Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Primary low-grade B-cell lymphomas of the thymus are rare, with only 7 reported cases in the literature. We describe 3 cases of primary low-grade thymic lymphoma. All had histologic features of extranodal marginal zone lymphoma and were composed predominantly of small lymphocytes with variable components of monocytoid cells and plasma cells. Overt transformation to large cell lymphoma occurred in 1 case. The neoplastic cells were immunoreactive for the B-cell marker CD20 and were positive for bcl-2 in 2 cases. Two of 3 patients had a long-standing history of autoimmune disease. Based on these findings and those of previously reported cases, marginal zone lymphoma is the predominant type of low-grade thymic B-cell lymphoma. These tumors seem to be more common in patients with autoimmune disorders, and as observed with marginal zone lymphoma arising at other anatomic sites, they may undergo transformation to a higher grade lymphoma.
 ...
PMID:Primary marginal zone lymphoma of the thymus. 1087 78

Primary cutaneous B-cell lymphomas (CBCLs) should be clearly separated from non-Hodgkin's B-cell lymphomas with secondary cutaneous involvement and from cutaneous B-cell pseudolymphomas. The majority of CBCLs are characterized by a homogeneous clinical presentation and behavior, with good response to local radiotherapy, low tendency to extracutaneous spread, and excellent prognosis. According to the European Organization for Research on the Treatment of Cancer classification of primary cutaneous lymphomas, CBCLs with an indolent behavior are divided into 2 subgroups: follicular center cell lymphoma and immunocytoma/marginal zone lymphoma, due to putative histologic similarities with their purported nodal counterparts. In addition, a third subgroup with intermediate prognosis (large B-cell lymphoma of the leg) is identified. Conversely, the identification of distinct subgroups is disputable from a strictly histologic, immunophenotypic, and genotypic point of view, and has neither correlation with the clinical course nor the prognosis of the disease. Moreover, the majority of CBCLs show a uniform immunophenotype (CD5-, CD10-) and genotype (lack of bcl-1/bcl-2 and c-myc gene rearrangement) of neoplastic cells. Therefore, we favor the use of the term Skin-Associated Lymphoid Tissue (SALT)-related B-cell lymphomas, due to the close similarities between CBCLs and mucosa-associated lymphoid tissue (MALT) lymphomas, and the evidence for an acquired B-cell arm of SALT.
 ...
PMID:The skin-associated lymphoid tissue-related B-cell lymphomas. 1089 14

The bcl-2 oncogene plays an important role in carcinogenesis by inhibiting cell death (apoptosis). It was initially discovered in follicular B cell lymphoma with t(14,18) and subsequently found in other malignant and premalignant lesions. Alteration of the normal controls of cell proliferation is also a significant factor in the multistep process of tumorigenesis. The proliferative activity of a given lesion is commonly evaluated by MIB 1, a monoclonal antibody to Ki67 proliferation antigen. Mutation of the p53 gene is considered the most common genetic aberration in colorectal cancer. Immunohistochemical (IHC) staining expression of bcl-2, Ki67, and p53 was retrospectively investigated in a series of 52 colorectal carcinomas and 56 adenomas. The aim of the study was twofold: (i) to investigate any correlation between MIB 1, p53, and bcl-2 immunostaining expression in colonic adenomas and carcinomas and (ii) to identify any relation between these markers and several histopathologic parameters including tumor size, pathologic stage, lymph node metastasis, angiolymphatic invasion, tumor grade, and differentiation in colon carcinomas. bcl-2 was consistently higher in adenomas than in carcinomas. There were 44 of 56 (78.6%) adenomas and 27 of 52 (51.9%) carcinomas positive for bcl-2 (P = 0.004). The mean Ki67 labeling index (LI) was 30.05 +/- 7.6 and 38.12 +/- 11.01 in adenomas and carcinomas, respectively (P = 0.0001). p53 was significantly higher in carcinomas (35 of 52 [67.3%]) than in adenomas (18 of 56 [32.1%]) (P = 0.0004). Expression of bcl-2 in carcinoma was associated with a lower p53 levels and lower mean Ki67 LI and with favorable histopathologic parameters. Higher p53 and Ki67 values were associated with prognostically poor histopathologic features (differentiation and Duke's stage). We conclude that, in contrast to p53 and Ki67, bcl-2 oncoprotein expression is probably an early step in the process of colon carcinogenesis, and its expression may be associated with favorable pathologic parameters. Furthermore, an inverse relation exists between p53 and Ki67, and bcl-2 IHC expression in colonic neoplasia. Evaluation of bcl-2, p53, and Ki67 IHC expression in colonic carcinoma may be of value in predicting the clinical course in these patients.
 ...
PMID:Immunohistochemical expression of bcl-2 and p53 oncoproteins: correlation with Ki67 proliferation index and prognostic histopathologic parameters in colorectal neoplasia. 1098 68

A series of B-cell lymphoma lines with an immature phenotype has been used as a model system to study molecular events associated with receptor ligation induced death. B-cell receptor (BCR) cross-linking with antibodies to membrane IgM (but not with anti IgD) induces c-Myc downregulation via nuclear factor kappaB inactivation and p27(Kip1) accumulation in these B lymphomas. Anti-mu-treated cells then undergo G1 arrest and die by apoptosis independent of Fas. Steroids and retinoids similarly downregulate c-Myc and induce apoptosis in these B cells and synergize with anti-mu. Rescue from apoptosis induced by anti-mu or steroids occurs with T-cell signals, like CD40L, or a broad-range caspase inhibitor, but only CD40L prevents the loss of c-Myc, p27 accumulation and growth arrest. Both IgM and IgD signaling lead to modulation of phosphatidylinositol 3-kinase (PI3K) signals, including the activation of p70(S6K), but this pathway recovers under anti-IgD treatment. Blockade of the PI3K pathway augments anti-mu-induced death and converts anti-delta to an apoptotic signal. Resistance to Fas-mediated death may be an important factor in B-cell transformation in vivo. Many of our panel of lymphomas are insensitive to Fas-mediated death signals, although all can form a death-inducing signaling complex (DISC). Additional studies suggest that some lymphomas can be blocked at the DISC complex by anti-apoptotic proteins, whereas others are inhibited downstream of caspase 8 activation. Anti-Ig treatment of a Fas-sensitive line, A20.2J, activated a number of genes whose products may block apoptosis proximally (like FLICE-inhibitory protein (FLIP1)) or at late points, such as bcl-2-family members. Our data suggest that B lymphomas develop multiple pathways of resistance to Fas-mediated signals during lymphomagenesis, in part via signaling through the BCR.
 ...
PMID:B-cell receptor and Fas-mediated signals for life and death. 1104 71

Translocation t(14; 18) has been observed in 50-85% of follicular and in 30% of diffuse non-Hodgkin lymphomas. About half of follicle center lymphoma (FCL) undergo histological conversion at relapse to more aggressive diffuse large B-cell lymphoma (DLBCL). This report correlates the molecular bcl-2/IgH rearrangement by PCR and Bcl-2 immunohistochemical (IHC) expression in a series of high grade DLBCLs with and without FCL remnant. Twenty-three paraffin-embedded lymph nodes from DLBCL patients were analyzed. Eleven patients showed FCL remnant (Group A) and 12, did not (Group B). Single PCR from paraffin extracted DNA followed by Southern transfer of products, hybridisation with internal oligoprobes for the MBR/JH and MCR/JH bcl-2 rearrangements and IHC analysis of Bcl-2 expression, were performed. PCR analysis was positive in 34.8% of patients. Bcl-2/IgH gene rearrangements were observed in 8 (34%) cases and 7 (30%) showed Bcl-2 expression on large noncleaved B-cells (centroblasts). All patients from Group A showed IHC positive reaction on FCL remnant (small cleaved cells) but only 2 (18%) were positive in DLBCL areas, suggesting either the loss of the bcl-2 expression on the transformed lymphoma, or, alternatively, the development of a second disease when the first lymphoma transforms. Group B patients showed a clear correlation between PCR and IHC studies. Our results suggest a similar frequency of t(14; 18) in DLBCLs to that reported in Europe and USA series. The discordance observed between PCR and IHC, particularly in Group A, points out the necessity to perform both studies in order to detect bcl-2 gene involvement in DLBCLs.
 ...
PMID:Bcl-2 molecular analysis in paraffin-embedded biopsies from diffuse large B-cell lymphomas. 1105 Aug 5

We report a series of 31 cases of splenic marginal zone lymphomas with an enlarged spleen and a multimicronodular macroscopic pattern. Two groups, A and B, were distinguished based on the presence (A) or absence (B) of a lymphoplasmacytic component with monoclonal immunoglobulin expression in the cytoplasm. There were no differences between the groups as far as age, sex, spleen weight, and progression. The only difference was the presence in group A of a monoclonal serum component and autoimmune disorders, particularly autoimmune hemolytic anemia. In most cases in which a liver and/or bone marrow biopsy was performed, lymphomatous infiltration was detected. Seven cases had a seric monoclonal IgM of 5 g/L or more and liver or bone marrow infiltration, corresponding to the definition of Waldenstrom's macroglobulinemia. Lymphoma cells had a monocytoid, centrocytoid and, in group A, lymphoplasmacytic morphology. The lymphomatous cells were positive for CD20, CD45 RA, and bcl-2. They expressed IgD in 9 cases, partially in 6, and were negative for IgD in 9 of the 24 cases studied. Progression seems to be slow, with a long survival. Three patients presented with transformation into a large B-cell lymphoma, which was responsible for death in two patients.
 ...
PMID:Splenic marginal zone lymphoma with or without plasmacytic differentiation. 1111 78

An association between chronic hepatitis C virus (HCV) infection and clonal proliferation of B cells, including B cell lymphoma, has recently been demonstrated. However, the mechanism of malignant transformation is still unknown. It has been shown that B cells from patients with type II mixed cryoglobulinaemia (MC), strongly express the antiapoptotic bcl-2 oncogene product. Therefore, we investigated a possible mechanism of lymphomagenesis, the occurrence of bcl-2 and immunoglobulin gene rearrangement (IgH) in HCV-infected patients. Three groups of patients were studied: (1) 44 patients with HCV and MC (anti-HCV and HCV RNA positive); (2) 59 patients with chronic HCV infection without MC; (3) 50 patients with chronic liver disease (CLD) not related to HCV infection. The t(14;18) translocation (MBR bcl-2-JH) and IgH rearrangement (FR3/JH) were detected by polymerase chain reaction (PCR) in peripheral mononuclear cells. bcl-2 translocation was detected in 17/44 (39%), 7/59 (12%) and in none of the patients of groups 1, 2 and 3 respectively (P < 0.01). Monoclonal IgH rearrangement was detected in 15/44 (34%), 5/59 (8.5%) and 2/50 (4%) patients of groups 1, 2 and 3 respectively (P < 0.05). HCV-infected patients had a higher prevalence of monoclonal IgH rearrangement and bcl-2 translocation than patients with CLD of other aetiologies. These data suggest that HCV may play a role in the multistep mechanism of lymphomagenesis by inducing clonal proliferation of B cells and inhibition of apoptosis.
 ...
PMID:bcl-2 and immunoglobulin gene rearrangement in patients with hepatitis C virus infection. 1116 30

In the REAL classification system, follicular lymphomas (FL) were subdivided into three grades depending on the number of blasts (6). In this study, we were interested in defining biological parameters possibly being important in the delineation of subgroups. Between 1990 and 1998, biological and cytogenetic investigations were performed on 91 FL. Clonal aberrations were found in all cases. The tumours were subclassified according to the blast content and the morphology of the centrocytes into 29 FL 1, 33 FL 2, 15 FL 3, and 14 FL 3 with a diffuse large B-cell lymphoma component (FL 3 + DLBL). They were characterised by classical cytogenetics, for their mitotic (MI) and proliferative (PI) indices, and CD10, bcl-2, and p53-expression. In contrast to FL 1 and FL 2, which showed a common genetic background with t(14;18), and only differed by their blast content and MI/PI, FL 3 (with or without associated DLBL) turned out to be an inhomogeneous group. 11 follicular lymphomas (with > 150 blasts/10HPF) still showed maturation to centrocytes. They were positive for CD10 and harboured the t(14;18) in 73%. These cases correspond to a "high grade" variant of centroblastic-centrocytic lymphoma according to the Kiel classification (FL 3a). In 18 cases with a follicular or follicular and diffuse growth pattern, the infiltrate consisted of centroblasts exclusively. These tumours were CD10+ in only 50% and were t(14;18)+ in only 22%. Secretory differentiation (clg+) was found in 44%. They were--with respect to primary and secondary chromosome aberrations--more comparable to a follicular variant of DLBL and hence, correspond to centroblastic lymphoma, follicular or centroblastic lymphoma, follicular and diffuse according to the Kiel classification (FL 3b). By histomorphological, biological and cytogenetic investigations, therefore, FL 3 can be delineated into two different biological subgroups with obviously different transformation pathways.
 ...
PMID:[Genetic and biological features define two types of follicular non-Hodgkin grade 3 lymphoma]. 1121 35

Based on the histological criteria proposed by the REAL and adopted by the WHO Classification, 30 cases of MALT type lymphoma, 18 cases of diffuse large B cell lymphoma (DLCL), and 17 cases of DLCLs, associated with a MALT type, were identified in a series of 65 surgically treated primary gastric lymphomas. The clinical records of the patients were analyzed retrospectively and the resected specimens were immunostained for bcl-2, p53 and Ki-67. Primary gastric DLBCLs, with or without a MALT type component, disclosed a higher stage of local extension, a more frequent nodal involvement and a significantly worse survival than pure MALT types. High p53 expression and high proliferation rate correlated with the presence of a large cell component and appeared useful for its identification in mixed forms. Low bcl-2 expression discriminated DLCL from DLCL/MALT. Tumor size, stage and Mib-1 index revealed a value in predicting prognosis.
 ...
PMID:[Primary gastric lymphomas. Clinico-pathological study and evaluation of prognostic factors in 65 cases treated surgically]. 1123 1

We hereby present a retrospective clinicopathological and immunohistochemical study of surgically resected primary gastrointestinal (GI) lymphoma with an analysis of parameters of potential prognostic relevance. From a larger series of 144 cases of primary GI lymphomas, we chose 61 cases with sufficient clinical follow-up (mean 60, range 1-219 months), classified either as extranodal marginal zone B-cell lymphoma of MALT type (MALT lymphoma) or diffuse large B-cell lymphoma (DLBCL), after having excluded other subtypes. In addition to conventional clinical and morphological parameters, the expression levels of Ki-67 (MIB-1), bcl-2 and p53 were evaluated for prognostic significance. Twenty-one (34.4%) cases were classified as pure low grade marginal zone B-cell lymphoma of MALT type, 12 (19.7%) cases as low grade MALT lymphoma with a high grade component (mixed type), and 28 (45.9%) cases as primary extranodal DLBCL. Most of the lymphomas (53/61; 86.9%) were localized in the stomach, 3 (4.9%) in the small bowel, 3 (4.9%) multifocal in both stomach and small intestine and 2 (3.3%) in the large bowel. MIB-1 expression in more than 30% of tumor cells was detected in 42 (68.6%), bcl-2 expression in 20 (32.8%) and p53 accumulation in more than 10% of neoplastic cells in 16 (26.2%) lymphomas. Both high Ki-67 expression and p53 accumulation were more prevalent in the DLBCL. 30 (49%) patients showed lymph node involvement at surgery, 14 (23%) patients suffered tumor recurrence, and 24 (38.5%) died during the follow-up period. Tumor recurrence occurred primarily in patients who had presented lymph node involvement (9/14, 64.3%). The 5-year survival rate was 66.1% for all patients. Important prognostic factors for overall survival were tumor stage (p < .004) and p53 accumulation (p < .05) in univariate analysis, and tumor stage in multivariate analysis (p < .001). Although p53 accumulation did not reach statistical significance in our small study group, it may be both important in the transformation of low grade MALT lymphoma and an indicator for aggressive behavior in high grade tumors.
 ...
PMID:Primary gastrointestinal B-cell lymphoma. A clincopathological and immunohistochemical study of 61 cases with an evaluation of prognostic parameters. 1143 65


<< Previous 1 2 3 4 5 6 7 8 9 10