t(9;11)(p21;q22) Translocation in acute monoblastic leukemia M5A-FAB

A patient with acute monoblastic leukemia (M5A-FAB) with a karyotype 48, XX, +2, +8, t(9;11)(p21;q22) is reported. This new case confirms that the t(9;11) translocation is a characteristic marker in some cases of M5-FAB (French-American-British classification) leukemias.     

Acute myeloid leukemia with t(16;21)(q24;q22) in a child

The t(16;21)(q24;q22), a rare chromosomal translocation observed mostly in therapy-related acute myelogenous leukemia (AML), produces a RUNX1-CBFA2T3 fusion gene. Here we report a de novo AML case of 1-year-old girl with t(16;21)(q24;q22). In this case, we demonstrated the RUNX1-CBFA2T3 fusion gene and established quantitative RT-PCR for detecting minimal residual disease.     

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).     

Therapy-related acute promyelocytic leukemia with a t(9;22)(q34;q11) and t(15;17)(q22;q11 to approximately 12) subclone

The translocation (15;17) is a typical marker of acute promyelocytic leukemia, whereas t(9;22) is predominantly associated with chronic myelogenous leukemia, and seldom with acute myelogenous leukemia. Furthermore, the association between t(15;17) and t(9;22) in the same cell is extremely rare. We present a case of therapy-related acute promyelocytic leukemia (t-APL) with a subclone accompanied by karyotype 46, XX, t(9; 22)(q34;q11), t(15 ;17)(q22;11 to approximately 12) at onset. A 75-year-old woman was diagnosed as having non-Hodgkin lymphoma of the thyroid gland in July 1997. She was treated with a CHOP-like regimen, but complete remission (CR) was not achieved. She then underwent surgical resection of her thyroid gland, and was treated with etoposide (total dose 16775 mg) from February 1998 to May 2000. In June 2000, having developed t-APL, she was referred to our department. The patient attained CR following treatment with chemotherapy containing all-trans retinoic acid. Ten months later she relapsed, but lost the t(9;22), while maintaining the t(15;17).     

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.     

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.     

Complete remission induced by G-CSF in a patient with acute myeloid leukemia with t(8;21)(q22;q22)

We describe a case of acute myeloid leukemia (AML) with t(8;21) in which complete remission (CR) was obtained with G-CSF given at 10 microg/kg in the absence of concomitant cytotoxic chemotherapy. CR was achieved following 2 weeks of therapy and confirmed by investigating minimal residual disease by four-color flow cytometry analysis. During treatment with G-CSF, maturing cells with cytoplasmic Auer Rods were observed in the peripheral blood, suggesting a differentiation effect. This case adds further evidence for a specific role of G-CSF in the treatment of AML with t(8;21), namely in patients who are not eligible for aggressive chemotherapy.     

Novel constitutional translocations t(3;5)(p25;q22) and t(1;14)(p31;q21) in patients with acute leukemia

Certain constitutional translocations have been described to be associated with an increased risk of malignant diseases. We report here two patients, one with acute myeloid leukemia (AML) and another with biphenotypic acute leukemia, in whom constitutional translocations t(3;5)(p25;q22) and t(1;14)(p31;q21) were observed, respectively. To our knowledge, none of the above translocations has been previously reported.