Trisomy 11 in chronic myelomonocytic leukemia: report of two cases and review of the literature

Adult chronic myelomonocytic leukemia with trisomy 11: a case report

Chronic myelomonocytic leukemia (cmml) is an indolent disease in the category of myelodysplastic and myeloproliferative neoplasms, which can often evolve into acute leukemic neoplasms. Although cytogenetic abnormalities such as trisomy 8 or absence of chromosome Y are well known, few reports about cmml with trisomy 11 have been published. Here, we report a case of cmml with trisomy 11 as the sole chromosomal abnormality, resulting in a very poor outcome. Based on a bone marrow specimen, cmml-1 with trisomy 11 was diagnosed in a 79-year-old man presenting with anemia and atypical peripheral blood cells. Because of the patient's age, he was followed without receiving anticancer treatment. Two months after his diagnosis, the patient's leucocytosis and anemia rapidly worsened, with increasing numbers of immature peripheral cells, which was strongly suggestive of leukemic transformation. Because of acute kidney injury superimposed on chronic kidney disease that led to poor performance status, cytotoxic chemotherapy was not considered feasible, and the patient was transferred to a hospice care facility.

Trisomy 11 in myelodysplastic syndromes defines a unique group of disease with aggressive clinicopathologic features

Trisomy 11 in myelodysplastic syndromes (MDS) is rare, with undefined clinical significance and is currently assigned to the International Prognostic Scoring System (IPSS) intermediate-risk group. Over a 15-year period, we identified 17 MDS patients with trisomy 11 either as a sole abnormality (n=10) or associated with one or two additional alterations (n=7), comprising 0.3% of all MDS cases reviewed. Of 16 patients with Bone Marrow material available for review, 14 (88%) patients presented with excess blasts, 69% patients evolved to acute myeloid leukemia (AML) in a 5-month median interval and the median survival was 14 months. For comparison, we studied 19 AML patients with trisomy 11 in a noncomplex karyotype, of which, a substantial subset of patients had morphologic dysplasia, and/or preexisting cytopenia(s)/MDS. Genomic DNA PCR showed MLL partial tandem duplication in 5 of 10 MDS and 7 of 11 AML patients. A review of literature identified 17 additional cases of MDS with trisomy 11, showing similar clinicopathologic features to our patients. Compared with our historical data comprising 1165 MDS patients, MDS patients with trisomy 11 had a significantly inferior survival to patients in the IPSS intermediate-risk cytogenetic group (P=0.0002), but comparable to the poor-risk group (P=0.97). We conclude that trisomy 11 in MDS correlates with clinical aggressiveness, may suggest an early/evolving AML with myelodysplasia-related changes and is best considered a high-risk cytogenetic abnormality in MDS prognostication.

Screening for MLL tandem duplication in 387 unselected patients with AML identify a prognostically unfavorable subset of AML

Partial tandem duplications of the MLL gene have been associated with trisomy 11 in acute myeloid leukemia (AML) and recently, have also been reported for karyotypically normal AML. In order to test the incidence and prognostic importance of this molecular marker, we have analyzed eight cases of AML with trisomy 11 and 387 unselected consecutive cases with AML for partial duplications of the MLL gene. Patients with normal karyotypes and those with various chromosome aberrations were included. De novo as well as secondary leukemias including all FAB subtypes were analyzed. Performing a one-step RT-PCR with 35 cycles using an exon 9 forward primer and an exon 3 reverse primer partial tandem duplications of the MLL gene were demonstrated in 3/8 (37.5%) patients with trisomy 11. In addition, 13/387 (3.4%) of unselected cases revealed a tandem duplication. Ten of these 13 cases were cytogenetically normal, the other three cases had < or =2 additional chromosomal alterations. Sequencing of the RT-PCR products of all 16 positive cases revealed fusions of MLL exon 9/exon 3 (e9/e3) (six cases), e10/e3 (three cases), e11/e3 (four cases) or combinations of differentially spliced e10/e3 and e11/e3 (three cases) transcripts. The duplications were confirmed by genomic long range PCR and Southern blot hybridization. Twelve cases with the MLL duplication were de novo myeloid leukemia, one was a secondary AML after MDS, three were therapy-related AML (t-AML). Of the 16 MLL-duplication positive cases, seven were classified as FAB M2, two as M1, five as M4, one as M0, one as M5b. The mean age was 62.3 years for patients with MLL duplication vs 50.3 years for the control group. Of 15 adult patients, 12 received treatment. Of these, three were nonresponders, five had early relapse (< or =6 months), four relapsed between 7 and 12 months. Median survival and relapse-free interval of the MLL duplication positive group was significantly worse than those of an age-matched karyotypically normal control group. In conclusion, MLL tandem duplications (1) are less common than previously reported; (2) are preferentially observed in AML with normal karyotypes, but can also be found in the presence of chromosome alterations; (3) are not strongly associated with an FAB subtype; (4) were not observed with the prognostically favorable t(8;21), inv(16), and t(15;17), other recurrent translocations, or in complex karyotypes; and (5) identifies a subgroup of patients with an unfavorable prognosis.

Trisomy 11 and a complex t(11;11;22) in a patient with acute myelomonocytic leukemia (AML-M4) following myelodysplasia (MDS): a cytogenetic study of a mechanism of leukemogenesis

We describe a 73-year-old man diagnosed with acute myelomonocytic leukemia (AML-M4) following myelodysplasia with trisomy 11 and with a t(11;11;22). This is the first case with both abnormalities present in the same cells and with the t(11;11;22) involving a chromosome 11 already duplicated at 11q23. This band contains the MLL gene that undergoes partial tandem duplication in patients with +11, which is "promiscuous," being translocated with a large number of genetic partners. Our patient had a complex karyotype that was completely defined by in situ hybridization. This technique demonstrated that the t(11;11;22) derivative with a duplication of band 11q23 carried from three to four copies of MLL. Two copies of the gene were close to each other and centromeric to the break-point region. Therefore, a partial tandem duplication of the MLL gene might have happened before the occurrence of t(11;11;22). Considering the associated chromosome defects, the monosomy for the long arm of chromosome 7, due to an unbalanced translocation t(7;17), further underlines the possibility that a partial tandem duplication of the MLL gene might have taken place.

Clinical characteristics of patients with de novo acute myeloid leukaemia and isolated trisomy 11: a Cancer and Leukemia Group B study

Isolated trisomy 11 is the third most common sole trisomy in de novo acute myeloid leukaemia (AML). However, only 49 cases have been published, and for only a fraction of these cases has full description of clinical and haematological features been provided. As a result, little is known about the clinical characteristics of de novo AML patients with solitary trisomy 11. We have identified 13 patients (0.9%) with isolated trisomy 11 among a total of 1496 consecutive adult patients successfully karyotyped as part of a prospective Cancer and Leukemia Group B (CALGB) cytogenetic study (CALGB 8461). Nine patients (69%) were over the age of 60 (range 29-73 years). Eight patients (62%) were diagnosed with AML of FAB M2 subtype, three patients (23%) had FAB M1 AML and one patient each had AML of FAB M0 and M7, respectively. Seven patients (54%) had high, >100 x 10(9)/l, platelet counts (median 102 x 10(9)/l; range 17-207 x 10(9)/l). All patients received CALGB induction therapy with standard doses of cytarabine and daunorubicin. Six patients (46%) achieved a complete remission (CR). The median CR duration was 17.5 months (range 8.7-49.8). Only one patient, who underwent bone marrow transplantation in first CR, continues in initial CR. The median survival was 14.3 months (range 0.5-50.7); only one patient survives. We conclude that de novo AML with isolated trisomy 11 is predominantly associated with older age, M2 and M1 FAB subtypes, high platelet count and few long-term disease-free survivals, although it is currently unknown whether isolated trisomy 11 constitutes an independent prognostic factor.

Minimal residual disease in acute monocytic leukemia patient with trisomy 11 and partial tandem duplication of MLL

We studied MLL rearrangements in five patients with myeloid hematologic malignancies with trisomy 11. Two had acute monocytic leukemia (AMoL), one had chronic myelomonocytic leukemia, one had refractory anemia, and the other had juvenile chronic myelogenous leukemia. Only one patient, a 15-year-old boy with AMoL and simple trisomy 11, showed rearrangement of MLL. He did not respond to chemotherapy, and successfully underwent bone marrow transplantation, but suffered a relapse 22 months later. Reverse transcription-polymerase chain reaction (RT-PCR) and sequencing analyses of bone marrow cells revealed a tandem duplication of MLL, and his relapse was predictable by sequential RT-PCR studies before it was clinically evident. Of 16 acute myeloid leukemia patients with trisomy 11 and rearrangement of MLL reported, our patient was the youngest in age and the only one with AMoL.

Tandem duplication of the MLL gene in myelodysplastic syndrome-derived overt leukemia with trisomy 11

Trisomy 11 as a sole chromosomal abnormality is a rare aberration observed in myelodysplastic syndrome (MDS) or acute myeloblastic leukemia (AML). Recently a partial tandem duplication of the MLL gene, located on chromosome band 11q23, has been identified in de novo AML with trisomy 11. We describe a 72-year-old woman suffering from MDS-derived overt leukemia with trisomy 11 and a tandem duplication of the MLL gene. At first the patient was found to have myeloblasts with Auer rods in the peripheral blood and diagnosed as MDS, refractory anemia with excess of blasts in transformation (RAEB-T). After 2 months a picture of overt leukemia (AML; M2) developed as shown by an increased number of myeloblasts. Various chemotherapy regimens had little effect, and she died of disease progression 15 months after admission. During her clinical course, the chromosome analyses consistently showed 47,XX, +11. Southern blot analysis of leukemic blasts on admission and in accelerated phase revealed identical rearranged bands of the MLL gene. Fluorescence in situ hybridization analysis excluded the possibility of masked translocation of the MLL gene to other chromosomes. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using a forward exon 6 primer and a backward exon 3 primer demonstrated an in-frame fusion of exon 8 with exon 2. Our results indicated that a partial tandem duplication of exons 2-8 of the MLL gene could be observed in MDS-derived overt leukemia as well as de novo AML with trisomy 11.

Correlation of cytogenetic results with immunophenotype, genotype, clinical features, and ras mutation in acute myeloid leukemia. A study of 235 Chinese patients in Taiwan

Of 235 consecutive patients with de novo acute myeloid leukemia (AML), clonal chromosomal abnormalities were detected in 151 (64%) of them. Twenty-four of the 71 patients with M2 AML had t(8;21), 35 of the 36 M3 patients had t(15;17), and 11 of the 45 M4 leukemia disclosed inv(16). Six of the eight patients with 11q23 abnormality had M4 or M5 subtype of leukemia. The incidence of t(15;17) and t(8;21) was higher in our patients than in patients from most Western countries. Immunophenotyping was performed on 197 patients. Patients with t(15;17) were associated with negativity to HLA-DR, CD11b, and CD34. Patients with t(8;21) expressed CD13 and CD33 less frequently than other patients, but all showed CD15 positivity. Coexpression of lymphoid-associated antigens on the leukemic blasts was detected in 52 patients (26%), including all 7 patients with t(9;22), 3 of the 8 patients with t/del(11)(q23), 2 of the 25 patients with t(15;17), and 2 of the 22 patients with t(8;21). Seven (35%) of the 20 patients coexpressing lymphoid markers showed immunoglobulin heavy chain or T-cell receptor beta-chain gene rearrangements, while only 2 (4%) of the 53 patients without lymphoid antigen expression did so. Patients with inv(16), t(8;21), and t(15;17) had a better prognosis than other patients. Of all surface antigens tested, only CD15, CD11b, and HLA-DR were of prognostic value: CD15 with a higher complete remission (CR) rate and CD11b or HLA-DR with a shorter CR duration. N-ras mutations were detected in 7 (18%) of the 40 patients in the study, including two of the three patients with inv(16). This study demonstrated differences in clinical features, immunophenotypes, and genotypes among different cytogenetic subgroups.

Trisomy 11: an association with stem/progenitor cell immunophenotype

The clinicopathological features and the prognostic significance of acute myeloid leukaemia (AML) with trisomy 11 are currently unknown. In this study we describe 15 adult AML cases with trisomy 11. Trisomy 11 was the sole chromosomal anomaly in eight cases; the remaining seven cases were characterized by +11 in association with other karyotypic aberrations. Patients ages ranged from 34 to 79 years. 12 patients were male; three were female. Although there was no correlation of trisomy 11 with any specific FAB subgroup [M2 (n = 7), M1 (n = 5), M4/5 (n = 2), M3 (n = 1)] less mature forms predominated. Immunologically, the leukaemic blasts showed a strikingly consistent stem cell phenotype with expression of HLA-DR, CD34 and the myeloid antigens (CD15, CD33 and/or CD13). In addition, two cases expressed the B-cell associated antigen CD19. The presence of trilineage dysplasia, suggesting the presence of an underlying myelodysplasia (MDS), was observed at presentation in five cases; in another case MDS was evident at relapse only. Unexpectedly, MLL gene rearrangements were observed in two of four cases characterized by trisomy 11 as the sole karyotypic abnormality; however, MLL aberrations were not identified in three cases with trisomy 11 accompanied by other karyotypic anomalies. The majority of patients in each subgroup (i.e. those with and without additional cytogenetic abnormalities) achieved a short first complete remission (CR) (mean 8 months) and failed to obtain a second CR. Only one patient in each trisomy 11 subgroup is in a continuous CR for > 34 months. These findings suggest that trisomy 11 leukaemia is characterized by a stem/progenitor cell immunophenotype with poor response to standard chemotherapeutic regimens and an unfavourable prognosis.

Involvement of erythrocytic and granulomonocytic lineages by trisomy 11 in two cases of acute myelomonocytic leukemia with trilineage myelodysplasia. An interphase cytogenetic study

To study the cytologic profile and lineage involvement in acute myeloid leukemia (AML) with trisomy 11, cytologic, cytogenetic, and interphase cytogenetic studies were performed at presentation in two cases of acute myelomonocytic leukemia (AML-M4). Patient 1 had +11 as the sole chromosome aberration in 16/20 karyotypes whereas two related clones with +11 in all abnormal metaphases (14/18) were detected in patient 2. A proportion of interphase cells with three signals, comparable to the proportion of abnormal metaphases, was detected by fluorescent in situ hybridization (FISH) in these patients. Morphologic aberrations of the nonblast cell population affecting multiple cell lineages, along with a circulating minor megakaryoblastic component, were observed at diagnosis in both patients. By separation of bone marrow cells over a density gradient of Percoll two cell fractions were obtained, the former containing more than 80% erythroid precursors (collected at a density of 1065-1075 mg/ml), the latter containing more than 78% blast cells plus granulomonocytic precursors (collected at a density of 1060-1055 mg/ml). FISH documented the presence of a majority of interphase nuclei with three signals in the erythroblast-enriched cell fraction and in the blast-enriched cell fraction. It is concluded that cytologic features, as well as interphase cytogenetic findings on enriched cell fractions, suggest the occurrence of multipotent stem cell involvement in AML-M4 with +11.

Chromosome aberrations in CD34-positive acute myeloid leukemia. Correlation with clinicopathologic features

Morphologic, immunologic, and cytogenetic features were studied in 30 newly diagnosed patients with CD34-positive (CD34+) de novo acute myeloid leukemia (AML) in comparison with 30 patients with CD34-negative (CD34-) AML. Karyotype at diagnosis was abnormal in 25/30 CD34+ AML patients, of which nine had major karyotype aberrations (MAKA). Clonal chromosome changes were detected in 9/30 patients with CD34- AML. The most frequent chromosome aberration in CD34+ patients was -5/5q-, an aberration showing a strong association with the M2 FAB subtype of AML. Other recurring chromosome changes involved chromosome 16q (four cases) and chromosome 17p (three cases). Total or partial monosomy 7q was detected in three cases. Among CD34- AML, two patients had the classical t(15;17) and two had structural aberrations of 6q. Among patients with CD34+ AML, nine had MAKA in association with trilineage myelodysplasia (TMDS). TMDS was infrequent in CD34+ AML without MAKA and in CD34- AML. Complete remission (CR) was achieved in 8/30 CD34+ AML (26%), as compared with 22/30 CD34- AML (73%), and median survival was 2 months in the former group and 8 months in the latter. No patient with CD34+ AML and MAKA achieved CR, whereas 8/21 CD34+ AML without complex chromosome changes or with normal karyotype achieved CR. In conclusion, a distinct cytogenetic profile may be associated with CD34+ AML. Cytogenetic findings in CD34+ AML may be clinically relevant in that they may disclose a subset of patients with MAKA with a low CR rate.

Clinical review on features and cytogenetic patterns in adult acute myeloid leukemia with lymphoid markers

Cytogenetic patterns in correlation with cytologic, biomolecular and clinical findings were studied in 45 adult patients with AML expressing at least one of the following lymphoid associated markers (LM): CD2, CD7, CD10, CD19, CD22, TdT. Four cytogenetic groups were recognized: group I, including 8 patients with 11q23 rearrangements; group II including 5 patients with the Ph chromosome; group III, with 19 patients and aberrations of the "myeloid type" including 4 cases with aberrations of chromosome 13, 3 cases with 1q and 7q anomalies, 2 cases with trisomy 11q; group IV, including 13 patients with normal karyotype. Patients showing extensive lineage infidelity were encountered more frequently in cytogenetic groups I and II than in groups III and IV. Two of 4 cases with aberrations of chromosome 13 showed two or more lymphoid features either at immunophenotyping or at biomolecular analysis of the configuration of lg and TCR genes. Patients with 11q23 rearrangements and with the Ph chromosome were generally young, presented with high WBC count and had low complete remission rate. Survival in Ph chromosome positive patients was uniformly short. We conclude that, although there is no cytogenetic anomaly specific for AML with LM, chromosome findings may be clinically relevant in AML with LM. A morphologic, immunologic and cytogenetic classification of AML with LM may constitute a working basis for future studies aimed at a better definition of clinicopathological features and optimal treatment strategy for these leukemias.

Morphologic, immunologic and cytogenetic studies in acute myeloid leukemia following occupational exposure to pesticides and organic solvents

In order to analyze the correlation between environmental exposure and the clinicopathological picture in acute myeloid leukemia (AML), cytogenetic, cyto-immunologic and clinical studies were performed in 70 newly diagnosed AML patients, 30 of which were anamnestically exposed to pesticides (21 cases) or to organic solvents (9 cases). Clonal chromosome aberrations, with involvement of chromosome 5 and/or 7 were more frequently encountered among exposed patients. While the classical t(15;17), t(8;21) and t(9;11) were detected more frequently among non-exposed patients, other recurring chromosome changes in the exposed group were: rearrangements leading to total or partial monosomy 17p (5 cases), structural aberrations involving the band 16q22 (4 cases), trisomy 11q (2 cases), breaks involving bands 6p23, 7p14, 11q13 (2 cases each). Cytologically, trilineage myelodysplasia was observed in 21 exposed patients, whereas morphologic aberrations of the non-blast cell population were confined to a minority of cells in most patients non-exposed. Immunologic studies revealed positivity for the CD34 stem cell marker in 80% exposed patients vs 22% in the non-exposed group. Conventional chemotherapy achieved complete remission in 3/21 patients exposed and in 16/32 patients non-exposed. Median survival was 2 months in the former group and 9 months in the latter group. These findings show that AML following occupational exposure to pesticides and organic solvents may represent a distinct cytogenetic and clinicopathological entity.

Distinct cytogenetic and clinicopathologic features in acute myeloid leukemia after occupational exposure to pesticides and organic solvents

BACKGROUND

To study the correlation of environmental exposure to potentially mutagenic agents and the clinicopathologic picture in acute myeloid leukemia (AML), clinical features, morphologic characteristics, immunophenotype, and cytogenetics were studied in 59 patients with newly diagnosed AML.

METHODS

Based on interviews on occupational hazards and hobbies showing prolonged contact with pesticides (18 patients) and organic solvents (7 patients), 25 patients were categorized as "exposed". Thirty-four patients were categorized as "unexposed,", based on anamnestic findings.

RESULTS

Light microscopic studies showed myelodysplasia involving multiple cell lineages in all assessable patients with professional exposure to pesticides and organic solvents, whereas morphologic aberrations of the non-blast cell population were confined to a minority of cells in unexposed patients. These findings were confirmed by electron microscopic studies in 31 patients. Immunologic analysis showed the presence of a minor megakaryoblastic component in six exposed patients and showed positive findings for the CD34 stem cell marker in 85% of exposed patients, a figure significantly higher as compared with that for unexposed subjects. Cytogenetic studies confirmed the frequent occurrence of 5q and/or 7q aberrations in patients occupationally exposed (10 of 25 cases). Other recurring chromosome aberrations in the exposed group were 17p-, trisomy 11q, and translocation of 16q, 6p, 7p, and 11p, whereas the classic AML-specific translocations (i.e., t[15;17]; t[8;21]) were detected only in unexposed subjects. Conventional chemotherapy achieved complete remission in 1 of 19 exposed patients, as opposed to 14 of 29 unexposed patients, with a median survival of 2 months in the former group and 8 months in the latter.

CONCLUSIONS

Taken together, these findings document that AML in patients professionally exposed to toxic substances may represent a distinct cytogenetic and clinicopathologic entity. The clinicobiologic characteristics in these exposed patients are similar to the features of AML arising in patients with prior chemotherapy for another tumor, thus suggesting that similar transformation pathways may underlie leukemogenesis induced by cytotoxic drugs and by environmental exposure to some pesticides or organic solvents.

Karyotypically unrelated clones in acute leukemias and myelodysplastic syndromes

Karyotypically unrelated clones were observed in nine of 399 newly diagnosed acute leukemia or myelodysplastic syndrome (MDS) patients: two (3.0%) of 66 French-American-British classification (FAB)-M2 patients, five (12.5%) of 40 M5 patients, one (20%) of five chronic myelomonocytic leukemia (CMMoL), patients, one (12.5%) of eight refractory anemia with excess blasts in transformation (RAEBT) patients, and none (0%) of 177 acute lymphoblastic leukemia patients had such clones. Cytogenetically unrelated clones occurred more frequently in FAB-M5 than in the other subtypes of AL or MDS (p less than 0.01). Five (55%) of the nine patients had trisomy 8, two (22%) had partial deletion of the long arm of chromosome 5 and two had (22%) trisomy 11. Patients had short survival times (median 2 months, range 1-26 months) after detection of unrelated clones; eight of the nine failed to respond to chemotherapy. None of our patients had two phenotypically different leukemic cell populations or underwent phenotypic conversion of leukemic cells during the course of the disease. These findings suggest that the unrelated clones may have been derived from the common leukemic clone without microscopic chromosome changes, and that the different chromosome abnormalities of the unrelated clones may represent additional genetic changes in leukemogenesis.

Morphologic, immunologic and cytogenetic studies in erythroleukaemia: evidence for multilineage involvement and identification of two distinct cytogenetic-clinicopathological types

Clinical features, as well as morphology, immunophenotype and cytogenetics were retrospectively studied in 20 patients with an original diagnosis of erythroleukaemia (EL) reclassified according to the FAB criteria. Fifteen patients had de novo EL, five patients had therapy-related EL. Myelodysplasia preceded the onset of EL in eight cases and myelodysplastic features involving multiple haemopoietic lineages were observed at leukaemia presentation in all cases. Immunologic findings confirmed multilineage involvement, showing sub-population of cells expressing platelet-associated markers in more than 50% of cases tested and the presence of a myelomonocytic component, besides glycophorin A-positive cells. Cytogenetically, major karyotype aberrations (MAKA), defined by the presence of three or more aberrant events in the same clone, were observed in 14 cases, minor karyotype aberrations (MIKA) were observed in four cases and normal karyotype in two cases. No differences in the cytological-cytogenetic picture of our patients with de novo EL, and with therapy-related EL were found suggesting that aetiological factors and/or pathogenetic mechanisms common to EL and secondary leukaemia may exist. All patients with MAKA had leftward shift of erythropoiesis with proerythroblasts and basophilic erythroblasts usually representing more than 50% of all erythroid cells. In patients with MIKA or normal karyotype, maturatio of erythroid cells, though morphologically abnormal, was quantitatively preserved and early erythroblasts never exceeded 25% of erythroid cells. Clinically, the haemoglobin level at presentation, as well as in the proportion of patients achieving complete remission after chemotherapy, appeared to be lower in the maturation arrest-MAKA group as compared to the preserved maturation-MIKA/normal karyotype group. Median survival was shorter in the former group (3.5 months) than in the latter (median 13 months). Morphologic-immunologic-cytogenetic studies thus allow for the identification of two distinct cytogenetic-clinicopathological types of EL.

Trisomy 11 in myelodysplastic syndrome-derived acute myeloblastic leukaemias

Here we report 3 cases of trisomy 11 observed in 1 patient with secondary acute myeloblastic leukaemia and in 2 patients with spontaneous acute myeloblastic leukaemia. In all 3 patients, the picture of overt acute leukaemia arose following a clinically established myelodysplastic syndrome. These findings, together with the previously reported occurrence of trisomy 11 in myelodysplastic syndrome and in acute myeloblastic leukaemia, suggest that this abnormality can be considered specifically associated with myelodysplastic syndrome and with the subsequent and related acute myeloblastic leukaemia.

Myelodysplastic syndrome with trisomy 11 associated with polycythemia vera

A 52-year-old male with myelodysplastic syndrome (MDS) who had a prior history of polycythemia vera is reported. Chromosome analysis revealed that the bone marrow and blood cells at the MDS phase contained trisomy of chromosome 11 as the sole cytogenetic change. Trisomy 11 is rarely found in hematologic neoplasia, and all of the reported cases with trisomy 11 were diagnosed as having nonlymphocytic neoplasia. In this report, a correlation between the chromosome change and leukemia/MDS developed in polycythemia vera is discussed.

Cytogenetic analysis of different cellular populations in chronic myelomonocytic leukemia

Karyotypes of different cellular populations made after separation of bone marrow cells on a gradient of Percoll were evaluated in seven patients affected by chronic myelomonocytic leukemia diagnosed according to FAB criteria. Megakaryocytes, monocytic cells, and granulocytic and erythroid precursors were preferentially collected after centrifugation between density layers of 1045-1050 mg/ml, 1050-1060 mg/ml, and 1065-1070 mg/ml, respectively. The enriched cell fractions were cultured separately and submitted to cytogenetic investigation after short-term culture. Some chromosome aberrations (5q-,+8) were observed in all cellular fractions in three patients, thus providing cytogenetic evidence of the involvement of a common progenitor stem cell in this myelodysplastic disorder. On the other hand, chromosome abnormalities such as del(3)(q21) and del(11)(q23) appeared to be confined to the megakaryocytic and the monocytic fractions, respectively, in two patients. It is conceivable that lineage-restricted aberrations may develop as a consequence of a multistep clonal evolution and may show a close relationship with the hemopoietic differentiative processes.

Is trisomy 11 another nonrandom chromosomal anomaly in acute nonlymphocytic leukemia and myelodysplastic syndromes?

Four cases with trisomy 11 as the sole chromosomal anomaly are reported, three with de novo acute nonlymphocytic leukemia (ANLL) and one with a myelodysplastic syndrome (MDS) after treatment for multiple myeloma. In reviewing the literature, we found 19 additional cases with trisomy 11 as the sole cytogenetic defect. All patients except one were reported to have ANLL or MDS. Thus, it seems that trisomy 11 is another rare but nonrandom chromosomal anomaly in ANLL and MDS. So far, no apparently characteristic clinical or cytologic signs have been found in these cases.