11/98. Amplification of the MLL region in acute myeloid leukemia.We report amplification of the MLL gene region (11q23-->11qter) in a 72-year-old woman with myelodysplastic syndrome progressing to acute myelomonocytic leukemia and in a 51-year-old man with a history of hairy cell leukemia and secondary myelodysplasia progressing to acute myelogenous leukemia. The amplicons containing MLL were shown by molecular cytogenetics to extend from chromosomal region 11q23 to the distal long arm of chromosome 11 and to be present in the first patient in five copies on a large ring chromosome and present in the second patient also in five copies on two derived chromosomes. Other karyotypic findings in the first patient included del(5q), 8, and der(21)t(17;21), resulting in the loss of a copy of 17p, whereas deletion 7q was observed in the second patient. Southern-blot analysis for the second patient was consistent with MLL amplification but did not demonstrate rearrangement of the germ-line MLL band. Amplification of MLL and the 11q23 region has been documented in only a few cases and appears to be yet another mechanism by which MLL contributes to the leukemia phenotype.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
12/98. A novel dicentric deleted chromosome 21 arising from tandem translocation.We present a 26-year-old patient with myelodysplastic syndrome (MDS). Initial bone marrow cytogenetics with G-banding showed a rearranged chromosome 21, which was dicentric and bisatellited on CBG- and NOR-banding. fluorescence in situ hybridization helped to characterize the structure, using a whole chromosome 21 paint and the locus specific AML1 gene probe. The rearranged 21 consisted solely of chromosome 21 material, contained only one copy of AML1, and was not a trisomy, but a deleted tandem translocation. The MDS transformed to acute myeloid leukemia (AML), and the patient died almost 12 months post-diagnosis. cytogenetics was performed three times during the course of the disease, and the dicentric chromosome 21 was present throughout. Although there are a number of published rearrangements of chromosome 21 in MDS and AML, most are isodicentrics. We could not find another case of an abnormal chromosome 21 with the same structure as reported here.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
13/98. 17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia.A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
14/98. Amplification of the AML1(CBFA2) gene on ring chromosomes in a patient with acute myeloid leukemia and a constitutional ring chromosome 21.In the genesis of hematologic neoplasms gene amplification is a mechanism for illegitimate activation of proto-oncogenes. We report a phenotypically normal patient with a constitutional ring chromosome 21 who developed acute myeloid leukemia (AML). The leukemic cells revealed size-variable ring chromosomes 21 with amplification of the proto-oncogene AML1, located in the chromosomal band 21q22, within the rings. Hitherto, amplification of the proto-oncogene AML1-also in form of a ring chromosome-has been described recently only in one patient with myelodysplastic syndrome (MDS). In AML, gene amplification by ring formation has been demonstrated only in another three patients (amplification of the MLL gene in two cases and of the ETV6 gene in one case). Here we present the new evidence that the internal rearrangement of a constitutional ring chromosome 21 resulted in multiplication of a proto-oncogene in bone marrow cells and provided obviously a selective growth advantage. Moreover the amplification of ribosomal dna was observed in the ring chromosomes of the tumor cells.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
15/98. Acute myeloid leukemia with concomitant trisomies 4 and 10: a distinctive form of myeloid leukemia?The occurrence of trisomy 4 or trisomy 10 as the sole chromosomal abnormality in acute myeloid leukemia (AML) is very rare, the reported frequency being less than 1%. We describe two cases of AML-M2 with concomitant trisomy 4 and trisomy 10, a hitherto undescribed phenomenon. They showed two unusual features, including immunoreactivity for CD56 and a short-lived but rapidly progressive myelodysplastic phase preceding the appearance of frank leukemia. These findings raise the possibility that AML with concommitant trisomy 4 and trisomy 10 may constitute a distinctive subtype of AML.- - - - - - - - - - ranking = 0.28857849416468keywords = myelodysplastic (Clic here for more details about this article) |
16/98. Derivative (1;18)(q10;q10): a recurrent and novel unbalanced translocation involving 1q in myeloid disorders.We report two cases of hematological malignancies, comprising a case of myelodysplastic syndrome (MDS) that rapidly evolved into acute myeloid leukemia, and a case of myeloproliferative disorder (MPD), in which der(1;18)(q10;q10) was found as the sole acquired karyotypic abnormality. This observation indicates that the unbalanced translocation is a recurrent aberration in myeloid disorders. To the best of our knowledge, centromeric fusion between long arms of chromosomes 1 and 18, leading to a normal chromosome 18 substituted with a der(1;18) chromosome, is novel and has not been described in cancer. Mechanistically, either trisomy 1q or monosomy 18p that results from the translocation may potentially contribute to leukemogenesis. Finally, chromosomes with large constitutive heterochromatin bands such as chromosome 1 may be at risk of centromeric instability and be predisposed to centromeric fusion with other chromosomes.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
17/98. Chromosomal aberrations in bloom syndrome patients with myeloid malignancies.bloom syndrome (BS) predisposes affected individuals to a wide variety of neoplasms including hematological malignancies. Thus far, cytogenetic findings in hematological neoplasms have been reported in only a few BS patients. We present the karyotypic findings in a BS patient diagnosed with acute myeloid leukemia (AML), FAB subtype M1, and a review of the literature, showing the preferential occurrence of total or partial loss of chromosome 7 in BS patients with AML or myelodysplastic syndromes (MDS).- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
18/98. Abnormal dicentric chromosome with co-amplification of sequences from chromosomes 11 and 19: a novel rearrangement in a patient with myelodysplastic syndrome transforming to acute myeloid leukemia.A 66-year-old man with a myelodysplastic syndrome transforming to acute myeloid leukemia showed a complex abnormal karyotype on bone marrow aspirate. An unbalanced dicentric translocation with a very long der(11) long arm-dic(11;19)(q25;p13.4)-was present. fluorescence in situ hybridization studies utilised paints for chromosomes 11 and 19 as well as the locus specific probe MLL, localised to 11q23. The abnormal chromosome 11q contained 6 copies of intact MLL and 6 copies of chromosome 19 (unidentified) sequences. To our knowledge, gene co-amplification of chromosomes 11 and 19 sequences has not been reported before.- - - - - - - - - - ranking = 5keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
19/98. skin involvement in chronic myelomonocytic leukaemia as a predictor of transformation into acute myeloid leukaemia.We report on the case of a patient with myelodysplastic syndrome (MDS) who presented with leukaemia cutis preceding development of acute myeloid leukaemia. Leukaemic infiltration of the skin should be considered an early manifestation of leukaemic transformation and an indicator of poor prognosis in MDS.- - - - - - - - - - ranking = 1keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
20/98. An unusual association of monoclonal gammopathy, paroxysmal nocturnal haemoglobinuria and myelodysplastic syndrome transformed into acute myeloid leukaemia: coexistence of triple clonal disorders.An unusual association of paroxysmal nocturnal haemoglobinuria (PNH), myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML) and monoclonal gammopathy is reported. A 60-year old male, who had a history of IgA monoclonal gammopathy, presented with haemoglobinuria and colic pain. flow cytometry showed CD55negative/59dim peripheral red cells, and bone marrow examination disclosed MDS. Eleven months, he developed later AML with disappearance of the PNH clones, although the monoclonal gammopathy persisted. The relationship between PNH and MDS has not fully been assessed, although our findings indicate that these triple clonal disorders, all coexisted in one patient.- - - - - - - - - - ranking = 5keywords = myelodysplastic syndrome, myelodysplastic (Clic here for more details about this article) |
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