1/8. 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 = hybridization (Clic here for more details about this article) |
2/8. 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 = 1keywords = hybridization (Clic here for more details about this article) |
3/8. Fatal coronary artery disease after unrelated donor bone marrow transplantation.Several factors are responsible for the occurrence of cardiac complications after bone marrow transplantation (BMT). These factors include the cardiotoxic effects of radiation therapy, antineoplastic and immunosuppressive drugs, abnormal immunologic reactions associated with graft-vs-host disease, and infectious agents. We report the case of a 45-year-old woman with T-cell prolymphocytic leukemia and no prior risk factors for coronary artery disease in whom sudden cardiac death occurred 2 1/2 years after allogeneic BMT from an unrelated male donor. autopsy revealed severe 3-vessel coronary disease with grade 4/4 stenosis. This process was primarily nonatherosclerotic, with intimal hyperplasia of undetermined etiology. Furthermore, fluorescence in situ hybridization to identify the donor y chromosome with simultaneous immunofluorescence labeling of smooth muscle actin suggested the presence of donor cells that transformed into myocytes. coronary artery disease is an important, albeit rare, complication of BMT. Donor hematopoietic cells may contribute to its pathogenesis.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
4/8. Successful treatment of B-cell prolymphocytic leukemia with monoclonal anti-CD20 antibody.We report a patient with B-cell prolymphocytic leukemia (PLL) who was treated successfully with the monoclonal anti-CD20 antibody (rituximab). The patient had recurrent infections due to relative neutropenia, secondary to bone marrow infiltration. After treatment with monoclonal anti-CD20 antibodies (rituximab) 375 mg/m(2) weekly for 4 weeks, complete remission was obtained. It was documented by normalization of peripheral blood counts, disappearance of organomegaly, and by molecular cytogenetics-fluorescent in situ hybridization (FISH) on bone marrow cells. She remains in complete remission 8 months following the discontinuation of treatment. This is the second reported case of successful treatment of B-cell PLL with rituximab.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
5/8. Translocation (8;14)(q24;q32) as the sole cytogenetic abnormality in B-cell prolymphocytic leukemia.B-cell prolymphocytic leukemia is a relatively rare lymphoproliferative disorder. No specific cytogenetic abnormality has yet been associated with it. The most common translocation reported in patients with this disease is t(11;14)(q13;q32). We describe the case of a patient with B-cell prolymphocytic leukemia and a hitherto unreported genetic translocation (8;14)(q24;q32) as the sole genetic abnormality, classically seen in patients with B-cell acute lymphoblastic leukemia/burkitt lymphoma. This patient presented with an asymptomatic leukocytosis and splenomegaly. Her marrow showed lymphoid hyperplasia, with immunophenotyping consistent with prolymphocytic leukemia; however, t(8;14)(q24;q32) was the only cytogenetic aberration with both standard karyotyping and fluorescence in situ hybridization analysis.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
6/8. Case report: mantle cell lymphoma, prolymphocytoid variant, with leukostasis syndrome.A 76-year-old man presented with leukostasis syndrome, including oculodynia, blurred vision, and visual field defects, due to mantle cell lymphoma, prolymphocytoid variant, with marked leukocytosis, 1227 x 10(9)/l. He had splenomegaly but no lymphadenopathy or hepatomegaly. The tumor cells were CD5 , CD19 , CD20 , FMC-7 , and kappa light chain restricted. immunohistochemistry showed expression of p53 and of cyclin d1. Fluorescent in situ hybridization demonstrated t(11;14) with translocation between cyclin d1 and the immunoglobulin heavy-chain genes. The patient received leukapheresis and aggressive chemotherapy, but the leukocyte count remained above 100 x 10(9)/l. The patient's condition rapidly deteriorated with lymphomatous infiltration of his lungs and soft tissues, and he expired 6 months after diagnosis. While it is known that mantle cell lymphoma may have a leukemic phase, the degree of leukocytosis in this case exceeds that previously reported in the literature and resulted in a clinical syndrome of leukostasis.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
7/8. Burkitt-type acute leukemia in a patient with B-prolymphocytic leukemia: evidence for a common origin.Burkitt-type acute leukemia cells were present in the bone marrow of a patient with B-prolymphocytic leukemia diagnosed from peripheral blood cell morphology. Immunophenotype analysis confirmed morphological patterns. Cytogenetic and fluorescence in situ hybridization (FISH) analysis showed an identical t(8;22)(q24;q21) with MYC locus rearrangement in blood and bone marrow cells, with additional chromosome abnormalities in the bone marrow. In addition, the loss of one copy of the TP53 gene and identical IGH dna clonal rearrangements were shown with FISH and polymerase chain reaction analysis respectively in the two types of leukemic cells. These data indicated the common origin of the two coexisting leukemias and are the first example of such occurrence in a leukemic patient.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |
8/8. Cytogenetic abnormalities in three patients with B-cell prolymphocytic leukemia.We present the cytological features, conventional cytogenetics, and in situ hybridization (ISH) findings of three cases of B-cell prolymphocytic leukemia (B-PLL). The diagnosis was made according to the French-American-British (FAB) criteria. We considered a diagnosis of B-PLL when a predominance (> 50%) of lymphoid cells with coarse chromatin but prominent central nucleoli and more abundant cytoplasm than typical chronic lymphocytic leukemia (CLL) cells were present. B-PLL express strong SIg, B-cell antigens, and reactivity with the monoclonal antibody FMC7. Chromosome analysis was carried out on lymphoid cells from peripheral blood and, in one patient, from lymph node. The phytohemagglutinin (PHA) mitogen was used. ISH was performed with two types of probes: the biotin-labeled chromosome 12-specific alpha satellite dna probe to detect trisomy 12, and biotin-labeled libraries of whole chromosomes 1, 7, and 14. Clonal chromosome abnormalities were found in all three patients; in one, a complex karyotype was observed. The most frequent recurrent abnormality was trisomy 12. Our results suggest that PLL usually presents with cytogenetic abnormalities. The finding of translocation (11;14) is noteworthy; chromosomes 1 and 3 are also involved.- - - - - - - - - - ranking = 0.5keywords = hybridization (Clic here for more details about this article) |