Occurrence and type of chromosomal abnormalities in consecutive malignant monoclonal gammopathies: correlation with survival

Clinical implications of abnormalities of chromosomes 1 and 13 in multiple myeloma

Stratification of patients with multiple myeloma according to clinical severity was attempted by chromosomal analysis of 180 bone marrow specimens from 79 patients. The 79 patients were hospitalized and treated between 1994 and 1999. Abnormalities of chromosome 1 were detected at the initial medical examination in 8 (10%) of the 79 patients and were found during follow-up in additional 3 patients. Abnormalities of chromosome 1 were often detected in IgA (4/17) and IgD (2/4) multiple myeloma, while detection in IgG myeloma was relatively rare (4/42). The relevant break points were 1q12 in 5 patients and 1q42 and 1q21 in 3 patients, while 3 patients had trisomy 1. Deficiency of the long arm of chromosome 13 was detected in 6 patients, and this was believed to imply a prognosis. The long arm was completely deleted in 2 patients and part of the arm (13q10-14) was deleted in 4 patients. It is interesting that all 6 patients had concomitant abnormalities of chromosome 1. Although the initial response to treatment of patients having abnormal chromosomes 1 and 13 was comparable to that of patients having other chromosomal abnormalities or patients who were karyotypically normal, the median survival time was only 18 months (p < 0.02). Consequently, aggressive treatment such as early stem cell transplantation and so on is needed to improve their survival.

Cytogenetic features of multiple myeloma: impact of gender, age, disease phase, culture time, and cytokine stimulation

Relatively little is known about the cytogenetic features of multiple myeloma (MM) when compared to other hematologic malignancies. The reasons for this are most likely manifold, and include a low mitotic index of the malignant cells and the presence of cytogenetically cryptic abnormalities as well as of complex karyotypes with poor chromosome morphology. In the present study, we have investigated whether various culture conditions may influence the yield of abnormal metaphases in MM and, in the related plasma cell dyscrasias, monoclonal gammopathy of undetermined significance (MGUS) and plasmacytomas (PC). In addition, the possible impact of age, gender, and disease phase on the cytogenetic features has been analyzed. A total of 95 samples from 74 cases (68 MM, three PC, and three MGUS patients) were obtained for cytogenetic analysis. The samples were cultured either in conventional medium or in medium containing IL-6 and GM-CSF, and the culture times varied from 24 to 120 h. In total, 186 cultures were analyzed. Metaphase fluorescence in situ hybridization analysis using probes specific for 14q32, i.e. IGH rearrangements, could be performed in 57 of the 74 cases, and revealed 14q32 aberrations in 10 cases not seen by conventional G-banding. Abnormal karyotypes were detected in 77 (41%) of the 186 cultures, 46 (48%) of the 95 samples, and in 41 (55%) of the 74 patients, revealing a total of 20 chromosomal aberrations previously not reported in plasma cell dyscrasias. We found no evidence that gender, age, disease phase, culture time, or cytokine stimulation significantly influences the karyotypic features of MM.

Use of novel t(11;14) and t(14;18) dual-fusion fluorescence in situ hybridization probes in the differential diagnosis of lymphomas of small lymphocytes

Increasingly, molecular biologic techniques have become important in the diagnosis of non-Hodgkin lymphomas. In the differential diagnosis of lymphoma(s) of small lymphocytes (LSL), reliable detection of t(11;14) or t(14;18) would confirm the diagnosis of mantle cell lymphoma (MCL) or follicle center lymphoma (FCL), respectively. A total of 87 LSL cases (27 MCL, 39 FCL, 17 small lymphocytic lymphoma [SLL], 3 marginal zone lymphomas, and 1 paraimmunoblastic variant of SLL) were diagnosed by a combination of light microscopy, immunohistochemistry, and flow cytometric immunophenotyping. Interphase fluorescence in situ hybridization (FISH) for t(11;14) and t( 14;18) using dual-fusion probes (Vysis, Downers Grove, IL) was performed on touch (n = 69) or gravity (n = 18) preparations from these cases. Of 27 MCL cases tested, 25 (93%) had demonstrable t(11;14), none had t(14;18), and 2 were negative for t(11;14) and t(14;18). Twenty-five of 39 (64%) FCL cases had t(14;18), none had t(11;14), and the remaining FCL cases (14 cases [35%]) had neither t(11;14) nor t(14;18). All 17 (100%) SLL cases had neither t(11;14) nor t(14;18). All 3 (100%) marginal zone lymphoma cases had neither t(11;14) nor t(14;18). The case of paraimmunoblastic variant of SLL had t(11;14) and was negative for t(14;18). No discrepant [i.e., positive for both t(11;14) and t(14;18)] or false-positive cases were noted. Interphase FISH using these commercially available probes is a useful adjunct to light microscopy, immunohistochemistry, and flow cytometric immunophenotyping in the diagnosis of LSL. FISH can be performed successfully on archival single-cell preparations (touch preparations or gravity preparations) when fresh tissue is unavailable. No discordant or false-positive cases were identified.

The (11;14)(q13;q32) translocation in multiple myeloma. A morphologic and immunohistochemical study

We identified 24 cases of multiple myeloma with the t(11;14)(q13;q32). In 22 cases, the t(11;14)(q13;q32) was part of a complex karyotype, and in 2 cases it was an isolated abnormality. All patients had clinical and laboratory features consistent with multiple myeloma. The median degree of plasma cell involvement in the bone marrow was 60%, and in 10 cases, the plasma cells had a lymphoplasmacytoid appearance. Of the 24 cases, 21 had intermediate or high proliferative rates based on labeling index studies. Immunohistochemical studies performed on all bone marrow biopsy specimens showed strong cyclin D1 nuclear positivity in 19 cases. There also was strong cyclin D1 nuclear positivity found in 6 of 30 additional cases without the t(11;14)(q13;q32) demonstrated by routine cytogenetics. The t(11;14)(q13;q32) in multiple myeloma results in overexpression of the cyclin D1 protein, which can be demonstrated by immunohistochemical stain. The cyclin D1 stain results in the additional cases of multiple myeloma suggest that the t(11;14)(q13;q32) may be more common than previously thought and may be missed by routine cytogenetics, particularly if the proliferative rate is low.

Cytogenetics in multiple myeloma: a multicenter study of 24 patients with t(11;14)(q13;q32) or its variant

Twenty-two patients with multiple myeloma (MM) with a classical t(11;14)(q13;q32) and two complex variants also involving 11q13 and 14q32 regions are reported. We show that t(11;14) (q13;q32) is predominantly noticed in stages II and III and never in stage I patients. Translocation (11;14)(q13;q32) is predominantly observed in hypodiploid or pseudodiploid clones associated with total or partial monosomy of chromosome 13 and additional structural changes in chromosome 1. These translocations may be discovered not only in standard cultures (24-48 hours) without stimulation, but also in cytokine-stimulated cultures (granulocyte macrophage colony-stimulating factor and interleukin 6). The t(11;14)(q13;q32) as a primary or secondary event in MM is discussed, because, in one patient, it was only discovered at relapse.

Development of myeloma and secondary myelodysplastic syndrome from a common clone

We report the case of a 49-year-old woman who presented with a monoclonally IgG kappa expressing myeloma since October 1989. Four years later, after 24 cycles of Melphalan-containing chemotherapy, bone marrow (BM) cells of the patient cytologically revealed myelodysplastic changes for the first time. Cytogenetic examination of the BM obtained in January 1994 showed two clonally aberrant main lines. Each of them represented one of the hematological neoplastic diseases. The quantitatively major clone (MDS-clone) showed a deletion of the long arm of chromosome 7, typical for secondary myeloid disorders. The other clone (myeloma (MM) clone) was characterized by a reciprocal translocation between the short arm of chromosome 8, band q24, a region known to contain the c-myc gene, and the long arm of chromosome 2, band p12, where the Ig kappa gene is located. An unusual finding, however, was that an abnormality of the long arm of chromosome 16 could be detected in both obviously unrelated clones. In the further course of the disease, the MDS and MM clones could be detected, both of them showing cytogenetically a clonal evolution characterized by additional clonal abnormalities. Our data stress the significance of cytogenetics in detecting typical clonal abnormalities in different malignant hematological disorders and in detecting "clonal evolution" as an indicator of the progress of the disease. Moreover, our data suggest that MM and MDS may arise from a common stem cell, which may be characterized by a clonal cytogenetic abnormality.

Monosomy X as a recurring sole cytogenetic abnormality associated with myelodysplastic diseases

Solitary loss of the X chromosome is associated with Turner syndrome and not hematological disorders. We describe five patients with non-constitutional loss of the X chromosome as the sole cytogenetic abnormality in their bone marrow. Three of the five patients had myelodysplastic syndrome (MDS), one case had AML M-6 with evidence suggestive of an evolving MDS, and the last patient had a dysplastic marrow. A review of the literature identified sporadic reports of an association of monosomy X and several hematologic disorders, as well as a few solid tumors. In this series of patients, monosomy X as a sole non-constitutional cytogenetic abnormality in bone marrow is associated with myelodysplastic diseases. In addition, fluorescence in situ hybridization analysis with an X centromere probe indicated that monosomy X was present in erythroid precursors, myeloblasts, promyelocytes, myelocytes, metamyelocytes, granulocytes, and monocytes, while mature lymphocytes presented with two copies of the X chromosome. The molecular cytogenetic evidence supports the diagnosis of a myelodysplastic disorder in these cases and documents the potential role of FISH in hematological disease.

Fluorescence in situ hybridization (FISH) for retrospective detection of trisomies 3 and 7 in multiple myeloma

The malignant plasma cells of multiple myeloma (MM) have a low proliferative activity and therefore cytogenetic studies of the disease have been severely limited. We evaluated the role of fluorescence in situ hybridization (FISH) in the detection of numerical chromosomal abnormalities in early stages of myeloma and the applicability of the method to stored archival slides. Old air-dried bone marrow smears from 15 myeloma patients obtained at presentation were probed with alpha satellite DNA sequences to chromosomes 3 and 7. Numerical chromosome aberrations were found in eight (53%) of the patients, including six (of 12) with trisomy 7, and two (of eight) with trisomy 3. This study demonstrates that FISH is a sensitive method for the detection of numerical aberrations in myeloma and for the study of old slides for retrospective analysis.

Burkitt translocation (8;22)(q24;q11) in a patient with multiple myeloma

The prevalence of chromosomal abnormalities in multiple myeloma (MM) has been difficult to detect by karyotyping primarily because of the low proliferative rate of malignant plasma cells. The reported incidences of abnormal karyotypes range from 24% to 63% in bone marrows obtained from MM patients, with the higher rates being seen in aggressive disease [1-8]. Detection of abnormal karyotypes in MM has been associated with a poor prognosis. We report a MM patient with an 8;22 Burkitt translocation, the first such reported case.

Cytogenetic findings in 200 patients with multiple myeloma

Cytogenetic studies were performed in 200 consecutive patients with multiple myeloma and related disorders. Structurally or numerically abnormal clones were found in 63 patients (32%), including 8 of 45 untreated patients (18%), and 55 of 155 treated patients (35%). The abnormal karyotypes generally showed numerous numerical and structural aberrations and in some patients multiple abnormal clones. The most striking feature of patients with hyperdiploid karyotypes was the finding of consistent recurring trisomies for chromosomes 3, 5, 7, 9, 11, 15, 19, and 21, cosegregating together in many cases. Monosomy for chromosome 13 was the most common chromosome loss, occurring in 18 abnormal patients (29%), while interstitial deletions involving band 13q14 occurred in an additional 9 patients, indicating a loss of all or part of chromosome 13 in a high percentage of patients with abnormal karyotypes (43%). Structural aberrations of chromosome 1 were most frequent, occurring in 30 of 63 patients (48%), and involved almost equally the short and long arms. The single most frequent chromosome breakpoint involved band 14q32 and was found in 21 patients (33%), including 11 patients with a 14q+ chromosome, 8 with t(11;14)(q13;q32), and 2 with t(8;14)(q24;132).

Cytogenetic data in 41 patients with multiple myeloma. Karyotype and other clinical parameters

Cytogenetic data of 41 patients diagnosed with multiple myeloma (MM) are reported. In all samples, cytogenetic studies were made of short-term and B-cell-stimulated culture: 20 cases (48.8%) showed chromosome abnormalities; 14 karyotypes were hypo- or pseudodiploid, and six were hyperdiploid. The most frequent numerical changes affected chromosomes 7, 11, 5 (gains), 14, 20, and Y (losses). Chromosome structural rearrangements of 22q were noted in six patients. Other and recurrent cytogenetic abnormalities were changes involving chromosomes 1, 14, and 17. A significant relation was observed between presence of chromosome abnormalities and the following hematologic parameters: clinical stage III (p = 0.0212), bone marrow (BM) plasma cell infiltration greater than 30% (p = 0.0379), presence of bone lesions (p = 0.0051), and beta 2-microglobulin levels greater than 4,000 md/dl (p = 0.0194).

Chromosomal and in vitro culture studies in a case of primary plasma cell leukemia

We present a cytogenetic study of a case of primary plasma cell leukemia (PCL) whose plasma cells were cultured in vitro with different mitogens. Cytogenetic studies demonstrated a reduction of the genome, monosomy of chromosomes 8, 13, and 22 being the most frequent. Neither structural changes nor marker chromosomes were observed. The hypodiploid karyotype was confirmed and confined to the neoplastic clone (lambda positive cells) by the MAC (Morphology, Antibody, Chromosome) method, which allows a simultaneous study of chromosomes, cell morphology, and immunologic phenotype. Stimulating the culture of plasmocytes in vitro with IL-6 + PHA, only normal metaphases could be obtained; on the other hand, a large number of abnormal metaphases were observed with the use of LPS as a mitogen. A surprisingly high yield of metaphases was obtained in this case, contrary to the rule in the in vitro growth of plasmocytic proliferations. Possible explanations of this fact are considered.

Image analysis in multiple myeloma at diagnosis. Correlation with cytogenetic study

The DNA content of plasma cells (DNA Index or DI) was determined after Feulgen reaction using computed image analysis in 46 patients with multiple myeloma at diagnosis. Aneuploidy was found in 40/46 (87.0%) patients; 27 (58.7%) were hyperdiploid (DI = 1.05-1.45), 11 (24.0%) were hypodiploid (DI = 0.90-0.95), and two (4.3%) were biclonal. Cytogenetic study showed at least one abnormal mitosis in 21/46 (45.7%) cases. All patients with numeric changes had aneuploid DI, and thus confirmed DI > or = 1.05 and DI < or = 0.95 as good limits for aneuploidy with image analysis. Since abnormal karyotypes were observed mainly in stages II and III (55.6% and 54.5%, respectively) rather than in stage I (26.7%), aneuploid DI was found in most patients in all three stages, namely in all 15/15 (100%) patients in stage I. The prognostic value of aneuploidy was difficult to ascertain in our series. Hypodiploidy or DI > 1.15 was not especially associated with aggressive disease, as it was observed in 7/15 patients in stage I; however, with the same limits, patients with stages II and III were refractory to first-line chemotherapy. Image analysis is a highly sensitive method showing aneuploidy in most patients with MM at diagnosis and, in association with cytogenetic study, may help to better understand the pathogenesis of the disease. The independent prognostic value of aneuploidy was not fully established in this report.

Improved cytogenetic analysis of bone marrow plasma cells after cytokine stimulation in multiple myeloma: a report on 46 patients

Cytogenetic analysis was successfully performed in 46 consecutive myeloma patients (40 newly diagnosed and six relapsed patients). Karyotype was performed on bone marrow cells after long-term cultures (6 d) stimulated by GM-CSF, GM-CSF+IL6 or GM-CSF+IL6+IL3. Nineteen patients (41%) had cytogenetic abnormalities including 17/40 patients at diagnosis (42.5%) and 2/6 patients at relapse. Hyperdiploidy was found in 12 patients and hypodiploidy in four patients. Of the 17 newly diagnosed patients with cytogenetic abnormalities, five died from myeloma after 1-14 months and three other patients had primary drug resistance. Our results suggest that cytogenetic analysis after stimulation of cultures by cytokines detects clonal abnormalities in 40-50% of newly diagnosed myeloma patients and that these patients often have a short survival and/or primary drug resistance.

Use of fluorescence in situ hybridization for retrospective detection of aneuploidy in multiple myeloma

In malignancies with a low mitotic index such as multiple myeloma (MM), conventional cytogenetic studies may not be informative. This study's purpose was to assess specific numerical chromosomal aberrations in non-dividing MM cells by fluorescence in situ hybridization (FISH) of DNA chromosome probes on bone marrow smears. Old air-dried bone marrow smears from 18 MM patients were probed with alpha satellite DNA sequences for chromosomes 7, X, and Y, and a whole painting probe for chromosome 11. Plasma cells were identified by their morphologic characteristics so that counts of fluorescent signals in the nuclei of MM cells could be differentiated from those of normal marrow cells. Numerical chromosome aberrations were found in 66.7% of the cases (12 of 18), including 5 cases of trisomy 7, 2 cases of tetraploidy, 2 cases of monosomy X in females, 2 cases of disomy X in males, and 1 case of nullisomy Y. In addition, 2 of the 7 cases probed with chromosome 11 paint demonstrated 3 signals in about 15% of the cells. This study illustrates the advantages of FISH for interphase analysis of chromosome aberrations in slowly dividing cells, as well as the ability to use old slides for retrospective studies.

Chromosome studies in plasma cell leukemia and multiple myeloma in transformation

Four patients with plasma cell leukemia (PCL) and two with multiple myeloma (MM) in transformation had complex numerical and structural chromosome abnormalities. From data published in the literature, the cytogenetic patterns of 46 cases of PCL or MM in the leukemic phase are compared with chromosomal abnormalities found in MM. Although the spectrum of chromosomal abnormalities is comparable in both diseases, the incidence of chromosome abnormalities is higher in PCL than in MM. Hypodiploidy with monosomies for chromosomes 13, 16, 17, and 18 is also more frequent in PCL than in MM. A mutation within the TP53 gene was detected in one of the three patients studied molecularly.

Characterization of a human plasmacytoma line

The TH line was established by bringing tumour cells from a multiple myeloma patient into suspension culture and subsequently cloning them by limiting dilution. The cultured cells show marked heterogeneity; there are ultrastructural differences between small and large TH cells, particularly with respect to the rough endoplasmatic reticulum (RER). Karyotyping revealed chromosome numbers in the triploid range, with many structural abnormalities, at the 14q32 region among others. A t(14;18) could not be demonstrated. TH was shown to have germline and a rearranged allele for kappa light chain, and only a single rearranged gene for heavy chain immunoglobulin. TH expressed PCA-1, CD9, CD28 and CD38 antigens, HLA class II, RER and kappa light chain, but few or no other antigens associated with the B-cell lineage. Light chain kappa and trace amounts of IgG3 were found intracellularly as well as in culture supernatant. The addition of IL-6 to cultures of TH increased proliferation, as well as the secretion of kappa light chain and the membrane expression of CD28 and CD38 antigens. Because TH has relatively few B cell markers on its membrane, it may be useful for the induction of monoclonal antibodies specific for human plasma cells. It also provides a model for the demonstration that IL-6 can act as a paracrine growth and differentiation factor for cells of myelomal origin.

Cytogenetic studies in patients with multiple myeloma

Fourteen patients diagnosed as having multiple myeloma were studied cytogenetically. In eight patients a sufficient number of metaphases was obtained and four of them showed abnormal karyotypes of bone marrow cells. Hypodiploidy was a consistent finding, as was the involvement of chromosome 9.

Similar cytogenetic abnormalities in two cases of plasma cell leukemia

Plasma cell leukemia (PCL) is a very rare disease. We report two cases of PCL with complex chromosomal abnormalities: long arm trisomy and short arm partial monosomy of chromosome 1, a marker derived from chromosome 8, and monosomy 13 were found in both cases; other additional chromosome abnormalities were also present in each case. Bastard et al. reports two similar cases in this issue. Cytogenetic studies in PCL have seldom been reported in the literature: chromosomal abnormalities are most often complex: chromosomes 1, 8, 11, 13, and 14 are those most frequently involved. Such cytogenetic findings are observed in advanced multiple myeloma. Cytogenetic, clinical, and immunological findings observed in PCL and the advanced stage of multiple myeloma are arguments for the single origin of pathogenesis.

Ring chromosomes in hypodiploid and hypotetraploid clones from an elderly patient with plasma cell leukemia

We describe a 77-year-old woman who had with what appears to be the first case of plasma cell leukemia (PCL) with a ring chromosome of variable size. Of the three clones evident, two of them were abnormal: a 41,X,-X hypodiploid clone with rings of two different sizes, and a 81-82,XX hypotetraploid clone with a double-sized dicentric ring or variable double rings. Additional structural and numerical abnormalities included a 14q+ marker, deletions of two chromosomes 1 and monosomies 8 and 13, all previously reported in PCLs. Ring chromosomes have been associated with a poor prognosis, especially in elderly patients. The patient declined active treatment and died within 4 weeks of diagnosis.