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

To investigate the roles of interferon regulatory factor 4 (IRF4) in B-cell development, we established germinal center B cell-derived Burkitt's lymphoma cell lines that exogenously express IRF4. Daudi-IRF4 expressed IRF4 in the presence of doxycycline (inducible expression), and Raji-IRF4 constitutively expressed an IRF4-estrogen receptor chimeric protein, which was activated by 4-hydroxytamoxifen. Expression or activation of IRF4 resulted in growth inhibition accompanied by accumulation of cells in G0/G1. Upregulation of the plasma cell markers CD38 and CD138 and downregulation of the germinal center cell marker B-cell lymphoma 6 (BCL6) were also observed. Furthermore, mRNAs for BCL6 and paired box gene 5 (PAX5) were decreased and those for B-lymphocyte-induced maturation protein-1 (BLIMP1)/PR domain containing 1 (PRDM1) and X-box binding protein 1 (XBP1) were increased, which corresponds to the characteristic changes in transcription factor expression in B cells differentiating toward plasma cells. Impairment in proliferation and differentiation toward plasma cells induced by IRF4 were not inhibited by enforced expression of BCL6. These results suggest that IRF4 inhibits cell cycle progression of germinal center B cell-derived Burkitt's lymphoma cells and induces terminal differentiation toward plasma cells through mechanisms independent of BCL6 downregulation.
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PMID:IRF4 negatively regulates proliferation of germinal center B cell-derived Burkitt's lymphoma cell lines and induces differentiation toward plasma cells. 1765 61

We have had a recent spurt in cases of AIDS-related lymphoma (ARL) at our centre. Most of these cases are aggressive mature B cell lymphomas, mainly plasmablastic lymphoma (PBL) and diffuse large B-cell lymphoma (DLBCL). Most of the PBL are extranodal in location and are mucosa-based. We reviewed the morphological features of 34 cases of PBL. Diagnosis was based on morphology, immunohistochemistry, proliferation index, HIV positive status and its preference to extranodal sites (mostly mucosa based). We classified PBL into three morphological subtypes (immunoblastic - 25, Burkitt's - 7, plasmacytic - 2). Tumor cells expressed as leucocyte common antigen (LCA) in 60%, CD138 in 100%, EMA in 45% and light chain restriction in 86% cases. CD20 was negative in all cases. Pathologists need to be aware of PBL and its various morphological subtypes as the identification of this entity from its close differentials carries major therapeutic implications.
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PMID:Morphological spectrum of AIDS-related plasmablastic lymphomas. 1841 82

The most common non-Hodgkin lymphomas in Uganda are neoplasms of B-cell derivation. The field of B-cell lymphoma immunophenotype has rapidly progressed because of the increasing availability of markers applicable to routine sections. Although the latter have allowed the identification of distinctive lymphoma entities in the developed countries, such approach has not yet been used in Uganda. One hundred twenty-nine formalin-fixed, paraffin-embedded tissue samples from the Department of Pathology of Makerere University were used for tissue micro-array (TMA) construction. Four-micrometer-thick sections were cut from TMAs and stained with hematoxylin and eosin and Giemsa. They were also used for immunohistochemistry and in situ hybridization. According to morphology and immunohistochemistry, lymphoid neoplasms were classified as Burkitt's lymphoma (BL) (95 cases), diffuse large B-cell lymphoma (19 cases), mantle cell lymphoma (4 cases), and B-cell lymphoblastic lymphoma (1 case). In BL, a homogeneous phenotype (CD10(+), Bcl-6(+), Bcl-2(-), MUM1/IRF4-, and Ki-67 approximately 100%) and a stable Epstein-Barr virus integration were found. A distinctive and unusual feature was the frequent plasma cellular differentiation, along with the positivity for CD30 and CD138 (recorded in 35 and 43 cases, respectively). According to our findings, most non-Hodgkin B-cell tumors in Uganda are endemic BLs followed by diffuse large B-cell lymphomas. The rest consist of rare but clinically important entities such as mantle cell lymphoma and B-cell lymphoblastic lymphoma. The availability of TMAs and immunohistochemistry has enabled us to precisely categorize tumors that have so far been diagnosed in Uganda as "high-grade/aggressive" lymphomas on the basis of cell morphology alone.
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PMID:B-cell non-Hodgkin lymphomas in Uganda: an immunohistochemical appraisal on tissue microarray. 1843 78

Follicular lymphoma (FL) is one of the most common subtypes of non-Hodgkin lymphoma and frequently transforms to diffuse large B-cell lymphoma (DLBCL). To clarify some aspects of the natural history of FL, we retrospectively examined 43 consecutive patients who had DLBCL with pre- or coexisting FL grade 1 or 2. The patients comprised 22 men and 21 women with a median age of 53 years. Most of the patients (34/43) showed advanced-stage (III or IV) disease initially. We examined both FL and DLBCL components morphologically, immunohistochemically, and by interface fluorescence in situ hybridization (FISH: IGH/BCL2 fusion, BCL6 translocation) analysis. Most of the DLBCLs were classified as the centroblastic subtype, with two exceptions of the anaplastic subtype. Immunohistochemical analysis of both the FL and DLBCL components revealed the following respective positivity rates: CD20 100%/100%, CD10 86%/66%, Bcl-2 96%/91%, Bcl-6 84%/88%, MUM1 16%/34%, CD30 0%/20%, CD138 0%/0%, and CD5 0%/3%. Loss of CD10 (6/36, 17%) and gain of MUM1 (7/28, 25%) and CD30 (5/21, 24%) through transformation were not infrequent. High positivity rates for Bcl-2 and Bcl-6 were maintained throughout transformation. Among the DLBCLs, 84% were classified as the germinal center B-cell phenotype (GCB) and 16% as non-GCB in accordance with the criteria of Hans et al. IGH/BCL2 fusion was detected by FISH in 89% of FLs and 82% of DLBCLs. BCL6 translocation was detected in 1/6 (17%) DLBCLs without IGH/BCL2 fusion. Thus, although the morphological features and FISH results for DLBCL were consistent with transformed FL, the immunophenotype showed wide heterogeneity.
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PMID:Diffuse large B-cell lymphoma after transformation from low-grade follicular lymphoma: morphological, immunohistochemical, and FISH analyses. 1854 5

Plasmablastic lymphoma (PBL) is a rare form of diffuse large B-cell lymphoma characterized by weak/absent expression of conventional B-cell markers and strong expression of plasma cell markers. It is strongly associated with human immunodeficiency virus (HIV) and Epstein Barr virus infection, and shows an unusual tropism to the oral cavity. Herein we describe a patient with AIDS who presented with weight loss and dysphagia owing to a large gastroesophageal mass. His radiographic and endoscopic findings and long history of cigarette consumption suggested carcinoma. Biopsy demonstrated a poorly differentiated tumor stained negatively to routine lymphoid markers including CD20. However, gene rearrangement studies confirmed a B-cell process and a more detailed immunohistochemical analysis revealed the cells stained positively for CD138 (plasma cell antigen). These findings were diagnostic of PBL. Our report reviews the wide differential diagnosis of PBL and underscores the importance of a broad array of viral and molecular studies needed to establish this diagnosis.
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PMID:AIDS-associated plasmablastic lymphoma presenting as a poorly differentiated esophageal tumor: a diagnostic dilemma. 1866 32

Anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma is a rare subtype of diffuse large B-cell lymphoma (DLBCL). Although a few cases of ALK-positive large B-cell lymphoma harbor nucleophosmin-ALK chromosomal translocation similar to ALK-positive anaplastic large cell lymphoma, most reported cases are characterized by t(2;17)(p23;q23) involving the clathrin gene. Here, we report 2 cases of ALK-positive DLBCL. The 2 cases presented similar morphologic features and immunohistochemical characteristics, that is, positivity for ALK, IgA, CD138, and MUM1; weak positivity for CD30 and CD79a; and negativity for CD20. The clathrin-ALK transcript was identified by reverse transcription-polymerase chain reaction, and the sequence was determined by direct sequencing. Recently, the essential role of STAT3 activation as well as STAT 5 activation in nucleophosmin-ALK fusion protein-mediated lymphomagenesis was reported. However, differential effects of ALK-fusion variant proteins on proliferation, transformation, and invasion properties were reported. Thus, we evaluated the phosphorylation status of STAT 3 and STAT 5, and found highly hyperphosphorylated STAT 3 on tyrosine 705 but not STAT 5 in our 2 cases of ALK-positive DLBCL with clathrin-ALK fusion. Furthermore, STAT 5A expression was not detected in either of the ALK-positive DLBCL cases, although 11 of the 36 ALK-negative DLBCL cases revealed STAT 5A expression. Expression of the antiapoptotic proteins survivin and BCL-X(L), which were believed to be the targets of STAT 3, was investigated. However, there were no significant associations between expression of survivin or BCL-X(L) and ALK positivity among the diffuse large B-cell lymphomas. In summary, similar signaling transduction mechanism involving STAT proteins seems to underlie DLBCL harboring the clathrin-ALK or nucleophosmin-ALK fusion gene.
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PMID:Hyperactivated STAT3 in ALK-positive diffuse large B-cell lymphoma with clathrin-ALK fusion. 1875 94

Plasmoblastic lymphoma (PBL) is a subtype of the diffuse large B-cell lymphoma, typically present as extranodal disease associated with human immune deficiency virus (HIV) infection. PBLs are often the initial manifestation of AIDS. Here we present a case of PBL concerning the oral cavity. A 34-year-old woman presented a tumor in the oral cavity that involved the maxilla and gingiva (confirmed by CT-scan). The gingival biopsy showed a massive infiltration by large lymphoid cells with round, vesicular nuclei, prominent nucleoli, fine chromatin and an significant amount of basophilic cytoplasm which express CD79a, CD138, cytoplasmic lambda light chain and LCA, without staining for CD20, CD38, CD3 and CTK. Serological analysis confirmed HIV positivity. PBLs lack most B-lineage markers, but many express CD79a in at least some of the cells, therefore generate difficulties in differential diagnosis. Overall assessment and correlation of the histopathological and immunohistochemical features with the clinical findings and serology investigation are the most helpful diagnostic tools and can lead to the final diagnosis.
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PMID:Plasmoblastic lymphoma associated with human immunodeficiency virus. 1875 34

Post-transplant lymphoproliferative disorders (PTLDs) represent a frequent complication of solid organ transplantation. Although most PTLDs arise from recipient lymphoid cells, a considerable fraction of cases may arise from donor B-cells. In an attempt to clarify the histogenesis and pathogenesis of PTLDs derived from donor B-cells, monoclonal PTLDs occurring in liver transplant recipients were chosen as a model to compare donor (D-PTLDs) versus recipient PTLDs (R-PTLDs). The tumour panel included nine D-PTLDs and six R-PTLDs. D-PTLDs were early-onset, EBV-infected lymphoproliferations classified as polymorphic PTLD (P-PTLD; n = 7) or diffuse large B-cell lymphoma (DLBCL; n = 2) with tumour localization confined to the hepatic hilum. All R-PTLDs were late-onset DLBCLs and showed extrahepatic localization. A BCL-6(-)/MUM1(+)/CD138(+/-) phenotype, consistent with a post-germinal centre (GC) stage of pre-terminal B-cell differentiation, was observed in all D-PTLDs and in 2/6 R-PTLDs, whereas a BCL6(+)/MUM1(-)/CD138(-) profile, reminiscent of GC B-cells, was detected in 4/6 R-PTLDs. The presence of somatic IGHV hypermutation was observed in 6/9 D-PTLDs and in 4/6 R-PTLDs, suggesting derivation from antigen-experienced B-cells. IGHV4-39 was the IGHV gene most frequently encountered, being rearranged in 3/9 D-PTLDs. Among IGHV-mutated PTLDs, a mutational profile suggesting antigen stimulation and/or selection was observed in 4/6 D-s and in 2/4 R-PTLDs. The presence of ongoing IGHV mutations was detected in 2/4 D-PTLDs. Aberrant SHM was detected in 10/15 (66.7%) PTLDs, including 6/9 D-PTLDs and 4/6 R-PTLDs. Our findings suggest that (i) D-PTLDs show a clinical presentation distinct from R-PTLDs; (ii) immunophenotypic and genetic features of D-PTLDs are consistent with mature, GC-experienced B-cells; (iii) transformed donor-derived B-cells may experience antigen-driven stimulation and selection, and may acquire genetic lesions during neoplastic expansion in the recipient environment; and (iv) EBV infection and expression of viral oncoproteins may be relevant in the pathogenesis of D-PTLDs.
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PMID:Molecular characterization of post-transplant lymphoproliferative disorders of donor origin occurring in liver transplant recipients. 1939 Nov 28

This review aims to interrelate the major lymphoma types in the current World Health Organization (WHO) classification to construct a framework for understanding and diagnostic application. Multiple morphological, phenotypical and molecular genotypical data are assessed in order to categorise lymphomas into germinal centre (GC) and extracentric (EC) subgroups. GC entities [lymphocyte-predominant Hodgkin, follicular, Burkitt's, angioimmunoblastic T-cell and diffuse large B-cell lymphoma (DLBCL) with GC profile] express bcl-6, CD10 and/or the GC-homing chemokine CXCL13, and harbour ongoing somatic hypermutations (SHM), but not Epstein-Barr virus (EBV) in its higher latency states. Post-GC entities [classical Hodgkin, marginal zone and lymphoplasmacytic lymphomas, half of chronic lymphocytic leukaemia (CLL)/small lymphocytic lymphoma (SLL), DLBCL with 'activated' or post-GC profile, primary effusion lymphoma, plasmacytoma and myeloma] express, instead, MUM.1 and/or CD138, harbour static rather than ongoing SHM, and may harbour EBV in higher latency states. The remainder of CLL/SLL and the majority of mantle cell lymphoma without SHM constitute the pre-GC ('naive') category, with coexpression of IgD and CD5. Lymphomas can be categorised across lineage (B- or T-cell) and relationship against host immune response (Hodgkin or non-Hodgkin) into GC and EC groups, affording leverage in their differential diagnosis.
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PMID:A practical approach to the understanding and diagnosis of lymphoma: an assessment of the WHO classification based on immunoarchitecture and immuno-ontogenic principles. 1940 43

Anetoderma is a rare condition, consisting of well-circumscribed areas of slack skin, in which dermal elastic fibres are destroyed or deficient. We present the case of a 45-year-old man with a 25-year history of deep nodules and plaques gradually progressing to areas of anetoderma. Histological examination found an infiltrate composed of neoplastic cells with lymphoplasmocytoid morphology. The cells were positive for CD20, CD38 and CD138, and there was a monoclonal kappa light chain gene rearrangement of plasma cells. A diagnosis of cutaneous marginal-zone B-cell lymphoma was made. The pathogenesis of anetoderma remains unknown, but it is possible that cytokines or other soluble factors produced by the infiltrating lymphocytes have a role in this process.
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PMID:Anetoderma in cutaneous marginal-zone B-cell lymphoma. 1977 7


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