t(3;21)(q26;q22): a recurring chromosomal abnormality in therapy- related myelodysplastic syndrome and acute myeloid leukemia

We have identified an identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints at bands 3q26 and 21q22, [t(3;21)(q26;q22)], in the malignant cells from five adult patients with therapy-related myelodysplastic syndrome (t-MDS) or acute myeloid leukemia (t-AML). Primary diagnoses were Hodgkin's disease in two patients and ovarian carcinoma, breast cancer, and polycythemia vera in one patient each. Patients had been treated with chemotherapy including an alkylating agent for their primary disease 1 to 18 years before the development of t-MDS or t-AML. We have not observed the t(3;21) in over 1,500 patients with a myelodysplastic syndrome or acute myeloid leukemia arising de novo or in over 1,000 patients with lymphoid malignancies. We have previously reported that the t(3;21) occurs in Philadelphia chromosome-positive chronic myelogenous leukemia (CML). Thus, the t(3;21) appears to be limited to t-MDS/t-AML and CML, both of which represent malignant disorders of an early hematopoietic precursor cell. These results provide a new focus for the study of therapy-related leukemia at the molecular level.     

B-Lymphoid and myeloid lineages biphenotypic acute leukemia with t(8;21)(q22;q22)

By analyzing the characteristics of morphology, immune phenotype, chromosome karyotype and clinical manifestations of six cases of B-lymphoid and myeloid lineages biphenotypic acute leukemia (BAL) with t(8;21)(q22;q22), a new subgroup of BAL was reported. Bone marrow eosinophilia (more than 5%) and pseudo-Chediak abnormalities were not found. Auer rods were also not identified in four of six cases. Immunophenotype revealed B-lymphoid and myeloid lineages positive, together with frequent and high expression of CD34 and CD33, and weak expression of HLA-DR. In addition to t(8;21) chromosomal translocation, deletion of Y chromosome and complex chromosome abnormalities were also found. Chemotherapy for myeloid and lymphoid leukemia simultaneously produced good response in the patients. BAL with t(8; 21)(q22; q22) might be a new subgroup of BAL, and it was suggested that the leukemia clone with t(8;21)(q22;q22) might have originated from an early phase of hematopoiesis, and AML1/ETO fusion gene might be related to differentiation of B lymphocyte.     

Secondary acute myeloblastic leukemia with t(16;21)(q24;q22) involving the AML1 gene

A t(16;21)(q24;q22) translocation was detected by fluorescence in situ hybridization in a patient with acute myeloblastic leukemia previously treated for malignant lymphoma. While the breakpoint on chromosome 21 was within the AML1 gene as determined by FISH, the gene partner on chromosome 16 could not be identified. Band 16q24 appears to be rearranged in several types of myeloid proliferation and a review of the literature shows that these rearrangements most often occur in secondary leukemia and myelodysplastic syndrome or are part of complex chromosomal rearrangements.     

Secondary acute myeloblastic leukemia with t(16;21)(q24;q22) involving the AML1 gene

A t(16;21)(q24;q22) translocation was detected by fluorescence in situ hybridization in a patient with acute myeloblastic leukemia previously treated for malignant lymphoma. While the breakpoint on chromosome 21 was within the AML1 gene as determined by FISH, the gene partner on chromosome 16 could not be identified. Band 16q24 appears to be rearranged in several types of myeloid proliferation and a review of the literature shows that these rearrangements most often occur in secondary leukemia and myelodysplastic syndrome or are part of complex chromosomal rearrangements.     

Acute myeloid leukemia secondary to a myelodysplastic syndrome with t(3;3) (q21;q26) in an HIV patient treated with chemotherapy and highly active antiretroviral therapy

We describe the first case of secondary acute myeloid leukemia (AML) with t(3;3) (q21;q26) occurring in a human immunodeficiency virus (HIV)-infected patient sequentially treated with chemotherapy and highly active antiretroviral therapy (HAART). The t(3;3) is a nonrandom abnormality found in a small percentage of patients with myelodysplastic syndrome, secondary AML or chronic myeloid leukemia and is strongly associated with abnormal thrombopoiesis and a particularly poor prognosis. So far, it has never been observed in HIV-positive patients. Sporadic cases of AML have been reported in HIV patients and the feasibility of chemotherapy in association with HAART and disease outcome are still not clearly defined. Despite the poor response to chemotherapy in our case, which might also be related to the unfavorable karyotype, the secondary nature of the disease and the HIV positivity, the patient had a relatively long period of survival that could be due to the use of HAART. The association of chemotherapy with HAART appeared to be feasible and tolerable and could be suggested as a choice treatment in this peculiar subset of HIV/AML patients.     

Acute myelocytic leukemia with ins(21;8)(q22;q13q22) presenting with AML1/MTG8 chimeric mRNA

We report a case of acute myelocytic leukemia (AML) showing a chromosomal abnormality, ins(21;8), with AML1/MTG8 chimeric mRNA. The patient, a 73-year-old woman, was admitted to our hospital because of AML relapse. Bone marrow aspiration showed 44% blasts and ins(21;8)(q12;q13q22) by cytogenetic study. Moreover, the size of chimeric AML1/MTG8 mRNA detected by RT-PCR in this case was shorter than that of previously reported. The patient was diagnosed as having relapse of AML (M2), but achieved complete remission with DCP therapy. Four months later, extramedullary relapse occurred, and this was followed five months later by bone marrow relapse. However, the patient again achieved complete remission. Most cases of AML1/MTG8 fusion gene are caused by t(8;21), and only very rarely by ins(21;8). In this case, the AML1/MTG8 fusion gene is thought to have been involved in the onset of leukemia.     

Therapy-related myelodysplastic syndrome with trisomy 1q due to der(1;7) and megakaryoblastic proliferation developing during complete remission of therapy-related acute myeloid leukemia with t(8;21)

Therapy-related acute myeloid leukemia (t-AML) with t(8;21) and therapy-related myelodysplastic syndrome (t-MDS) with trisomy 1q due to der(1;7) developed in the same patient with T-cell lymphoma at intervals of six years. After the development of t-MDS with trisomy 1q, during complete remission of t-AML, the number of megakaryoblasts increased to maximally 74% of leukocytes in the blood. This is a very rare case of two separate therapy-related myeloid malignancies (early t-AML and late t-MDS) and is also a notable case of t-MDS with trisomy 1q due to der(1;7) accompanied by megakaryoblastic proliferation.     

Childhood acute myeloid leukemia with bone marrow eosinophilia caused by t(16;21)(q24;q22)

Acute myeloid leukemia with abnormal bone marrow eosinophilia (AML-M4Eo) is often reported in core binding factor (CBF) leukemia, with translocations such as inv(16)(p13q22), t(16;16)(p13;q22) or t(8;21)(q22;q22); however, it is rarely reported with t(16;21)(q24;q22), which produces the RUNX1-CBFA2T3 (AML1-MTG16) chimera. The similarity between this chimera and RUNX1-RUNXT1 (AML1-MTG8) by t(8;21)(q22;q22) remains controversial. Adult leukemia with t(16;21)(q24;q22) was primarily therapy related, and shows poor prognosis; however, pediatric AML with this translocation was quite rare and tended to be de novo AML. We present here a 4-year-old boy with de novo AML-M4Eo and t(16;21)(q24;q22). He received chemotherapy and survived for more than 70 months without transplantation. We speculated that pediatric AML with t(16;21)(q24;q22) showed favorable prognosis, as with t(8;21)(q22;q22).     

A subtype of the prototypic karyotype in acute myeloid leukemia t (8; 21) (q22; q22), del 9 (q13; q23)

Summary Two patients with acute myeloid leukemia are described in whom G- and C-banding analysis of bone marrow cells revealed, besides the translocation t(8;21), an additional structural anomaly characterized by the deletion of bands q13 to q23 of one chromosome no. 9. Findings in the literature support the proposal that this constellation represents a hitherto unreported subtype of the prototypic karyotype in AML.Supported by the Deutsche Forschungsgemeinschaft (SFB 102)