A rare translocation (4;11)(q21;p14-15) in an acute lymphoblastic leukemia expressing T-cell and myeloid markers.

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.     

Mature B-cell acute lymphoblastic leukemia with t(9;11) translocation: a distinct subset of B-cell acute lymphoblastic leukemia.

Mature B-cell acute lymphoblastic leukemia (ALL) is typically associated with the FAB-L3 morphology and rearrangement of the MYC gene, features characteristic of the leukemic phase of Burkitt's lymphoma. However, the term 'mature' has also been used to describe other rare cases of B-ALL with light-chain surface immunoglobulin expression. In contrast, infantile B-cell ALL is generally characterized by rearrangement of the MLL gene, an immature pro-B-cell phenotype, and CD10 negativity. We describe two unusual cases of infantile B-ALL with non-L3 morphology, expressing a mature B-cell phenotype (lambda sIg+, CD19+, CD10-, TdT-, and CD34-), and showing MLL rearrangement without MYC rearrangement at presentation. Both infants relapsed after months of morphologic and genetic remission. At relapse, the t(9;11) translocation was detected in both cases by spectral karyotyping. After the initial relapse, both cases followed a rapid and aggressive course. Literature search identified few similar cases, all expressed lambda surface immunoglobulin and showed MLL rearrangement (majority with the t(9;11) translocation). These cases show that B-ALL with MLL rearrangement, especially the t(9;11) translocation, can express a 'mature' B-cell phenotype and may represent a distinct subset. Identification of additional cases will further clarify the significance of MLL rearrangements in mature B-ALL.     

Rearrangement of the T-cell receptor beta-chain gene in non-T-cell, non-B-cell acute lymphoblastic leukemia of childhood

We studied 50 patients with childhood acute lymphoblastic leukemia (ALL), including 11 with T-cell ALL and 39 with non-T-cell, non-B-cell ALL. In addition to characterizing surface-antigen expression and immunoglobulin-gene rearrangement, we determined whether the T-cell receptor beta-chain gene also undergoes somatic rearrangement. All 11 patients with T-cell ALL had rearrangements of the beta-chain gene, with no persistence of the germline configuration. In two of these patients we demonstrated rearrangements of both the T-cell receptor gene and the immunoglobulin mu-heavy-chain gene. All 39 patients with non-T-cell, non-B-cell ALL had immunoglobulin heavy-chain gene rearrangements; in addition, 10 had rearrangements of the T-cell receptor beta-chain gene, indicating heterogeneity at the level of the T-cell receptor gene in this form of the disease. The results of our analysis of T-cell receptors and immunoglobulin heavy-chain genes offer new insight into normal and abnormal lymphocyte differentiation.     

Translocation between chromosomes 8q24 and 14q11 in T-cell acute lymphoblastic leukemia

Cytogenetic study was performed on a patient with T-cell acute lymphoblastic leukemia (T-ALL). It revealed a chromosomal translocation between chromosome bands 8q24 and 14q11. 8q24 is known to encode the oncogene c-myc, while 14q11 encodes the genes for T-cell receptor-alpha (TCR-alpha) and T-cell receptor-delta (TCR-delta). Therefore, this chromosomal translocation t(8;14) (q24;q11) seemed to be unique and specific to T-cell malignancy.     

Characterization of the breakpoint of a t(14;14)(q11.2;q32) from the leukemic cells of a patient with T-cell acute lymphoblastic leukemia

The leukemic cells and derivative cell line from a 74-year-old male with T-cell acute lymphoblastic leukemia showed chromosomal abnormalities including a t(14;14)(q11.2;q32). This translocation is characteristic of a variety of T-cell malignancies, particularly T-cell prolymphocytic leukemia and the clonal proliferations of peripheral T cells in patients with ataxia-telangiectasia. Using DNA probes that spanned the T-cell receptor alpha chain (TCRA) joining (J) locus, the DNA rearrangement caused by the translocation was identified, cloned, and sequenced. The breakpoint shows site-specific juxtaposition of a TCRA joining segment and DNA from a region of 14q32 centromeric to the immunoglobulin heavy chain locus. Comparison of restriction map and nucleotide sequence from this translocation with other related chromosomal breakpoints suggests a dispersion of breakpoints throughout the 14q32 region.     

A translocation t(9;11)(p11;q23) in T-cell acute lymphoblastic leukemia (FAB-l2)

We here report a t(9;11)(p11;q23) as the only abnormality in the affected cells of a 20-year-old male with acute lymphoblastic leukemia (L2) of T-cell origin. One hundred six patients with acute leukemia and involvement of band 11q23 were reviewed. Young age, hyperleukocytosis, and poor prognosis characterized almost all the cases in the acute leukemias with the 11q23 translocation, despite involvement of different recipient chromosomes and different morphologic and immunologic phenotypes.     

Hand mirror variant of adult acute lymphoblastic leukemia. Evidence for a mixed leukemia.

Blast cells from a female patient with acute lymphoblastic leukemia-hand mirror variant were examined using various techniques, including light and ultrastructural morphologic examination, cytochemical analysis, surface antigen characterization, cytogenetic analysis, and gene rearrangement studies. The blast cells were found to be pre-B cells (CD19+ and Tdt+) that also expressed the myeloid antigens CD13 and CD33 and demonstrated a heavy chain immunoglobulin gene rearrangement. Cytogenetic studies revealed a t(11;19) translocation previously described in biphenotypic leukemias. A subset of acute lymphoblastic leukemia-hand mirror cells has been previously defined and includes predominately female patients with an indolent course. The authors' findings place this case, a mixed leukemia, within that subgroup. The possibility of mixed lineage should be considered in future cases of hand mirror variants of adult acute lymphoblastic leukemia. Furthermore, hand mirror morphologic features in any case of acute leukemia should alert the hematopathologist/hematologist to the possibility of mixed lineage.     

t(10;11)(p13–14;q14–21): A New Recurrent Translocation in T-Cell Acute Lymphoblastic Leukemias

A workshop held by the ?Groupe Français de Cytogénétique Hématologique”? has identified a t( 10; 11)(p13–14;q14–21) in four acute lymphoblastic leukemias of T-cell lineage. The immunophenotypes were consistent with immature thymocytes. This translocation is therefore a new candidate for a recurrent translocation in early T-cell leukemia. A similar translocation has been reported as a rare change in early pre-B lymphoid leukemias and also in myeloid leukemias. It is not known whether the similar cytogenetic changes involve different molecular breakpoints or whether the same rearrangement affects a multipotential stem cell capable of lymphoid and myeloid differentiation.     

Cytogenetic study of acute lymphoblastic leukemia and its correlation with immunophenotype and genotype.

Among 72 Chinese patients with acute lymphoblastic leukemia (ALL), 50 had clonal chromosomal abnormalities. Structural abnormalities were detected in 42 patients: these included t(9;22) in 9, t(1;19) in 6, t(4;11) in 5, del(11)(q23) in 4, and del(6q) in 4. Adults had a higher incidence of t(9;22) and t(1;19) but a lower incidence of t(4;11) and hyperdiploid greater than 50 karyotype than children. A significant difference was also noted in white blood cell (WBC) count among various karyotypic groups. Patients with chromosomal abnormalities t(9;22), t(1;19), t(4;11) and del(11) (q23) had a shorter complete remission duration as compared with patients free of these abnormalities. Immunophenotyping was performed on 69 patients. All patients with t(9;22), t(1;19), and t(4;11) had B-lineage ALL restricted to certain stages of maturation: groups III and IV, groups IV and V, and group II, respectively (according to the classification of Foon and Tood). Among patients with t(9;22), t(4;11), and del(11)(q23), which have been considered to be associated with acute mixed-lineage leukemia, one each, respectively, showed myeloid antigen expression on the leukemic blasts (My+ ALL). No cross-lineage rearrangements of immunoglobulin (Ig) or T-cell receptor (TCR) genes were detected in these karyotypic subgroups of patients who underwent gene analysis.     

Immunophenotypic and immunogenotypic analyses of acute leukemia and lymphoblastic lymphoma expressing myeloid and lymphoid antigens]

By using monoclonal antibodies against lymphoid and myeloid differentiation antigens, surface marker analysis was performed on the tumor cells from 42 patients with acute leukemia and lymphoblastic lymphoma. Nine (21%) of 42 cases were diagnosed biphenotypic leukemia. Two (17%) of the 12 patients with acute myeloid leukemia, four (18%) of 22 with acute lymphocytic leukemia and three (38%) of 8 with lymphoblastic lymphoma expressed both lymphoid and myeloid antigens. Tumor cells from six patients expressed both T-cell and myeloid antigens, and those from three other expressed both B-cell and myeloid antigens. Southern blot analysis was performed on the DNA from four patients with biphenotypic leukemia cells expressing T-cell and myeloid antigens. DNA from one patient showed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene, and that from one other showed clonal rearrangement of both IgH gene and T-cell receptor beta-chain gene. DNA from two other patients showed a germline configuration of both genes. These results indicate that biphenotypic leukemia, especially T-cell and myeloid phenotype, is not so rare in acute leukemia and lymphoblastic lymphoma. The results of immunogenotypic analysis were not consistent with those of immunophenotypic analysis in biphenotypic leukemia.     

Pediatric T-cell acute lymphoblastic leukemia with aberrations of both MLL loci

Translocations involving the MLL gene at 11q23 have been implicated in acute lymphoblastic leukemia (ALL), as well as acute myeloid leukemia (AML). Such translocations result in gain of function fusion proteins that drive cell proliferation. Except in cases of T-cell ALL, MLL rearrangement is typically associated with a poor prognosis. We report a case of T-cell ALL with a t(11;19)(q23;p13.3) and deletion of the other chromosome 11 homolog at band q23. Fluorescence in situ hybridization (FISH) analyses confirmed involvement of the MLL loci in both the translocation and deletion. This case is unique in that deletions of 11q23 reported in ALL generally do not involve MLL. We are unaware of a previous report showing rearrangement of the MLL loci on both chromosome 11 homologues.     

Surface immunoglobulin light-chain expression by the "common" all cell line REH

To provide further support of the B-cell lineage of "common" acute lymphoblastic leukemia (ALL), we studied the REH cell line and found not only cytoplasmic heavy chain but also surface lambda light-chain expression by flow cytometry. Nucleic acid blotting experiments on REH revealed that both kappa genes had been deleted and that lambda genes had been rearranged, as expected in B cells expressing lambda light chain. Moreover, REH cells contained mu and lambda RNA. When REH cells were treated with TPA the amount of mu chain RNA increased by approximately fivefold and the amount of lambda chain RNA increased by approximately twofold. The finding of surface immunoglobulin lambda light chain in the REH cell line, suggests that these leukemic cells are further differentiated along the B-cell lineage than was previously believed.     

T-cell acute lymphoblastic leukemia with add(1)(p36) and del(12)(p11) following acute myelocytic leukemia with partial deletion of 9p

We describe the case of a 40-year-old man whose disease was initially diagnosed as acute myelocytic leukemia. The patient achieved remission with chemotherapy, but relapsed shortly afterwards with an acute T-cell lymphoblastic leukemia. He died of intracranial bleeding. Karyotyping analysis showed a del(9p?) as a common abnormality in the leukemic cells at onset and relapse. Fluorescence in situ hybridization analysis demonstrated allelic loss of the CDKN2A gene in cells from both stages of the disease. At relapse the leukemia cells had additional abnormalities such as add(1)(p36) and del(12)(p11). We postulate that the loss of CDKN2A is involved in leukemogenesis but does not determine the lineage of the leukemic cells. Instead, abnormalities of genes at 1p36, 12p11, or both may be involved in driving a lymphoid phenotype.     

Translocation between chromosomes 1 and 9 in childhood acute lymphoblastic leukemia

A case of a non-T, non-B acute lymphoblastic leukemia with a translocation between chromosomes #1 and #9 is described. The breakpoints in these chromosomes were determined to be at bands 1q23 and 9p22, respectively. The breakpoint in chromosome #1 was at the same site as that in a subgroup of acute lymphoblastic leukemia with t(1;19), and the breakpoint in #9 was the same as that in t(9;11)(p22;q23) in acute monoblastic leukemia. We discuss the possible association between these chromosome bands (1q23, 9p22, 11q23, and 19p13) and the morphologic features of the leukemic cells. The breakpoint in chromosome band 1q23 may be specifically associated with acute lymphoblastic leukemia.     

Molecular and phenotypic analysis of Philadelphia chromosome-positive bilineage leukemia: possibility of a lineage switch from T-lymphoid leukemic progenitor to myeloid cells

The occurrence of acute bilineage leukemia is thought to be the malignant transformation of a myeloid or lymphoid leukemic progenitor with the potential to differentiate into the other lineages; however, the mechanisms of this lineage switch are not well understood. Here, we report on the extremely rare case of adult Philadelphia chromosome-positive acute bilineage leukemia, which is characterized by T-cell acute lymphoblastic leukemia and acute myelomonocytic leukemia. Chromosome analysis showed 46,XY,del(7)(p11.2),t(9;22)(q34;q11.2) in all metaphases and a minor BCR/ABL chimeric gene was detected in these leukemic cells by PT-PCR. When the CD5+ and CD5- cells were sorted, a fusion gene of BCR/ABL and the same clonally rearranged band of a T-cell receptor (TCR) gene were detected in both populations. Nucleotide sequencing of the TCR-gamma gene revealed the clonal rearrangement of the V8-JGT2 complex in both populations. Overexpression of PU.1, which plays a fundamental role in myelomonocyte development, was found in the sorted CD34+CD7+ and CD5-, but not CD5+ cells. These results suggest that leukemic progenitor cells in the T-lineage with the del(7) and t(9;22) have the potential to differentiate into myeloid lineage, and that enforced PU.1 expression may contribute in part of this phenomenon.     

Rearrangements of genes for the antigen receptor on T cells as markers of lineage and clonality in human lymphoid neoplasms

The T alpha and T beta chains of the heterodimeric T-lymphocyte antigen receptor are encoded by separated DNA segments that recombine during T-cell development. We have used rearrangements of the T beta gene as a widely applicable marker of clonality in the T-cell lineage. We show that the T beta genes are used in both the T8 and T4 subpopulations of normal T cells and that Sézary leukemia, adult T-cell leukemia, and the non-B-lineage acute lymphoblastic leukemias are clonal expansions of T cells. Furthermore, circulating T cells from a patient with the T8-cell-predominantly lymphocytosis associated with granulocytopenia are shown to be monoclonal. Finally, the sensitivity and specificity of this tumor-associated marker have been exploited to monitor the therapy of a patient with adult T-cell leukemia. These unique DNA rearrangements provide insights into the cellular origin, clonality, and natural history of T-cell neoplasia.     

Epstein-Barr virus-related post-transplant lymphoproliferative disorder with t(9;14)(p11-12;q32)

The immunoglobulin heavy chain gene locus on 14q32 is known to be involved in translocations that are associated with B-lymphoproliferative disorders, typically Burkitt lymphoma and B-cell acute lymphoblastic leukemia. Several cytogenetic abnormalities have been described in post-transplant lymphoproliferatve disease (PTLD), some of which include this locus. To our knowledge, we report the first case of translocation t(9;14)(p11-12;q32) in a PTLD that developed after orthoptic liver transplantation.     

A complex genetic rearrangement in a t(10;14)(q24;q11) associated with T-cell acute lymphoblastic leukemia.

The t(10;14)(q24;q11) is observed in the leukemia cells of 5-10% of cases of T-cell acute lymphoblastic leukemia (T-ALL). Recently, molecular analyses of a number of these translocations revealed simple reciprocal translocations between the T-cell receptor delta chain gene (TCRD) and a region of 10q24. We have characterized, at the molecular level, a t(10;14)(q24;q11) in a patient with T-ALL. The translocation in this case, in contrast to the previous cases, is part of a complex genetic rearrangement. In addition to a reciprocal translocation between the D delta 3 gene segment of TCRD and a region of 10q24, a local inversion occurred within TCRD, involving the D delta 2 and V delta 2 gene segments. As a consequence, the entire joining and constant regions and most of the diversity regions of TCRD are located on the derivative 14 chromosome, whereas the joining and constant regions of TCRA are positioned on the derivative 10 chromosome. The chromosome 10 breakpoint in our patient, as in other t(10;14), clusters within a 9 kb breakpoint region. The occurrence of seven breakpoints within a localized region of chromosome 10 implies the existence of a nearby gene whose activation may have conferred a selective advantage on the leukemia cells. Moreover, as in the previous cases, the translocation in the present study exhibits recombination signal sequences or signal-like sequences adjacent to the breakpoint junction. The presence of such motifs suggests the involvement of the recombinase enzyme system in the generation of this genetic alteration.