Large Noncleaved Cell Research Articles

Diffuse large B-cell lymphoma presenting as sternal mass in a patient with ankylosing spondylitis: a case report study.

The authors present a rare case of primary diffuse large B-cell lymphoma of the sternum in a 41-year-old Iranian woman with ankylosing spondylitis (AS). Physical examination revealed a 7×7.5cm firm swelling of the anterior midline chest wall above the breasts, and MRI showed a lesion within the sternal marrow with an associated soft-tissue mass in the anterior aspect of the sternum. Following core-needle biopsy under ultrasound guidance, a histopathological study demonstrated diffuse sheets of large noncleaved atypical cells with large multilobated prominent nuclei and fine chromatin compatible with diffuse large B-cell lymphoma. Primary and exclusive involvement of the sternum is an uncommon presentation of lymphoma. Radiological, histological, and clinical characteristics of primary bone lymphoma can resemble those of other medical disorders. Although infrequent, existing evidence shows that AS seems to be associated with a small but significant risk for malignancy. Even though inflammatory involvement of the anterior chest wall could be a common clinical finding in patients with AS, it is recommended that anterior chest wall pain or any mass almost always needs comprehensive assessment and imaging evaluation in such patients to avoid any delayed diagnosis, misdiagnosis, and ensuing morbidity or mortality.

Differential Expression of BCL-6, CD138/Syndecan-1, and Epstein-Barr Virus–Encoded Latent Membrane Protein-1 Identifies Distinct Histogenetic Subsets of Acquired Immunodeficiency Syndrome–Related Non-Hodgkin's Lymphomas

AbstractThis study was aimed at defining the histogenesis of the pathologic spectrum of acquired immunodeficiency syndrome–related non-Hodgkin's lymphomas (AIDS-NHL), including AIDS-related small noncleaved cell lymphoma (AIDS-SNCCL), AIDS-related large noncleaved cell lymphoma (AIDS-LNCCL), AIDS-related large cell immunoblastic lymphoma plasmacytoid (AIDS-IBLP), and AIDS-related primary effusion lymphoma (AIDS-PEL). Forty-six cases of AIDS-NHL were investigated for the expression pattern of BCL-6, a protein specifically expressed by germinal center (GC) B-cells, and CD138/syndecan-1 (syn-1), a marker of post-GC B-cell differentiation. Expression of BCL-6 and syn-1 segregated two major phenotypic patterns among AIDS-NHL: (1) the BCL-6+/syn-1− pattern associated with AIDS-SNCCL and AIDS-LNCCL; (2) the BCL-6−/syn-1+ pattern associated with AIDS-IBLP and AIDS-PEL. Among systemic AIDS-NHL infected by Epstein-Barr virus (EBV), expression of the EBV-encoded latent membrane protein-1 (LMP-1) preferentially associated with the BCL-6−/syn-1 + profile. Analysis of nonneoplastic lymph nodes showed that the two phenotypic patterns detected in AIDS-NHL correspond to physiologic stages of B-cell development, ie, GC B-cells (BCL-6+/syn-1−) and preterminally differentiated post-GC B-cells (BCL-6−/syn-1+). Thus, BCL-6+/syn-1− AIDS-NHL reflects a GC stage of differentiation, whereas AIDS-NHL which are BCL-6−/syn-1+, and LMP-1+when infected by EBV, derive from B cells that have entered post-GC plasmacell differentiation. These findings are relevant for the pathogenesis and differential diagnosis of AIDS-NHL.

The Molecular and Phenotypic Profile of Primary Central Nervous System Lymphoma Identifies Distinct Categories of the Disease and Is Consistent With Histogenetic Derivation From Germinal Center–Related B Cells

AbstractPrimary central nervous system lymphoma (PCNSL) is a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected individuals. The precise histogenetic derivation and the molecular pathogenesis of PCNSL is poorly understood. In an attempt to clarify the histogenesis and pathogenesis of these lymphomas, 49 PCNSL (26 acquired immunodeficiency syndrome [AIDS]-related and 23 AIDS-unrelated) were analyzed for multiple biologic markers, which are known to bear histogenetic and pathogenetic significance for mature B-cell neoplasms. PCNSL associated frequently (50.0%) with mutations of BCL-6 5′ noncoding regions, which are regarded as a marker of B-cell transition through the germinal center (GC). Expression of BCL-6 protein, which is restricted to GC B cells throughout physiologic B-cell maturation, was detected in 100% AIDS-unrelated PCNSL and in 56.2% AIDS-related cases. Notably, among AIDS-related PCNSL, expression of BCL-6 was mutually exclusive with expression of Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP)-1 and, with few exceptions, also of BCL-2. All but one PCNSL expressed hMSH2, which among mature B cells selectively stains GC B cells. These data suggest that PCNSL may be frequently related to GC B cells and may be segregated into two major biologic categories based on the expression pattern of BCL-6, LMP-1, and BCL-2. BCL-6+/LMP-1−/BCL-2− PCNSL occur both in the presence and in the absence of HIV infection and consistently display a large noncleaved cell morphology. Conversely, BCL-6−/LMP-1+/BCL-2+ PCNSL are restricted to HIV-infected hosts and are represented by lymphomas with immunoblastic features. These data are relevant for the pathogenesis and histogenesis of PCNSL and may be helpful to segregate distinct biologic and prognostic categories of these lymphomas.© 1998 by The American Society of Hematology.

Classificação de 86 casos de linfoma em bovinos de acordo com a Working Formulation (WF) of Non-Hodgkin's Lymphomas for Clinical Usage e a Revised European-American Classification of Lymphoid Neoplasms (REAL)

Resumo Por meio de um estudo retrospectivo, realizou-se avaliação fenotípica (histologia) e imunofenotípica (imuno-histoquímica [IHQ]) de 86 casos de linfoma bovino. Quanto ao padrão de distribuição, todos os linfomas foram incluídos como difusos. Em relação à dimensão dos linfócitos neoplásicos, 83,8% dos linfomas foram considerados como de grandes células e 11,6% como de pequenas células. Linfomas mistos, ou seja, constituídos por grandes e pequenas células, representaram apenas 4,6% dos casos. Quanto ao número de mitoses, 84,9% dos linfomas foram incluídos como de grau intermediário, 10,5% como de baixo grau e 4,6% como de alto grau. No que se refere à morfologia do núcleo, linfomas em que predominavam linfócitos não clivados (58,2%) ou linfócitos clivados (37,2%) foram mais frequentes do que aqueles em que havia uma mistura igualmente proporcional de linfócitos clivados e não clivados (4,6%). Com base nestes resultados, os 86 linfomas foram assim distribuídos utilizando-se a classificação proposta pela Working Formulation (WF) of Non-Hodgkin's Lymphomas for Clinical Usage: difuso de grandes células não clivadas (46,5%), difuso de grandes células clivadas (33,7%), difuso de pequenas e grandes células (4,6%), difuso de pequenas células - tipo plasmocitoide (7%), imunoblástico (3,5%), difuso de pequenas células - tipo intermediário (2,3%), difuso de pequenas células não clivadas (1,2%) e difuso de pequenas células não clivadas - tipo Burkitt (1,2%). Na imuno-histoquímica, 27 dos 86 (31,4%) linfomas foram positivos para o anticorpo monoclonal CD79αcy, utilizado para detecção de linfócitos B, e nenhum caso foi positivo para o anticorpo policlonal CD3, utilizado para detecção de linfócitos T. Com base nestes resultados, os 27 linfomas B foram assim distribuídos utilizando-se a Revised European-American Classification of Lymphoid Neoplasms (REAL): linfoma difuso de grandes células B (81,5%), linfomas imunoblásticos de grandes células (11,1%) e linfomas linfoplasmocíticos (7,4%). Os resultados aqui apresentados permitem concluir que à semelhança do que vem sendo descrito em outras partes do mundo, os linfomas bovinos são basicamente difusos e predominantemente de grau intermediário, de grandes células, com núcleos clivados ou não clivados. Esses linfomas são decorrentes da proliferação neoplásica de linfócitos B e correspondem, em sua quase totalidade (92,6%), ao que atualmente é incluído na REAL como linfoma difuso de grandes células B.

Radiotherapy of primary cutaneous follicle center lymphoma: case report and review of literature

Primary cutaneous follicle center lymphoma is an indolent primary cutaneous B-cell lymphoma originating from the follicle center cells, composed of a combination of centrocytes (small and large cleaved cells) and centroblasts (large noncleaved cells) with a follicular, follicular/diffuse, or diffuse growth pattern. Lesions are mostly located on the head, neck and trunk. A case is presented of a 56-year-old male patient with primary cutaneous follicle center lymphoma, with lesions involving the skin of the back, shoulders, presternal area and right forearm. As the patient presented a disseminated cutaneous form of the disease that involved several anatomical regions, complete work-up was followed by superficial fractionated radiotherapy of eight fields in VI expositions, with total irradiation dose of 1400 cGy upon the following fields: right and left pectoral region, left and right shoulders, right suprascapular region, and proximal third of the right forearm. Total irradiation dose applied upon each field for the lesions located on the left and right side of the back was 1500 cGy. This therapy resulted in significant reduction of visible tumor. The patient was regularly followed up on outpatient basis for 12 months of radiotherapy, being free from local recurrence and systemic spread of the disease.

Guidelines for the diagnosis and treatment of follicular lymphoma in China.

Follicular lymphoma (FL) is a common type of nonHodgkin’s lymphoma (NHL), accounting for 22% to 35% of NHL in western countries. The proportion in China, 8.1% to 23.5%, is less than that in western countries, although its incidence in China has increased with time. Compared with foreign countries, the age of onset is younger in China, and in terms of geographical distribution, the incidences in coastal regions and economically developed areas are higher 1 -3 . FL is from germinal-center B-cells, and is manifested morphologically as a tumor retaining follicular growth. FL comprises a group of malignant lymphoproliferat ive diseases including follicular center cells (small cleaved cells) and follicular center matricytes (large non-cleaved cells). Under microscopy, FL sometimes appears to be associated with diffused components. Based on different follicular components and their proportions, FL can be divided into the following (1) follicle-dominant type (proportion of follicles >75%); (2) follicle and diffuse mixed type (follicles accounting for 25% to 75%); and (3) focal follicle (proportion of follicles <25%)

Etiopathogenesis of Burkitt's lymphoma: a lesson from a BL-like in CD1 mouse immune to Plasmodium yoelii yoelii

IntroductionThere is a jaw cancer that develops in children five to eight years old in holoendemic malaria regions of Africa, associated to malaria and Epstein Barr virus infections (EBV). This malignancy is known as endemic Burkitt's lymphoma, and histopatologically is characterized by a starry sky appearance. To date, no histopathologic expression of Burkitt's lymphoma has been reported in non-genetically manipulated experimental animals. The purpose of the study is to describe the case of a mouse immune to Plasmodium yoelii yoelii (Pyy) that developed a Burkitt's lymphoma-like neoplasm after repeated malaria infections.ResultsImmune mouse 10 (IM-10) developed neoplasms at eight months of age, after receiving three Pyy inoculations. At autopsy eight subcutaneous tumors were found of which the right iliac fosse tumor perforated the abdominal wall and invaded the colon. The histopathologic study showed that all neoplasms were malignant lymphomas of large non-cleaved cells also compatible with variants or previous states of development of a Burkitt's lymphoma-like. The thymus, however, showed a typical starry sky Burkitt's lymphoma-like neoplasm.ConclusionsNeoplasm development in CD1 mouse is associated to both, immunity against malaria and continuous antigenic stimulation with living parasites.It is the first observation of a histopathologically expressed Human Burkitt's lymphoma-like neoplasm in a non-genetically manipulated mouse.Chronic immune response associated to neoplasms development could probably be not an exclusive expression of malaria-host interaction but, it could be a pattern that can bee applied also to other agent-host interactions such as host-bacteria, fungus, virus and other parasites.

Coexistence of Two Distinct Histological Subtypes of Follicular Lymphoma and Burkitt's-Like Lymphoma in the Single Lymph Node: A Case Report and Literature Review.

Transformation to a high-grade lymphoma occurs in approximately 20% to 30% of cases of follicular lymphoma, usually to diffuse large B-cell lymphoma and small cases to Burkitt's or Burkitt-like lymphoma, are reported. This transformation from follicular lymphoma to Burkitt's lymphoma, namely the mechanism of the acquisition of c-MYC gene to tumor cells already immortalized by BCL2, are not completely understood. Case: A 49-year-old man visited our hospital because of high fever and generalized lymph node swelling for several weeks. The WBC count was 20x109/l including 60% of Burkitt-like blasts. Immunophenotype was positive for CD10, CD19 and CD20. FISH analysis with IGH/BCL2 probe set and sprit signal of 5′c-MYC /3′c-MYC showed positive for 79.3% and 3.9%, respectively. Needle biopsy of the bone marrow (BM) consisted of cells large non-cleaved lymphocytes arranged diffusely. Immunophenotype was positive for CD10, CD20, CD45LCA, CD79a, and strongly positive for MIB-1 by immunohistochemistry. FISH analysis of BM cells was performed as same way of peripheral blood (PB), and the result showed similar findings with peripheral blast cells. Excision biopsy of the neck lymph node showed effacement of architecture with the presence of 2 distinctive components in absolutory separated with each other. The first component consisted of follicles, some showing predominance of small-to medium-sized cells, termed centrocyte. The second consisted of large non-cleaved cells, known as centroblasts. The follicular lesion was positive for CD10, CD20, CD79a and BCL2 by immunohistochemistry. On the other hand, the diffuse component, the Burkitt-like lesion, was positive for CD10, p53 and strongly positive for MIB-1, but negative for CD20, CD79a and BCL2. The diagnosis was interpreted as a follicular lymphoma, grade 2, composite a Burkitt-like lymphoma in a diffuse pattern in the single lymph node. After he underwent 2 courses of chemotherapy, he relapsed in the cerebrospinal fluid. Inverted cells showed positive for CD10, CD19 but negative for CD20 and CD79a. FISH analysis of inverted cell was strongly positive for IGH/BCL2 and sprit signal of c-MYC, 98.8% and 98.5% respectively. Mukhopadhyay et al. reported the first case of the transformation of follicular lymphoma to Burkitt-like lymphoma within a single lymph node (Human Pathol. 2005, 36, 571). One study of transformed follicular lymphoma, 8% harbored c-MYC translocations (Blood 1992, 80, 756). We estimated that major gene expression was IGH/BCL2 with harbored c-MYC translocations in lymphoma cells and in a subset of follicular lymphoma, the gain of a c-MYC translocation confers an additive oncogenic stimulus and gain the inhibition of apoptosis by BCL2 combined with the cell growth activity by c-MYC.

Expression of X-Linked Inhibitor of Apoptosis Protein in Reactive Lymphoid Tissues, Non-Hodgkin's Lymphomas, and Hodgkin's Disease.

X-linked inhibitor of apoptosis protein (XIAP) is an important regulator of apoptosis which binds to and inhibits caspases-3, -7 and -9, blocking the caspase 9-mediated apoptosis pathway. This pathway is activated by p53 and DNA damage and may be an important determinant of responsiveness to chemotherapy. Apoptosis also plays a major role in the regulation of follicle center B-cell proliferation and BCL2-mediated inhibition of apoptosis is a key factor in B-cell lymphomagenesis. In this study we examined the expression of XIAP in 65 reactive and neoplastic lymphoid proliferations utilizing a monoclonal antibody to XIAP (#610763 BD Biosciences, San Jose, CA) and immunohistochemistry with avidin-biotin-complex immunoperoxidase technique on formalin-fixed, paraffin-embedded sections. In reactive lymph nodes and tonsils, expression of XIAP was limited to large noncleaved cells in follicle centers (5 of 6 cases). XIAP was absent in plasmacytoma (3 cases) and small lymphocytic lymphoma/chronic lymphocytic leukemia (1 case). XIAP was expressed in follicular lymphoma, predominantly in large noncleaved cells (6 of 9 cases) and in diffuse large B cell lymphoma (11 of 16 cases), including cases of T-cell/histiocyte-rich diffuse large B cell lymphoma (2 cases), primary mediastinal large B cell lymphoma (1 case), and posttransplantation diffuse large B cell lymphoma (1 case). XIAP was consistently expressed in Burkitt and Burkitt-like lymphoma (3 of 3 cases) and anaplastic large cell lymphoma (3 of 3 cases) and in one case of adult T cell leukemia/lymphoma. XIAP was variably expressed in marginal-zone B cell lymphoma, predominantly in large blasts (2 of 4 cases) and in mantle cell lymphoma (2 of 3 cases). XIAP was not detected in peripheral T cell lymphoma, unspecified (1 case), extranodal NK/T cell lymphoma, nasal type (1 case), precursor B cell lymphoblastic leukemia (1 case), or granulocytic sarcoma (1 case). XIAP was consistently expressed in the Reed-Sternberg and mononuclear Reed-Sternberg-variant cells of classical Hodgkin disease (9 of 9 cases) and the L+H Reed-Sternberg-variant cells of nodular lymphocyte predominance Hodgkin disease (3 of 3 cases). XIAP is expressed across a broad range of lymphoproliferative disorders, including classical and nodular lymphocyte predominance Hodgkin disease, diffuse large B cell lymphoma, follicular lymphoma, Burkitt lymphoma, marginal-zone and mantle cell lymphoma, and anaplastic large cell lymphoma. XIAP appears to be selectively expressed in the proliferating elements of these lymphomas. The possible prognostic and therapeutic significance of XIAP expression needs to be determined.

B-cell activation and lymphoma in patients with HIV.

The risk of developing non-Hodgkin lymphoma (AIDS lymphoma) is greatly increased in HIV infection. Disruption of immune function by HIV infection may contribute to lymphomagenesis by inducing (1) loss of immunoregulation of Epstein-Barr virus-infected B cells [immunoblastic and central nervous system (CNS) lymphoma] caused by loss of T-cell function, and (2) chronic B-cell hyperactivation enhancing the generation of genetic lesions (c- :immunoglobulin gene translocation, -6 overexpression) associated with some forms of AIDS lymphoma (Burkitt lymphoma-like small noncleaved cell lymphoma and large noncleaved cell lymphoma). Also, the overproduction of B-cell-stimulatory cytokines (interleukin 10 and 6) has the potential to contribute to tumor development by supporting the growth and viability of nascent lymphoma cell clones. Therefore, HIV infection-associated B-cell hyperactivation, including direct activation of B cells by various mechanisms, and chronic overproduction of B-cell-stimulatory cytokines have the potential to contribute to the development and growth of AIDS lymphoma. Several recent reports are discussed in this review, including recent work relevant to understanding the potential of a virus-encoded cytokine-like molecule, HHV8 vIL6, to induce B-cell hyperactivation in HIV-infected people, work pointing to the potential role of a chemokine (stromal cell-derived factor 1) in lymphomagenesis, and studies on phenotypic changes in circulating B cells in HIV infection.

DIFFERENTIAL EXPRESSION OF BCL-6, CD 138/SYNDECAN-1 AND EBV-ENCODED LATENT MEMBRANE PROTEIN-1 IDENTIFIES DISTINCT HISTOGENETIC SUBSETS OF AIDS-RELATED NON-HODGKIN'S LYMPHOMAS.

102 Background: Among HIV-infected individuals, non-Hodgkin's lymphomas (NHL) are a morphologically heterogeneous group of malignancies that derive from B-cells and display and aggressive clinical behavior. Their precise histogenetic derivation, however, is poorly understood. This study was aimed at defining the histogenesis of the pathologic spectrum of AIDS-related NHL (AIDS-NHL), including AIDS-related small noncleaved cell lymphoma (AIDS-SNCCL), AIDS-related large noncleaved cell lymphoma (AIDS-LNCCL), AIDS-related large cell immunoblastic lymphoma plasmacyloid (AIDS-IBLP), and AIDS-related primary effusion lymphoma (AIDS-PEL). Methods: Forty-six cases of AIDS-NHL were extensively characterized based on immunohistochemical and molecular studies. All AIDS-NHL cases were also investigated for the expression pattern of BCL-6, a protein specifically expressed by germinal center (GC) B-cells, and CD138/syndecan-1 (syn-1), a marker of post-GC B-cell differentiation. Results: Expression of BCL-6 and syn-1 segregated two major phenotypic patterns among AIDS-NHL: i) the BCL-6+/syn-1− pattern associated with AIDS-SNCCL and AIDS-LNCCL: ii) the BCL-6−/syn-1+ pattern associated with AIDS-IBLP and AIDS-PEL. Among systemic AIDS-NHL infected by Epstein-Barr virus (EBV), expression of the EBV-encoded latent membrane protein-1 (LMP-1) preferentially associated with the BCL-6−/syn-1+ profile. Analysis of nonneoplastic lymph nodes showed that the two phenotypic patterns detected in AIDS-NHL correspond to physiologic stages of B-cell development, i.e. GC B-cells (BCL-6+/syn-1−) and pre-terminally differentiated post-GC B-cells (BCL-6−/syn-1+). Conclusion: BCL-6+/syn-1− AIDS-NHL reflect a GC stage of differentiation, whereas AIDS-NHL which are BCL-6−/syn-1+, and LMP-1+ when infected by EBV, derive from B-cells which have entered post-GC plasmacell differentiation. These findings are relevant for the pathogenesis and differential diagnosis of AIDS-NHL.

THE STATUS OF BCL-6, CD138/SYNDECAN-1, LMP-1 AND BCL-2 IDENTIFIES DISTINCT CATEGORIES OF AIDS-RELATED PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA: PATHOGENETIC AND HISTOGENETIC IMPLICATIONS.

89 Background: Primary central nervous system lymphoma (PCNSL) is a major cause of morbidity and mortality among HIV-infected individuals. AIDS-related PCNSL (AIDS-PCNSL) derive from B-cells, display an aggressive clinical behavior, and are histologically classified as diffuse large cell lymphoma. The precise histogenetic derivation of AIDS-PCNSL, as well as their molecular pathogenesis, are poorly understood. This study aimed at clarifying the histogenesis and pathogenesis of AIDS-PCNSL by defining the genotypic and/or phenotypic profile of cancer-related genes and of other biologic markers harboring pathogenetic and histogenetic implications for B-cell neoplasia. Methods: Twenty-six AIDS-PCNSL formed the basis of this study. For comparison. 23 AIDS-unrelated PCNSL were also investigated. All PCNSL were monoclonal B-cell expansions. PCNSL were investigated for protein expression of the BCL-6 and BCL-2 proto-oncogenes, the CD138/syndecan-1 antigen, the hMSH2 DNA mismatch repair enzyme, and the EBV-encoded LMP-1 antigen. These markers bear histogenetic relevance throughout the B-cell lineage, since expression of BCL-6 and hMSH2 cluster with germinal center (GC) B-cells, whereas expression of CD138/syndecan-1 associates specifically with late stages of B-cell differentiation. Molecular investigations of PCNSL included infection by EBV, rearrangements of BCL-2, BCL-6, and c-MYC proto-oncogenes, as well as analysis of mutations of BCL-6 5′ noncoding regions, which denote B-cell transition through the GC. Results: Expression of the BCL-6 protein was detected in 56.2 % AIDS-PCNSL. Expression of BCL-6 was mutually exclusive with expression of LMP-1, of CD138/syndecan-1 and, with few exceptions, of BCL-2, BCL-6+/LMP-1−/BCL-2− AIDS-PCNSL generally displayed a large noncleaved cell morphology, whereas cases expressing the BCL-6−/LMP-1+/BCL-2+ phenotype displayed features consistent with large cell immunoblastic plasmacytoid lymphoma. All AIDS-PCNSL expressed the hMSH2 protein. The most frequent proto-oncogene alteration of AIDS-PCNSL was represented by mutations of BCL-6 5′ regions, occurring in 42 % of cases. Conversely, all AIDS-PCNSL tested were devoid of gross rearrangements of BCL-6, BCL-2, or c-MYC. Infection by EBV occurred in all AIDS-PCNSL. Conclusions: The implications of these data are threefold. First, AIDS-PCNSL are heterogeneous and may be distinguished into two major phenotypic categories, i.e. BCL-6+/syndecan-1−/LMP-1−/BCL-2− and BCL-6−/syndecan-1+/LMP-1+/BCL-2+. Second, the combination of positive BCL-6 expression, hMSH2 expression and frequent BCL-6 5′ mutation suggests that a substantial fraction of AIDS-PCNSL derive from GC B-cells. Finally, BCL-6 mutations represent the most frequent proto-oncogene lesion of AIDS-PCNSL and may provide a molecular inarker for disease monitoring.

BCL2 Overexpression Associated With Chromosomal Amplification in Diffuse Large B-Cell Lymphoma

AbstractGene activation by translocation between an oncogene and an immunoglobulin heavy-chain gene, which leads to increased expression of the oncoprotein, is a well-known mechanism in the genesis of B-cell lymphomas. In contrast, the role of gene amplification in activation of oncogenes in non-Hodgkin's lymphomas is poorly characterized. To study the BCL2 amplification we performed comparative genomic hybridization (CGH), Southern blot hybridization, Western analysis, immunohistochemistry, metaphase fluorescence in situ hybridization, and chromosome analysis on 26 cases of diffuse large B-cell lymphoma (large noncleaved cell lymphoma). The gain or high-level amplification of 18q was found in eight tumors (31%) by CGH, and Southern analysis revealed BCL2 amplification in these cases, but not in the cases with normal chromosome 18 or t(14; 18)(q32; q21). Western immunoblot analysis and immunohistochemistry revealed a high-level expression of BCL2 protein in the cases with BCL2 amplification and t(14; 18)(q32; q21). However, translocation (14; 18)(q32; q21) was not detected in any of the cases with BCL2 amplification. Therefore, our results suggest that amplification of the BCL2 gene is an important mechanism for BCL2 protein overexpression in diffuse large B-cell lymphoma.

BCL2 Overexpression Associated With Chromosomal Amplification in Diffuse Large B-Cell Lymphoma

Gene activation by translocation between an oncogene and an immunoglobulin heavy-chain gene, which leads to increased expression of the oncoprotein, is a well-known mechanism in the genesis of B-cell lymphomas. In contrast, the role of gene amplification in activation of oncogenes in non-Hodgkin's lymphomas is poorly characterized. To study the BCL2 amplification we performed comparative genomic hybridization (CGH), Southern blot hybridization, Western analysis, immunohistochemistry, metaphase fluorescence in situ hybridization, and chromosome analysis on 26 cases of diffuse large B-cell lymphoma (large noncleaved cell lymphoma). The gain or high-level amplification of 18q was found in eight tumors (31%) by CGH, and Southern analysis revealed BCL2 amplification in these cases, but not in the cases with normal chromosome 18 or t(14; 18)(q32; q21). Western immunoblot analysis and immunohistochemistry revealed a high-level expression of BCL2 protein in the cases with BCL2 amplification and t(14; 18)(q32; q21). However, translocation (14; 18)(q32; q21) was not detected in any of the cases with BCL2 amplification. Therefore, our results suggest that amplification of the BCL2 gene is an important mechanism for BCL2 protein overexpression in diffuse large B-cell lymphoma.

Primary cutaneous large B-cell lymphomas of the legs. A distinct type of cutaneous B-cell lymphoma with an intermediate prognosis. Dutch Cutaneous Lymphoma Working Group

Primary cutaneous follicular center cell lymphomas represent a distinct type of cutaneous B-cell lymphoma, clinically characterized by localized skin lesions on the head or trunk and an excellent prognosis. Histologically similar lymphomas may occur on the legs. The clinical behavior of this group is still undefined, and controversy exists whether these lymphomas should be classified as follicular center cell lymphoma or B-immunoblastic lymphoma. We reviewed the clinical, histologic, and follow-up data of 18 patients with primary cutaneous large B-cell lymphoma of the legs. Primary cutaneous large B-cell lymphoma of the legs generally occurred in elderly patients (median age at diagnosis, 76 years), in particular women (male-female ratio, 7:2), and preferentially affected the lower legs (14 of 18 patients). Radiotherapy and/or systemic polychemotherapy resulted in complete remissions in 16 of 17 patients. Follow-up data demonstrated estimated 2- and 5-year survival rates of 77% and 58%, respectively. Histologic evaluation showed diffuse dermal infiltrates with variable proportions of centroblasts (large noncleaved cells), large centrocytes (large cleaved cells), and B immunoblasts. Seventeen of 18 patients were diagnosed as having primary cutaneous follicular center cell lymphoma; only 1 patient, whose histologic examination showed more than 30% immunoblasts, was diagnosed as having B-immunoblastic lymphoma. Primary cutaneous large B-cell lymphoma of the legs is a distinct clinicopathologic entity that mainly affects elderly patients and has an intermediate prognosis. Although most cases have a follicular center cell origin, primary cutaneous large B-cell lymphoma is proposed as the most appropriate term for this type of cutaneous lymphoma.

Primary Cutaneous Large B-Cell Lymphomas of the Legs

<h3>Background and Design:</h3> Primary cutaneous follicular center cell lymphomas represent a distinct type of cutaneous B-cell lymphoma, clinically characterized by localized skin lesions on the head or trunk and an excellent prognosis. Histologically similar lymphomas may occur on the legs. The clinical behavior of this group is still undefined, and controversy exists whether these lymphomas should be classified as follicular center cell lymphoma or B-immunoblastic lymphoma. We reviewed the clinical, histologic, and follow-up data of 18 patients with primary cutaneous large B-cell lymphoma of the legs. <h3>Results:</h3> Primary cutaneous large B-cell lymphoma of the legs generally occurred in elderly patients (median age at diagnosis, 76 years), in particular women (malefemale ratio, 7:2), and preferentially affected the lower legs (14 of 18 patients). Radiotherapy and/or systemic polychemotherapy resulted in complete remissions in 16 of 17 patients. Follow-up data demonstrated estimated 2- and 5-year survival rates of 77% and 58%, respectively. Histologic evaluation showed diffuse dermal infiltrates with variable proportions of centroblasts (large noncleaved cells), large centrocytes (large cleaved cells), and B immunoblasts. Seventeen of 18 patients were diagnosed as having primary cutaneous follicular center cell lymphoma; only 1 patient, whose histologic examination showed more than 30% immunoblasts, was diagnosed as having B-immunoblastic lymphoma. <h3>Conclusions:</h3> Primary cutaneous large B-cell lymphoma of the legs is a distinct clinicopathologic entity that mainly affects elderly patients and has an intermediate prognosis. Although most cases have a follicular center cell origin, primary cutaneous large B-cell lymphoma is proposed as the most appropriate term for this type of cutaneous lymphoma. Arch Dermatol. 1996;132:1304-1308

Primary mediastinal large cell lymphoma in children: a report from the Childrens Cancer Group.

Malignant lymphomas arising in the mediastinum account for approximately 60% of all mediastinal tumors in children; two-thirds are non-Hodgkin's lymphomas and one-third represent Hodgkin's disease. In contrast to adults, in children mediastinal non-Hodgkin's lymphomas are usually synonymous with lymphoblastic lymphoma, and nonlymphoblastic lymphomas are rare. We describe nine children with primary mediastinal large cell lymphoma who were treated with the Children's Cancer Group protocol CCG-503, a randomized phase III protocol for disseminated nonlymphoblastic lymphoma. Histologic subclassification revealed three immunoblastic lymphomas, three multilobated large cell lymphomas, one with clear cell features, and two large noncleaved cell lymphomas. Sclerosis, of variable degrees, was seen in all tumors. Immunophenotyping revealed all tumors to be of B cell lineage. Thymic epithelial cells could be demonstrated, utilizing antibody to keratin, in two of nine patients, suggesting that some of the tumors are of thymic origin. None of the patients had central nervous system or bone marrow involvement. It appears that primary mediastinal nonlymphoblastic lymphomas in children, although much less common, are similar to those seen in adults. These tumors must be differentiated from lymphoblastic lymphoma and Hodgkin's disease, as the therapeutic approach may depend on histologic subtype. Primary mediastinal large cell lymphoma in children appears curable with aggressive treatment in the majority of patients.

A PCR ANALYSIS OF BCL-2 GENE REARRANGEMENT IN NODAL AND EXTRANODAL NON-HODGKINS-LYMPHOMA (NHL) - SOME UNUSUAL OBSERVATIONS IN SAUDI PATIENTS

Non-Hodgkin's lymphoma (NHL) is the most common malignancy referred to our institute which is the largest tertiary referral cancer centre in Saudi Arabia, The proportion of follicular low grade NHL appears to be extremely small in this population (<5% of all NHL). To date, there is no data available regarding any correlation between bcl-2 gene rearrangement and different cell types of nodal and extranodal NHLs in Saudi patients. We used a sequential polymerase chain reaction (PCR) technique to determine the frequency of bcl-2/J(H) recombination occurring via the major breakpoint region (mbr) in 16 GI tract NHLs including 4 MALT lymphomas and 13 follicular (nodal) NHLs. The results showed only 2/13 (15%) nodal follicular NHLs with bcl-2/J(H) fusion DNA whereas 9/16 (56%) of the extranodal NHLs with at least 2 of them exhibiting MALT characteristics were positive for the bcl-2 gene rearrangement. A breakdown of the proportion of extranodal NHLs of different cell types showing bcl-2 rearrangement via mbr was as follows: 5/8 diffuse large non-cleaved cell (DLNCC), 1/3 diffuse small cleaved cell (DSCC), 1/1 follicular small cleaved cell (FSCC) and 2/4 MALTs. The PCR amplified bcl-2/J(H) fusion DNA from 5 randomly selected tumors (2 MALTs, 1 DLNCC, 1 DSCC and 1 nodal follicular lymphoma) were cloned and sequenced. All 5 of them showed different bcl-2/J(H) N-regions confirming the clonality of each tumor sample. The data indicating a very low incidence of bcl-2 translocation in nodal follicular NHLs and a surprisingly high incidence of it in extranodal NHLs are intriguing, and quite contrary to the findings in Western patients. These unusual observations warrant further studies and may suggest that different genetic events are involved in the development of extranodal NHLs including MALT and follicular center-cell NHLs in Saudi patients.

Epstein-Barr virus-associated gastric lymphoma in Hong Kong Chinese

We report 11 cases of gastric lymphoma that harbor the Epstein-Barr virus (EBV) encoded small messenger RNA, EBER-1, detected by in situ hybridization. The cases represented 18% of 61 consecutive gastric lymphomas from three institutions in Hong Kong between 1988 and 1993. The mean age of patients was 62 years (range, 33 to 87). The male to female ratio was 5:6. Nine of the 11 (81.8%) EBER-1+ gastric lymphomas were diffuse large cell lymphomas of B-cell type without low grade components. Macroscopically these lymphomas appeared either as large noncleaved cell (centroblastic) or immunoblastic type. From the available follow-up data, five of the nine patients with B-cell lymphoma were alive and well 48, 40, 14, 13, and 12 months, respectively, after gastrectomy and chemotherapy. One patient died of postoperative pneumonia and one died of a second malignancy (esophageal squamous carcinoma) 40 months after gastrectomy. None of the EBER-1+ B-cell gastric lymphomas showed histological features characteristic of low grade lymphoma of the mucosa-associated lymphoid tissue (MALT) type reported to be common in some Western countries. Of the two patients with T-cell lymphoma, one had a pleomorphic T-cell lymphoma and the other had an angiocentric lymphoma. The former was lost to follow-up after the biopsy and the latter presented with gastric perforation and died 1.5 months after gastrectomy. It is concluded that a significant proportion of gastric lymphomas in Hong Kong Chinese are EBV-related and that they show histological features more akin to conventional node-based lymphomas than to MALT-type lymphomas.

Mutations in the Coding Region of c-myc Occur Frequently in Acquired Immunodeficiency Syndrome-Associated Lymphomas

We have analyzed 30 cases of high- and intermediate-grade acquired immunodeficiency syndrome-associated non-Hodgkin's lymphoma (AIDS-NHL) for mutations in the c-myc coding region. In addition, in these same tumors, we have sought the presence of mutations in a regulatory region within the first c-myc intron defined by the binding to a factor that inhibits c-myc transcription (MYC intron factor, or mif). Mutations in the c-myc coding region were present in 10 of 16 small noncleaved cell lymphoma (SNCL), but in only 3 of 14 other histologic subtypes tested (0/3 large non-cleaved cell, 2/8 immunoblastic, and 1/3 anaplastic large cell lymphomas). Nineteen of the AIDS-NHLs analyzed contained a c-myc rearrangement and in 10 of these the c-myc gene was mutated in its coding region. In contrast, we could detect a mutation in the coding region in only 2 of 8 AIDS-NHL without a c-myc rearrangement. Mutations in the mif region were detected in 5 of 16 SNCL. Among AIDS-NHL carrying mutations in the c-myc coding region, only 4 carried mutations in the regulatory region. These results suggest that the mutations in the coding region of the c-myc protein may either be a consequence of the translocations involving c-myc, or may be necessary only in tumors where c-myc is deregulated as a result of a c-myc/lg translocation.