1/67. MYC amplification in two further cases of acute myeloid leukemia with trisomy 4 and double minute chromosomes.We report two cases of trisomy 4 with double minute chromosomes (dmin): one in a woman with acute myeloid leukemia (AML), French-American-British subtype M2, the other in a man with chronic myelomonocytic leukemia. In the former case, many cells without trisomy 4 but with dmin were present, a finding not observed in previously reported cases. In both cases, fluorescence in situ hybridization studies demonstrated the double minutes to be MYC amplicons. Ten cases of AML with trisomy 4 and dmin have now been described; in the five cases investigated, the dmin have been shown to be amplified MYC gene sequences.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/67. Isolated tetrasomy 8 in minimally differentiated acute myeloid leukemia (AML-M0).tetrasomy 8 as a sole anomaly in hematological disorders is relatively rare. To the best of our knowledge, only 19 such cases have been described in the literature to date. Of them, acute myeloid leukemia (AML) in 13 (M1, one; M2, three; M4, one; M5, eight), acute lymphoblastic leukemia(ALL) in one, myelodysplastic syndrome(MDS) in 3, polycythemia vera(PV) and myelofibrosis(MF), one case each. Their median survival was 20 weeks. Here, we report the first case of a 29-year-old man with minimally differentiated AML (AML-M0) displaying a tetrasomy 8 clone. immunophenotyping showed positivity with CD33, CD34 and intracellular MPO, but all lymphoid markers tested were negative. Conventional cytogenetics of bone marrow cells showed 84.9% of metaphases with tetrasomy 8 in addition to 15.1% with normal diploidy. However, fluorescence in situ hybridization(FISH) using a centromeric probe specific for chromosome 8 revealed trisomy 8 in 14.2% of interphase nuclei besides tetrasomy 8 in 82.4%. The patient died four weeks after diagnosis without therapy. In conclusion, these findings suggest that tetrasomy 8 is associated with a heterogeneous group of myeloid disorders and heralds a bad prognosis. It may be a consequence of clonal evolution of trisomy 8.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/67. Identification of amplified genes in a patient with acute myeloid leukemia and double minute chromosomes.A case of acute myeloid leukemia (M2) with double minute chromosomes and complex karyotypic abnormalities was analyzed cytogenetically and molecularly. comparative genomic hybridization (CGH) showed that the 8q24 region that contains the MYC oncogene was not amplified. Instead, amplification of chromosomal regions 11q23-->qter and 9p11-->pter was identified. Southern blot analysis confirmed the CGH findings and showed that the ETS1, FLI1, SRPR, NFRKB, and KCNJ5 genes located at 11q23-->24 were amplified, whereas the MLL at 11q23 was not amplified. Additionally, the IFN beta 1 and CDKN2A genes at 9p were amplified, but to a lesser degree. This is the first example of a case of acute myeloid leukemia with double minute chromosomes that has not involved amplification of either the MYC or the MLL genes.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/67. Identification of novel chromosomal rearrangements in acute myelogenous leukemia involving loci on chromosome 2p23, 15q22 and 17q21.Chromosomal translocations are frequently linked to multiple hematological malignancies. The study of the resulting abnormal gene products has led to fundamental advances in the understanding of cancer biology. This is the first report of t(2;15)(p23;q22) and t(2;17)(p23;q21) translocations in human malignancy. Patient 1, a 73-year-old male, was diagnosed with myeloblastic (FAB M1 sub-type) AML. cytogenetic analysis showed a 47,XY,t(2;15)(p23;q22), 13 karyotype. Fluorescent in situ hybridization (FISH) showed that the PML gene was transferred intact to the short arm of chromosome 2 while the ALK gene on chromosome 2p23 was passively transferred to the long arm of chromosome 15. Patient 2 was a 60-year-old male diagnosed with monocytic (FAB M4-type) AML. cytogenetic analysis showed 46,XY,t(2;17)(p23;q21) karyotype. FISH analysis showed that neither RARalpha nor ALK were disrupted by the translocation. None of the coding region of the three genes studied were translocated in these patients. This raises the possibilities that other neighboring genes could be involved or that noncoding regulatory sequences of the studied genes could be put in contact and deregulate expression of other genes. Alternatively, displacement of ALK, RARalpha and PML to novel positions could lead to loss of their normal regulation- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/67. A new translocation, t(2;4;12)(p21;q12;p13), in CD7-positive acute myeloid leukemia: a variant form of t(4;12).We describe a 41-year-old man with CD7-positive acute myeloid leukemia (AML-M0) with trilineage-myelodysplasia. Chromosome analysis of the bone marrow cells showed 46.XY.t(2;4;12) (p21;q12;p13). Cytological and clinical features of our case were quite similar to those of AML with t(4;12)(q11-12;p13). The karyotypic interpretation was confirmed by fluorescence in situ hybridization (FISH) by using the whole-chromosome painting probes specific for chromosomes 2, 4, and 12. FISH analysis with the use of the YAC 936e2 probe, which covers the TEL gene, did not show the split signal, suggesting that a gene other than TEL was involved in the leukemogenesis of the present case. Our case with AML with t(2;4;12)(p21;q12;p13) appears to be the first case of a variant type of AML with t(4;12) (q11-12;p13).- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/67. Jumping translocations of 11q in acute myeloid leukemia and 1q in follicular lymphoma.Jumping translocation is a rare cytogenetic aberration in leukemia and lymphoma, and its etiologic mechanisms are not clearly known. We report two cases with jumping translocations. One had follicular lymphoma and jumping translocations of 1q onto the telomeric regions of 5p, 9p, and 15q in three cell lines, co-existing with the specific translocation t(14;18)(q32;q21). The second case had acute myeloid leukemia (AML) and jumping translocations of 11q as the sole aberration, onto multiple derivative chromosomes in each of the abnormal cells. A total of 17 telomeric regions were seen as the recipients of 11q in this case, and 9q was always involved as one of the recipients in all abnormal cells. fluorescence in situ hybridization (FISH) confirmed the identification of 11q material in the derivative chromosomes. While 1q has been the most common donor of acquired jumping translocations, this is the first report on jumping translocations of 11q. Different from all previously reported jumping translocations which involve only one recipient in each cell line and lead to a mosaic trisomy, multiple recipients in most of the abnormal cells in this case had led to a tetrasomy, or a pentasomy of 11q. The pattern of chromosome involvement as the recipients of 11q appears to show a continuing evolutionary process of jumping, stabilization, and spreading of the donor material into other chromosomes. Somatic recombinations between the interstitial telomeric or subtelomeric sequences of a derivative chromosome and the telomeric sequences of normal chromosomes are believed to be the underlying mechanism of jumping translocations and their clonal evolution.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/67. A novel t(11;12)(q23-24;q24) in a case of minimally-differentiated acute myeloid leukemia (AML-M0).Acute myeloid leukemia with minimal signs of myeloid differentiation (AML-M0) is a recent addition to the FAB group classification. Chromosome data is scarce, but existing reports describe a high incidence of complex karyotypes and myelodysplastic syndrome-like chromosome alterations, while single chromosome translocations have rarely been reported. We describe the case of a 60-year-old woman diagnosed with AML-M0 with a novel translocation t(11;12)(q23-24;q24) as the sole karyotypic marker. fluorescence in situ hybridization analysis to assess MLL gene splitting did not show rearrangement of this oncogene.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/67. A novel syndrome of radiation-associated acute myeloid leukemia involving AML1 gene translocations.AML1 is a transcriptional activator that is essential for normal hematopoietic development. It is the most frequent target for translocations in acute leukemia. We recently identified 3 patients in whom pancytopenia developed almost 50 years after high-level radiation exposure from nuclear explosions during or after world war ii. In all 3 patients, acute myeloid leukemia (AML) eventually developed that had similar characteristics and clinical courses. cytogenetics from the 3 patients revealed a t(1;21)(p36;q22), a t(18;21)(q21;q22), and a t(19;21)(q13.4;q22). By fluorescent in situ hybridization (FISH), all 3 translocations disrupted the AML1 gene. Two of these AML1 translocations, the t(18;21) and the t(19;21), have not been reported previously. It is possible that the AML1 gene is a target for radiation-induced AML. (blood. 2000;95:4011-4013)- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/67. fluorescence in situ hybridization evaluation of minimal residual disease on stem-cell harvests.The usefulness of fluorescence in situ hybridization (FISH) analysis to detect minimal residual disease (MRD) in autologous bone marrow and peripheral blood stem-cell harvests has been tested in three patients with hematologic malignancies. Conventional cytogenetics and FISH were used to characterize the leukemic clones identifying the specific chromosomal abnormalities (monosomy 7 in a myelodysplastic patient and trisomy 8 in two acute myeloid leukemic patients). Such analysis was useful to monitor the MRD persistent after treating these patients with intensive chemotherapy. The myelodysplastic patient underwent eight peripheral blood-stem cell harvests in which FISH detected the persistence of monosomy 7 cells, precluding their use for autologous transplantation. This patient relapsed and died. In two acute myeloid leukemia patients who underwent an autologous marrow harvest, FISH did not show a significant proportion of trisomy 8 cells. Nevertheless, autologous transplantation was not performed, owing to an insufficient CD34 cell content in the harvests. One of these patients relapsed with the reappearance of trisomy 8 and died. The other patient, on the contrary, is alive in complete remission 3 years after the bone marrow harvest. The usefulness and applicability of MRD quantification in stem-cell harvests is discussed on the basis of the sensitivity of the methodology applied.- - - - - - - - - - ranking = 5keywords = hybridization (Clic here for more details about this article) |
10/67. Epstein-Barr virus-negative high grade B cell lymphoma of donor origin developing 19 months after unrelated allogeneic bone marrow transplantation.A 22-year-old man, in first complete remission of acute myelogenous leukemia, developed a high grade B cell lymphoma 19 months after an allogeneic bone marrow transplant (allo-BMT) from an HLA-identical unrelated donor. biopsy of a cervical lymph node revealed a lymphoma that was negative for Epstein-Barr virus-encoded small nuclear RNAs (EBERs) in situ hybridization. Genotypic analyses identified the lymphoma to be of donor origin, and there was no evidence of the Epstein-Barr virus (EBV) dna in the lymphoma by Southern blot analysis. The lymphoma went into complete remission, following four courses of combination chemotherapy, but relapsed after a month and the patient died of congestive heart failure. The patient was thought to be persistently immunosuppressed 11 months after cessation of immunosuppressants, and the lymphoma was thought to be induced by one or more factors other than EBV.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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