Characteristic karyotypic pattern in T-cell lymphoproliferative disorders with reactive "angioimmunoblastic lymphadenopathy with dysproteinemia-type" features

We report the clinical, histological, immunophenotypic, and cytogenetic findings in ten patients with T-cell lymphoproliferative disorders demonstrating reactive "angioimmunoblastic lymphadenopathy with dysproteinemia (AILD)-type" features. Fifteen available specimens were diagnosed as atypical hyperplasias (four) or malignant lymphomas (11). The latter were classified as AILD-type (five), T-zone (four), lymphoepithelioid (one), and low-grade, unclassified lymphoma (one). Despite the histologic differences, all these lesions shared minor nuclear atypicalities and reactive AILD-type features such as prominent vascularity, plasma cells, eosinophils, macrophages, and residual germinal centers. All lesions were immunophenotyped as predominantly T cell. The chromosome pattern was characterized by the frequent presence of karyotypically unrelated abnormal clones and/or cells with nonclonal chromosome abnormalities, a large population of normal mitotic cells, and a high incidence of trisomies 3 and 5. Sequential cytogenetic and histologic studies in five patients revealed that atypical hyperplasia and lymphoma with AILD-type features shared the same cytogenetic characteristics, ie, an unstable coexistence of normal mitotic cells and small-clonal and/or nonclonal abnormal cells, and that histologic transformation from low-grade lymphoma to immunoblastic lymphoma was accompanied by a selective proliferation of abnormal clonal cells. The AILD-type histology and the characteristic karyotypic pattern may be the expression of a specific pathogenesis and may warrant the separation of these neoplasias from other peripheral T-cell lymphomas.     

Chromosome abnormalities in AIDS-associated lymphadenopathy

Cytogenetic studies were performed on direct and 24-hour culture preparations of eight lymph node biopsies from seven patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC)- associated lymphadenopathy in whom histological evidence of lymphoma was not detected. Three of these seven had chromosomal abnormalities, including chromosome instability in one and clonal chromosomal abnormalities in two; one of the latter was a t(8;14)(q24;q32). The remaining five showed normal karyotypes. Epstein-Barr virus (EBV) titers were elevated in all three patients that exhibited chromosome abnormalities, two of whom later developed malignant lymphoma. A control group of five patients with reactive lymphadenopathy not associated with AIDS failed to reveal chromosomal aberrations, but elevated EBV titers were present in two. These data are consistent with current views on the role of EBV and chromosome change in the development of lymphoma in immunodeficient states and suggest that karyotypically abnormal AIDS-related lymphadenopathy represents a prelymphomatous proliferation.     

Chromosome studies in adult T-cell leukemia in Japan: significance of trisomy 7

Chromosomes were studied in cells from 15 japanese patients with adult T-cell leukemia (ATL). Mitoses were obtained from unstimulated peripheral blood in 12 patients and a lymph node in one patient. In two other patients, mitotic cells were obtained solely from peripheral blood stimulated with phytohemagglutinin (PHA). Chromsomally abnormal cells were seen in 14 of the 15 patients. The abnormal cells had a modal number of chromosomes in near diploid range in 12 patients, and in near triploid and tetraploid range in the remaining 2 patients, respectively. Eight of the nine patients analyzed by Q-banding had clonal chromosome abnormalities. The most common abnormality was trisomy no.7 or 7q, which was seen in 5 cases and has been primarily observed in lymphoid neoplasms. A 14q+ marker chromosome was found in two patients and a Dq+ in one patient; loss of a sex chromosome was found in three patients. Most chromosomes were involved in gains, losses, or structural rearrangements, but abnormalities of no. 11, which have been frequently found in lymphoid malignancies, was not observed in our series. The significance of these chromosome abnormalities is discussed.     

rHuEpo administration in patients with low-risk myelodysplastic syndromes: evaluation of erythroid precursors' response by fluorescence in situ hybridization on May-Grunwald-Giemsa-stained bone marrow samples

The issue of whether, in patients affected by myelodysplastic syndromes (MDS), haematological response to cytokines, particularly to recombinant human erythropoietin (rHuEpo), is a phenomenon related to the stimulation of normal haemopoietic cells or to the differentiation of cells belonging to the abnormal clone remains an open question. To assess the pattern of response to rHuEpo treatment of bone marrow (BM) cells, we evaluated in 13 low-risk MDS patients with known cytogenetic abnormalities the number of cytogenetically normal and abnormal cells by conventional cytogenetic analysis (CCA) and by a fluorescence in situ hybridization (FISH) technique, enabling the simultaneous visualization of FISH chromosomal abnormalities in morphologically and immunophenotypically identifiable BM elements. Patients responding to rHuEpo presented a lower number of abnormal metaphases at diagnosis in comparison with patients who did not respond (22.74% vs 76.23%, P = < 0.001). This was confirmed by the combined morphological FISH analysis, showing that, before treatment, BM samples from patients responding to rHuEpo had a lower proportion of both FISH abnormal erythroid (36.48% vs 66.93%, P = 0.002) and myeloid (40.76% vs 67.70%, P = 0.014) elements than unresponsive patients. After rHuEpo treatment, responding patients presented a significantly lower proportion of FISH abnormal erythroid precursors than observed before treatment (16.93%vs 36.48%, P = 0.017). Likewise, in responding patients, a significantly lower proportion of FISH abnormal erythroid elements (16.93% vs 66.30%, P < 0.001) was detected in comparison with unresponsive patients. These findings provide evidence that, in low-risk MDS patients with known cytogenetic abnormalities, response to rHuEpo may be due to the proliferation of karyotypically normal erythroid precursors, possibly representing residual normal erythroid elements.     

Secondary Abnormalities of Chromosome 6q in B-Cell Chronic Lymphocytic Leukemia: A Sequential Study of Karyotypic Instability in 51 Patients

Although karyotypic abnormalities are well documented in B-cell chronic lymphocytic leukemia (B-CLL), few sequential cytogenetic studies have been done. In this study, peripheral blood lymphocytes from fifty-one patients with B-CLL were sequentially karyotyped over a mean interval of 13.8 months (range, one to 51 months). Cytogenetic clones were detected in 33/51 patients (66%) on initial study, including 17 patients with structural abnormalities of chromosome 13q14, and three patients with trisomy 12. Karyotypic evolution was documented in 22/51 patients (43%). The most common secondarily acquired chromosome aberrations were structural abnormalities of the long arm of chromosome 6 involving the region of 6q21-q24 (six patients). Four patients each had acquired structural abnormalities of 1q, 3p, 12q, and 13q. Disease progression, as measured by advance in Rai stage or death from the disease, was observed more often in the clonal evolution group than in the karyotypically stable group (11/22 vs. 5/29; P = 0.017). Patients with secondary abnormalities of 6q had a significantly decreased progression-free survival interval compared with other patients in the study (P = .023). The authors conclude that clonal karyotypic evolution is common in B-CLL, and that clonal evolution correlates with clinical disease progression. Furthermore, the poor outcomes previously attributed to CLL with 6q abnormalities may be related to the clonal acquisition of these abnormalities over time. Future studies should focus on the relevant genetic events underlying the clinical progression observed with karyotypic evolution of B-CLL. Am. J. Hematol. 59:223–229, 1998. © 1998 Wiley-Liss, Inc.     

难治性病毒感染和原发噬血细胞性淋巴组织细胞增多症相关基因突变研究

目的 研究难治性病毒感染或噬血细胞性淋巴组织细胞增多症(HLH)中免疫基因突变的发生率、类型及其临床特征.方法 采用基因测序方法 检测难治性病毒感染或HLH患者是否有原发性HLH相关的PRF1、UNC13D、STX11、STXBP2、SH2D1A和XIAP基因突变,并追踪其临床特点及转归.结果 共25例难治性病毒感染性疾病或HLH患者接受了基因突变筛查,其中13例检测到上述基因突变:PRF1突变6例,UNC13D突变3例,STX11、STXBP2、SH2D1A、XIAP突变各1例;其中6例起病表现为病毒相关性HLH,1例为原因不明HLH,4例为慢性活动性EB病毒(EBV)感染(CAEBV),2例为EBV相关性淋巴瘤.12例未检测出基因突变的患者中,4例为EBV相关HLH,其中1例发展为外周T细胞淋巴瘤,另8例为CAEBV.结论 原发性HLH相关免疫基因突变是难治性病毒感染或HLH的重要原因,大部分表现为HLH,部分患者以CAEBV或EBV相关淋巴瘤起病.基因检测是明确此类疾病诊断的有力证据.

Abstract：

Objective To study the type and corresponding clinical characteristics of primary hemophagocytic lymphohistocytosis (HLH) associated immune gene mutations in the refractory virus infection or HLH of unknown causes. Methods From December 2009 to July 2010, the patients with refractory virus infection or HLH of unknown causes were screened for the primary HLH associated immune genes mutations by DNA sequence analysis, including PRF1, UNC13D, STX11, STXBP2, SH2D1A and XIAP. The clinical characteristics and outcomes were followed up. Results Totally 25 patients with refractory virus infection or HLH of unknown causes were investigated for the 6 genes and 13 cases were found carrying gene mutations, composing of 6 of PRF1 mutation, 3 of UNC13D, and each one of STX11,XIAP, SH2D1A and STXBP2, respectively. Among the 13 cases with gene mutations, 5 suffered from Epstein-Barr virus associated HLH( EBV-HLH), 1 human herpes virus 7 associated HLH (HHV7-HLH),1 HLH without causes, 4 chronic activated EB virus infection (CAEBV) with 1 progressing to Hodgkin's lymphoma carrying abnormal chromosome of t ( 15; 17 ) (q22; q25 ) and hyperdiploid, 2 EBV associated lymphoma. Among the other 12 patients without gene mutation, 4 suffered from EBV-HLH with 1 progressing to peripheral T lymphoma, 8 suffered from CAEBV. Conclusions Primary HLH associated immune gene mutations are critical causes of refractory virus infection of unknown causes, most patients manifest as HLH,some cases appear in CAEBV and EBV associated lymphoma. DNA sequence analysis is helpful to early diagnosis and correct decision-making for treatment.     

Cytogenetic and immunologic characterization of mitotic cells in chronic lymphocytic leukaemia

Lymphocytes from 14 patients with chronic B-cell leukaemia (B-CLL) and one with chronic T-cell leukaemia (T-CLL) were studied by the MAC (Morphology, Antibodies, Chromosomes) method, which allows simultaneous analysis of the morphology, immunologic phenotype and karyotype of the same mitotic cell. Use of the MAC-method in present studies has yielded new information about the cytogenetics of CLL. Although most of the interphase cells from patients with B-CLL were positive for B-cell markers, many of the mitotic cells turned out to be T cells, supporting the notion that the cells studied by conventional chromosome analysis are often non-neoplastic T cells. In some B-CLL cases with normal karyotype in the conventional chromosome study, however, most of the mitotic cells were B cells, indicating that neoplastic B cells may also have a normal karyotype. The patient with T-CLL had normal karyotype even though most of the mitoses were T cells. The chromosome abnormalities found were restricted to cells with light chain clonality. Our results show that clonal chromosome abnormalities do occur in neoplastic B cells of patients with B-CLL.     

Haemophagocytic lymphohistiocytosis and Epstein–Barr virus: a complex relationship with diverse origins,expression and outcomes

Epstein–Barr virus (EBV) is a ubiquitous herpesvirus with rare but severe potential for lymphoproliferative complications. EBV is associated with a variety of presentations of haemophagocytic lymphohistiocytosis (HLH). HLH is a life-threatening hyperinflammatory syndrome that can occur in patients with genetic defects associated with dysregulation of the immune response (familial HLH) or arise in patients with underlying infection or malignancy (non-familial or secondary HLH). EBV can both serve as the incidental trigger of familial HLH or as the driving factor in patients with selective inherited vulnerability (e.g. X-linked lymphoproliferative disease). Alternatively, acute infection can idiosyncratically cause non-neoplastic HLH in patients without inherited predisposition (i.e. secondary HLH), while EBV-associated T/natural killer (NK)-cell lymphoproliferative disorders and lymphomas can cause neoplasia-associated HLH. The present review will discern between EBV-associated familial and non-familial HLH and highlight diagnostic and therapeutic considerations. Non-familial EBV-associated HLH is a major diagnostic dilemma, as it represents a diverse spectrum of disease ranging from highly curable (non-neoplastic EBV-HLH) to indolent but incurable (chronic active EBV) to acutely fatal (systemic EBV-positive T-cell lymphoma of childhood). Increased clinical awareness and understanding of this rare and potentially devastating subset of EBV-related complications is desperately needed to improve survival for patients with neoplasia-associated HLH.     

Chromosome aberrations in T lymphocytes carrying adult T-cell leukemia- associated antigens (ATLA) from healthy adults

Chromosomes were studied in cultured T lymphocytes carrying adult T- cell leukemia-associated antigens (ATLA) that were obtained from five Japanese anti-ATLA seropositive healthy adults. Chromosomally abnormal cells were observed in three of the five healthy adults, and these cells were clonal in two subjects. All cells examined in one subject had rearrangements of chromosome nos. 7 and 14. Clonal cells from the second had a minute chromosome of unknown origin. A few cells in the third had nonclonal rearrangements of chromosomes. Thus, ATLA-positive T lymphocytes in some anti-ATLA seropositive healthy people have chromosome aberrations.     

Bone marrow in vitro growth and cytogenetic studies in patients with FAB-classified primary myelodysplastic syndromes

Thirty-eight consecutive patients with a FAB-classified primary myelodysplastic syndrome (MDS) were investigated for in vitro growth of colony-forming units for granulocyte-macrophage precursors (CFU-GM) and cytogenetic analysis of bone marrow cells. Abnormal CFU-GM growth was found in 30 patients (79%), and clonal chromosome abnormalities were found in 13 patients (34%). The eight patients who showed normal CFU-GM growth were either cytogenetically normal (n = 5), or had a 5q-deletion (n = 3) as single or dominating karyotypic abnormality. Among the 30 patients with reduced or no colony growth, ten patients had a clonal chromosome abnormality. Leukemia developed in eight patients. None of them grew any CFU-GM colonies, and three of them were cytogenetically abnormal at the time of diagnosis of MDS. Analysis of the bone marrow in vitro growth for CFU-GM and the karyotype in patients with MDS emphasizes the close relationship between these disorders and manifest acute leukemia. Subgroups of MDS may be defined by a cytogenetic classification (e.g., the 5q-syndrome), and the CFU-GM growth pattern can be of value for predicting leukemic transformation.     

Fatal Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis with clonal karyotype abnormality

We report a case of Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis (HLH) with clonal karyotype abnormality. A 5-year-old boy was admitted to our hospital with persistent high-grade fever, hepatomegaly, and pancytopenia. Laboratory data disclosed a coagulation abnormality and severe liver damage. Clonal proliferation of EBV-infected cells was detected in the bone marrow by Southern hybridization, and bone marrow cells exhibited clonal chromosomal abnormality. Although the patient was treated with immunochemotherapy according to the HLH94 protocol, the disease recurred during the induction therapy, and the patient died of disseminated intravascular coagulopathy. Considering this aggressive and fatal clinical course, it is important to take intensive therapeutic measures if karyotype abnormality is noted in the treatment of EBV-HLH patients.     

Immunophenotypic analysis of Epstein-Barr virus (EBV)-infected CD8(+) T cells in a patient with EBV-associated hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe and often fatal condition characterized by uncontrolled activation of T cells and macrophages. In Epstein-Barr virus (EBV)-associated HLH (EBV-HLH), the pathogenic roles of ectopic EBV infection in the T-cell population and of clonal proliferation of EBV-infected T cells has been described. However, the immunophenotype of EBV-infected T cells has not been fully characterized. Here we describe a case of EBV-HLH presenting with a massive clonal proliferation of CD8(+) T cells with TCR VB14. Analysis of in situ hybridization for EBV-encoded small RNA1 showed that only CD8(+) T cells harbored EBV in this patient. The EBV-infected TCR VB14(+) CD8(+) T cells exhibited unique immunophenotypic features including lacked CD5 expression and a markedly bright expression of HLA-DR. After initiation of treatment with prednisolone, etoposide, and cyclosporin A, the percentage of infected cells declined progressively in parallel with other serum markers such as ferritin. These findings suggest that lacking expression of CD5 on CD8(+) T cells with specific TCR VB may serve as a useful marker of dysregulated T-cell activation and proliferation in EBV-HLH.     

Cytogenic characterization of primary refractory anemia.

Refractory anemia (RA) is the only myelodysplastic syndrome (MDS) devoid of quantitative marrow diagnostic criteria. The diagnosis rests mainly on the subjective identification of qualitative abnormalities according to the French-American-British criteria (FAB) involving one or more bone marrow hematopoietic cell lineages. The occurrence of nonrandom chromosome abnormalities remains the hallmark of the disease and the only means of investigation which confirms the disease objectively. With the purpose in mind to further characterize RA among MDS, we have undertaken a prospective high resolution banding chromosome analyses of bone marrow cells in patients with primary refractory anemia (PRA) with the aim of defining a cytogenetic phenotype and of assessing the clinical relevance of clonal abnormalities at initial diagnosis. Of 39 patients consecutively referred for chromosome analyses with a diagnosis of RA according to the FAB criteria, 27 patients had PRA and fulfilled our criteria for adequate chromosome analyses. Median age was 68 years. Fourteen of 27 patients (52%) had clonal chromosomal abnormalities at diagnosis. None of the patients showed a complex karyotype; 9/14 (64%) had a mixture of normal and abnormal cells. Interstitial or terminal deletions, involving chromosomes 5, 6, 7, 9, 11, 12, and 20, were found in 11/14 (79%) of the patients. Comparison of survival between patients with and without abnormalities showed no difference. The presence of clonal abnormalities did not predict transformation to acute myeloblastic leukemia (AML) nor was it associated with poor survival. In this study, patients with PRA were found to have a predominant pseudodiploid karyotypic pattern characterized by interstitial and/or terminal deletions as opposed to derivatives, specific and non-specific balanced translocations, or other structural and numerical abnormalities. We were unable to reveal any prognostic significance to the presence of these clonal abnormalities at initial diagnosis.     

Simultaneous Demonstration of Clonal Chromosome Abnormalities and Apoptosis in Individual Marrow Cells in Myelodysplastic Syndrome

Bone marrow samples from 18 patients with myelodysplastic syndrome (MDS) with clonal cytogenetic abnormalities were characterized by combining fluorescence in situ hybridization (FISH) with in situ end-labeling (ISEL) or with annexin V staining and flow cytometry (AV/FLOW) to determine the clonal nature of hematopoietic cells undergoing apoptosis in marrow cells. Apoptosis occurred in both normal and clonal cells. However, the proportion of clonal cells identified by FISH among apoptotic cells was lower than the proportion among nonclonal cells in 17 of 18 patients, regardless of whether ISEL or AV/ FLOW was used to identify apoptosis. This technique allows us to identify simultaneously clonality (as determined by FISH) and apoptosis in individual cells and shows that although apoptosis occurs predominantly in residual normal (FISH-negative) cells, a proportion of clonal precursors in MDS marrow also die from programmed cell death. Such a mechanism may be responsible for the generally slow expansion of the clone in MDS.     

Specificity of haematological indicators for '5q- syndrome' in patients with myelodysplastic syndromes

83 patients with myelodysplastic syndromes were analyzed for the presence of three haematological features: (1) macrocytic anaemia, (2) normal or high platelet count and (3) megakaryocytic hypolobulation in most megakaryocytes. In 10 of the 83 patients, a 5q- chromosome was the only clonal aberration; 31 patients had other chromosomal aberrations (including 6 patients with 5q- chromosome and other abnormalities in the same clone) and 42 patients had a normal karyotype in their bone marrow cells. 9 patients displayed all three haematological features investigated. In 8 of these patients the 5q- chromosome was the only clonal aberration. The 9th patient had a karyotype of 47,XX, + 8. None of the 6 patients with 5q- chromosome and additional abnormalities in the same clone fulfilled all criteria. The '5q- syndrome', a situation with the 5q- chromosome as a sole aberration, should be accepted as a diagnostic entity within the macrocytic anaemias. This syndrome can be suspected on the basis of the above haematological indicators and the diagnosis confirmed with bone marrow karyotype analysis.     

Lymphohaematopoietic chimaerism after bone marrow transplantation for chronic myeloid leukaemia: results of simultaneous cytogenetic analyses on T-cell colonies, myeloid, and erythroid progenitor cells

Various lymphohaematopoietic compartments represented by cells from T-cell colonies, myeloid progenitor cells (CFU-GM), erythroid progenitor cells (BFU-E), and bone marrow after short-term culture (BM) have simultaneously been analysed in 15 patients receiving 17 bone marrow transplants for Philadelphia chromosome (Ph) positive chronic myeloid leukaemia (CML) or acute lymphoblastic leukaemia (ALL). The marrow grafts were not T-cell depleted. Ten patients without relapse did not show any myeloid cells of host origin until their last follow-up or until death. However, in four of these patients single lymphoid host cells not carrying the Ph chromosome were found after BMT without clinical consequences. In patients with cytogenetic or haematological relapse Ph positive metaphases were first detected in any of the progenitor cell compartments along with residual donor cells in two of three patients. BM became Ph positive after various time intervals. Another patient with CML became Ph positive in all compartments investigated at the same time. The only patient with Ph positive ALL remained completely Ph negative also when haematological and clinical relapse was evident. All patients with relapse exhibited complex clonal and non-clonal chromosomal aberrations at the time of recurrence of the Ph chromosome. Such abnormalities not identical to those usually found with evolution of the disease and preferentially occurring in progenitor cells preceded the reappearance of Ph positive metaphases in one of our patients.     

Peripheral blood cells in the study of chromosome aberrations of patients with chronic myeloid leukaemia or myelofibrosis

Chromosome studies were performed on peripheral blood (PB) cells with and without stimulation, and/or on bone marrow (BM) cells from 21 patients with chronic myeloid leukaemia (CML), and 18 patients with myelofibrosis (MF). Our results show that almost all the patients with immature granulocyte precursors in PB also had mitotic cells in their unstimulated PB. In CML all unstimulated mitoses had the Philadelphia chromosome. In each patient the abnormal karyotype in the PB was the same as in the BM. Because of the high frequency of dry taps in myelofibrosis, the tissue of choice for chromosome study is peripheral blood.     

Abnormal chromosomes in histocytic lymphoma

Five of six diffuse histocytic lymphoma patients had chromosomal abnormalities. Four had abnormal clones; three, a large acrocentric chromosome (LAC); and one, an abnormal large submetacentric chromosome (LSC). The LAC was a 14q+ and the LSC, a 4q+. Although no cytogenetic abnormality was found in a normal lymph node of a patient whose diseased lymph node had an LAC, abnormal chromosomes were seen in three patients with normal morphological bone marrow and in two peripheral blood specimens with a normal differential count. Since staging is important in aiding the clinician to select the type of treatment in this disease, it is recommended that cytogenetic studies in all biopsied tissues should be done as part of an overall diagnostic procedure in patients suspected of this disease.     

In multiple myeloma, bone-marrow lymphocytes harboring the same chromosomal abnormalities as autologous plasma cells predict poor survival

Chromosomal abnormalities in plasma cells (PCs) from multiple myeloma (MM) provide a clonal signature to identify malignant cells. BM-lymphocytes from MM aspirates, defined by stringent criteria, were screened for the same chromosomal abnormalities as autologous PCs, including translocations, deletions, and amplifications. For 200 MM patients, we evaluated BM mononuclear cells to identify lymphocytes and autologous PCs on the same slide, followed by interphase fluorescence in situ hybridization to characterize their chromosomal abnormalities. Of all patients having a given chromosomal abnormality(s) in PCs, 45% showed that same abnormality(s) in 2-37% (median = 5%) of BM-lymphocytes. Most translocations, amplifications, and deletions found in MM PCs were also detected in lymphocytes, above the healthy-donor "cut-off." In patients having chromosomally abnormal CD20(-) PCs, chromosomally abnormal lymphocytes were found among CD20+ cells confirming them as B cells. Exceptions were amplification of 1q21 or p53 deletion, which characterize PCs but were undetectable in BM-lymphocytes, suggesting that processes leading to these abnormalities may be exclusive to PCs. For a set of 75 patients whose BM-lymphocytes and PCs were analyzed by all six probe sets, 58% of those with abnormal PC also had abnormal BM-lymphocytes harboring from one to five different abnormalities. Confirming the clinical significance of chromosomally abnormal BM-lymphocytes, MM patients having abnormalities in both lymphocytes and PC had significantly worse survival than those with abnormalities only in PC (HR = 2.68). The presence of at least one chromosomal abnormality in BM-lymphocytes appears to have greater clinical significance than particular abnormalities. Chromosomally abnormal BM-lymphocytes correlate with poor outcome and by extrapolation with more aggressive disease.