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Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The recognition and classification of the different varieties of splenic low-grade B-cell lymphomas have been hampered by the rarity of histological studies of surgical splenectomy specimens of B-cell lymphoma. In an effort to characterize the recently described splenic marginal zone lymphoma (SMZL), we conducted a survey of 13 patients with this type of tumor using the criteria defined by Schmid for its recognition (Schmid et al., Am J Surg Pathol 1992;16:455-66). Primary splenic high-grade lymphomas, T-cell lymphomas, and secondary infiltration by other recognized low-grade B-cell lymphomas, with the exception of splenic lymphoma with villous lymphocytes, were excluded. This selection gave rise to a homogeneous group of tumors with similar clinical, histological, immunohistochemical, and molecular features. Our study showed the critical parameters for their recognition to be morphological, including macroscopic micronodularity and the constant presence of white- and red-pulp infiltration, marginal zone pattern, and plasmacytic differentiation. No t(14;18) or PRAD-1/cyclin D1 overexpression was detect able in any case. Clinically, the tumors were widespread with a protracted evolution. Nodal infiltration by SMZL in our cases was morphologically similar to monocytoid B-cell lymphoma. SMZL could constitute the largest group of primary splenic malignant lymphomas, partially overlapping with splenic lymphoma with villous lymphocytes. Specific molecular markers for SMZL have yet to be defined. Because of the limited number of cases, the question of therapy for this group of lymphomas must remain open for the future.
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PMID:Splenic marginal zone lymphoma: a distinctive type of low-grade B-cell lymphoma. A clinicopathological study of 13 cases. 757 73

Neoplastic monocytoid B-cells (MBCs) are present in different amounts in several types of non-Hodgkin's lymphomas (NHLs), including monocytoid B-cell lymphoma (MBCL), splenic marginal zone lymphoma (SMZL), mucosa-associated lymphoid tissue (MALT) low-grade B-cell lymphomas, and follicular centroblastic-centrocytic (CB-CC) lymphomas. In an attempt to clarify the relationships between different groups of tumors with a significant monocytoid component, we studied six primary lymph node MBCL, three SMZL, seven MALT lymphomas, and four CB-CC with monocytoid differentiation. Their clinical, morphological, immunohistochemical and molecular features were compared. The results show wide overlapping between MALT and MBCL in terms of morphology, immunophenotype, and molecular features. Follicular colonization was a characteristic finding in both groups. Some MBCL revealed mucosal involvement during the course of the disease, suggesting a possible MALT origin. Our data support the suggestion that the use of the term MBCL should be discontinued in cases with mucosal involvement, as they are probably examples of lymph node involvement brought about by MALT lymphomas. Although SMZL have some overlapping features with MBCL and MALT lymphomas, some of the clinical and morphological specific findings justify their distinction from the other groups. The CB-CCs with monocytoid differentiation frequently harbored t(14;18), lacking any significant differentiating features from conventional follicular CB-CC lymphomas. Additional studies are needed to define the molecular features of MBCL and other marginal zone tumors.
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PMID:Monocytoid B cells. A comparative clinical pathological study of their distribution in different types of low-grade lymphomas. 794 34

Splenic marginal zone lymphoma (SMZL) has recently been proposed as a distinctive type of low-grade B-cell lymphoma. Although there is general agreement that this entity exists, its precise definition is blurred by uncertainty in differential diagnosis from other low-grade B-cell lymphomas. There is even more uncertainty as to the histology of splenic hilar and peripheral lymph nodes involved by SMZL. We therefore reviewed the histological and immunohistochemical features of 19 of these lymph nodes (14 hilar and five peripheral) from 14 cases of classical SMZL and compared them with the features of lymph nodes involved by other B-cell lymphomas. The morphology and immunohistology of the lymph nodes resemble those found in the white pulp of the spleen, showing a distinctive pattern, different from that which is observed in other B-cell lymphomas. In these cases, the overall architecture of the lymph nodes is effaced and replaced by a nodular infiltrate, although the sinuses are preserved in most hilar lymph nodes. Some of the nodules contain a central reactive follicular center, around which there is a broad zone of small lymphocytes. In other cases, the central area is partially infiltrated or, more commonly, totally replaced by these small lymphocytes, which in the periphery of the nodules showed a pale, slightly larger cytoplasm. Scattered nucleolated blasts are present, largely confined to the periphery of the nodules. The tumoral cells express immunoglobulin (Ig)D, IgM, and Ig light chain restriction and show a low proliferation fraction. These findings confirm that SMZL is a real entity, and not merely a morphological pattern of splenic infiltration by different types of low-grade B-cell lymphoma.
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PMID:Lymph node involvement by splenic marginal zone lymphoma: morphological and immunohistochemical features. 923 33

Splenic marginal zone lymphoma (SMZL) is a low-grade primary splenic B cell lymphoma, originally thought to be related to splenic marginal zone B cells. Later studies showed that SMZL sometimes may be accompanied by villous lymphocytes in the peripheral blood, a condition previously characterized as splenic lymphoma with villous lymphocytes (SLVL). The relationship between SMZL and splenic marginal zone B cells has recently been called into question. We report four further cases of SMZL, two of which were associated with villous lymphocytes in the peripheral blood. In addition to immunophenotypical analysis, we have studied the IgV(H) genes in each case, because the extent and patterns of their mutation can indicate the normal B cell counterpart of lymphomas. The IgV(H) genes in the four cases of SMZL studied are mutated, which is consistent with their origin from postfollicular marginal zone B cells. Evidence of ongoing mutation was also observed. This contrasts with a study showing that blood-borne tumor cells in SLVL show no sign of ongoing mutation. It is possible that the ongoing mutations in the cases studied here are acquired in a splenic microenvironment, such as that found in the follicle center.
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PMID:Analysis of immunoglobulin genes in splenic marginal zone lymphoma suggests ongoing mutation. 963 78

The PAX-5 gene codes for the transcription factor BSAP, which is expressed throughout B-cell development. Although loss-of-function mutation in the mouse showed an essential role for Pax-5 in early B lymphopoiesis, gain-of-function mutations have implicated the human PAX-5 gene in the control of late B-cell differentiation. PAX-5 (on 9p13) has been involved together with the immunoglobulin heavy-chain (IgH) gene (on 14q32) in the recurring t(9;14)(p13;q32) translocation that is characteristic of small lymphocytic lymphoma with plasmacytoid differentiation. Here we have characterized a complex t(2;9;14)(p12;p13;q32) translocation present in a closely related non-Hodgkin's lymphoma referred to as splenic marginal zone lymphoma (MZL). In this MZL-1 translocation, the two promoters of PAX-5 were replaced on the derivative chromosome 14 by an immunoglobulin switch Smicro promoter that was linked to the structural PAX-5 gene upstream of its translation initiation codon in exon 1B. Expression analyses confirmed that PAX-5 transcription was upregulated due to efficient initiation at the Smicro promoter in the malignant B lymphocytes of patient MZL-1. For comparison we have analyzed PAX-5 expression in another B-cell lymphoma, KIS-1, indicating that transcription from the distal PAX-5 promoter was increased in this tumor in agreement with the previously characterized translocation of the immunoglobulin Emicro; enhancer adjacent to PAX-5 exon 1A. In both lymphomas, the J-chain gene, which is thought to be under negative control by BSAP, was not expressed, whereas transcription of the putative target gene p53 was unaffected by PAX-5 overexpression. Together these data indicate that the t(9;14)(p13;q32) translocation contributes to lymphoma formation as a regulatory mutation that leads to increased PAX-5 expression in late B-cell differentiation due to promoter replacement or enhancer insertion.
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PMID:Deregulated PAX-5 transcription from a translocated IgH promoter in marginal zone lymphoma. 980 80

New insights into the pathogenesis of lymphoid malignancies have been gained through novel techniques such as genetic, molecular and immunologic methods. Recently, based on those findings, a new classification system for lymphoid malignancies, known as the REAL classification, has been proposed. To clarify the relation between the histological classification and prognosis of B-cell lymphoid malignancies, we re-classified 708 cases. In all cases, the B-cell phenotype and/or genotype was confirmed by immunohistochemical staining and/or receptor gene analysis. The most common B-cell lymphoma types were diffuse large B-cell lymphoma (58.8%), follicular lymphoma (12.1%), marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) (9.0%) and mantle cell lymphoma (5.9%). Minor types were lymphoblastic lymphoma (3.4%), Burkitt's lymphoma (2.4%), nodal marginal zone lymphoma (2.1%), lymphoplasmacytic lymphoma (2.0%) and plasmacytoma (1.4%). Rare types were prolymphocytic lymphoma and splenic marginal zone lymphoma. Using overall survival rates, the various B-cell lymphoma types could be divided into three broad groups for prognostic purposes: (1) the low risk group consisted of follicular lymphoma, marginal zone lymphoma of MALT, nodal marginal zone lymphoma, plasmacytoma and lymphoplasmacytic lymphoma; (2) the intermediate risk group consisted of diffuse large B-cell lymphoma, Burkitt's lymphoma and mantle cell lymphoma; and (3) the high risk group consisted of lymphoblastic lymphoma. In MALT, the low grade type had a better prognosis than the high grade type. In diffuse large B-cell lymphoma, the common type had a better prognosis than the variant type, which mainly consisted of the immunoblastic lymphoma. The histological classification will have a benefit for the clinical approach.
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PMID:B-cell lymphoma of 708 cases in Japan: incidence rates and clinical prognosis according to the REAL classification. 1007 24

The cell of origin of parafollicular (monocytoid) B cell lymphoma (PBCL), splenic marginal zone lymphoma (SMZL), and hairy cell leukemia (HCL) is controversial. To better understand the relationship between these low-grade B-cell neoplasms, we analyzed the nucleotide sequences of the rearranged immunoglobulin heavy (IgH) chain variable (V) region of the clonal population of cells in five cases of PBCL, four cases of SMZL, and seven cases of HCL to determine whether these neoplasms could be differentiated by the degree of somatic mutation in the IgH V gene or by the IgH V gene family usage. DNA was extracted from diagnostic material and clonality confirmed by PCR. The DNA was reamplified using V heavy chain family specific primers, and the amplicons were sequenced. Sequences were compared with germline IgH V gene sequences, and base changes were determined to be silent or to represent amino acid replacements by using three different methods. Four of five (80%) cases of PBCL, three of four (75%) cases of SMZL, and three of seven (43%) cases of HCL showed evidence of antigen selection, suggesting that these neoplasms involved clonal expansions of postgerminal center memory lymphocytes. Only SMZL showed a preferential usage of V(H)1 family genes.
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PMID:Somatic mutation analysis of IgH variable regions reveals that tumor cells of most parafollicular (monocytoid) B-cell lymphoma, splenic marginal zone B-cell lymphoma, and some hairy cell leukemia are composed of memory B lymphocytes. 1008 50

Marginal zone B cell lymphomas (MZBCLs) represent a category of non-Hodgkin's lymphoma which may arise in a wide variety of extranodal organs where they are termed low grade B cell lymphomas of mucosa-associated lymphoid tissue (MALT). MZBCLs may involve primarily lymph nodes and or spleen where they are designated monocytoid B cell lymphoma or splenic marginal zone lymphoma, respectively. Recognition of this category of lymphoma, in particular, extranodal MALT lymphoma, is clinically significant in determining optimal therapy. Although there have been recent case reports describing the cytologic findings in low grade MALT lymphoma in various extranodal organs, this category of lymphoma has not been widely recognized or discussed in the cytology literature. The cytologic findings in seven fine-needle aspirations and two bronchial washings of histologically confirmed marginal zone lymphoma (five extranodal MALT lymphomas and four nodal marginal zone lymphomas) are described. In all of the cases, the cytologic specimens showed a polymorphous proliferation comprising a predominant population of intermediate sized lymphoid cells with centrocyte-like or monocytoid features, transformed cells, and variable numbers of plasma cells. These findings, while highly suggestive of MALT lymphoma in extranodal proliferations, may be more difficult to distinguish from reactive conditions in lymph nodes.
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PMID:Fine-needle aspiration biopsy findings in marginal zone B cell lymphoma. 1020

Chemotaxis in leukocytes is mediated through binding of soluble chemokines to transmembrane G-protein coupled receptors. The chemokine receptor CXCR3 has been previously shown to be widely expressed on activated T cells and to mediate T-cell chemotaxis on binding to various ligands, including Mig, IP-10, and ITAC. By using immunohistochemical and flow cytometric analysis, we report that CXCR3 is also expressed on a subset of peripheral blood B cells and in distinct subtypes of B-cell lymphoma. CXCR3 immunohistochemical or flow cytometric expression was seen in 37 of 39 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (diffusely positive in 33 cases), whereas mantle cell lymphoma (30 cases), follicular lymphoma (27 cases), and small noncleaved cell lymphoma (8 cases) were negative in all but 2 cases. Strong CXCR3 expression was also seen in splenic marginal zone lymphoma (14 of 14 cases) and in the monocytoid and plasmacytic cells in extranodal marginal zone lymphoma (15 of 16 cases). This differential expression of CXCR3 in B-cell tumors contrasts with that of another B-cell-associated chemokine receptor, BLR1/CXCR5, which we show here is expressed on all types of B-cell lymphoma tested. We also report that the CXCR3 ligand, Mig, is coexpressed on tumor cells in many cases of CLL/SLL (10 of 13 cases examined) with Mig expression less frequently seen in other B-cell lymphoma subtypes. Coexpression of CXCR3 and its ligand, Mig, may be an important functional interaction in B-CLL, as well as a useful diagnostic marker for the differential diagnosis of small cell lymphomas. (Blood. 2000;95:627-632)
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PMID:The chemokine receptor CXCR3 is expressed in a subset of B-cell lymphomas and is a marker of B-cell chronic lymphocytic leukemia. 1062 72

In this study the authors explored the value of immunostaining for follicular center B-cell markers, BCL-6 and CD10, in paraffin sections as a tool for the differential diagnosis of B-cell lymphomas. The cases studied comprised reactive lymphoid hyperplasia (RLH; n = 19), follicular lymphoma (FL; n = 50), low-grade mucosa-associated lymphoid tissue (MALT) lymphoma (n = 24), mantle cell lymphoma (n = 19), splenic marginal zone lymphoma (n = 13), diffuse large B-cell lymphoma (DLBCL; n = 54), Burkitt's lymphoma (BL; n = 20), nodular lymphocyte predominance Hodgkin's disease (NLPHD; n = 16), and classic Hodgkin's disease (CHD; n = 13). In RLH, CD10 and BCL-6 were expressed almost exclusively by the follicular center cells. In contrast in FL, the expression of CD10 (39/50) and BCL-6 (34/36) was seen in both follicular and interfollicular neoplastic B cells. Marginal zone/MALT lymphomas and mantle cell lymphoma were always negative. In DLBCL the expression was variable for both CD10 (21/54) and BCL-6 (39/47), with some tumors, including cases of transformed follicular lymphoma (9/10), coexpressing CD10 and BCL-6, and others expressing only BCL-6, and a small group expressing neither marker, possibly reflecting the underlying primary pathogenetic events such as the rearrangement of BCL-2 or BCL-6 genes. BL was always both CD10 and BCL-6 positive. In NLPHD the L&H cells expressed BCL-6 (11/13) but not CD10, whereas in CHD BCL-6 expression was seen in half of the cases. This study demonstrates that both CD10 and BCL-6 are reliable markers of follicular center B-cell differentiation. CD10 and BCL-6 immunostaining have an important role in differential diagnosis of FL from RLH and other low-grade B-cell lymphomas. The results also suggest that a CD10/BCL-6 expression pattern may be helpful in identifying main subsets of DLBCL. However, additional studies comparing genotype with immunophenotype are required.
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PMID:CD10 and BCL-6 expression in paraffin sections of normal lymphoid tissue and B-cell lymphomas. 1084 87


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