1/59. Inheritance of chromosomally integrated human herpesvirus 6 dna.Human herpesvirus 6 (HHV-6) genome has been detected in several human lymphoproliferative disorders with no signs of active viral infection, and found to be integrated into chromosomes in some cases. We previously reported a woman with HHV-6-infected Burkitt's lymphoma. fluorescence in situ hybridization showed that the viral genome was integrated into the long arm of chromosome 22 (22q13). The patient's asymptomatic husband also carried HHV-6 dna integrated at chromosome locus 1q44. To assess the possibility of chromosomal transmission of HHV-6 dna, we looked for HHV-6 dna in the peripheral blood of their daughter. She had HHV-6 dna on both chromosomes 22q13 and 1q44, identical to the site of viral integration of her mother and father, respectively. The findings suggested that her viral genomes were inherited chromosomally from both parents. The 3 family members were all seropositive for HHV-6, but showed no serological signs of active infection. To confirm the presence of HHV-6 dna sequences, we performed polymerase chain reaction (PCR) with 7 distinct primer pairs that target different regions of HHV-6. The viral sequences were consistently detected by single-step PCR in all 3 family members. We propose a novel latent form for HHV-6, in which integrated viral genome can be chromosomally transmitted. The possible role of the chromosomally integrated HHV-6 in the pathogenesis of lymphoproliferative diseases remains to be explained.- - - - - - - - - - ranking = 1keywords = chromosome (Clic here for more details about this article) |
2/59. Variant translocations in sporadic Burkitt's lymphoma detected in fresh tumour material: analysis of three cases.Burkitt's lymphoma/Burkitt cell leukaemia (BL) is characterized by one of the reciprocal translocations involving the MYC oncogene on chromosome 8 and one of the immunoglobulin (Ig) loci on chromosomes 14, 2 or 22. In the few cell lines with the variant translocations t(2;8) and t(8;22) reported to date, the breakpoints on chromosome 8 were located downstream of MYC at a distance of up to 300 kb and more. Here, we describe three new cases with variant translocations. Fresh tumour material from paediatric patients, negative for the common translocation t(8;14), was analysed using a long-distance (LD) polymerase chain reaction (PCR) approach. On chromosome 8, primers were derived from several different regions 3' of MYC, and on chromosomes 2 and 22 from the constant regions of the Ig kappa (Igkappa) and lambda (Iglambda) genes. One translocation t(2;8) and two t(8;22) were detected. In the t(2;8) translocation, the chromosome 8 breakpoint was located 2 kb 3' of the MYC exon 3 and the chromosome 2 breakpoint within an unrearranged Igkappa locus. The breakpoints of the two translocations t(8;22) were detected 16 kb for one and 58 kb for the other downstream of MYC. Sequencing the t(8;22) translocation in one of the cases showed hypermutation of the translocated variable Vlambda4b gene. The presence of hypermutated variable regions in the t(8;22) case suggests germinal centre B cells as the origin of this translocation. The t(2;8) translocation is the first description of a translocation t(2;8) involving an unrearranged Igkappa gene. A mechanism different from V-J recombination and somatic hypermutation has to be proposed for this translocation.- - - - - - - - - - ranking = 1.75keywords = chromosome (Clic here for more details about this article) |
3/59. Detection of diagnostically critical, often hidden, anomalies in complex karyotypes of haematological disorders using multicolour fluorescence in situ hybridization.Multicolour fluorescence in situ hybridization (M-FISH) simultaneously detects all 24 human chromosomes in unique fluorescent colours. The identification of diagnostically critical gene rearrangement(s) in complex karyotypes of haematological disorders continues to be a challenge. We present five cases in which t(9;11), complex t(8;22), t(12;21) and t(11;14) were detected primarily using M-FISH and were confirmed using locus-specific probes. We conclude that M-FISH can be effective in complete characterization of critical gene rearrangements in haematological disorders.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
4/59. Establishment and comprehensive analysis of a new human transformed follicular lymphoma B cell line, Tat-1.A spontaneously EBV transformed follicular lymphoma (FL) cell line, Tat-1, was established from the lymph node biopsy specimen of a patient with B cell FL, grade 1 in transformation to high grade disease. Tat-1 cells expressed lymphoid markers and developed tumor masses in immunodeficient mice. Bcl-2, Bcl-X(L), Bax and p53 protein expression was revealed by Western blotting. Flow cytometric analysis confirmed P-gp expression. Cytogenetically, the Tat-1 cell line showed identical chromosomal alterations to that of the initial biopsy specimen, among which the most notable were the t(14;18) typical of FL and additional abnormalities involving chromosomes 1, 8 and 13. Multicolor FISH analysis delineated all abnormalities, including a t(1p;8q), a der(8)(8q24::14q32::18q21) and a der(13)(13q32::8q24::14q32::18q21). Further FISH investigations using a locus-specific probe cocktail containing c-myc, IgH and bcl-2 revealed fusion of these three loci on the derivatives 8 and 13, in addition to the derivative 14 IgH/bcl-2 fusion and an extra copy of c-myc on derivative chromosome 1. These results demonstrate an additional example of the deregulation of bcl-2 and c-myc expression through recombination with a single IgH enhancer region. The unusual molecular features of the Tat-1 cell line render it a unique tool for studies focused on cytogenetic alterations, expression of multidrug resistance phenotype and expression of anti-apoptotic proteins in FL.- - - - - - - - - - ranking = 0.5keywords = chromosome (Clic here for more details about this article) |
5/59. Mature B-cell acute lymphoblastic leukemia with associated translocations (14;18)(q32;q21) and (8;9)(q24;p13). A Burkitt variant?The translocation t(14;18)(q32;q21) is most commonly associated with follicular lymphoma but has also been described in acute lymphoblastic leukemia (ALL) of B-cell origin. Although these ALL cases have had a pre-pre-B, pre-B, or mature B-cell immunophenotype and L2 or L3 morphology, all have been associated with an abnormality of 8q24. In fact, 91% (10 of 11) have been associated with t(8;22) or t(8;14), marker chromosomes for Burkitt-type ALL. The other case was associated with del(8)(q24). Thus, Burkitt-type ALL may have various immunophenotypes and morphology when associated with t(14;18). We describe a case of mature B-cell ALL associated with t(14;18) and t(8;9)(q24;p13). The morphology was suggestive but not entirely characteristic of the L3 subtype. However, on the basis of the cytogenetic findings and the review of the literature, perhaps this case represents a variant of Burkitt-type ALL, which would be important to recognize for prognostic and therapeutic purposes. We describe our findings and review the literature to heighten awareness of this group of ALLs associated with t(14;18). Additional cases need to be accrued and documented to determine the significance of an associated abnormality of 8q24 in this setting.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
6/59. Burkitt transformation of mantle cell lymphoma.The associated poor prognosis and potentially aggressive behavior of mantle cell lymphoma and its blastoid variants make differentiation from other non-Hodgkin B-cell lymphomas especially important. We present a case of mantle cell lymphoma with a marked leukemic component, which demonstrated both a typical nodular mantle cell pattern and burkitt lymphoma within a single lymph node removed at the time of splenectomy. The presence of CD5, CD10, and Bcl-1 co-expression by immunohistochemistry and detectable t(11;14) and cMYC gene rearrangement by FISH analyses in the Burkitt region support a transformation of mantle cell lymphoma over a concomitant malignancy. A limited number of mantle cell lymphomas demonstrating dual t(11;14) and chromosome 8q24 cMYC gene rearrangements have been previously reported in the literature. They demonstrate an extremely aggressive course with a very poor prognosis. Although the accelerated terminal phase of this patient's clinical course mirrors these previous published cases; none have described the combined morphologic and immunophenotypic features of burkitt lymphoma reported here. This case provides further support for the aggressive nature of these lymphomas and demonstrates the utility of flow cytometry, immunohistochemistry, and cytogenetic techniques in avoiding potential errors in their diagnosis, prognosis, and treatment.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
7/59. M-FISH in gastric lymphoma.The majority of gastric B-cell lymphomas histologically are classified as low grade mucosa-associated lymphoid tissue (MALT lymphoma) and diffuse large B-cell lymphomas (DLBCL). There is evidence that the different histologic types are genetically heterogeneous, evolving through different pathogenetic pathways. Recurrent cytogenetic aberrations have been found in MALT lymphoma, whereas in DLBCL, limited cytogenetic data are available. We report here a DLBCL and a Burkitt-like gastric lymphoma case, cytogenetically studied by G-banding and M-FISH technique. In the first case, gains of chromosome 3, 7, 13, and 18 were found. An additional ring chromosome 1 identified as a clonal abnormality suggested clonal evolution. In the second case, trisomy 8, del(6)(q13), as well as t(8;14), t(1;5), and t(1;7), were observed. To our knowledge, cytogenetic data for gastric Burkitt-like lymphoma have not been reported, and M-FISH has not previously been used in the study of gastric lymphomas.- - - - - - - - - - ranking = 0.5keywords = chromosome (Clic here for more details about this article) |
8/59. Secondary burkitt lymphoma in a retinoblastoma patient with 13q deletion syndrome.We report a boy with constitutional deletion 13q chromosome associated with dysmorphic features and bilateral retinoblastoma. The patient developed secondary burkitt lymphoma 5 years after the diagnosis of retinoblastoma at the age of 8 months. He has completed treatment for both malignancies. At present, he is 7 years old and still in remission.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
9/59. Structural rearrangements of chromosome 13 as additional abnormalities in burkitt lymphoma and type 3 acute lymphoblastic leukemia.We report three cases of chromosome 13 rearrangements as additional abnormalities in two patients with burkitt lymphoma (BL) and one with type 3 acute lymphoblastic leukemia (ALL). Involvement of chromosome 13 has been reported most often as 13q , without identification of the supplementary chromosomal material; in our three cases with 13q , we identified two duplications: dup(13)(q13q22) and dup(13)(q21q22).- - - - - - - - - - ranking = 1.5keywords = chromosome (Clic here for more details about this article) |
10/59. A Case of Burkitt's Lymphoma Involving Both Breasts.Primary malignant lymphoma of the breast is rare, and Burkitt's lymphoma is especially rare. We report the case of a 44-year-old woman in whom Burkitt's lymphoma involving both breasts was diagnosed. The patient was referred to our hospital because of a diffuse, firm swelling, like a bulky ball, in both breasts. Fine-needle aspiration cytology (FNAC) of both breast masses revealed malignant lymphoma(ML), and diffuse large B-cell lymphoma was diagnosed based on the results of immunohistochemical studies of a core needle biopsy specimen. The gallium scan revealed very hot lesions in both breasts, but there was no evidence of disseminated disease. We instituted initial therapy, with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus intrathecal chemotherapy without performing a chromosome analysis, because the clinical course was very aggressive. A CR was achieved, but after eight cycles of CHOP therapy, the ML relapsed. We then resected the mass in the left breast, and when examination of the surgical specimen revealed relapse of ML and t (8;11) (q24;q32) translocation, Burkitt's lymphoma was diagnosed. High-dose chemotherapy followed by peripheral-blood stem cell transplantation was performed, but the patient died 10 months after her initial presentation at our hospital.- - - - - - - - - - ranking = 0.25keywords = chromosome (Clic here for more details about this article) |
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