Hyperfibrinolysis in a case of myelodysplastic syndrome with leukemic spread of mast cells

Mast cells (MC) are multipotent hemopoietic effector cells producing diverse mediators like histamine, heparin, or tissue type plasminogen activator. We report a 75-year-old male patient with myelodysplastic syndrome (MDS) of recent onset (3 months' history) associated with a massive leukemic spread of immature tryptase+ MC (tentative term: myelomastocytic leukemia). The patient presented with pancytopenia, bleeding, hypofibrinogenemia, and an increased cellular tryptase level. Moreover, an excessive elevation of plasmin-antiplasmin complexes (9,200 ng/ml; normal range: 10-150), an elevated D-dimer, and an increase in thrombin-antithrombin III complexes were found. The identity of the circulating MC was confirmed by immunophenotyping (CD117/c-kit+, CD123/IL-3R alpha-, CD11b/C3biR-), biochemical analysis (cellular ratio [ng:ng] of tryptase to histamine >1), and electron microscopy. Bone marrow (bm) examination showed trilineage dysplasia (17% blasts), 30% diffusely scattered MC, and a complex karyotype. No dense, compact MC infiltrates (mastocytosis) were detectable in bm sections. Despite hyperfibrinolysis and mediator syndrome (flushing, headache), the patient received remission induction polychemotherapy (DAV) followed by two cycles of consolidation with intermediate dose ARA-C (2 x 1 g/m2/day on days 1, 3, and 5). He entered complete remission after the first chemotherapy cycle without evidence of recurring MDS. Moreover, in response to chemotherapy, the hyperfibrinolysis and mediator syndrome resolved, and the circulating c-kit+ MC disappeared. We suggest consideration of polychemotherapy as a therapeutic option in patients with high-risk MDS of recent onset, even in the case of MC lineage involvement.

Myelodysplastic syndrome, juvenile myelomonocytic leukemia, and acute myeloid leukemia associated with complete or partial monosomy 7. European Working Group on MDS in Childhood (EWOG-MDS)

We reviewed the clinical features, treatment, and outcome of 100 children with myelodysplastic syndrome (MDS), juvenile myelomonocytic leukemia (JMML), and acute myeloid leukemia (AML) associated with complete monosomy 7 (-7) or deletion of the long arm of chromosome 7 (7q-). Patients with therapy-induced disease were excluded. The morphologic diagnoses according to modified FAB criteria were: MDS in 72 (refractory anemia (RA) in 11, RA with excess of blasts (RAEB) in eight, RAEB in transformation (RAEB-T) in 10, JMML in 43), and AML in 28. The median age at presentation was 2.8 years (range 2 months to 15 years), being lowest in JMML (1.1 year). Loss of chromosome 7 as the sole cytogenetic abnormality was observed in 75% of those with MDS compared with 32% of those with AML. Predisposing conditions (including familial MDS/AML) were found in 20%. Three-year survival was 82% in RA, 63% in RAEB, 45% in JMML, 34% in AML, and 8% in RAEB-T. Children with -7 alone had a superior survival than those with other cytogenetic abnormalities: this was solely due to a better survival in MDS (3-year survival 56 vs 24%). The reverse was found in AML (3-year survival 13% in -7 alone vs 44% in other cytogenetic groups). Stable disease for several years was documented in more than half the patients with RA or RAEB. Patients with RA, RAEB or JMML treated with bone marrow transplantation (BMT) without prior chemotherapy had a 3-year survival of 73%. The morphologic diagnosis was the strongest prognostic factor. Only patients with a diagnosis of JMML fitted what has previously been referred to as the monosomy 7 syndrome. Our data give no support to the concept of monosomy 7 as a distinct syndrome.

Comparative expression analysis of the antagonistic transcription factors EVI1 and MDS1-EVI1 in murine tissues and during in vitro hematopoietic differentiation

An alternative form of the transcription factor EVI1, MDS1-EVI1, which previously had been believed to exist only in the context of leukemic fusion mRNAs, has recently been shown to be expressed also in normal human tissues. Moreover, it acts as an antagonist of EVI1, activating transcription of reporter constructs repressed by EVI1. We cloned the murine homolog of MDS1-EVI1 as well as mMds1 and show localization of mMds1 close to mEvi1 on chromosome 3. Using RT-PCR, we demonstrate widespread expression of both Evi1 forms in the adult mouse, as well as their upregulation during in vitro hematopoietic differentiation. Our data underscore the biological importance of both EVI1 and MDS1-EVI1 and provide the basis for further studies of their function in the mouse model system.

Alveolar rhabdomyosarcoma in a 68-year-old patient identified by cytogenetic analysis of bone marrow

Pancytopenia and fulminant disseminated intravascular coagulation in a 68-year-old woman suggested an acute hematologic malignancy. However, cytogenetic analysis on a bone marrow sample revealed a near-tetraploid karyotype with an isochromosome 1q and a translocation (2;13) (q35;q14), which was suggestive of an alveolar rhabdomyosarcoma (ARMS). This diagnosis was subsequently confirmed by indirect immunohistochemistry. ARMS has not yet been observed in a patient of this age. Thus, our case underlines the importance of cytogenetics, to establish an a priori unexpected tumor diagnosis.

Fluorescence in situ hybridization characterization of the chromosomal breakpoints in a case with ins(17;3)(q11.2;q21q26.3) and acute monocytic leukemia

A 63-year-old patient with acute myeloid leukemia of FAB M5 subtype revealing chromosomal breakpoints in 3q21 and 3q26 is presented. Although rearrangements of 3q21 and 3q26 are relatively common in patients with myelocytic malignancies, this is the first report of ins(17;3)(q11.2;q21q26.3). We defined the chromosomal breakpoints and the extent of the insertion by fluorescence in situ hybridization (FISH) with yeast artificial chromosomes (YACs).

Immunophenotypic and genotypic features, clinical characteristics, and treatment outcome of adult pro-B acute lymphoblastic leukemia: results of the German multicenter trials GMALL 03/87 and 04/89

In contrast to childhood acute lymphoblastic leukemia (ALL), the cell-biological features, clinical characteristics, and treatment outcome of CD10(-) pro-B ALL have not yet been determined in larger series of adult patients. Therefore, we studied 57 adult patients with newly diagnosed pro-B ALL (median age, 30 years) enrolled in two consecutive German multicenter ALL studies (03/87 and 04/89). Extensive immunophenotypic characterization of leukemic blasts could be performed on all patients, whereas adequate cytogenetic data were available in 33 cases and molecular studies in 18 cases, using reverse transcription-polymerase chain reaction to detect MLL-AF-4 transcripts. Twenty-two patients demonstrated a t(4;11)(q21;q23) and/or MLL-AF-4 rearrangements, and 6 patients had other structural abnormalities, including a t(9;22)(q34;q11) (N = 2). Nine patients had a normal karyotype. Patients with 11q23 abnormalities tended to be younger (median age, 29 years) and were characterized by male predominance (64%), hyperleukocytosis (median leukocyte count, 168 x 10(9)/L), and a frequent coexpression of CD65s (64%) as compared with patients with other cytogenetic abnormalities or a normal karyotype. Twelve of 16 (75%) pro-B ALL patients in study 03/87 and 30 of 41 (73%) in study 04/89 achieved a complete remission (CR). Sixteen of 30 patients in study 04/89 remain in continuous CR (CCR) in contrast to only 2 of 12 patients in study 03/87. Interestingly, all 7 patients treated with high-dose cytarabine and mitoxantrone as consolidation in study 04/89 remain alive and leukemia-free. One patient in study 03/87 and 8 in study 04/89 underwent autologous (N = 2) or allogeneic (N = 7) bone marrow transplantation (BMT). The median remission duration was 420 days for patients in study 03/87 and has not yet been reached in study 04/89. The median survival time of all pro-B ALL patients was 571 days in study 03/87 and 747 days in study 04/89. Among the 22 patients with a t(4;11) and/or MLL-AF-4 rearrangements, 17 achieved a CR and 8 are still in CCR, of whom 4 underwent an allogeneic BMT. Remission duration and overall survival did not differ significantly between pro-B ALL patients with 11q23 abnormalities and those with a normal karyotype or other structural abnormalities. These data indicate that intensification of postremission treatment may improve the prognosis of adult pro-B ALL, including patients with a t(4;11).

High rate of chromosome abnormalities detected by fluorescence in situ hybridization using BCR and ABL probes in adult acute lymphoblastic leukemia

The value of dual-color fluorescence in situ hybridization (FISH) with BCR and ABL probes for the detection of the Philadelphia (Ph) translocation and of other alterations involving ABL and/or BCR was evaluated in adult acute lymphoblastic leukemia (ALL). One hundred and four patients were studied prospectively using interphase nuclei FISH, chromosome analysis (CA), and PCR assays for the chimeric BRC/ABL transcript. FISH detected a Ph translocation in 24 cases (23.1%), as was confirmed by CA and/or PCR. FISH revealed a false positive diagnosis of a Ph translocation in four cases (5% false positive rate). Among 54 cases with combined FISH, CA and PCR assays, FISH failed to establish a correct diagnosis in 3.7%, PCR in 5.6%, and CA in 7.4%. The combination of two screening methods led to discrepant results in 9.3% (FISH + PCR), 11.1% (FISH + CA), or 13% (CA + PCR) of the cases. In seven of 80 (8.8%) Ph-negative patients, gain of BCR and/or ABL was identified. Overall, FISH detected alterations of the BCR and/or ABL genes with an incidence of 29.8% of the current study. Due to the possibility of false positive diagnosis of a Ph translocation using dual-color FISH the combination with chromosome and/or RT-PCR analyses is recommended in adult ALL patients.

Mutational analysis of the tumor suppressor Smad2 in acute lymphoid and myeloid leukemia

Smad4 is a tumor suppressor that is inactivated in about 50% of pancreatic carcinomas. Mutations in this gene have also been found with variable, yet much lower frequency in other tumor types and were absent from a large number of samples from patients with hematological malignancies. Smad2 shows considerable sequence similarity with Smad4 and cooperates with it in the growth inhibitory TGF-beta pathway. Smad2 mutations have been found in a fraction of colon carcinomas and have been shown to impair the function of the corresponding proteins. However, only a few other tumor types have been screened for Smad2 mutations so far. Therefore, we analyzed 50 primary tumor samples from patients with acute lymphoid or myeloid leukemia (ALL or AML) and five cell lines of hematopoietic origin for alterations in the Smad2 gene. None of the specimens tested carried mutations in the conserved MH1 or MH2 domains of Smad2.

MLL and CALM are fused to AF10 in morphologically distinct subsets of acute leukemia with translocation t(10;11): both rearrangements are associated with a poor prognosis

The translocation t(10;11)(p13;q14) has been observed in acute lymphoblastic leukemia (ALL) as well as acute myeloid leukemia (AML). A recent study showed a MLL/AF10 fusion in all cases of AML with t(10;11) and various breakpoints on chromosome 11 ranging from q13 to q23. We recently cloned CALM (Clathrin Assembly Lymphoid Myeloid leukemia gene), the fusion partner of AF10 at 11q14 in the monocytic cell line U937. To further define the role of these genes in acute leukemias, 10 cases (9 AML and 1 ALL) with cytogenetically proven t(10;11)(p12-14;q13-21) and well-characterized morphology, immunophenotype, and clinical course were analyzed. Interphase fluorescence in situ hybridization (FISH) was performed with 2 YACs flanking the CALM region, a YAC contig of the MLL region, and a YAC spanning the AF10 breakpoint. Rearrangement of at least one of these genes was detected in all cases with balanced t(10;11). In 4 cases, including 3 AML with immature morphology (1 AML-M0 and 2 AML-M1) and 1 ALL, the signals of the CALM YACS were separated in interphase cells, indicating a translocation breakpoint within the CALM region. MLL was rearranged in 3 AML with myelomonocytic differentiation (2 AML-M2 and 1 AML-M5), including 1 secondary AML. In all 3 cases, a characteristic immunophenotype was identified (CD4+, CD13-, CD33+, CD65s+). AF-10 was involved in 5 of 6 evaluable cases, including 1 case without detectable CALM or MLL rearrangement. In 2 complex translocations, none of the three genes was rearranged. All cases had a remarkably poor prognosis, with a mean survival of 9.6 +/- 6.6 months. For the 7 AML cases that were uniformly treated according to the AMLCG86/92 protocols, disease-free and overall survival was significantly worse than for the overall study group (P = .03 and P = .01, respectively). We conclude that the t(10;11)(p13;q14) indicates CALM and MLL rearrangements in morphologically distinct subsets of acute leukemia and may be associated with a poor prognosis.

Characterization, mapping and partial cDNA sequence of the 57-kD intracellular Ki-1 antigen

A novel antigen was identified by the cross-reactivity of the anti-CD30 antibody Ki-1. This 57-kD intracellular Ki-1 antigen (Ki-1/57) is induced upon activation of leukocytes and is transported to the nuclear compartment. We describe the partial cloning and sequencing of the Ki-1/57 cDNA from a lambda gt 11-cDNA library derived from the Hodgkin-analogous cell line L540. New monoclonal antibodies were produced against the recombinant Ki-1/57 protein fragment which were used to confirm that the Ki-1/57 antigen is associated with kinase activity and is expressed in a variety of tumor cell lines and in activated but not resting leukocytes. The Ki-1/57 gene was mapped to the bands 9q22.3-31 of human chromosome 9. This is an area which appears to be associated with secondary chromosomal aberrations in acute myeloid leukemias.

Leukemia-free survival and mortality in patients with refractory or relapsed acute leukemia given marrow transplants from sibling and unrelated donors

Between April 1982 and February 1997 39 patients (24 male, 15 female) with refractory acute leukemia and a median age of 31 years (19-51 years) received allogeneic marrow grafts from an HLA-identical sibling (n = 27), HLA-identical unrelated donor (MUD; n = 10) or 1-antigen mismatched unrelated donor (n = 2). Twenty-eight patients had acute myelogenous leukemia and 11 acute lymphoblastic leukemia. For conditioning most patients received total body irradiation combined with cyclophosphamide (n = 23) or etoposide (n = 7). For graft-versus-host disease prophylaxis patients received cyclosporin A (CsA) and methotrexate (MTX) (n = 20), MTX alone (n = 3), CsA and methylprednisone (n = 6), or CsA alone (n = 10), respectively. As of June 1997 probability of leukemia-free survival projected to 3 years after BMT was 14% for patients given sibling marrow grafts and 28% after MUD transplantation. Transplant-related mortality projected to 3 years was 32% after sibling and 37% after MUD marrow grafting. Although not significantly different, probability of relapse projected to 3 years after BMT was lower after MUD at 56% compared to 78% with sibling BMT. Thus, high-dose chemo/radiotherapy followed by allogeneic marrow infusion has a curative potential for patients with refractory leukemia and offers the chance of long-term disease-free survival for some patients.

Correlation of cytogenetic, molecular cytogenetic, and clinical findings in 59 patients with ANLL or MDS and abnormalities of the short arm of chromosome 12

Abnormalities of the short arm of chromosome 12 (12p) are found in about 5% of acute nonlymphocytic leukaemias (ANLL) and myelodysplastic syndromes (MDS). They are described to be characteristic of secondary leukaemias, especially after prior mutagenic exposure, and to be associated with a poor prognosis. In our series of 59 patients with 12p abnormalities and ANLL or MDS, exposure to genotoxic agents was proven only in five patients, but in 13/44 patients ANLL evolved from an MDS. Patients with a small deletion del(12)(p11.2p13) having a mild clinical course were distinguished from those with a large del(12)(p11.2), additional chromosomal anomalies, and a poor clinical course. Among the 31 patients with translocations or dicentric chromosomes involving 12p, a group of eight with t/dic(12;13) was the most frequent and was associated with a poor prognosis. The clinical outcome was adverse in the majority of patients with complex karyotype abnormalities, but in some patients a milder clinical course seems likely. A new, hitherto undescribed, abnormality in an MDS case with a duplication dup(12)(p11.2p13) was the amplification of the signal of the yeast artificial chromosome (YAC) clone 964c10 (D12S736). In 38 cases with deletions or unbalanced translocations/dicentrics one YAC signal was lost. Five patients with balanced translocations demonstrated breakpoints within the YAC, containing the ETV6 (TEL) gene. The breakpoints were telomeric to the YAC 964c10 in seven cases and centromeric in one patient.

The significance of trisomy 8 in de novo acute myeloid leukaemia: the accompanying chromosome aberrations determine the prognosis. German AML Cooperative Study Group

Trisomy 8 is the most frequent numerical chromosome aberration in acute myeloid leukaemia (AML). It occurs either as the sole anomaly or together with other clonal chromosome aberrations. We investigated whether accompanying chromosome anomalies influence the clinical outcome in patients with trisomy 8 and de novo AML. Since 1986, in 713 AML cases treated according to the protocols of the German AMLCG trials, chromosome analyses have been successfully performed. The overall incidence of trisomy 8 was 7.6%. Complete clinical follow-up data were available for 51 patients who were divided into three different categories: group 1: trisomy 8 as the sole cytogenetic anomaly (n = 20); group 2: trisomy 8 in addition to favourable chromosome aberrations (t(8;21)(q22;q22), t(15;17)(q22;q21), inv(16)(p13q22)) (n = 10); and group 3: trisomy 8 accompanied by other anomalies, in most cases of complex type (n = 21). Complete remission (CR) rates were 70%, 90% and 67% for groups 1, 2 and 3, respectively. Event-free survival (EFS) at 3 years differed significantly between patients with trisomy 8 only (37.5%), patients with trisomy 8 in combination with favourable aberrations (55.0%) and patients with trisomy 8 and other accompanying anomalies, mostly complex chromosome aberrations (9.0%) (group 1 v group 2: P=0.12; group 1 v group 3: P=0.005; group 2 v group 3: P=0.05). In this study patients with +8 as the sole cytogenetic anomaly had an intermediate prognosis, patients with +8 in addition to favourable chromosome aberrations maintained a good clinical outcome, and patients with +8 in combination with other abnormalities showed the worst prognosis.

A case of atypical myelodysplastic syndrome with micromegakaryocytes, normal platelet count, and t(3;12)(q21;p13) with inv(3)(q21q26)

A 49-year-old woman patient with atypical myelodysplastic syndrome (MDS) showing a der(3)t(3;12)(q21;p13), and der(12)t(3;12)(q21;p13)inv(3)(q21q26) as an acquired chromosomal abnormality in the bone marrow is described. The chromosomal breakpoints of the presented complex aberration with combination of the inv(3)(q21q26) and t(3;12)(q21;p13) were defined by fluorescence in situ hybridization (FISH) with yeast artificial chromosomes (YACs). The inv(3) is a relatively frequent chromosomal rearrangement in patients with myeloid malignancies and dysmegakaryopoiesis and t(3;12)(q26;p13) has also been reported as a recurrent abnormality in MDS and in blast crisis of chronic myelogenous leukemia (CML). Whereas the t(3;12), inv(3), and t(3;3) are associated with a very poor prognosis, our patient surprisingly had a mild clinical course.

Activation of a novel gene in 3q21 and identification of intergenic fusion transcripts with ecotropic viral insertion site I in leukemia

We have identified a novel gene, GR6, located within the leukemia breakpoint region of 3q21, that is normally expressed in early fetal development but not in adult peripheral blood. GR6 is activated in the UCSD-AML1 cell line and in a leukemic sample, both of which carry a t(3;3)(q21;q26). In UCSD-AML1, we have also identified fusion transcripts between the ecotropic viral insertion site I (EVI1) gene in 3q26 and GR6 and between EVI1 and Ribophorin I that maps 30 kb telomeric to GR6 in 3q21. All fusions splice the 5' ends of the 3q21 genes into exon 2 of the EVI1 gene, an event that is similar to the normal intergenic splicing of MDS1-EVI1 and to those previously documented in leukemias with t(3;21) and t(3;12), in which acute myelogenous leukemia 1-EVI1 fusions and ETV6-EVI1 fusions, respectively, occur. The Ribophorin I-EVI1 fusion in particular may be a common occurrence in t(3;3).

Morphological and cytochemical findings in 150 cases of T-lineage acute lymphoblastic leukaemia in adults. German Multicentre ALL Study Group (GMALL)

We evaluated the morphological findings in 150 consecutive cases of T-lineage acute lymphocytic leukaemia (T-ALL). Cytochemistry including PAS staining and acid phosphatase reaction proved of limited value for the diagnosis of ALL. The diagnosis of acute leukaemia was easy to establish in most instances. However, in a few cases the leukaemic cells were difficult to recognize as blasts. The nuclei of such cells showed condensed chromatin and nucleoli were lacking, and was encountered particularly in thymic ALL. Basophilic cytoplasm combined with prominent vacuolization suggestive of mature B-ALL (ALL-L3 type), was observed in 16 cases. Other features, however, such as cell size, polymorphism, chromatin structure, sparse cytoplasm or focal positivity for acid phosphatase, excluded a diagnosis of ALL-L3 in those cases. Distinction from hybrid leukaemia was difficult in 20 cases, because of a low percentage of peroxidase-positive blasts or other features which suggested a separate myeloid leukaemia component. In nine of these the hybrid nature of the leukaemia was considered as certain on the basis of morphology. Seven cases had been diagnosed as biphenotypic with coexpression of myeloid and lymphoid markers by immunological techniques. In conclusion, our analysis showed some serious pitfalls of the morphology in T-ALL, clearly indicating the need for immunological analysis of the leukaemic cells. However, morphology remains an essential component of the diagnostic repertoire, especially when the marrow is difficult to aspirate and in cases with equivocal immunological findings. Furthermore, recognition of a separate myeloid leukaemic component in addition to the lymphatic one requires a morphological analysis.

Prognostic significance of additional chromosome abnormalities in adult patients with Philadelphia chromosome positive acute lymphoblastic leukaemia

The clinical and biological significance of additional chromosome aberrations was investigated in a large series of 66 adult patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia (ALL). Additional chromosome changes were observed in 71% of the cases. 9p abnormalities were identified in 26%, and monosomy 7 as well as hyperdiploid karyotypes 50 were both found in 17% of cases. 9p anomalies were characterized by a low complete remission (CR) rate (58%) and an extremely short median remission duration (MRD: 100 d). In patients with monosomy 7, the poor treatment outcome was confirmed (CR rate 55%: MRD 113 d). In contrast, all patients with hyperdiploid karyotypes 50 achieved CR, and the overall survival was superior to all other Ph-positive ALL patients except those without additional chromosome aberrations. Exclusive rearrangement of the minor breakpoint cluster region of the BCR gene and lack of coexpression of myeloid-associated antigens in cases with 9p anomalies as well as a high frequency of rearrangements of the major breakpoint cluster region of the BCR gene in patients with monosomy 7 (89%) further substantiated that additional chromosome aberrations may characterize distinct subgroups of Ph-positive ALL. Moreover, the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph-positive patients has become evident due to variant Ph translocations in 3%, and negative PCR assays in 4% of the cases.

Refined chromosomal localization of the human thrombopoietin gene to 3q27-q28 and exclusion as the responsible gene for thrombocytosis in patients with rearrangements of 3q21 and 3q26

Thrombocytosis is a characteristic clinical feature in patients with myelocytic malignancies and chromosomal rearrangements of 3q21 and 3q26, sometimes called the '3q21q26 syndrome'. The function of thrombopoietin (TPO) in megakaryocytopoiesis and thrombopoiesis as well as its chromosomal location, marked TPO as a candidate gene for malignancies with 3q rearrangements combined with dysmegakaryopoiesis. In this study 12 cases with inv(3)(q21q26) or t(3;3)(q21;q26) were analyzed by means of PFGE, but no rearrangements near the TPO locus were detectable. Six YACs containing the TPO locus were isolated and characterized. By dual color in situ hybridization using a YAC from 3q26 containing the EVI1 gene and a YAC from the TPO locus, the localization of the human TPO gene could be refined to 3q27-q28 about 15-20 Mbp telomeric to the 3q26 breakpoints occurring in myeloid malignancies. TPO levels were analyzed in the serum of three patients and were found to be in the normal range. These results confirm the findings of two previous studies that thrombopoietin expression is not the main cause of thrombocytosis in the 3q21q26 syndrome.

Prognostic significance of additional chromosome abnormalities in adult patients with Philadelphia chromosome positive acute lymphoblastic leukaemia

The clinical and biological significance of additional chromosome aberrations was investigated in a large series of 66 adult patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia (ALL). Additional chromosome changes were observed in 71% of the cases. 9p abnormalities were identified in 26%, and monosomy 7 as well as hyperdiploid karyotypes 50 were both found in 17% of cases. 9p anomalies were characterized by a low complete remission (CR) rate (58%) and an extremely short median remission duration (MRD: 100 d). In patients with monosomy 7, the poor treatment outcome was confirmed (CR rate 55%: MRD 113 d). In contrast, all patients with hyperdiploid karyotypes 50 achieved CR, and the overall survival was superior to all other Ph-positive ALL patients except those without additional chromosome aberrations. Exclusive rearrangement of the minor breakpoint cluster region of the BCR gene and lack of coexpression of myeloid-associated antigens in cases with 9p anomalies as well as a high frequency of rearrangements of the major breakpoint cluster region of the BCR gene in patients with monosomy 7 (89%) further substantiated that additional chromosome aberrations may characterize distinct subgroups of Ph-positive ALL. Moreover, the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph-positive patients has become evident due to variant Ph translocations in 3%, and negative PCR assays in 4% of the cases.

Acute myeloid leukemia with translocation (8;21). Cytomorphology, dysplasia and prognostic factors in 41 cases. AML Cooperative Group and ECOG

The translocation t(8;21) is one of the most common structural aberrations in acute myeloid leukemia (AML). Excellent response rates and a better relapse-free survival have been described. We analyzed specific morphologic and cytochemical features including dysplasia and other prognostic factors in 41 patients with AML and t(8;21) who underwent aggressive chemotherapy in two national cooperative group studies. Five patients were classified as AML M1 and 36 as AML M2 according to the FAB criteria. Auer rods were detected in 28 patients (68%), however in only 16 patients were they "thin and elongated" as has been described as typical for t(8;21). The presence or absence of Auer rods did not appear to be associated with disease-free survival in this sample. Dysgranulopoiesis was detected in 31/41 patients (90%); five of these patients additionally had dyserythropoiesis (12%). In six cases (15%), dysmegakaryopoiesis was seen in combination with dysgranulopoiesis. Only one patient had trilineage dysplasia. Dysplastic features had no influence on prognosis. Additional cytogenetic abnormalities were detected in 24/41 patients. Twelve male (48%) and four female (25%) had a loss of a sex chromosome. This was correlated with a better disease-free survival (p = 0.039). The complete remission rate (CR) to chemotherapy was 90%. The early death rate was 10%. Disease-free survival of the complete responders was 60% at two years with no relapses observed in ten patients with 2-6 years of follow up. This favorable disease-free survival was observed with a variety of post-induction regimens and t(8;21) had been detected as an independent factor for good prognosis. The need for very intensive therapy, such as bone marrow transplantation, is unanswered at this time.

Incidence and implication of additional chromosome aberrations in acute promyelocytic leukaemia with translocation t(15;17)(q22;q21): a report on 50 patients

Acute promyelocytic leukaemia (APL) is characterized by the translocation t(15;17)(q22;q21). Usually t(15;17) is the sole cytogenetic abnormality, but some patients show other chromosome aberrations in addition to t(15;17). The influence of additional chromosome aberrations on the clinical outcome of patients with t(15;17) is unclear. We have analysed 50 cases of APL carrying the translocation t(15;17). Additional chromosome aberrations were observed in 17/47 patients (36%) studied at initial diagnosis and in all three patients studied at relapse. In nine cases (18%) an additional chromosome 8 and in six cases (12%) an isochromosome of the long arm of the derivative chromosome 17 was observed. Various structural rearrangements in addition to t(15;17) were detected in nine patients (18%). Clinical follow-up data were available for 44 patients studied at diagnosis. A complete remission (CR) was achieved in 34 patients (77%). 10 patients (23%) died within 1 month after diagnosis due to infection or bleeding, eight (24%) relapsed within 10-18 months after initial diagnosis. 28 patients are alive 2-93 months after diagnosis (25 in first CR, two in second and one in third CR) (median follow-up 18.5 months). Bone marrow transplantation was performed in six patients (three in first CR, two in second CR, one in third CR), all are alive and in CR. An influence of secondary chromosome anomalies on prognosis was not observed. However, if a higher rate of long-term remission can be reached, specific secondary chromosome aberrations might turn out to be of prognostic value.