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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 differences between reactive and malignant processes are sometimes blurred. Homogeneity is no longer a requisite for the diagnosis of lymphoma, as witnessed in mucosa-associated lymphatic tissue lymphoma and T-cell-rich B cell lymphoma, which are composed of an admixture of neoplastic clonal B cells and reactive T cells which occasionally are very prominent in the histological picture. Infectious mononucleosis, anaplastic large cell lymphoma, composite lymphoma and Hodgkin's disease, all share many similarities and may actually represent a continuous spectrum of pathological conditions. Immunodeficiency states, whether primary or acquired, are commonly associated with clonal lymphatic malignancies preceded by a polyclonal lymphoproliferative stage, which is usually reversible by reducing immunosuppression. The distinction between these stages is sometimes difficult to assess. Immunologists have so far failed to find a lymphatic tumor-specific antigen, hence, monoclonality is usually based on a constellation of factors, namely homogeneity of the phenotypic expression of few antigens, aberrant expression of antigens and restricted expression of kappa- or lambda-chains in malignancies expressing surface immunoglobulins. Nonrandom chromosomal translocations as well as other aberrations, usually important in the diagnosis of malignancy, are sometimes of limited value. This is mainly due to the existence of translocations [like t(14;18) and t(2;5)] in nonmalignant states, and their non-specificity [the existence of t(8;14) in Burkitt's lymphoma and large cell lymphoma, t(2;5) in Hodgkin's disease and anaplastic large cell lymphoma, and t(14;18) in large cell lymphoma evolving from follicular lymphoma and Burkitt's lymphoma]. The diagnostic tools available in 1995, although usually sufficient, are sometimes unable to distinguish between malignancy and reactivity. Some problematic cases will be more accurately defined as lying in the gray zone, or as belonging to a spectrum ranging between reactivity and malignancy.
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PMID:The gray zone between malignant and reactive processes in lymphoproliferative diseases. 887 7

Seven cases of large B-cell lymphoma which define a previously unrecognized subgroup are reported. Morphologically they are comprised of monomorphic large immunoblast-like cells, containing large central nucleoli, which tend to invade lymphatic sinuses. Superficially they resemble anaplastic large cell lymphoma (ALCL) but they lack CD30. These lymphomas express epithelial membrane antigen (as do ALCL), but also contain intracytoplasmic IgA of a single light chain type (five cases) and an endoplasmic reticulum-associated marker detected by antibody VS38. They lack lineage-associated leukocyte antigens with the exception of CD4 (5 of 5 cases) and CD57 (5 of 7 cases). They are labeled by antibodies detecting both the intracytoplasmic and extracellular regions of the ALK receptor kinase, suggesting that they express the full-length form of this molecule. This was confirmed by Western blotting (in the one case tested) which showed a band of 200 kD in tumor cell lysates, and by polymerase chain reaction (PCR) amplification of mRNA encoding intracellular and extracellular ALK sequences (in the two cases tested). There was no evidence by cytogenetics (one case analyzed) or reverse transcriptase-PCR (three cases tested) of the 2; 5 translocation or the resultant NPM-ALK gene, as is commonly found in ALCL. All but one of the patients were male and all but one were adults, and in all but the latter case the disease followed an aggressive course.
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PMID:A new subtype of large B-cell lymphoma expressing the ALK kinase and lacking the 2; 5 translocation. 905 27

Ligation of CD28 on T cells with its natural ligands B7-1 (CD80) or B7-2 (CD86) provides a major costimulatory signal for T cells and is of potential importance for tumor rejection. We previously reported a strong expression of B7-1 on Reed-Sternberg cells and anaplastic large cell lymphoma cells. We report here our findings on B7-2 expression by malignant lymphomas (n = 70). B7-2 was present on the neoplastic cells of anaplastic large cell lymphoma in two of three cases studied, and on a subpopulation of the malignant cells in one out of four cases of follicular lymphoma. B7-2 was not expressed by the neoplastic cells of the other non-Hodgkin's lymphomas (n = 32), including T cell-rich B cell lymphoma. In contrast, Reed-Sternberg cells in lymph nodes affected by Hodgkin's disease are strongly positive for B7-2 (n = 31). Evidence for a functional correlate of this expression was obtained by our findings that the combination of anti-B7-1 and anti-B7-2 monoclonal antibodies was more effective than each separately in blocking allogeneic T cell activation (proliferation and cytokine secretion) by Hodgkin's disease-derived cell lines as stimulators. The possible role of B7-1 and B7-2 expression for the course and symptomatology of Hodgkin's disease is discussed.
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PMID:Expression of B7-2 (CD86) molecules by Reed-Sternberg cells of Hodgkin's disease. 917 39

We report on a patient with malignant histiocytosis (MH) presenting as multiple erythematous plaques and cutaneous depigmentation on her neck and chest. In a biopsy of an erythematous plaque, atypical large, foamy histiocytes infiltrated the dermis and positively stained with antibodies to lysozyme, leukocyte common antigen, and KP-1 (CD68). A few similar atypical cells were present in the superficial dermis focally in the depigmented areas. With use of immunohistochemical studies, most cases previously diagnosed as MH have been reclassified as T-cell lymphoma, B-cell lymphoma, or Ki-1-positive anaplastic large cell lymphoma. However, a few cases of "true" MH characterized by authentic histiocytes have been reported, presenting usually as red nodules. To our knowledge, our patient is the first with MH to present with erythematous plaques and vitiligo-like depigmentation.
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PMID:Malignant histiocytosis presenting as multiple erythematous plaques and cutaneous depigmentation. 918 20

Relationship and histogenesis of Hodgkin's disease (HD) and anaplastic large cell lymphoma (ALCL) still remain unclear. Recently, Reed-Sternberg cells or Hodgkin cells in HD with B cell phenotype (B-HD) are considered to originate from germinal center B cells, ALCLs of B cell phenotype (B-ALCL) are involved in diffuse large B cell lymphoma (DLBCL) as anaplastic variant, but an origin of tumor cells of B-ALCL has not been elucidated. We have therefore investigated somatic mutation of the lg heavy chain (IgH) genes among 17 cases of B-ALCL to clarify whether there is a difference in characteristic and origin of tumor cells between B-ALCL, B-HD and DLBCL. Amplificates of IgH variable (V) region of 10 cases by the polymerase chain reaction method were sequenced and compared with reported germ line configurations. Nine cases (90%) with heavily somatic mutations were found. A case with an out-of-frame rearrangement and a case with 9 base pairs insertion were included. The mutation pattern revealed the tumor cells were selected for antibody expression and discriminated from B-HD. These findings suggest the tumor cells of B-ALCL are derived from germinal center or postgerminal center (memory and effector) B cells and an origin of B-ALCL is not different from DLBCL.
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PMID:Most of CD30+ anaplastic large cell lymphoma of B cell type show a somatic mutation in the IgH V region genes. 959 74

Recently, a novel phosphatase designated PTEN/MMAC1/TEP1 and located on chromosome 10q23.3 has been implicated as a new tumor suppressor gene in human cancer. Allelic loss and mutation of this gene has been reported in epithelial derived tumors, including breast cancer and prostate cancer, and in glioblastoma multiforme. The present study was designed to evaluate the potential involvement of PTEN in the pathogenesis of lymphoid neoplasms. We analyzed 27 hematopoietic cell lines (representing a variety of lymphoid lineages), 65 primary lymphoid tumors (including 24 lymphoblastic leukemia/lymphoma [LBL], 30 large B-cell lymphoma [LBCL], 7 Burkitt's lymphoma [BL], and 4 anaplastic large cell lymphoma [ALCL]), and 25 nonmalignant lymph node controls. Gene deletion and gross rearrangement were evaluated using Southern blot analysis, and mutations were studied by polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) (PCR-SSCP) and sequencing. Six of 27 cell lines (22.2%) and 3 of 65 primary lymphomas (4.6%) contained alterations of this gene. A large homozygous deletion spanning exons 2 through 5 was detected in one LBL cell line, and two insertions potentially resulting in premature termination, were detected in a second LBL cell line. Nonconservative nucleotide variations were found in two other cell lines (one LBCL and one BL) and in one primary case of LBCL. In addition, two other cell lines (one BL and one myeloma) and two primary lymphomas, both LBCL, contained small deletions within intron 7. These deletions mapped to a poly-T-rich tract just 5' to the intron 7/exon 8 spice site. Their significance is unclear, as they may represent polymorphisms. Overall, our results suggest that abnormalities of the PTEN gene can contribute to pathogenesis in a small percentage of malignant lymphomas.
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PMID:PTEN gene alterations in lymphoid neoplasms. 978 81

The clinical and pathological features of acquired immune deficiency syndrome (AIDS)-related lymphomas, including their relationship with other viruses, such as Epstein-Barr virus (EBV) and human herpes virus-8 (HHV8), have been the subject of several studies from North America and Europe. No consistent data have been reported in Africa, where AIDS runs an epidemiological and clinical course different from that observed in Western countries. We retrospectively evaluated the presence of human immunodeficiency virus (HIV), HHV8, and EBV in 146 cases of malignant lymphomas collected in Kenya (Equatorial Africa), with the use of polymerase chain reaction (PCR) and in situ hybridization (ISH). The PCR technique confirmed HIV infection in 16 HIV-seropositive subjects (11%) and showed the presence of HIV sequences in five additional cases (3%) in which the occurrence of lymphoma was the only clinical manifestation. Our findings suggest that AIDS-related lymphomas are not pathogenetically homogenous, and different mechanisms may contribute to lymphomagenesis in these severely immunocompromised patients. In our series, no association of Hodgkin's disease (HD) with HIV infection could be shown. Among non-HIV-related lymphomas, EBV was present in 94% of Burkitt lymphoma (BL) occurring in patients younger than 15 years of age, in 87% of HD independently of age, sex, and histological types, in 60% of anaplastic large cell lymphoma (ALCL), and to a lesser extent (13%) in large B-cell lymphoma (LBCL) cases. Only one tumor, a case of HD, showed HHV8 by PCR.
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PMID:HIV-associated malignant lymphomas in Kenya (Equatorial Africa) 1053 80

Tyrosine kinases causing the abnormal phosphorylation of intracellular proteins have been shown to contribute to oncogenic transformation in a number of human neoplasms. Immunohistological staining of routine biopsy sections for increased levels of phosphotyrosine may therefore provide a simple means of screening for tumours containing activated tyrosine kinases. In this study, monoclonal antibodies to phosphotyrosine were used to immunostain a cell line and tumour biopsies from lymphomas known to contain the activated anaplastic-lymphoma-kinase (ALK) tyrosine kinase. A range of normal and other neoplastic tissues were also immunostained for comparison. An anaplastic large cell lymphoma (ALCL) cell line carrying the (2;5) translocation, which creates the activated nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) tyrosine kinase, was strongly labelled. Routine tissue biopsies from five cases of ALK-positive ALCL were also strongly positive for phosphotyrosine. The characteristic granular cytoplasmic labelling pattern for phosphotyrosine observed in a B-cell lymphoma (expressing full length ALK kinase) was identical to that obtained using an ALK-specific antibody, thus confirming that labelling for phosphotyrosine in lymphoma cells reflects the presence of an activated kinase. When normal lymphoid tissues were stained, there was little or no labelling for phosphotyrosine, but stronger labelling was seen in other cells and tissues; for example, endothelial cells and some carcinoma samples. Whilst the strong labelling for phosphotyrosine observed in the lymphoma cells is due to the presence of activated ALK, the strong staining of some normal cells presumably represents physiologically active kinases and this should be taken into account when interpreting the immunostaining of non-lymphoid tumours. The simplicity of this method, however, means that it offers a new rapid approach to the screening of large numbers of tumours for the presence of aberrant tyrosine kinase activation, particularly if they arise from tissues which normally contain only background levels of phosphotyrosine.
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PMID:Immunohistochemical screening for oncogenic tyrosine kinase activation. 1039 26

Non-Hodgkin's lymphomas (NHL) were often erroneously diagnosed as other malignancies and treated accordingly. In this study cisplatin combined with vincristine, cyclophosphamide, and Adriamycin was used incidentally as a front-line treatment in seven children with NHL, because the initial histologic diagnosis was that of a sarcoma. After reevaluation three patients had Ki-1 anaplastic large cell lymphoma of T-cell origin, two abdominal B-cell diffuse high-grade NHL, one mediastinal diffuse large B-cell lymphoma, and one B-cell lymphoma in the stomach. They received at least two courses of cisplatin combined regimen and continued with other protocols for NHL. All patients showed an extremely good response from the first course of therapy and the masses vanished completely. They were followed up for a mean time of 29.5 months and are all in complete remission. The data indicate that cisplatin is active against NHL and might be a promising alternative front-line therapy.
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PMID:Could cisplatin as a front-line treatment in childhood non-Hodgkin's lymphoma be a promising therapy? 1040 71

Clinically aggressive lymphomas are defined by the Revised European-American Classification for lymphoid neoplasms as diffuse large B-cell lymphoma, peripheral T-cell lymphoma, anaplastic large cell lymphoma, and lymphoblastic lymphoma. Mantle cell lymphoma is atypical due to its indolent presentation and refractoriness to treatments. A review of current therapeutic possibilities for these different lymphomas is presented.
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PMID:Treatment of aggressive non-Hodgkin's lymphoma. 1056 Oct 13


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