title: A rare translocation (4;11)(q21;p14-15) in an acute lymphoblastic leukemia expressing T-cell and myeloid markers.
abstract: A 21-year-old male presented with a large mediastinal mass and a white cell count of 420 x 10(9)/L. A diagnosis of acute lymphoblastic leukemia (ALL) was made, with 90% of cells in the bone marrow (BM) and 99% in the peripheral blood (PB) being lymphoblasts (FAB L1). Cytogenetic analysis of these cells revealed a rare variant of the t(4;11) translocation involving chromosome arm 11p rather than 11q, namely t(4;11)(q21;p14-15). The standard form of the (4;11) translocation has been associated with leukemias with mixed-lineage phenotypes. Three cases of ALL with t(4q;11p) have previously been reported. One of these cases showed phenotypic heterogeneity involving myeloid and lymphoid lineages. The leukemia reported here also exhibits lymphoid/myeloid features. Immunophenotyping of the blasts showed that most of the cells were positive for CD2, CD5, CD7, CD10 (CALLA), CD34, and HLA-DR. A significant proportion of the cells expressed CD33. These results suggest a biphenotypic rather than a biclonal disease. Molecular analysis showed rearrangement of both immunoglobulin heavy-chain genes (JH) and of a single allele of the T-cell receptor (TCR) gamma 1 gene, while retaining germline TCR beta genes.
authors.affiliation: Department of Hematology-Oncology, Queen Elizabeth Hospital, Woodville, Australia.
authors.forename: J E
authors.initials: JE
authors.lastname: Hardingham
authors.forename: G B
authors.initials: GB
authors.lastname: Peters
authors.forename: A
authors.initials: A
authors.lastname: Dobrovic
authors.forename: B M
authors.initials: BM
authors.lastname: Dale
authors.forename: D
authors.initials: D
authors.lastname: Kotasek
authors.forename: H E
authors.initials: HE
authors.lastname: Ford
authors.forename: C J
authors.initials: CJ
authors.lastname: Story
authors.forename: R E
authors.initials: RE
authors.lastname: Sage
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D002880:Chromosomes, Human, Pair 11; D002894:Chromosomes, Human, Pair 4; D015321:Gene Rearrangement / Q000235:genetics; D015329:Gene Rearrangement, T-Lymphocyte; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D016130:Immunophenotyping; D007621:Karyotyping; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D014178:Translocation, Genetic
chemical_list: D015703:Antigens, CD; D006684:HLA-DR Antigens; D007143:Immunoglobulin Heavy Chains; D011948:Receptors, Antigen, T-Cell