV within the lymphoid infiltrate showed the same morphology and immunophenotype as cases in which EBV was not detected either by serology or by in situ hybridization. These findings indicate that EBV is not uniformly found in either the tissue or serum of these patients, and may not have a pathogenetic role in HIV-associated lymphoepithelial lesions in the pediatric age group.     

Accumulation of p53 in infectious mononucleosis tissues

Epstein-Barr virus (EBV) infects lymphocytes, where it persists indefinitely for the life of the host; whether the virus interacts with p53 to maintain itself in these cells is unknown. Lymphoid biopsy samples from 10 patients with infectious mononucleosis (IM) were examined for expression of p53 by immunohistochemistry. Accumulation of p53 was detected in all 10 cases, primarily in large lymphocytes of the expanded paracortex. The presence of EBV was confirmed in all 10 cases by EBER1 (EBV-encoded RNA) in situ hybridization, whereas 11 non-IM control samples lacked significant EBER1 and did not express p53 in paracortical lymphocytes. Interestingly, EBV infection alone does not cause accumulation of intracellular p53, because many more cells expressed EBER1 than p53 in the IM tissues. To determine whether p53 was confined to the subset of infected cells in which viral replication was occurring, BZLF1 immunostains were performed. Viral BZLF1 was detected in 8 of 10 IM tissues; however, the paucity and small size of the BZLF1-expressing lymphocytes suggests that they are not the same cells overexpressing p53. To further examine the relationship between p53 and EBV gene expression, the tissues were studied for latent membrane protein 1 (LMP1) expression by immunohistochemistry. Viral LMP1 was observed in the large paracortical lymphocytes of all 10 cases of IM, indicating co-localization of p53 and LMP1 in these cells. Our findings confirm that p53 overexpression is not specific for nodal malignancy and that p53 accumulation is characteristic of IM. Because p53 was not coexpressed in the same cells as BZLF1, it appears that BZLF1 is not directly responsible for p53 accumulation. Nevertheless, co-localization of p53 and LMP1 in activated-appearing lymphocytes suggests that EBV infection is responsible for p53 accumulation. HUM PATHOL 31:1397-1403.     

皮下脂膜炎样T细胞淋巴瘤的细胞毒颗粒相关蛋白TIA—1的表达及 …

目的 认识皮下脂膜炎样Ｔ细胞淋巴瘤（ＳＰＴＣＬ）的临床和病理特点。研究细胞毒颗粒相关蛋白ＴＬＡ－１在ＳＰＴＣＬ中的表达及与Ｅｐｓｔｅｉｎ－Ｂａｒｒ（ＥＢ）病毒感染的关系。方法 和ＴＩＡ－１、ＣＤ４５ＲＯ、ＣＤ３、ＣＤ２０和ＣＤ６８等抗体作免疫组织化学ＡＢＣ法染色应用ＥＢＥＲ１／２原位杂交检测ＥＢ病的潜伏感染。结果 １７例ＳＰＴＣＬ男女之比１：１．１．中位发病年龄２４岁,主要表现为下肢、躯干无症状性     

EB病毒感染与中线恶性网织细胞增多症

使用一个针对ＥＢ病毒编码的小分子ＲＮＡ（ＥＢＥＲ）的寡核苷酸探针对１９例中线恶性网织细胞增多症病变组织进行了原位杂交检测，并配合免疫表型分析。结果为：（１）本组病例中１８／１９例（９４．７％）的病变组织中的异形淋巴样细胞表达Ｔ细胞分化抗原。ＣＤ３阳性１５例，ＵＣＨＬ１阳性９例，其中二者均阳性６例，但各例中的异形淋巴样细胞均未表达Ｂ细胞及组织细胞分化抗原；（２）ＥＢＥＲ原位杂交检测的阳性数高（１５／     

Epstein-Barr virus-latent gene expression and tumor cell phenotype in acquired immunodeficiency syndrome-related non-Hodgkin's lymphoma. Correlation of lymphoma phenotype with three distinct patterns of viral latency.

We investigated 49 acquired immunodeficiency syndrome-related lymphomas (ARLs) for Epstein-Barr virus (EBV) by Southern blotting and in situ hybridization and, in positive cases, used cryostat immunohistology to compare EBV-latent gene expression (EBV encoded small RNA-1 [EBER-1], EBV nuclear antigen-2 [EBNA-2], latent membrane protein-1 [LMP-1] and host cell immunophenotype (CD11a, CD18, CD54, CD58, CD21, CD23, CD30, CD39, CDw70, immunoglobulin) patterns with those reported in other EBV infections. EBV+ immunoblast-rich/large cell ARLs (n = 22) showed three patterns of latency: broad (EBER+EBNA-2+/LMP-1+; n = 9), reminiscent of a lymphoblastoid cell line phenotype; restricted (EBER+/EBNA-2-/LMP-1-; n = 6), similar to endemic Burkitt's lymphoma; and intermediate (EBER+/EBNA-2-/LMP-1+; n = 7), a pattern rarely described in vitro but seen in certain EBV-related malignancies. EBNA-2 expression was associated with extranodal lymphomas. EBV+ Burkitt-type ARLs (n = 11) usually showed the restricted latency pattern (n = 8), but some expressed the intermediate form (n = 3). Adhesion (CD54, CD58) and activation (CD30, CD39, CDw70) molecule expression varied with morphology (immunoblast-rich/large cell versus Burkitt-type), but was not independently correlated with EBV-positivity. CD30 and LMP-1 expression were associated. ARLs show heterogeneity regarding both the presence of EBV and latency pattern. Comparison of these phenotypically distinct lymphoma groups with known forms of EBV infection provides clues to their possible pathogenesis.