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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 clarify the clinicopathologic features of B-cell lymphoma associated with prominent epithelioid granulomatous responses other than immunocytomas, 12 patients were studied. There were six men and six women. The lymphoma generally affected elderly patients (median age, 58.5 years) and was mostly nodal in origin. Seven of the 12 patients had a localized lesion (stage I or II), and five had an advanced lesion (stage III or IV). Histologically, four patients showed a follicular growth pattern and eight a diffuse growth pattern. Based on the updated Kiel classification, nine patients showed centroblastic lymphomas, and three showed centroblastic-centrocytic lymphomas. The epithelioid cells were accumulated in large, poorly demarcated masses. Trabecular fibrosis compartmentalized in the lymph nodes, producing a vague nodular pattern in low-power fields. Immunohistochemical studies of the tumor cells revealed positive membrane staining with L26 in all 12 patients and with LN-1 antibody in 9 of 10 patients. Expression of the bcl-2 protein was present in all seven patients tested. Genotypic investigation exhibited germline configuration of the immunoglobulin heavy chain gene, the T-cell receptor beta-chain gene and the bcl-2 gene in all three patients investigated. By in situ hybridization, Epstein-Barr virus genomes were detected in only a few tumor cells in three of the patients tested. This study indicated that most, if not all, of the B-cell lymphomas with prominent epithelioid granulomatous responses other than immunocytoma were of follicular center cell origin.
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PMID:Centroblastic and centroblastic-centrocytic lymphomas associated with prominent epithelioid granulomatous response without plasma cell differentiation: a clinicopathologic study of 12 cases. 901 44

The translocation t(1;19)(q23;p13) is found in 3-5% of all acute lymphoblastic leukaemias (ALL) and results in the expression of an E2A/PBX1 hybrid gene transcript. This translocation is very closely associated with a pre-B phenotype. t(14;18) is associated with follicular B-cell lymphoma and is characterized by over-expression of the bcl-2 oncogene. We describe a case of ALL in an adult with a mature B-cell immunophenotype and a single abnormal cell line with a complex karyotype showing both t(1;19) and t(14;18). Two reports of this phenomenon have been published previously and molecular analysis, where performed, showed the E2A gene was not rearranged, suggesting the t(1;19) was a molecular variant of the established translocation. In contrast, molecular analysis of our case demonstrated expression of the E2A/PBX1 fusion transcript typically associated with t(1;19) in pre-B ALL but showed it to be present at an extremely low level, despite the abnormal karyotype being found in the majority of metaphase cells. Analysis of bcl-2 expression showed a significant up-regulation. A down-regulation of the E2A/PBX1 hybrid gene as a consequence of the enhanced expression of bcl-2 may be a possible mechanism for this finding.
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PMID:A case of mature B-cell ALL with coexistence of t(1;19) and t(14;18) and expression of the E2A/PBX1 fusion gene. 875 23

T-cell rich B-cell non-Hodgkin's lymphoma (T-cell rich B-cell lymphoma) is a morphological variant of diffuse large B-cell lymphoma. It is important to recognize this variant in the differential diagnosis of T-cell non-Hodgkin's lymphoma. The main differential diagnosis of T-cell rich B-cell lymphoma, nodular and diffuse lymphocyte predominance Hodgkin's disease (lymphocyte predominance Hodgkin's disease), is, however, even more difficult and differentiating criteria are still not satisfactorily defined. Moreover, T-cell rich B-cell lymphoma may not represent a clinicopathological entity. Twelve cases of T-cell rich B-cell lymphoma, selected on the basis of morphology and limited immunohistochemistry without previous knowledge of clinical data, were studied by immunohistochemistry and polymerase chain reaction for bcl-2 rearrangements to investigate the histogenetic background. In three of 12 cases, bcl-2 rearrangements were found, strongly suggesting a follicle centre cell origin. In three other cases, a documented history of definite nodular lymphocyte predominance Hodgkin's disease 29 months to 20 years prior to the diagnosis of the lymphoma was present. No differences in growth pattern, residual nodularity, tumour cell distribution, cellular morphology and composition, or immunophenotypical differences were noted in these six cases as compared to the remaining cases. These data underscore the histogenetic diversity in T-cell rich B-cell lymphoma and identify it as a progressed form of lymphoma derived from entities as diverse as follicle centre cell lymphoma and nodular lymphocyte predominance Hodgkin's disease. Moreover, it shows a complete morphological overlap with the diffuse form of lymphocyte predominance Hodgkin's disease and may actually encompass this disease entity.
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PMID:T-cell rich b-cell non-hodgkin's lymphoma: a progressed form of follicle centre cell lymphoma and lymphocyte predominance hodgkin's disease. 888 63

We report on two cases of low grade follicle centre cell lymphoma with a pronounced parafollicular monocytoid/ marginal zone B-cell component. One patient had a history of preceeding follicular high grade B-cell lymphoma of centroblastic type showing the same light chain restriction and identical immunoglobulin heavy chain gene rearrangement as the low grade lymphoma diagnosed 15 months later. Morphologically, in both cases the two constituents of the low grade tumours were clearly distinguishable. Immunohistochemically, the follicular component strongly expressed bcl-2 protein in contrast to a weak staining of the marginal zone B-cell component. Performing PCR, a rearrangement of the major breakpoint region of bcl-2 was not found. Identical light chain restriction of the follicular and the monocytoid B-cell/marginal zone components strongly indicates a clonal relationship between them. A monocytoid/marginal zone B-cell component in follicular lymphoma probably results from differentiation of the follicle centre cells and does not indicate a composite lymphoma.
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PMID:Monocytoid/marginal zone B-cell differentiation in follicle centre cell lymphoma. 888 47

The protein product of the proto-oncogene bcl-2, originally discovered by virtue of its chromosomal translocation in human follicular centre B cell lymphoma, is a physiological inhibitor of programmed cell death, apoptosis. Initial studies in transgenic mice overexpressing Bcl-2 in B or T lymphocytes demonstrated that Bcl-2 can potently antagonise cell death induced by multiple independent signal transduction routes and can contribute to oncogenesis, particularly in combination with other oncogenes, like c-myc, that promote cell proliferation. Further investigations using crosses between bcl-2 transgenic mice and T cell receptor or immunoglobulin transgenic mice or mutant mice deficient in proper antigen receptor gene rearrangement demonstrated that Bcl-2 can only block death of cells that failed to receive a positive stimulus, "death by neglect', but not activation induced apoptosis. Collectively, these results provide evidence that distinct signalling pathways for apoptosis converge upon a common effector machinery where Bcl-2 acts as an antagonist, but that there also exists a mechanism that can either bypass the Bcl-2 checkpoint or override its protective function. These experimental data are reviewed here and discussed in context of current knowledge of lymphocyte differentiation, tumorigenesis and cell death regulation.
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PMID:Lessons from bcl-2 transgenic mice for immunology, cancer biology and cell death research. 895 Apr 69

Local extension has been shown to be a major prognostic factor in primary gastric B-cell lymphoma. In order to evaluate whether this parameter might be correlated with cell proliferation or its regulation, a retrospective study was performed. Fifty-three surgical specimens with primary gastric B-cell lymphomas were analysed concerning histological grading, depth of infiltration and Ann-Arbor stage. In addition, immunohistochemistry (p53[Do7], bcl-2[bcl-2-124], Ki-67 [MiB1]) and in situ end-labeling (apoptotic bodies) were applied. The depth of infiltration was significantly correlated with Ann-Arbor stage (p < 0.001) and histological grading (p < 0.002). Furthermore, the semiquantitatively evaluated expressions of Ki-67, apoptotic bodies and p53 revealed that tumours limited to the mucosa and submucosa had lower numbers of stained cells than lymphomas infiltrating the muscularis propria or beyond (p < 0.001 in all cases). Analysis of bcl-2 expression showed an inverse picture (p < 0.05). The importance of local spread of gastric lymphomas is underscored by our findings: in gastric lymphomas infiltrating the muscularis propria or beyond, powerful proliferative stimuli have been acquired, e.g. associated with p53 mutations, that are independent of the known mucosa-associated stimuli, Helicobacter pylori and auto-immunity.
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PMID:Depth of infiltration of primary gastric B-cell lymphomas--correlations with proliferation, apoptosis and expression of p53 and bcl-2. 895 Jul 59

A 44-year-old male was evaluated for an iron deficiency anemia. Endoscopic investigation revealed marked serpiginous ulceration of the proximal small intestine due to a B cell lymphoma. Endoscopic small intestinal mucosal biopsies revealed a nodular lymphoid infiltrate, and polymerase chain reaction of biopsy material from the same site demonstrated rearrangement of the bcl-2 gene, the molecular equivalent of the t(14;18) chromosomal translocation. Primary small bowel follicular small cleaved cell lymphoma was diagnosed. Endoscopic tissue biopsies for immunophenotyping, molecular genetic studies or both are a valuable diagnostic aid for precise classification of lymphoid neoplasms in the gastrointestinal tract.
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PMID:Clinical, pathological and molecular genetic findings in small intestinal follicle centre cell lymphoma. 911 95

To study the incidence and clinical significance of bcl-2/JH fusion in 45 Chinese patients with non-Hodgkin's lymphoma, semi-nested polymerase chain reaction (PCR) was used to detect the fusion gene of non-Hodgkin's lymphoma. A total of 12 patients gave positive results, they include 9 of the 15 patients with follicular lymphoma and 3 of the 30 patients with diffuse B-cell lymphoma. The results were negative in 5 patients with reactive hyperplasia. The breakpoint was located within the major breakpoint region in 11 of the 12 patients, and the remaining patient had bcl-2 translocation in the minor cluster region. The results of the study show that bcl-2/JH fusion gene in non-Hodgkin's lymphomas is an important molecular biological marker and has a significant role in differentiating benign or malignant hyperplasia, determination of clonality, predicting prognosis and in the discovery of minor residual disease.
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PMID:[Detection of bcl-2/JH fusion gene in patients with non-Hodgkin's lymphoma by semi-nested polymerase chain reaction]. 927 69

Cholangiocarcinoma is a malignant neoplasm originating from cholangiocytes. The mechanisms responsible for oncogenesis of cholangiocytes are unknown. Resistance to apoptosis, especially by altered expression of B-cell lymphoma/leukemia 2 (Bcl-2) family members, has been implicated as a mechanism contributing to malignant transformation. Thus, our aim was to test the hypothesis that altered expression of Bcl-2 family members by cholangiocarcinoma cells renders them resistant to apoptosis. We compared the apoptotic threshold and expression of the Bcl-2 protein family members, Bcl-2, Bcl-XL, and Bax, in two human cell lines: 1) nonmalignant human cholangiocytes immortalized by transfection with the simian virus 40 (SV 40) large T antigen; and 2) a malignant human cholangiocarcinoma cell line. Apoptosis was induced pharmacologically using beauvericin. Bcl-2, Bcl-x long, and Bax protein expression were evaluated by immunoblot analysis, and Bcl-2 expression was modulated using antisense technology. The cholangiocyte and malignant/nonmaligant phenotype of both cell lines was verified using both in vitro and in vivo approaches. Beauvericin induced apoptosis of nonmalignant cholangiocytes in a concentration- (0 to 25 micromol/L) and time- (0 to 6 hours) dependent manner. In contrast, malignant cholangiocytes were resistant to apoptosis. Although expression of Bcl-x long and Bax protein were similiar in the two cell lines, Bcl-2 protein expression was 15-fold greater in malignant than in nonmalignant cholangiocytes. An 18 mer bcl-2 antisense oligonucleotide reduced expression of Bcl-2 protein by 50% and increased the rate of beauvericin-induced apoptosis more than threefold in the malignant cells. Our results support the hypothesis that resistance to apoptosis by overexpression of Bcl-2 may be a feature of cholangiocarcinoma.
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PMID:Bcl-2 is overexpressed and alters the threshold for apoptosis in a cholangiocarcinoma cell line. 932 9

We report the case of a 53 year-old woman with a gastric tumor showing morphological, phenotypical and molecular features of a plasmablastic lymphoma, a recently recognized subtype of diffuse large B-cell lymphoma. The tumor was composed of plasmablast-like cells, lacked CD45 and B-cell associated antigens, expressed the plasma cell-associated antigen CD38, and showed clonally rearranged IgH genes in the absence of bcl-2 and bcl-6 genes rearrangement.
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PMID:Plasmablastic lymphoma of the stomach. A case report. 954 26


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