1/11. B cell prolymphocytic leukaemia (B-PLL) with complex karyotype and concurrent abnormalities of the p53 and c-MYC gene.We report the cytogenetic, molecular and biological characterization of a case of B-PLL with a complex karyotype and concurrent abnormalities on the p53 and c-MYC genes. Conventional cytogenetics suggested that both 17q arms were translocated to chromosomes 1q and 14p, respectively, whereas both 17p arms were not identified. In addition, a Burkitt's-like variant translocation t(2;8) was found. Study of loss of heterozygosity at 17p13 and p53 direct sequencing demonstrated the presence of only one copy of the p53 gene. A 27 bp deletion in exon 8 that resulted in the expression of a p53 protein lacking nine amino acids from the dna binding region was also found. To confirm the presence of one copy of the p53 gene and localize it, fluorescent in situ hybridization (FISH) studies using a p53 gene probe was performed. Only one signal of p53 was visualized. Moreover, the DAPI profile of the chromosome containing the hybridization spot for the p53 probe did correspond to the cytogenetic marker identified as der(14)t(14;17). Whole chromosome 14 paint, centromere-specific for chromosome 17 and p53 gene probes were cohybridized to the preparations. This demonstrated that the der(14) contained the 17 centromere and distally the p53 gene suggesting that the der(14) contained the short arm of chromosome 17 with the breakpoint occurring in the long arm. FISH studies confirmed the involvement of c-MYC and KAPPA in the t(2;8) translocation. To our knowledge, this is the first case of B-PLL with inactivation of the p53 gene by mutation together with a Burkitt's-like t(2;8) translocation involving the c-MYC gene. The cooperation of these genes may have conferred a growth advantage which was critical in the development of this aggressive form of B-PLL.- - - - - - - - - - ranking = 1keywords = complex (Clic here for more details about this article) |
2/11. Unusual case of leukemic mantle cell lymphoma with amplified CCND1/IGH fusion gene.We describe a case of leukemic mantle cell lymphoma (MCL) with complex karyotype and amplification of the CCND1/IGH fusion gene. Testing for the presence of t(11;14), the hallmark of MCL, revealed multiple copies of the fusion signals. We therefore conducted extensive molecular cytogenetic studies to delineate the nature and consequences of such an abnormality. We localized the amplification to the der(14)t(11;14) and to a der(2) chromosome in a form of interspersed chromosome 11 and 14 material. This resulted in high expression of cyclin d1 mRNA and the protein expressed independently of the cell cycle phase. CGH analysis revealed that the overrepresentation on chromosome 11 included chromosomal band 11q23 in addition to the CCND1 locus at 11q13. The band 11q23 harbors the ataxia telangiectasia mutated (ATM) gene recently proposed to be involved in the pathogenesis of MCL with high incidence of deletions in this locus. Using YAC 801e11, containing the ATM gene, we demonstrated several hybridization signals, suggesting that this region also formed part of the amplicon. This case also showed TP53 gene abnormalities: protein expression, monoallelic deletion, and a mutation in exon 5. The clinical course was aggressive, and the patient died within 6 months of presentation. This is to our knowledge the first description of amplification of the CCND1/IGH fusion gene in a human neoplasm, which may have played a role in the fulminating course of the disease in this patient.- - - - - - - - - - ranking = 1.768keywords = neoplasm, complex (Clic here for more details about this article) |
3/11. Mature B-cell leukemias with more than 55% prolymphocytes: report of 2 cases with burkitt lymphoma-type chromosomal translocations involving c-myc.CONTEXT: The molecular genetic events involved in the pathogenesis of mature B-cell leukemias with more than 55% prolymphocytes are not well characterized. We have encountered 2 such cases in which conventional cytogenetic analysis identified burkitt lymphoma-type chromosomal translocations involving 8q24. OBJECTIVE: To assess these 2 cases for involvement of the c-myc gene using fluorescence in situ hybridization analysis with probes specific for the c-myc and immunoglobulin heavy-chain (IgH) genes. RESULTS: In both cases, conventional cytogenetic analysis demonstrated complex karyotypes, including chromosomal translocations involving 8q24. In case 1, a case of de novo prolymphocytic leukemia, the t(8;14)(q24;q32) was detected. In case 2, a case of chronic lymphocytic leukemia in prolymphocytoid transformation, the t(8;22)(q24;q11) was identified. fluorescence in situ hybridization studies showed c-myc/IgH fusion signals in case 1, proving the presence of the t(8;14). Split c-myc signals without fusion to IgH were observed in case 2, proving c-myc gene rearrangement and consistent with the t(8;22). CONCLUSION: These results suggest that c-myc gene alterations may be involved in the pathogenesis of a subset of mature B-cell leukemias with more than 55% prolymphocytes.- - - - - - - - - - ranking = 0.2keywords = complex (Clic here for more details about this article) |
4/11. Insertion of MLL sequences into chromosome band 5q31 results in an MLL-AF5Q31 fusion and is a rare but recurrent abnormality associated with infant leukemia.MLL gene rearrangements leading to production of MLL fusion proteins are commonly detected in infant leukemia patients; the most common MLL fusion associated with infant leukemia is the MLL-AF4 fusion. A single case of chromosomal rearrangement leading to production of an MLL fusion with AF5Q31, a gene structurally similar to AF4, has been detected recently in the malignant cells of an infant leukemia patient. We have identified a second case of MLL-AF5Q31 fusion, arising from an insertion of MLL sequences into chromosome 5, also in an infant leukemia patient. Because MLL and AF5Q31 are transcribed in opposite orientations, a simple balanced chromosomal translocation cannot produce a fusion protein, and complex chromosomal rearrangements such as insertions and inversions are required to produce an MLL-AF5Q31 fusion protein. This report demonstrates that chromosomal insertion of MLL sequences is a rare but recurrent abnormality associated with infant leukemia.- - - - - - - - - - ranking = 0.2keywords = complex (Clic here for more details about this article) |
5/11. Severe lactic acidosis due to thiamine deficiency in a patient with B-cell leukemia/lymphoma on total parenteral nutrition during high-dose methotrexate therapy.An 11-month-old girl with B-cell leukemia/lymphoma developed profound lethargy due to severe lactic acidosis during chemotherapy and total parenteral nutrition (TPN). Initial treatment with NaHCO3 was ineffective. Treatment with a vitamin cocktail (OH-cobalamin, pyridoxine, thiamine, riboflavine, biotin, carnitine) at pharmacologic doses rapidly improved the child's clinical and laboratory status. Lactic acidosis was caused by an impairment of pyruvate dehydrogenase complex, which was due to lack of its necessary cofactor thiamine in the TPN. This case report indicates that lactic acidosis may be a front-line diagnosis in patients on TPN with lethargy and outlines the need for monitoring thiamine supply in TPN.- - - - - - - - - - ranking = 0.2keywords = complex (Clic here for more details about this article) |
6/11. Mucoepidermoid carcinoma of the parotid gland as a second malignant neoplasm.We report two second malignant neoplasms (SMNs) of the parotid gland. Patient 1 was initially diagnosed with precursor B-cell lymphoblastic lymphoma of the scalp. Eight years after her initial diagnosis she presented with a small, painless mass in the region of her parotid gland. Patient 2 was diagnosed with pre-B-cell acute lymphoblastic leukemia (ALL). Thirteen years after her initial diagnosis she presented with a painless mass in her right cheek. Both patients underwent superficial parotidectomies following excisional biopsies. pathology revealed low-grade mucoepidermoid carcinoma (MEC) in both cases. Both patients are currently tumor free.- - - - - - - - - - ranking = 7.84keywords = neoplasm (Clic here for more details about this article) |
7/11. Hodgkin's disease in an elderly patient with B-cell chronic lymphocytic leukemia.Chronic lymphocytic leukemia (CLL) is the most common type of leukemia worldwide. It is an indolent disease, almost exclusively of B-cell origin. Some CLLs evolve into a more aggressive lymphoid malignancy. The most common of these is Richter's syndrome. Transformation to acute lymphoblastic leukemia, plasma cell leukemia, multiple myeloma, or Hodgkin's disease (HD) may also occur. CLL patients are also at a significantly increased risk of developing a second malignant neoplasm later in life. One of the most common of these is HD. Herein, we report a case of HD in an elderly man with a history of B-cell CLL.- - - - - - - - - - ranking = 1.568keywords = neoplasm (Clic here for more details about this article) |
8/11. trisomy 12-associated, t(11;14)-negative mature B-cell leukemia with gene expression profile resembling mantle cell lymphoma.trisomy 12 can be seen in many different lymphoid neoplasms. However, many or most mature B-cell leukemias associated with isolated trisomy 12 are reported in the literature as chronic lymphocytic leukemia (CLL) or 'atypical CLL'. This study reports a case of a mature B-cell leukemia, morphologically and immunophenotypically similar to cases previously published as atypical CLL, in which cytogenetic evaluation revealed an isolated clonal trisomy 12 but no evidence of the mantle cell lymphoma-associated t(11;14)(q13;q32). Further analysis confirmed absence of cyclin-D1 expression. Subsequent lymph node biopsy revealed evidence of large cell transformation of the underlying chronic lymphoproliferative disorder. gene expression profiling of the initial peripheral blood sample using a cDNA micro-array of approximately 10,000 expressed genes revealed a close resemblance between the reported case and 2 cases of known mantle cell lymphoma. When further compared to 7 known 'typical' CLL cases, the reported case was classified as mantle cell lymphoma by hierarchical cluster analysis. The case reported here raises interesting questions regarding the nature of cases reported previously as trisomy 12-associated CLL and reinforces the fact that other leukemic lymphoproliferative disorders should be included in the differential diagnosis of such cases. Further study is indicated to elucidate the nature and diversity of disorders previously reported as trisomy 12-associated chronic lymphocytic leukemia.- - - - - - - - - - ranking = 1.568keywords = neoplasm (Clic here for more details about this article) |
9/11. B-cell prolymphocytic leukemia expressing CD13 antigen.Although the expression of myeloid-associated antigen CD13 has been reported in aggressive B-cell chronic lymphocytic leukemia, its expression in other mature B-cell neoplasms appears to be rare. We report a 74-year-old female with B-cell prolymphocytic leukemia (B-PLL) expressing CD13 antigen. On admission, splenomegaly was noted. Hematological examination revealed a platelet count of 90 x 10(9)/l and a white cell count of 68 x 10(9)/l with 73% PLL cells. The hemoglobin concentration was 10.6 g/dl. A bone marrow aspirate showed a normocellular marrow with 64% PLL cells. Surface marker analysis of the PLL cells was positive for CD11b, CD13, CD19, CD20, CD24, HLA-DR, FMC7, mu and lambda. Simultaneous expression of CD13 and CD19 antigen was confirmed by dual color flow cytometry. Southern blot analysis of dna from circulating mononuclear cells gave a rearranged band for the immunoglobulin gene (JH) but not for TCR-beta. cytogenetic analysis of marrow cells showed an abnormal karyotype involving numbers 1, 7, 10, 12, 14, 15 chromosomes.- - - - - - - - - - ranking = 1.568keywords = neoplasm (Clic here for more details about this article) |
10/11. C-MYC translocations in de novo B-cell lineage acute leukemias with t(14;18)(cell lines Karpas 231 and 353).Rare de novo acute leukemias of mature B cells may exhibit the chromosomal translocation t(14;18)(q32.3; q21.3). We report the preliminary characterization of two cases that exhibited not only t(14;18)(q32.3;q21.3) but also the novel translocation t(8;9)(q24.1;p13.3), involving the C-MYC locus with unknown sequences at 9p13.3. From these cases, two Epstein-Barr virus negative cell lines (Karpas 231 and 353) with features identical to those seen in fresh cells from the patient have been derived. Both cell lines have complex karyotypes: in addition to both t(14;18)(q32.3;q21.3) and t(8;9)(q24.1;p13.3), cell line Karpas 231 exhibited three-way translocation t(1;3;11) (q42.3;q27.1;q23.1), whereas Karpas 353 exhibited t(1;3;7)(p32.1;q21.1;q22.1). Both cases retained immunophenotypes characteristic of mature B cells with no evidence for commitment to other hematopoietic lineages. Both cases expressed abundant, normal-sized C-MYC transcript, but no rearrangement of C-MYC dna sequences could be detected using probes that span 80 kb around the C-MYC coding sequences. Breakpoints within the BCL-2 gene were divergent. In Karpas 353 the BCL-2 breakpoint occurred within the 3' untranslated major breakpoint region (mbr) of the gene, whereas, in Karpas 231, breaks in both the 3' mbr and in the region 5' of the gene were detected. The cytogenetic combination of t(14;18)(q32.3;q21.3) and t(8;9)(q24.1;p13.3) has been previously reported in diffuse B cell lymphomas. This combination may be a new recurrent abnormality, of central pathogenic importance in the transformation of B cells to high grade malignancies through simultaneous deregulation of BCL-2 and C-MYC genes, constitutive expression of C-MYC being driven by currently unknown dna sequences on chromosome 9p13.3. The presence of other complex translocations including those affecting 11q23.1 may further accelerate the process of acute transformation.- - - - - - - - - - ranking = 0.4keywords = complex (Clic here for more details about this article) |
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