T-cell receptor beta-chain gene rearrangement in a case of Ph1-positive chronic myeloid leukemia blast crisis

Philadelphia-chromosome-positive T-lymphoblastic leukemia: acute leukemia or chronic myelogenous leukemia blastic crisis

The Ph1 chromosome has rarely been reported in T-lineage acute lymphoblastic leukemia (T-ALL), and the clinical relevance of this translocation in T-ALL is currently unknown. In chronic myelogenous leukemia (CML) some data indicate derivation of T-cells from the leukemic clone and only a few cases of T-derived blastic crisis have been reported and quite often disputed. Particularly in cases identified initially in blastic crisis it may be difficult to distinguish those from Ph1-positive T-ALL. We herein report 2 patients who presented with a clinical picture of Ph1-positive T-ALL and who raised a differential diagnosis from T-cell blastic crisis of CML. We review the literature and suggest clinical and laboratory features that can help in the diagnosis. According to our literature review, 23 cases of Ph1-positive T-ALL and 44 cases of T-cell blastic crisis of CML, including ours, were reported. Some major differences between the two entities could help in establishing a diagnosis of Ph1-positive T-cell blastic crisis of CML vs. Ph1-positive T-ALL: Male sex and younger age was more predominant in T-ALL. While in most cases of CML blastic crisis there was a history of CML there was no such history in the T-ALL cases. Medullary involvement with lymphoblastic leukemia was present in all cases of T-ALL but only in about half of the cases of CML blastic crisis. None of the CML-blastic crisis cases tested by RT-PCR showed the minor breakpoint transcript, while 2 cases with T-ALL had the minor breakpoint transcript and 1 had both transcripts. Combined morphologic and FISH analysis can help to distinguish between the two entities and was applied in one of our cases. Although both entities carry a severe prognosis, differentiating between them might have clinical relevance, especially in the imatinib era.

T-cell blast crisis of chronic myelogenous leukemia manifesting as a large mediastinal tumor

We report an unusual case of T-cell blast crisis of chronic myelogenous leukemia (CML) with a clinical presentation more typical of de novo T-cell lymphoblastic lymphoma. The patient was a 32-year-old man who presented with acute superior vena cava syndrome 19 months after an initial diagnosis of CML and 5 months after allogeneic bone marrow transplantation. The tumor was composed of primitive lymphoid cells expressing CD2, CD3, CD4, CD5, CD7, CD8, and CD10. Although the clinical features were more typical of acute lymphoblastic leukemia/lymphoma, fluorescence in situ hybridization analysis showed the bcr-abl fusion gene within blastic tumor cells. This finding confirmed that the mass represented a blastic transformation of CML. We use the unusual features of the current case and the previous reports to suggest that the development of T-cell blast crisis of CML is dependent on the presence of both marrow and extramedullary disease and a mechanism to evade apoptosis.

Chronic myelogenous leukemia in T cell lymphoid blastic phase achieving durable complete cytogenetic and molecular remission with imatinib mesylate (STI571; Gleevec) therapy

BACKGROUND

A T cell lymphoid blastic phase of chronic myelogenous leukemia (CML) is a rare occurrence, with only a few reported cases worldwide. Standard therapy for such patients is undetermined. Imatinib mesylate, a Bcr-Abl tyrosine kinase inhibitor, has shown activity in CML.

METHODS

The authors report on a patient with CML and marrow as well as extramedullary nodal T cell lymphoid blastic phase who was treated with imatinib mesylate.

RESULTS

The patient achieved complete morphologic and cytogenetic remission within two months of therapy. Competitive quantitative polymerase chain reaction analysis of marrow cells was negative after 15 months. Response had lasted for 26+ months at the time of writing.

CONCLUSIONS

The current data suggest that imatinib mesylate may produce long-term event free survival in patients with T-cell lymphoid blastic phase CML. Its potential role alone or in combinations should be further explored in this condition.

Extramedullary T lymphoid blast crisis representing an additional translocation, t(6;8)(q25;q22) in a patient with Philadelphia-positive chronic myelogenous leukemia after allogeneic bone marrow transplantation

A patient with extramedullary crisis from chronic myelogenous leukemia after allogeneic bone marrow transplantation is reported. A pathological neck lymph node observed after transplantation revealed pre-T lymphoblastic phenotype, and the fluorescence in situ hybridization (FISH) analysis showed recipient type sex chromosomes and bcr/abl fusion gene. The cells represented an additional translocation, t(6;8)(q25;q22). No rearrangements of the T-cell receptor (TCR) beta, gamma or delta chain genes were observed. The absence of TCR rearrangement indicated the clonogenic involvement of pluripotent hematopoietic stem cells by Philadelphia chromosome. Bone marrow specimens at that time showed donor type sex chromosomes and no bcr/abl-positive cells by FISH.

Nodal T cell blast crisis in chronic myeloid leukemia

We report the case of a 54 year old male with an original diagnosis of chronic myeloid leukemia (CML) who developed a nodal T cell blast crisis (BC) while he was in a complete hematological remission (CR). We describe the clinical presentation and the histological, immunophenotypic and molecular characterization of the lymph node blast cells. Our case, together with other rare similar reports in the literature, argue that a T cell nodal blast crisis of CML resembles the presentation of a T-cell non-Hodgkin's lymphoma.

Cytogenetic and immunogenotypic alterations of blast crisis cells in chronic myelogenous leukemia independently linked to immunophenotypic expression

Chronic myelogenous leukemia (CML) is a disease of the hematopoietic stem cells, which can differentiate into either B-lymphoid or myeloid cells, because most of them develop either lymphoid or myeloid blast crisis. Immunophenotypic, genotypic, and cytogenetic analyses of 22 patients (24 episodes) with Philadelphia (Ph) positive CML in blast crisis were performed to determine the genetic alterations of the blast crisis cells. In B-lymphoid blast crisis, all the five patients had immunoglobulin heavy-chain (IgH) rearrangements and most of them showed normal karyotypes. Among the five patients, T-cell receptor (TCR) genes were rearranged at the following occurrence rates: 20% in TCR-beta, 60% in TCR-gamma, and 40% in TCR-delta chain genes. A high incidence of additional chromosome changes was noted in patients with B-lymphoid/myeloid-mixed blast crisis, but about 80% of them had rearranged IgH and about 40% had TCR rearrangements. In contrast, most of the patients with non-lymphoid blast crisis showed further chromosomal abnormalities, including +8, +19, i(17q), and double Ph, and most of them had germline configurations of IgH and TCR-gamma chain genes. Notably, only one patient (dual lymphoid and myelomegakaryoblast crisis) in this group exhibited IgH rearrangement, and TCR-beta and TCR-delta rearrangements were also rarely noted. Rearrangement of the IgH gene in CML blast crisis might be linked to expression of lymphoid markers, especially CD19.

Immunophenotypic, genomic and clinical characteristics of blast crisis of chronic myelogenous leukaemia

We have studied phenotypic and clinical features in a consecutive series of 45 patients with chronic myelogenous leukaemia (CML) in blast crisis (BC). In addition, in 22 of these patients we have analysed the genotypic characteristics including immunoglobulin, T-cell receptor (TCR) and major breakpoint cluster region (M-bcr) gene organization. The granulomonocytic and megakaryoblastic lineages are the most commonly involved in these BC of CML (33% and 33% of cases, respectively); only 18% of our cases displayed a lymphoid phenotype. Moreover, both morphological and immunophenotypic studies revealed the frequent coexistence of two or three cell populations, especially when the megakaryoblast component is involved. The lymphoid BC displayed the highest incidence of complete remissions although this was not associated with a longer survival. Only minor differences between the different myeloid subgroups were observed. Immunoglobulin heavy chain (IgH) gene rearrangement was found in five of the six lymphoid BC and in one myeloid BC. Only one case showed k light chain gene rearrangement. In all but one myeloid BC the TCR-beta gene was in germline configuration. The TCR-gamma gene was rearranged in all lymphoid and one myeloid BC, while TCR-delta gene rearrangement was detected in 67% and 16% of the lymphoid and myeloid BC, respectively. Most of the lymphoid BC (4/5) had the M-bcr breakpoint in subregion 3, while the myeloid BC had the breakpoint either in subregion 2 or 3. No differences between the different myeloid phenotypic subgroups were observed in relation to breakpoint.

Non-lymphoid blast crisis of CML with rearrangement of immunoglobulin and T-cell receptor delta genes

We report a patient with chronic myeloid leukaemia (Philadelphia-positive with M-BCR rearrangement) in transformation whose blast cells had myelomonocytic morphology, absent terminal deoxynucleotidyl transferase expression and non-lymphoid cell surface markers (CD10-, CD19-, CD33+, CD14+, CD11+). Leukaemia cell DNA showed rearrangement of both immunoglobulin heavy chain and T-cell receptor delta genes. Such rearrangements may be a feature of a small proportion of patients with non-lymphoid transformation of CML as they are in a minority of cases of de novo acute non-lymphoblastic leukaemia.

Chromosomal characteristics of chronic and blastic phase of chronic myeloid leukemia. A study of 100 patients in India

We report the cytogenetic findings of 100 patients with chronic myeloid leukemia (CML) [72 patients in chronic phase (CP) and 28 patients in blastic phase (BP)]. Of the 95 Ph + patients, six had Ph variant translocations involving chromosomes 1, 6, 7, 10, and 12. The percentage frequency of patients with chromosomal changes other than Ph was 7.3%. The additional aberrations (e.g., + Ph, + 8, i(17q), and + 19 were observed in 66.6% of BP patients. Of these anomalies, the frequency of + Ph and + 19 was higher in our patients than the incidence reported in literature. The association of + Ph and + 19 in patients with extramedullary T-cell blast crisis is an unusual finding as compared with reports in the literature and could be explained by geographic heterogeneity. The extra chromosomal abnormalities were almost absent in lymphoid blast crisis patients with blast phenotype of common acute lymphoblastic leukemia (ALL) type. Discrepancies were noted in different tissues (bone marrow and lymph node) in patients with extramedullary blast crisis of both myeloid and lymphoid type. These findings indicate the cytogenetic correlation with clinical and morphological picture, which consequently implicates the diagnostic and prognostic significance of chromosomal aspects.

T-lymphoid blast crisis in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is considered to be a pleuripotential stem cell disorder with the capacity to differentiate into myeloid, erythroid, megakaryocytic, and lymphoid cell lines. Consequently, blast crisis (BC) involving each of the above lineages has been well described. Among lymphoblastic crises, differentiation frequently occurs along B-cell lineage. We report four patients of CML who terminated in T-cell extramedullary BC in lymph nodes after a variable duration of chronic phase. The T-lineage was established by characteristic cytochemical staining and reactivity with a panel of anti-T-cell monoclonal antibodies. All four cases were Philadelphia (Ph) chromosome positive and demonstrated the Ph chromosome and associated anomalies (extra Ph, +19) in the lymph nodes. Our data adds to the growing evidence that CML is a disorder of the common stem cell from which T, B, and myeloid precursors originate.

Dual rearrangement of immunoglobulin and T-cell receptor genes in blast crisis of CML

Dual rearrangement of immunoglobulin and T-cell antigen receptor (beta, delta) genes was demonstrated in a case of Philadelphia chromosome-positive chronic myeloid leukemia (CML) in blast crisis. The blast cells, showing L2 morphology and high activity of TdT, expressed pre-B cell (CD19+, Ia+) and myeloid (CD13+, CD34+) surface antigens but lacket T-cell antigens (CD2-, CD7-). Cytogenetic studies on bone marrow and peripheral blood revealed the Phl chromosome in all metaphases analyzed, majority of which also had the additional chromosome changes, +8, +10, +21. Furthermore, molecular analysis of the breakpoint cluster region (bcr) on chromosome 22 showed a rearrangement, confirming the CML origin of the blast cells.

Chronic myelogenous leukaemia: a model for human cancers

In this chapter I reviewed the biological and molecular abnormalities associated with CML and related disorders. Much is known about this disease and it is probably not an overstatement to say that there are more data regarding the molecular and biological events underlying CML than any other human cancer. Nevertheless, this review emphasizes how inadequate these data are in explaining most of the important aspects of this disorder. Thus, if CML is to be used as a model of other cancers, much work remains to be done.

Phenotypic and genotypic analysis of chronic myelogenous leukaemia with T lymphoblastic and megakaryoblastic mixed crisis

A case of blast crisis in chronic myelogeneous leukaemia (CML) in which two distinct cell lineages were involved is presented. The phenotype of blasts in lymph nodes was T11 (CD2)+, Ia+, TdT+, suggesting T cell lineage. On the other hand, blasts in bone marrow and peripheral blood expressed platelet glycoprotein IIb/IIIa complex on their surface, suggesting megakaryocyte lineage. Cytogenetic analysis of lymph node and bone marrow cells revealed the abnormalities, inv(7) (p15q34) and t(1;3) (q23;q21), respectively, as well as the presence of the Ph1 chromosome in both cell types. Rearrangement of the T cell receptor beta-chain gene was detected in lymph node blasts, although blast cells in peripheral blood showed a germ line configuration. The involvement of T cell and megakaryocyte lineages in the blast crisis phase of CML was confirmed in our phenotypic and genotypic analysis, and the pathogenic association between blast crisis lineages and the additional chromosome abnormalities present is discussed.