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.     

A biological role for deletions in chromosomal band 13q14 in mantle cell and peripheral t-cell lymphomas?

Structural aberrations of chromosomal band 13q14 are frequent in B-cell chronic lymphocytic leukemia (B-CLL) and target a putative tumor suppressor gene in the genomic region between the RB1 gene and the genetic marker D13S25. Recently, it has been suggested that alterations of this particular region might also be of relevance for the pathogenesis of mantle cell lymphomas (MCL). We applied dual-color fluorescence in situ hybridization (FISH) using probes for the RB1 and/or D13S25 loci and screened a total of 236 B- and T-cell non-Hodgkin's lymphomas (NHL) for deletions occurring in this genomic region. In MCL, the high rate (12/32; 38%) of hemizygous deletions and especially a deletion pattern similar to B-CLL in four of the cases provide further evidence that a substantial proportion of MCL cases may share a common way of pathogenesis with B-CLL. In other B-cell NHL, the frequency of allelic loss affecting 13q14 was overall low. However, the finding of 13q14 microdeletions in seven cases without detectable alterations of chromosome 13 at G-banding analysis might indicate a possible involvement of this genetic region also for the lymphomagenesis of single cases of B-cell NHL other than B-CLL and MCL. In T-cell NHL, allelic loss at 13q14 was encountered in three of 13 peripheral T-NHL, NOS. Taking into account the very limited cytogenetic data yet available in this entity, our series provides further evidence that 13q14 changes might represent one of the most frequent genetic abnormalities in T-cell NHL.     

Quantitative microsatellite analysis to delineate the commonly deleted region 1p22.3 in mantle cell lymphomas

The molecular pathogenesis of mantle cell lymphomas (MCL), a subset of B-cell non-Hodgkin's lymphomas with a poor prognosis, is still poorly understood. In addition to the characteristic primary genetic alteration t(11;14)(q13;q32), several further genetic changes are present in most cases. One of the most frequent genomic imbalances is the deletion of 1p22.1-p31.1 observed in nearly one-third of MCL cases. This might indicate the presence of tumor suppressor gene(s) in this critical region of deletion. Quantitative microsatellite analysis (QuMA) is a real-time PCR-based method to detect DNA copy number changes. Since QuMA has the resolving power to detect subtle genomic alterations, including homozygous deletions, this may help to identify candidate tumor suppressor genes from deleted regions. To gain more insight into the molecular pathogenesis of MCL, QuMA was performed on genomic DNA from 57 MCL cases. Eight microsatellite loci mapping to the chromosomal region 1p22.3 were analyzed. Losses were observed in 51 of the 57 ( approximately 89.5%) samples. Two cases showed a homozygous deletion at the locus containing the gene SH3GLB1, which plays a key role in Bax-mediated apoptosis. Two hotspots with copy number losses were detected at chromosomal localizations 85.4 and 86.6 Mb encompassing BCL10 and CLCA2. Both the genes seem to be attractive candidates to study tumor suppressor function in MCL.     

Clonal Epstein-Barr virus genome in T-cell-rich lymphomas of B or probable B lineage.

Seventeen nodal lymphomas (originally diagnosed as T-cell lymphomas based on histological features and immunohistochemical staining results) were studied for the presence of Epstein-Barr virus (EBV) genome, and the results correlated with immunoglobulin and T-cell receptor gene rearrangement analyses performed on the same tissue samples. All four EBV positive cases had clonal rearrangement of the joining region of the immunoglobulin heavy chain (IgJH) gene without clonal T-cell receptor beta-chain (TCR beta) gene rearrangement. Of these, two cases also showed clonally rearranged light chain gene, and they were reclassified as T-cell rich B-cell lymphomas (TRBL). The other two cases lacked clonal kappa or lambda light chain rearrangement and they were reclassified as T-cell rich lymphomas of probable B lineage, based on their isolated IgJH clonal rearrangement. These B-cell lymphomas may be easily misdiagnosed as T-cell lymphomas owing to the presence of an abundant reactive T-cell infiltrate masking the tumor population. The florid T-cell reaction may represent an unusual host response towards a clonal proliferation of EBV bearing B cells.     

Multiplex single-tube screening for mutations in the Nijmegen Breakage Syndrome (NBS1) gene in Hodgkin's and non-Hodgkin's lymphoma patients of Slavic origin

Patients with Nijmegen Breakage Syndrome (NBS) have a high risk to develop malignant diseases, most frequently B-cell lymphomas. It has been demonstrated that this chromosomal breakage syndrome results from mutations in the NBS1 gene that cause either a loss of full-length protein expression or expression of a variant protein. A large proportion of the known NBS patients are of Slavic origin who carry a major founder mutation 657del5 in exon 6 of the NBS1 gene. The prevalence of this mutation in Slav populations is reported to be high, possibly contributing to higher cancer risk in these populations. Therefore, if mutations in NBS1 are associated with higher risk of developing lymphoid cancers it would be most likely to be observed in these populations. A multiplex assay for four of the most frequent NBS1 mutations was designed and a series of 119 lymphoma patients from Slavic origin as well as 177 healthy controls were tested. One of the patients was a heterozygote carrier of the ACAAA deletion mutation in exon 6 (1/119). No mutation was observed in the control group, despite the reported high frequency (1/177). The power of this study was 30% to detect a relative risk of 2.0.     

A practical approach to immunophenotyping of lymphomas. Comparison of immunohistologic and immunocytologic techniques

Comparison of immunohistologic (IH) and immunocytologic (IC) techniques was conducted on 86 specimens. Forty-seven B-cell, five T-cell, and two null-cell lymphomas were identified by IH as well as 16 cases of lymphoid hyperplasia. The results of IC were generally identical to those of IH except for two T-cell and two B-cell lymphomas. The diagnosis of T-cell lymphoma was a major problem for IC because of the presence of normal T-cell count and/or normal helper/suppressor ratio in these cases. Twenty-one percent of the B-cell lymphomas failed to express surface immunoglobulin but did express B1 and HLA-DR antigens. Such a discrepancy was not demonstrated in cases of lymphoid hyperplasia, thus serving as a useful criterion in the diagnosis of B-cell lymphoma. While combined IH and IC should be used for immunophenotyping in large medical centers, IH is recommended for community hospitals. The identification of kappa, lambda, B1 and T11 (Leu 5) antigens in frozen sections with the immunoperoxidase technique should be sufficient to phenotype most lymphoproliferative diseases. The criteria for immunophenotyping of lymphomas are discussed.     

淋巴组织良性病变和淋巴瘤中SHP-1蛋白的表达及意义

目的探讨淋巴组织良性病变和淋巴瘤的SHP-1蛋白表达及其意义。方法应用免疫组化SP方法检测111例不同类型淋巴瘤和27例淋巴组织良性病变。结果(1)SHP-1的正常表达部位在淋巴结和扁桃体生发中心的套区和边缘区及部分的滤泡间区,脾脏主要在边缘区及部分动脉周围淋巴鞘;在淋巴瘤中残留的淋巴组织和反应性成分也可表达;淋巴瘤的SHP-1蛋白表达比良性病变弱。(2)SHP-1在淋巴瘤中的阳性表达率(36·04%,40/111)远低于良性病变的阳性表达率(100%,27/27),包括霍奇金淋巴瘤(62·5%,5/8)、B细胞非霍奇金淋巴瘤(37·68%,26/69)、T细胞非霍奇金淋巴瘤(26·47%,9/34);不同亚型淋巴瘤表达上有差异,其阳性表达率分别是:黏膜相关淋巴瘤(12·5%,2/16),弥漫性大B细胞淋巴瘤50%(11/22),滤泡性淋巴瘤42·11%(8/19),大细胞间变性淋巴瘤中有80%(4/5),NK/T细胞淋巴瘤16·67%(1/6),前驱T淋巴母细胞淋巴瘤14·29%(1/7),外周T细胞淋巴瘤0(0/7)。(3)滤泡性淋巴瘤的表达方式有:肿瘤性滤泡有阳性表达;肿瘤性滤泡无表达,滤泡周围也是阴性。结论(1)SHP-1在淋巴瘤鉴别诊断中有参考意义,尤其适合滤泡反应性增生的良性病变和滤泡性淋巴瘤的鉴别。(2)SHP-1蛋白的缺失与淋巴瘤的发生、发展密切相关,是重要的抑癌基因。     

Combined polymerase chain reaction approach for clonality detection in lymphoid neoplasms.

The present study analyzes the efficiency of a combination of four immunoglobulin heavy chain (IgH) gene polymerase chain reaction (PCR) primer systems and a multiplex T-cell receptor gamma chain (TRG) gene PCR for detection of clonality in 409 samples (234 paraffin sections, 175 bone marrow aspirates) of different lymphomas. Using the four IgH PCR systems together, clonality was detected in all samples of B-cell chronic lymphocytic leukemias, hairy cell leukemias, common acute lymphoblastic leukemias, and Burkitt-like B-cell lymphomas. Clonality was detected in all bone marrow aspirates with lymphoplasmacytoid immunocytoma, mantle cell lymphoma, marginal zone B-cell lymphoma, and unclassifiable low-grade B-cell lymphomas. The combined IgH gene PCR approach allowed clonality detection in 78.2% of myelomas, 75% of Burkitt lymphomas, 74.4% of diffuse large B-cell lymphomas, 68.7% of follicular center lymphomas, 50% of posttransplant lymphomas, 28.6% of anaplastic large cell lymphomas, 29% of T-cell lymphomas, and 18.8% of Hodgkin diseases. The combination of the four IgH gene primer systems with the multiplex TRG gene PCR allowed detection of clonality in 84.2% of B-cell neoplasms, 92.1% of T-cell non-Hodgkin lymphomas, and 18.8% of Hodgkin diseases, which was much more efficient than single PCR protocols.     

Primary bony peripheral T-cell lymphoma mimicking nasal type NK/T-cell lymphoma: a case report

Primary bony lymphomas are rare, and nearly all are high-grade B-cell lymphomas. Natural killer (NK)/T-cell lymphomas are highly aggressive lymphomas of NK- or T-cell lineage with predominant extranodal presentation and are divided into nasal and nasal-type (extra-nasal). We report a primary bony peripheral T-cell lymphoma mimicking NK/T-cell lymphoma, nasal type. A 22-year-old Taiwanese male presented with a frontal skull bone mass noted for 3 weeks, and received craniectomy with tumor removal. His tumor showed extensive coagulative necrosis with angioinvasion by large lymphoma cells expressing CD2, CD8, CD16, CD43, CD45, CD45RO, CD56, T-cell intracellular antigen-1, and granzyme B, but not CD3, CD4, CD20, CD57, CD68, and betaF1. In situ hybridization for Epstein-Barr virus-encoded mRNA was negative. Polymerase chain reaction study of formalin-fixed tissue showed clonal rearrangement of the T-cell receptor-gamma chain gene. The diagnosis was peripheral T-cell lymphoma, unspecified subtype. The initial stage was I(EA). His lymphoma was refractory to chemotherapy, and bony metastases developed in the right iliac bone 2 months later. He died of disease after 6 months without autopsy. We emphasize the importance of detailed immunohistochemical and gene rearrangement studies for the classification of malignant lymphomas via a very rare primary bony lymphoma of peripheral T-cell subtype.     

Immunophenotypic and genotypic characterization of primary non-Hodgkin's lymphoma of the gastrointestinal tract

Antigen receptor gene rearrangement studies have been applied to gastrointestinal (GI) lymphoid proliferations in only a limited number of cases, and their use and contribution to the diagnosis and characterization of GI lymphomas is unknown. We retrospectively studied 17 cases of primary GI lymphoma using fresh/frozen tissue with a combination of immunophenotypic and genotypic techniques. The vast majority of the neoplasms were B-cell lymphomas (88%) with rare T-cell tumors. The most common B-cell immunophenotype was IgM-kappa (40%), while five of the B-cell lymphomas (33%) lacked surface light chain immunoglobulin. Immunophenotypic evidence of histiocytic differentiation was not identified. Clonality was confirmed in 59% (10/17) of the neoplasms by immunophenotyping and 88% (15/17) by antigen receptor gene rearrangement studies. All of the 15 B-cell lymphomas (100%) demonstrated clonally rearranged immunoglobulin gene rearrangement. The two lymphomas with T-cell immunophenotypes did not demonstrate T-cell receptor beta-chain gene rearrangement. Antigen receptor gene rearrangement data can be useful and may even be necessary in certain cases for the proper classification and/or diagnosis of GI lymphoid proliferations.     

Allelic imbalance mapped to 6q14.1 is associated with loss of expression of 5-HT receptor 1B in non-Hodgkin lymphomas.

Previous studies on lymphomas suggested that the long arm of chromosome 6 harbors 1 or more tumor suppressor genes. This study analyzed the status of 25 microsatellite markers in 39 cases, including 9 nodal and 30 extranodal, of non-Hodgkin lymphomas. Thirty of the 39 cases (77%) showed abnormality in at least 1 of the markers. Of the 655 informative results, 135 (20%) were abnormal. These included 5 homozygous deletions, 91 allelic imbalances (AI), and 38 microsatellite instability. The 2 commonest regions of abnormality were mapped to 6q14.1 and 6q27. There was no significant difference in the frequency of these regional losses between nodal and extranodal lymphomas, B-or T-cell lineage, and association with Epstein-Barr virus. The first common deletion region at 6q14.1 is flanked by the HTR1B (5-hydroxytryptamine receptor 1B) gene proximally and a novel unknown gene. AI in the region was found associated with loss of expression HTR1B by RT-PCR. The deletion region at 6q27 was narrowed to approximately 3Mb and maximal at marker D6S386. This locus includes the recently identified SMOC2 (secreted modular calcium-binding protein 2), AF6, and DLL1 (human delta-like 1 protein) genes. RT-PCR analyses of AF6 and DLL1 expression showed poor correlation with the AI results.     

Malignant lymphomas of the nasal cavity and paranasal sinuses. A clinicopathologic and immunohistochemical study.

The clinicopathologic and immunohistological features of 20 Japanese patients with non-Hodgkin's lymphomas (NHLs) limited to the sinonasal area were studied using a broad panel of T- and B-cell markers on paraffin-embedded and fresh frozen tissue. All cases showed a diffuse growth pattern. Nine cases were B-cell lymphomas (immunoblastic n = 4, centroblastic n = 3, immunocytoma n = 1, centrocytic n = 1), and nine were T-cell lymphomas (pleomorphic medium and large cell n = 8, angioimmunoblastic n = 1). In two cases, the cell lineage could not be determined. No morphologic features of angiocentric/angiodestructive lymphoproliferative lesions or lymphoepithelial lesions in ductal or glandular epithelium were seen in our series. Eight (89%) of the nine T-cell tumors and four (44%) of the nine B-cell neoplasms involved both the nasal cavity and paranasal sinuses. Six of the nine T-cell neoplasms showed a clinical presentation of rhinitis, whereas all of the B-cell neoplasms showed tumor masses in the nasal cavity and/or paranasal sinuses. The two-year survival rate for T-cell lymphomas was poorer than that for B-cell lymphomas. The five-year survival of patients with NHLs involving both the nasal cavity and paranasal sinuses was also poorer than that of patients in whom NHLs were limited to the nasal cavity.     

Detection by fluorescence in situ hybridization of microdeletions at 1p36 in lymphomas,unidentified on cytogenetic analysis

The chromosomal band 1p36 exhibits frequent loss of heterozygosity in a variety of human malignancies, suggesting the presence of an as yet unidentified tumor suppressor gene. The faint terminal subbands often make cytogenetic analysis of 1p36 particularly difficult. Small deletions at this locus may therefore escape detection on analysis by conventional cytogenetics, a hypothesis that we have explored using fluorescence in situ hybridization (FISH) in malignant lymphoma. The study cohort consisted of 20 cases of lymphoma of various subtypes without any 1p abnormality on G-banded karyotyping. FISH was performed using a human chromosome 1 paint and a bacterial artificial chromosome probe RP4-755G5 localizing to 1p36.33, the most telomeric subband of 1p36. Tumors demonstrating 1p36.33 deletions were additionally analyzed by FISH using a second probe from the proximal 1p36.1 subband, to further define the breakpoint. Eight cases of follicular lymphoma (FL), 5 diffuse large B-cell lymphomas (DLBCL), 2 Hodgkin disease, 2 B-cell small lymphocytic lymphomas, 2 T-cell lymphomas, and 1 marginal zone lymphoma were analyzed. FISH identified deletions at 1p36.33 in 5 of the 20 cases: 3 DLBCL and 2 FL. FISH is considerably more sensitive for identifying lymphoma genetic alterations than conventional cytogenetics. Deletion of the distal part of the 1p36 may be a much more common aberration than previously recognized in lymphoma.     

Biclonality of composite B- and T-cell lymphomas. A case report

Most composite lymphomas which are composed morphologically of two different tumor cell types are considered to represent different morphological expressions of a single clone. However, in recent years, composite B- and T-cell lymphomas and biclonality of B-cell lymphoma have been reported. We experienced a case of composite lymphoma which initially developed as cutaneous lymphoma composed of lymphoplasmacytes associated with large clear cells. It was confirmed that the tumor cells of these two systems were biclonal on the basis of surface markers and DNA rearrangements, i.e. B cells of the IgG kappa type, showing IgH and kappa chain DNA rearrangement, and T-cells with CD4 surface marker, showing rearrangement of the T-cell receptor beta chain gene. This case showed a predominant B-cell pattern at the initial stage, and terminated in T-cell lymphoma, as revealed at autopsy. Therefore we considered this case to be a unique composite lymphoma showing biclonality of both B- and T-cell systems, providing a number of suggestions for future study of malignant lymphoma.     

Genotypic analysis of large cell lymphomas which express the Ki-1 antigen

The monoclonal antibody Ki-1 reacts with Reed-Sternberg cells in Hodgkin's disease and with the tumour cells in a minority of large cell non-Hodgkin's lymphomas. This study describes the results of immunophenotypic and DNA analysis in 30 cases of non-Hodgkin's lymphoma, all of which expressed the Ki-1 antigen. The genotypic analysis has been undertaken using both immunoglobulin and T-cell receptor gene probes. Sixteen cases were shown by this method to be of monoclonal T-cell origin, six of B-cell origin, while in eight cases there was no evidence of either T- or B-cell lineage. This confirms previous immunohistological data indicating that non-Hodgkin's lymphomas which express the Ki-1 antigen may be of either T-cell or B-cell origin.     

Testicular natural killer/t-cell lymphoma,nasal type,of true natural killer-cell origin

The majority of primary testicular lymphomas are of B-cell type. Other primary lymphomas are rarely encountered in the testes. Natural killer (NK)/T-cell lymphomas of nasal type are aggressive extranodal lymphomas associated with Epstein-Barr virus infection that are usually encountered in the upper aerodigestive tract. They also occur in the skin, soft tissue, and colon. Primary testicular NK/T-cell lymphomas are rarely reported. We describe the case of a 66-year-old Korean man who presented with right-sided painless testicular enlargement and underwent radical orchiectomy. Histologic examination revealed an angiocentric and angioinvasive infiltrate of medium to large tumor cells with moderately abundant pale pink cytoplasm and folded and indented pleomorphic nuclei. Paraffin immunohistochemical studies showed positivity of the tumor cells for CD45, TIA-1, granzyme B, CD56, and CD3 epsilon. In situ hybridization showed diffuse positivity for Epstein-Barr virus-encoding RNA. The results of gene rearrangement studies for the gamma chain of the T-cell receptor were negative. The results of paraffin immunohistochemical studies for CD20, CD8, CD45RO, beta f1, and ALK-1 were negative. An extensive workup showed no evidence of lymphoma outside the testes. We report a rare case of primary testicular NK/T-cell lymphoma of the nasal type of true NK-cell origin.     

T-cell lymphoma in HIV-infected patients

Linkage of AIDS and cancer registries has indicated an increase in T-cell lymphomas among individuals infected with the HIV. The characteristics of T-cell versus B-cell lymphoma in HIV-infected patients are not well described. Retrospectively, 11 cases of T-cell lymphoma were identified from the AIDS-Lymphoma Registry at the University of Southern California. These patients were compared with 418 consecutive HIV-seropositive patients with B-cell lymphoma diagnosed and treated within the same time period. T-cell lymphomas comprised 3% of all AIDS lymphomas. Pathologic types included peripheral T-cell lymphoma in 5; anaplastic large cell lymphoma in 3; and angioimmunoblastic, enteropathy type, and human T-cell lymphotropic virus-I-related adult T-cell lymphoma/leukemia in 1 case each. No differences in demographic characteristics, history of prior opportunistic infection, or immunologic characteristics were observed between T-cell and B-cell cases. Extranodal involvement of the skin (36% vs. 2%, P < 0.001) and bone marrow (45% vs. 15%, P = 0.019) was significantly more common in T-cell lymphomas. The median survival of patients with T-cell lymphomas was not significantly different from that of B-cell lymphoma patients (10.6 vs. 6.6 months, P = 0.13). T-cell lymphomas in HIV-infected patients represent a spectrum of pathologic types. T-cell lymphomas differ from B-cell cases in terms of a higher propensity for skin and bone marrow involvement. The median survival of patients with T-cell lymphoma is comparable to that of patients with B-cell AIDS-related lymphoma.