ABSTRACT
We report the cases of three adults with acute lymphoblastic leukemia (ALL) who had a dic(7;9)(p11.2;p11) on the diagnostic bone marrow cytogenetic analysis. All three were males with B-ALL (aged 25, 38, and 48 years) who at presentation had 90-100% replacement of marrow with lymphoblasts. One patient died 23 months post induction therapy, which was 9 months post allogeneic stem cell transplantation (SCT); as of writing, the other two patients were in remission and well, one of them at 4 years after SCT and the other at 7.5 years without SCT. To our knowledge, these cases are the first reported in adult ALL with dic(7;9) and demonstrate a consistent phenotype, with good initial response to therapy but variable long-term outcome.
Subject(s)
Chromosomes, Human, Pair 7/genetics , Chromosomes, Human, Pair 9/genetics , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bone Marrow/metabolism , Bone Marrow/pathology , Disease-Free Survival , Hematopoietic Stem Cell Transplantation , Humans , Karyotyping , Male , Middle Aged , Precursor Cell Lymphoblastic Leukemia-Lymphoma/diagnosis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy , Remission InductionABSTRACT
Deletions of chromosomes 17 and 20 are well-described abnormalities in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) but translocations involving these two chromosomes are uncommon. We present five male patients, one with MDS and four with AML, in whom a new, nonrandom unbalanced dicentric t(17;20), resulting in deletions of 17p and 20q, was identified. Conventional cytogenetics showed additional karyotypic abnormalities in most of the patients, including deletions of 5q, deletions or monosomy of chromosome 7, and deletions of 18q. Fluorescence in situ hybridization showed a deletion of the tumor suppressor gene TP53 on 17p. Of the four cases with follow-up data available, only two had received combination chemotherapy. Overall survival in these two cases was 6 and 7 weeks, respectively. Two other patients who had no active therapy administered died 6 weeks and 9 months after diagnosis, respectively. These five cases highlight a rare but recurrent abnormality in MDS and AML, potentially involving genes on 17p and 20q of importance in myeloid leukemogenesis.
Subject(s)
Chromosomes, Human, Pair 17/genetics , Chromosomes, Human, Pair 20/genetics , Leukemia, Myeloid, Acute/genetics , Myelodysplastic Syndromes/genetics , Translocation, Genetic/genetics , Aged , Aged, 80 and over , Humans , In Situ Hybridization, Fluorescence , Karyotyping , Male , Middle AgedABSTRACT
The onset of accelerated phase or blast crisis of chronic myelocytic leukemia (CML) is usually associated with the acquisition of new chromosome abnormalities in addition to the t(9;22)(q34;q11) that is characteristic of the chronic phase CML. We describe the cytogenetic and molecular genetic findings in two cases of myelocytic blast crisis of CML, one occurring 6 months after commencing treatment with the ABL-specific tyrosine kinase inhibitor imatinib mesylate (STI571, Glivec, or Gleevec) and the second treated with imatinib mesylate for established blast crisis. In both cases, multiple secondary cytogenetic abnormalities were observed at transformation, with homogeneously staining regions that were shown to contain BCR/ABL amplification by fluorescence in situ hybridization appearing after imatinib mesylate administration. BCR/ABL amplification is emerging as an important mechanism of acquired resistance to imatinib mesylate.
