Association of a chromosomal 3;21 translocation with the blast phase of chronic myelogenous leukemia

An identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints in bands 3q26 and 21q22, t(3;21)(q26;q22), was found in three male patients with the blast phase of chronic myelogenous leukemia (CML). The abnormality was clonal in all three patients and was always accompanied by either a standard or variant 9;22 translocation resulting in a Philadelphia chromosome (Ph1). In two cases, the t(3;21) was the only abnormality other than a t(9;22) in the primary clone. Serial studies of one patient demonstrated that the t(3;21) occurred as a result of clonal evolution near the time of development of the blast phase. We have not observed the t(3;21) in greater than 500 patients with CML in the chronic phase. Thus, the t(3;21) is a new recurring cytogenetic abnormality associated with the blast phase of CML.     

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.     

Detection of t(3 ; 21) (q26 ; q22) with AML1/EVI1 mRNA during progression of myelodysplastic syndrome to acute myeloid leukemia]

A 74-year-old woman had myelodysplastic syndrome (MDS) in 1986. In June 1994, she suffered exacerbation of pancytopenia with no chromosomal abnormalities, but AML1/EVI1 chimeric mRNA was detected by RT-PCR. Two months later, an increase in bone marrow blasts (5%) was noted, and chromosomal analysis detected t(3 ; 21) (q26 ; 22), del(7) (q22), del(11) (q23). In 1995, the marrow blasts increased to 30% and the patient died of disease progression. The AML1/EVI1 gene has been shown to cause blast crisis in chronic myelogenous leukemia. This case suggested that the AML1/EVI1 gene may be involved in the progression of MDS together with del(7) (q22) and del(11) (q23).     

Comparative biochemical and cytogenetic studies of childhood acute lymphoblastic leukemia with the Philadelphia chromosome and other 22q 11 variants

We studied the relationship of direct karyotypes, determined at diagnosis and remission, to Abelson-related tyrosine kinase activity and the cytogenetic features of erythroid and myeloid colonies derived from remission marrow of six children with acute lymphoblastic leukemia (ALL). These patients had either the characteristic Philadelphia chromosome (Ph1) [t(9;22)(q34;q11)] or cytogenetically similar variants with a 22q11 breakpoint but no detectable cytogenetic involvement of 9q34. The findings suggested two distinct subtypes of ALL: one defined by t(9;22)(q34;q11) and expression of P185BCR-ABL tyrosine kinase and one with variant karyotypes and no P185BCR-ABL expression. The former comprises cases with Ph1 + marrow cells and Ph1 + erythroid and (or) myeloid colonies in remission marrow and others in which the t(9;22) is undetectable in remission marrow cells. In the latter subgroup, the disease may reflect more extreme mosaicism with a similar stem cell that is cytogenetically undetectable. Variant karyotypes included a del(22)(q11) in one patient and a t(6;22;15;9) (q21;q11;q?22;q21) in another; in both instances, the malignant blast cells lacked P185BCR- ABL expression. Thus ALL with t(9;22)(q34;q11) should be distinguished from ALL with other involvement of the 22q11 breakpoint by molecular studies including protein expression. The diversity of karyotypic findings in cases with involvement of 22q11 suggests at least two mechanisms of leukemogenesis in patients with ALL defined by this breakpoint.     

Abnormalities of 3q21 and 3q26 in myeloid malignancy: a United Kingdom Cancer Cytogenetic Group study

Summary. Cytogenetic and clinical details are presented for 66 patients with myeloid malignancy and chromosome abnormalities of 3q21 and/or 3q26 (3qabns). Bone marrow and/or peripheral blood morphology was assessed for 52 cases. 3qabns in Philadelphia negative (Ph–ve) and positive (Ph + ve) cases were inv(3)(q21q26), (21 Ph-ve, 6Ph + ve); t(3;3)(q21;q26) (nine Ph-ve, four Ph + ve); and t(3;21)(q26;q22) (four Ph-ve, six Ph + ve). Ph-ve cases also had t(l;3)(p36;q21) (three cases), and t(3;5)(q21;q31)/ (q21;q35)/(q26;q21) (five cases aged <40 years). Three cases, aged < 30 years, had t(3;12)(q26;p13) which defines a new 3qabn subgroup. Monosomy 7 and/or 5q- accompanied inv(3) or t(3;3) in 17/30 cases. All cases had a myeloid malignancy (predominantly AML M1, M4 or M7), frequent trilineage myelodysplasia, and markedly abnormal megakaryopoiesis with micromegakaryocytes (<30/mi). Thrombocytosis occurred in two cases only. Most Ph + ve cases were in myeloid blast crisis and in Ph + ve cases alone, micro-megakaryocytes were uniquely small (10 μm) in 7/11 cases. There were equal numbers of males and females. Seven secondary leukaemias were found in Ph–ve cases with inv(3), t(3;3), t(3;21), t(l;3) or del(3)(q21). Three cases with t(3;21) (one Ph + ve) were de novo AML or had de novo aplastic anaemia. Survival was rarely greater than 12 months from detection of the 3qabn.     

Involvement of the AML1 gene in the t(3;21) in therapy-related leukemia and in chronic myeloid leukemia in blast crisis

A nonrandom translocation between chromosomes 3 and 21, t(3;21)(q26.2;q22) has been detected in patients with a myelodysplastic syndrome or acute myeloid leukemia after treatment (t-MDS/t-AML) for a primary malignant disease and in chronic myelogenous leukemia in blast crisis (CML-BC). In these patients, the breakpoint on chromosome 21 is at band 21q22. This band is also involved in the t(8;21)(q22;q22) detected in 40% of the patients with acute myeloid leukemia subtype M2 (AML-M2) de novo who have an abnormal karyotype. In the t(8;21), the AML1 gene is the site of the breakpoint on chromosome 21. The AML1 gene is transcribed from telomere to centromere, and in the t(8;21) the 5' part of AML1 is fused to the ETO gene on chromosome 8 to produce the chimeric AML1/ETO on the der(8) chromosome. We found that AML1 is also rearranged in two t-AML patients and in one CML-BC patient with the t(3;21), but the breakpoints are approximately 40 to 60 kb downstream to those of AML-M2 patients. This region contains at least one additional exon of AML1, as determined by using an AML1 cDNA as a probe in Southern blot analysis. The t(3;21) breakpoints for the remaining patients could not be determined because, by fluorescence in situ hybridization analysis, the breaks are outside of the region covered by the available probes.     

Mixed blast crisis with the cytogenetic evidence of three clonal evolutions

A 46-year-old man was diagnosed as having chronic myelogenous leukemia (CML) in chronic phase in Dec. 1985. In Dec. 1987, anemia and leukocytopenia progressed, and the percentage of blast cells increased in the bone marrow. The blast cells were lymphoblastoid and positive for TdT. It was treated as a lymphoid crisis with vincristine and prednisolone, and complete remission was achieved. However, the blasts (11%) were observed in the bone marrow in Mar. 1988, and the chromosomal analysis revealed 46, XY, t (2q-; 11q+), t (9q+; 22q-) in 13 out of 20 cells. In June, the percentage of the blasts increased again, but chromosomal analysis showed a different karyotype, 46, XY, t(2p-; 11p+), t(9q+; 22q-) which was observed in 9 out of 10 cells. Then, myeloblastoid cells increased rapidly in spite of the chemotherapy in Dec. 1988. The chromosomal analysis showed 46, XY, 2p-, 7q-, 9q+, 11p+, 22q- in all analyzed cells. The rearrangement of the bcr gene could be detected by the Southern blotting. The blasts were positive for CD7, CD11, CD13, CD33, CD36, CD41 and CD42, suggesting that the blasts had the surface phenotypes of both myeloid and megakaryocytoid-lineage. This is a case with the mixed blast crisis that changed from the lymphoid to the myelo-megakaryocytoid in nature, in which three clonal evolutions were observed during the clinical course.     

Clonal evolution in Ph-negative, bcr-positive chronic myeloid leukaemia before and after bone marrow transplantation

A 26-year-old man, who presented with bilateral fundal haemorrhages, was found to have chronic myeloid leukaemia (CML). The Ph chromosome was not present but a clone with t(1;9) (p32;q34) was detected. On referral for bone marrow transplant (BMT) he was found to be in accelerated phase with clonal evolution in three cell lines inv(3)(q21q26); inv(3)(q),i(17q); inv(3q)+8. Molecular investigation revealed a breakpoint on chromosome 22 within the breakpoint cluster region (bcr) similar to that found in Ph+ cases. After BMT, from an HLA-identical sister, successful engraftment (46,XX) was accompanied by evidence of a residual host cell population with further evolution (del(7)(q22)) and persistence of the bcr+ clone. Acute myeloid leukaemia, detected 5 months later, was associated with predominance of the clone 46XY,t(1;9),inv(3q),del(7)(q22) which failed to respond to treatment and the patient died 6.5 months after BMT. This case indicates that BMT, after the acquisition of additional chromosomal change in accelerated phase, may fail owing to persistence of the leukaemic clone. In addition the BMT conditioning regimen may produce further abnormalities which confer drug resistance on the persisting clone, which can emerge as an intractable myeloid blast crisis.     

Two karyotypically independent leukemic clones with the t(8;21) and 11q23 translocation in acute myeloblastic leukemia at relapse

Leukemic blast cells are thought to arise from clonal expansion of a single transformed hematopoietic cell. This generality is supported by the rarity of convincing reports on acute myeloblastic leukemia (AML) with two karyotypically independent clones. Relying on sequential cytogenetic analyses, we identified such clones in two children with relapsed AML. The first case, classified as M2 leukemia in the French-American-British (FAB) classification system, had a t(8;21) (q22;q22) at diagnosis; 16 months later, at relapse, the leukemic cells had uniform morphologic features similar to those observed at diagnosis, except that two independent clones were present: one with the original t(8;21) and the other with t(11;22)(q23;q13) [corrected]). The second case was initially classified as FAB M1 leukemia with a t(8;21) (q22;q22). At relapse, 16 months later, the blast cells appeared morphologically uniform and similar to the diagnostic specimen; however, in addition to the original t(8;21) clone, there was a t(1;11) (p32;q23) [corrected]. These findings suggest that separate leukemogenic events affecting different progenitor cells can occur in rare cases of AML. The presence of two karyotypically independent clones could also be explained by multistep leukemogenesis; that is, more than one cell from a common pool of preleukemic cells could be affected by the transforming event, resulting in two independent clones. Alternatively, in light of recent reports of therapy-related leukemias with an 11q23 translocation, the new independent clone in these two patients could represent a therapy-related secondary malignancy. Thus, 11q23 translocations may occur preferentially in stem cells that are more susceptible to treatment-induced malignant transformation.     

Association of the translocation (15;17) with malignant proliferation of promyelocytes in acute leukemia and chronic myelogenous leukemia at blastic crisis

Cytogenetic studies were performed on nine patients with acute promyelocytic leukemia. Every patient had an identical translocation (15;17) or, in one case, a variant three-way rearrangement between chromosomes 7, 15, and 17. Another patient with chronic myelogenous leukemia was examined at the time of blastic crisis when the patient's bone marrow was infiltrated by hypergranular promyelocytes and blasts. Bone marrow cells contained a t(15;17) as well as a Ph1 chromosome. Only the latter abnormality was observed in the chronic phase of the disease. The translocation (15;17) was detected in all ten patients when bone marrow or peripheral blood cells were cultured for 24 hours prior to making chromosome preparations. However, the t(15;17) was not seen in three of these same cases when bone marrow cells were processed directly. These findings indicate that the t(15;17) is closely associated with acute proliferation of leukemic promyelocytes and that detection of this karyotypic defect may be influenced by the particular cytogenetic processing method used in different laboratories. An analysis of the banding pattern in the variant translocation provided additional evidence favoring chromosomal breakpoints at or very near the junction between bands 17q12 and 17q21 and at 15q22.     

Complex chromosomal abnormalities in a patient with lymphoid blast crisis of chronic myelogenous leukemia

A 46-year-old Chinese man underwent lymphoid blast crisis (Ia+, CALLA+, TdT+) after 5 years of chronic phase, Philadelphia-chromosome positive chronic myelogenous leukemia. Chromosome analysis revealed a hyperdiploid karyotype, including two Philadelphia chromosomes--55,XY,t(9;22) (q34;q11), +2, +5, +5, +6, +10, +18, +19, +21, +del(22)(qll----qter)--in the majority of the leukemic blasts. The constellation of a lymphoid blast crisis and complex chromosomal abnormalities usually associated with myeloid blast crisis as well as the clinical data are discussed.     

Chronic myelogenous leukemia characterized by successive lymphoid and myelomonocytic blast crises

We report a 25 year-old male of CML, who repeated lymphoid blast crises twice and finally experienced a myelomonocytic blast crisis. In the first and the second crises, after 2 years of chronic phase, the blasts were only weakly positive or negative for terminal deoxynucleotidyl transferase. Based on other morphological features of the blasts, however, lymphoid blast crisis was strongly suspected. Actually, he responded well to the vincristine and prednisolone therapy. In the third crisis, the blasts showed myelomonocytic features. He did not respond to the same regimen, and died of intracranial infiltration during daunorubicin and cytosine arabinoside therapy after one year from the first crisis. Chromosomal analysis showed the karyotypes of 46, XY, t(9:22) (q34:q11) in the chronic phase, 45, XY, -7, -9, +der(9) t(7;9) (q11;p11), t(9:22) (q34:q11) in the lymphoid blast crisis, and 46, XY, t(9:22) (q34:q11), t(11:17) (q23:q25) in the myelomonocytic blast crisis.     

Chromosome banding studies in Philadelphia chromosome positive myeloid leukaemia.

A cytogenetic study of Ph1 positive myeloid leukaemia in both chronic and acute phases had been made by a chromosome banding technique. The translocation (t(9;22)(q34;q11), designated t(Ph1) was present in the myeloid cells of 43 of 44 patients; the exceptional case had normal number 9 chromosomes and a different translocation (t(19;22)(q13;q11)). A translocation additional to that involving the Ph1 was found as a stable abnormality present in all myeloid cells in 4 patients, chromosome 17 being involved in 2. The association of isochromosome number 17 with blast crisis was confirmed. New data were obtained concerning the significance of duplicated or dicentric Ph1 chromosomes and their relationship with the 9q+ anomaly. Monoclonal origin of Ph1 was confirmed in cases with polymorphic number 22 or 9 chromosomes.     

Clonal selection of CD56+ t(8;21) AML blasts: further suggestion of the adverse clinical significance of this biological marker?

Although patients with acute myelogenous leukaemia (AML) and t(8;21)(q22;q22) have a favourable prognosis, a subset die despite receiving appropriate treatment. Recent reports suggest that expression of the CD56 antigen might predict for both extramedullary disease and poor outcome in these patients. We describe a patient who presented with CD56-negative t(8;21) AML who achieved a complete remission and was subsequently treated with three consolidative courses of high-dose cytarabine therapy. She relapsed 9 months later with extramedullary and bone marrow involvement of CD56-positive t(8;21) AML. This case demonstrates clonal evolution and provides further support that blast expression of CD56 might be an unfavourable prognostic factor in t(8;21) AML.     

t(8;21) (q22;q22) Acute myelogenous leukemia in México: A single institution experience

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7–49); there was only one male. According to the French–American–British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.     

t(8;21) (q22;q22) acute myelogenous leukemia in Mexico: a single institution experience

We analyze the prevalence and clinical features of a group of patients with t(8;21) (q22;q22) acute myeloblastic leukemia, identified in a single institution in México over a 10-year period. Fifteen patients presented at the Centro de Hematología y Medicina Interna de Puebla from February 1995 to August 2005; only nine were treated and followed in the institution. Median age was 24 years, (range 7-49); there was only one male. According to the French-American-British (FAB) morphological classification of leukemia, the morphology was M2 in four cases, M4 in three cases, M3 in one case and M0 in one. In addition to the myeloid markers, lymphoid markers were identified in 6 patients. Patients were induced to remission with combined chemotherapy and three subsequently underwent bone marrow transplantation (BMT). The median overall and disease-free survival has not been reached, being above 3390 days, the probability of survival at this time was 73%. In this single-center experience in México, we found that the t(8;21) (q22;q22) variant of leukemia was more frequent than in Caucasian populations, that the co-expression of lymphoid markers in the blast cells is very frequent and that this malignancy is associated with a relatively good prognosis.     

Cytogenetic evidence for extramedullary blast crisis with t(8;13)(q11;p11) in chronic myelomonocytic leukemia.

A 27-year-old male developed massive generalized lymphadenopathy with chronic myelomonocytic leukemia (CMML) presenting as extramedullary blast crisis mimicking a lymphocytic lymphoma. On presentation, a consistent chromosomal abnormality involving chromosomes 8 and 13, i.e. 46,XY,t(8;13) (q11;p11), was present in lymph node tissue, bone marrow and unstimulated peripheral blood. The appearance of trisomy 21 in addition to the presence of the original cytogenetic abnormality is simply regarded as clonal evolution, i.e. 47,XY,t(8;13)(q11;p11),+21. The importance of the cytogenetics lies in finding the same abnormality in bone marrow and lymph node, adding evidence that the immunologically similar cells in the two sites have arisen from a common progenitor cell. To our knowledge, this novel chromosomal abnormality has not been reported in association with a unique case.