意义未明的单克隆免疫球蛋白血症的病程演变、鉴别诊断及其干预策略:第54届美国血液学会年会报道

 【摘要】　意义未明的单克隆免疫球蛋白血症（monoclonal gammopathy of undetermined significances,MGUS）被界定为癌前克隆性疾病。其在50岁以上人群中的发病率达到4.2 %,且以每年1 %的高风险向多发性骨髓瘤（multiple myeloma,MM）和相关的恶性疾病转化。确定其病程演变将指导临床诊断和治疗。大多数MGUS患者仅需随访观察。而少部分患者则经过冒烟型骨髓瘤（smoldering multiple myeloma,SMM）阶段进展为MM,或者因M蛋白导致终末器官损害,发展为轻链型疾病,如轻链型淀粉样变性、轻链沉淀病等,需要启动药物干预措施。2012年第54届美国血液学会（ASH）年会进行了这部分内容的详细报道。     

Monoclonal gammopathy of undetermined significance

Monoclonal gammopathy of undetermined significance (MGUS) is characterized by the presence of a monoclonal protein (M-protein) without evidence of multiple myeloma (MM), Waldenstrom's macroglobulinemia (WM), amyloidosis (AL), or a related plasma cell proliferative disorder. Agarose gel electrophoresis followed by immunofixation is recommended for recognition of an M-protein. Monoclonal gammopathy of undetermined significance is found in approximately 3% of persons > 70 years of age and in about 1% of those > 50 years old. In a series of 1384 patients from Southeastern Minnesota in whom MGUS was diagnosed at Mayo Clinic from 1960 through 1994, the risk of progression was 1% per year. This risk of progression continued even after > or = 25 years of a stable M-protein. The risk for developing MM, WM, or AL was increased 25-fold, 46-fold, and 8.4-fold, respectively. The concentration of the serum M-protein, abnormal serum free light-chain ratio, and the presence an immunoglobulin (Ig)M or an IgA M-protein were risk factors for progression. The presence of a urine M-protein or the reduction of > or = 1 uninvolved immunoglobulins was not a risk factor for disease progression. Patients must be monitored for progressive disease throughout their lives. Variants of MGUS consist of IgM MGUS, biclonal gammopathies, triclonal gammopathies, idiopathic Bence Jones (light-chain) proteinuria, and IgD MGUS. Monoclonal gammopathy of undetermined significance may be associated with many disorders, including lymphoproliferative diseases, leukemia, von Willebrand's disease, connective tissue diseases, and neurologic disorders. Epidemiologic and statistical methods must be used to evaluate these associations.     

Enumeration and identification of human leukemic lymphocytes by their natural binding of bacteria.

The recently described property of bacteria to bind to human lymphocytes was used to distinguish between normal and chronic leukemic lymphocyte (CLL) populations. Strains of the following bacteria were used in this study: Arizona hinshawii, Escherichia coli strains 1 and 2, Bacillus globigii, Brucella melitensis, Corynebacterium diphtheriae strains 1 and 2, Corynebacterium xerosis, Sarcina lutea, Staphylococcus aureus, and Staphylococcus epidermidis. For identification of immunoglobulin-bearing lymphocytes, a strain of E. coli that did not bind to human lymphocytes was coated with anti-human light-chain antibody. Labeling of lymphocytes with bacteria was promoted by centrifugation. In the eight CLL patients studied, in which greater than 90% of the lymphocytes were leukemic cells, 52 to 77% were labeled by anti-human light-chain antibody-E. coli, 80 to 93% were labeled by Br. melitensis, and 78 to 95% were labeled by E. coli 1 compared to 11 to 24, 11 to 22, and 30 to 44%, respectively, in normal individuals, Thus, Br. melitensis, E. coli 1, and the anti-human light-chain antibody-E. coli may have diagnostic value for CLL. The percentage of the lymphocyte population that bound each of the other bacteria varied from patient to patient. Preliminary results obtained by studying the pattern of binding of E. coli 2, B. globigii, Sa. lutea, or S. aureus by leukemic lymphocytes suggest that categories of CLL patients may be distinguished by this method.     

CD5, CD10, and CD23 expression in Waldenstrom's macroglobulinemia

CD5, CD10, and CD23 are cell surface antigens used to distinguish B-cell disorders. The expression of these antigens and their clinical significance in Waldenstrom's macroglobulinemia (WM), an uncommon B-cell disorder, remains to be clarified. We therefore determined expression of CD5, CD10, and CD23 by flow cytometric analysis on bone marrow lymphoplasmacytic cells (CD19+ k/l light chain restricted) for 171 serially biopsied patients with findings of the consensus panel definition of WM. Importantly, we also correlated laboratory and clinical data, as well as existence of a familial history of a B-cell disorder in view of reports suggesting familial predisposition in WM. These studies demonstrated tumor cell expression of CD5, CD10, and CD23 in 15 of 171 patients (9%), 11 of 161 patients (7%), and 37 of 105 patients (35%), respectively. Coexpression of CD23 with CD5 or CD10 was common. Tumor Lymphoplasmacytic from 10 of 15 (66%) and 3 of 11 (27%) patients with WM that expressed CD5 and CD10, respectively, also showed expression of CD23 (P = 0.01 and P = 0.08, respectively). Among patients with CD23 expression, increased serum immunoglobulin (Ig) M levels were observed compared with patients without CD23 expression (P = 0.05). No differences in age at diagnosis; presence of adenopathy and/or splenomegaly; bone marrow involvement; serum IgA, IgB, and b2 macroglobulin levels; hematocrit; platelet count; or familial history of WM or a related B-cell disorder were observed among patients with and without CD5, CD10, and CD23 expression. These studies demonstrate that CD5, CD10, and CD23 are commonly found in WM and that their expression should not exclude the diagnosis of WM. Moreover, expression of CD23 may define a clinically distinct subset of patients with WM.     

多发性骨髓瘤肾脏病变的研究进展

 多发性骨髓瘤（MM）患者肾损害谱包括"骨髓瘤肾"或管型肾病、轻链淀粉样变、单克隆免疫球蛋白沉积病、冷球蛋白血性肾小球肾炎和增生性肾小球肾炎等。MM肾脏病患者肾活组织病理检查研究显示,管型肾病占40 %～63 %,肾轻链沉积病（LCDD）占19 %～26 %,淀粉样变占7 %～30 %,冷球蛋白肾病＜1 %。管型肾病、MIDD和淀粉样变的肾病理学不同。骨髓瘤相关肾病的肾外表现较多样,进展为肾功能不全和末期肾病（ESRD）发生率高,并发症增加,死亡率显著升高,合并肾病的MM患者生存期和肾生存期短。治疗包括MM化疗、血液透析和自体造血干细胞移植（ASCT）等,ASCT有血液学反应和肾反应者的生存率明显改善,成功的ASCT给更多的患者以肾和其他脏器移植的机会。     

Heterogeneity of immunoglobulin gene rearrangements in B-cell lymphomas

We have examined 69 B-cell non-Hodgkin's lymphomas (NHL) for rearrangements of the immunoglobulin (Ig) or T-cell antigen receptor (TCR) genes. The lymphomas were assigned to the categories of the Kiel classification and their B-cell nature was confirmed by immunostaining. Only 2 cases (with CLL) displayed clonal T beta-chain TCR gene rearrangements together with rearranged heavy- and light-chain Ig genes. The remaining 67 lymphomas had a germline beta-chain TCR-gene configuration. Three different patterns of Ig gene rearrangements were identified; (A) presence of both heavy- and light-chain rearrangements (H+L+); (B) rearrangement of heavy-chain gene only (H+L-); (C) heavy- and light-chain genes in germline configuration (H-L-). All the 45 low-grade NHLs and the 4 immunoblastic lymphomas exhibited pattern A and all had their kappa gene rearranged or deleted. Of 24 low-grade lymphomas tested, 13 (54%) had an addition rearrangement of the lambda light-chain gene. In contrast, the 19 high-grade centroblastic (cb) B-NHLs had distinct patterns of Ig-gene rearrangement: 12 with pattern A, 4 with B and 2 with C. In this group only 2 of 17 (12%) cases analyzed had evidence of lambda light-chain rearrangement whereas 12 of 18 (67%) had a kappa gene rearrangement or deletion. In one case expressing sIgM/lambda and with heavy chain Ig-rearrangement, no DNA was available for Ig light-chain analysis.     

硼替佐米联合地塞米松治疗24例多发性骨髓瘤的疗效分析

背景及目的:硼替佐米(bortezomib)是一种有效、可逆性的蛋白酶体抑制剂,通过诱导骨髓瘤细胞的凋亡,在骨髓瘤患者的治疗中发挥持久的疗效。本研究旨在观察硼替佐米联合地塞米松治疗初治、难治/复发多发性骨髓瘤(multiple myeloma,MM)患者的疗效和毒副作用,及该方案在肾功能不全患者中应用的安全性。方法:24例MM患者接受硼替佐米联合地塞米松方案治疗,每3周为一个疗程。所有患者共接受中位3个疗程(1～8个疗程)的化疗。采用EBMT疗效评价标准评价疗效,按国立癌症研究所的常规毒性判定标准评价不良反应。结果:全组中位随访4个月,总有效率79.2%(19/24)。轻链型患者CR率57.1%(4/7),明显高于非轻链型患者5.9%(1/17),差异有统计学意义(P=0.014)。7例合并肾功能不全的患者与肾功能正常患者的疗效相近,差异无统计学意义(P=0.272)。Ⅲ～Ⅳ级不良反应包括白细胞减少(2/24,8.3%)、血小板减少(8/24,33.3%)、腹泻(2/24,8.3%)和乏力(1/24,4.2%),经对症治疗或推迟化疗后均可恢复。结论:硼替佐米联合地塞米松方案治疗MM患者有明显疗效,在轻链型患者疗效更加显著。副作用可以耐受,在合并肾功能不全的患者可安全应用。     

Nonsecretory myeloma, immunoglobulin D myeloma, and plasma cell leukemia

Nonsecretory myeloma, which accounts for 1% to 5% of all myelomas, is characterized by the absence of detectable M-protein in serum and urine. The presenting features of nonsecretory myeloma are similar to those in patients with a detectable M-protein, except for the absence of renal function impairment. The response to therapy and survival of patients with nonsecretory myeloma are similar to those of patients with measurable M-protein. Immunoglobulin D myeloma represents 2% of all myelomas. Patients with IgD myeloma usually present with a small band or no evident M-spike on serum electrophoresis and heavy light-chain proteinuria. Thus, IgD myeloma can be considered a variant of Bence Jones myeloma; the presence of the IgD M-protein and the predominance of the lambda light chain are the only distinctive features. The median survival of patients with IgD myeloma is almost 2 years, with one fifth of them surviving for more than 5 years. Plasma cell leukemia is also a rare form of plasma cell dyscrasia (2% to 4% of all myelomas). The primary form accounts for 60% of the cases. In primary PCL, the constellation of adverse biologic prognostic factors in patients with advanced aggressive myeloma is already present at diagnosis. In fact, primary PCL has a more aggressive clinical presentation than MM, with a higher frequency of extramedullary involvement, anemia, thrombocytopenia, hypercalcemia, and renal failure. Treatment with a single alkylating agent plus prednisone is not appropriate. Combination chemotherapy with VAD, cyclophosphamide and etoposide, or VCMP/VBAP is a better initial option. Given the poor prognosis of primary PCL, intensification with high-dose therapy followed by stem cell rescue should be offered to affected patients.     

New Approaches to Smoldering Myeloma

Smoldering multiple myeloma (SMM) is an asymptomatic plasma cell disorder characterized by the presence of one or both features of serum M-protein ≥?30 g/L and bone marrow plasma cell infiltration ≥?10 %. However, myeloma-related symptomatology is absent from this condition. The risk of progression to active MM is not uniform, and several markers are useful for identifying SMM patients at high risk of progression to active MM. These include the size of the M-protein and the infiltration in the bone marrow, the serum-free light-chain ratio, the presence of immunoparesis and percentage of plasma cell with aberrant phenotype by flow cytometry, or the presence of focal lesions in magnetic resonance imaging. Overall, the presence of these factors identifies patients who have a 50 % probability of progression at 2 years, and the forthcoming challenge will be to identify ultra-high-risk patients who have an 80 % risk of progression at 2 years. The current standard of care is not to treat until progression to symptomatic disease occurs. Several trials of melphalan, thalidomide and bisphosphonates have been conducted in the overall SMM patient population to examine the delay in time to progression (TTP) to symptomatic disease, but these have shown no significant benefit. However, a randomized trial that focused on high-risk SMM patients allocated to receive early treatment with lenalidomide plus dexamethasone versus observation did report a significant benefit with respect to TTP and overall survival. In summary, high-risk SMM patients should be targetted for early treatment, and more so efforts should be made to identify the ultra-high-risk subgroup within the high-risk SMM patient population which may be considered as early MM and thereby candidates for receiving therapy before they develop myeloma-related symptomatology.     

Anxiety disorders in cancer patients: their nature, associations, and relation to quality of life.

PURPOSE: We aimed to estimate the prevalence and types of anxiety disorders diagnosed according to standardized criteria in cancer patients, to compare screening tools in detecting them, and to examine their demographic, oncologic, and psychosocial associations. METHODS: In this cross-sectional observational study of 178 subjects with lymphoma, renal cell carcinoma, malignant melanoma, or plasma cell dyscrasia, we related responses to questionnaires (administered by computer touch-screen) measuring psychological symptoms, quality of life (QOL), and social support to standardized psychiatric interviews and cancer management. RESULTS: Forty-eight percent of subjects reported sufficient anxiety for anxiety disorder to be considered. At subsequent diagnostic interview, 18% fulfilled International Classification of Disorders, 10th Revision criteria for anxiety disorder, including 6% of patients who reported low levels of anxiety by questionnaire. When subjects reported anxiety by questionnaire, if disruptive somatic anxiety was present, this increased the probability of diagnosable anxiety disorder from.31 to.7. The most accurate screening questionnaires were the trait scale of the State-Trait Anxiety Inventory and the Hospital Anxiety and Depression scale. Female sex and negative aspects of social support were associated with anxiety disorder in multivariate analyses. Anxiety disorder was independently associated with a deficit in QOL, particularly insomnia. CONCLUSION: Anxiety symptoms are common in cancer patients. Screening by questionnaire seems to assess anxiety symptoms adequately but discriminates abnormal anxiety inadequately. To improve this, we may need to use criteria such as disruption from anxiety, as illustrated by the impact of anxiety disorders on QOL. There seem to be few oncologic variables that could target screening for anxiety disorders.     

Systemic immunoglobulin light-chain amyloidosis

Amyloidosis is a rare disease in which amyloid fibrils compromise organ function and lead to death. Systemic immunoglobulin light-chain amyloidosis, usually caused by free light chains (FLCs) made by clonal plasma cells, is the most frequent type. Hereditary and senile systemic amyloidosis are less frequent types. Rarely, a patient with a tissue diagnosis of amyloidosis might have a monoclonal gammopathy and a hereditary protein. In systemic immunoglobulin light-chain amyloidosis, circulating clonal light chains can be measured with the FLC assay and provide a target for therapy aimed at eliminating the underlying plasma cell disorder while supporting the patient. Elimination of the pathologic FLC can lead to resorption of amyloid deposits and improvement in organ function. Monthly oral melphalan and dexamethasone for 1 year is effective therapy for patients not eligible for autologous stem cell transplantation (SCT) but carries a risk of myelodysplasia. For patients with limited organ involvement, SCT is an effective approach and, when followed after SCT by adjuvant thalidomide and dexamethasone for persistent plasma cell disease, achieves a high 1-year hematologic response rate. Complete hematologic responses can be durable beyond a decade and are usually associated with organ recovery. New agents, such as bortezomib and lenalidomide, have shown promising activity, and novel monoclonal antibody approaches are also under active investigation.     

Comparison Among Immunologically Different Subtypes of 595 Untreated Multiple Myeloma Patients in Northern China

BackgroundGenerally, characteristics of heterogeneous multiple myeloma (MM) have been described as a whole. Actually, isolated immunologic subtypes of MM may be associated with prognostic significance.Patients and MethodsThe aim of this retrospective single-center study was to determine the characteristics of immunologically different subtypes among 595 evaluable cases with previously untreated MM in northern China.ResultsThe major distribution of MM subtypes were immunoglobulin (Ig)G, 47.9%; IgA, 23.3%; and light-chain, 21.0%. Nonsecretory, IgD, and biclonal subtypes were rarely seen, comprising only 7.7%. The male-to-female ratio was 1:7, and the median age was 59 years. In the IgG subtype, more patients presented with elevated M protein, fulfilling the major diagnostic criteria determined by Durie, and infection occurred more frequently; however, the prognosis was favorable. In the IgA subtype, in which survival was significantly poorer, the extent of anemia was more severe, and nonhyperdiploid abnormality may be its adverse indicator. In the light-chain subtype, the mean level of serum IL-6 was the highest, and more patients presented with advanced renal dysfunction, bone destruction, and thrombocytopenia. However, more light-chain patients were staged at International Staging System I, partially resulting in the favorable median survival of 51 months (almost equivalent to 50 months with the IgG subtype). Another rare subtype with unfavorable outcome was IgD myeloma, in which the median age was 50 years, and the serum calcium level was significantly decreased. Intriguingly, we also noted that more patients presented hypocalcemia than hypercalcemia (37.7% vs. 15.7%) in the current series. Multivariate analysis revealed that independent adverse indicators included age > 50 years, Durie-Salmon stage III, and increased values of C-reactive protein and β²-microglobulin.ConclusionThe median duration of survival in MM reached 36.0 months. Distinctions among immunologically different subtypes can predict prognostic significance, namely, favorable in IgG and light-chain subtypes but significantly poorer in IgA and IgD subtypes.     

Analysis of immunoglobulin light-chain mRNA in gastric malignant lymphoma using new highly sensitive in situ hybridization method

Background. To analyze B-cell monoclonality, we need fresh materials for the Southern blotting method. In situ hybridization (ISH) for the detection of immunoglobulin light-chain mRNA can be used in formalin-fixed and paraffin-embedded tissues. However, it is difficult to detect low levels of mRNA copies. So we must develop new highly sensitive in situ hybridization methods to diagnose gastric malignant lymphoma. Methods. We analyzed materials from 15 patients with gastric malignant lymphoma, using a new highly sensitive ISH method, and compared the results with those of a conventional method. Results. With this new method, 13 of 15 cases were shown to have monotypic cytoplasmic signals, and monoclonality was detected in 3 of 4 cases of mucosa-associated lymphoid tissue (MALT) lymphoma. Conclusions. The accuracy of endoscopic biopsies is not satisfactory. However, the detection of immunoglobulin light chain mRNA, using the new highly sensitive ISH method with a non-radioactive isotope oligonucleotide probe, can be used to diagnose gastric malignant lymphoma even when conventional immunoglobulin light-chain mRNA or proteins alone cannot demonstrate the clonality. Received for publication on Oct. 7, 1998; accepted on Jan. 11, 1999     

The implication of compromised renal function at presentation in myeloma

The purpose of the study was to determine the role of sequential therapy (ST) in new patients with myeloma presenting with renal dysfunction (RD): serum creatinine >140 μmol/L (1.6 mg/dL). Between April 1985 and June 1998, 251 patients, 59 (23%) with RD were entered into a ST program comprised of infusional chemotherapy (IC) with VAMP/C-VAMP (vincristine, doxorubicin, and methylprednisolone with/without cyclophosphamide) followed by autologous transplantation and interferon maintenance. The median overall survival (OS) of 251 patients from the start of IC was 4.2 yr with the RD group faring significantly poorer (median 2.5 yr) than those with no renal dysfunction (NRD; median 4.6 yr; p=0.0025). Mortality during the first 100 d of IC was significantly higher in patients with RD (11/59; p=0.01) compared to patients with NRD. In patients consolidated with high-dose therapy, the OS and event-free survival (EFS) were not significantly different between the two groups. Cox analysis of the variables at presentation failed to show RD as a factor influencing outcome, but it showed that patients with beta-2-microglobulin (β₂M)≥3.7 (p<0.0001), age ≥52.5 yr (p=0.002), performance status (PS) ≥2 (p=0.005) and patients with light-chain myeloma (p=0.03) had a significantly shorter OS, β₂M≥3.7, PS≥2, and light-chain myeloma were predictive of shorter EFS. The study shows that with modern intensive schedules of treatment, renal disease at presentation in isolation does not compromise outcome.     

Association of increased levels of heavy-chain ferritin with increased CD4+ CD25+ regulatory T-cell levels in patients with melanoma.

We have shown previously that melanoma cells in culture release heavy-chain ferritin (H-Ferritin) into supernatants and that this is responsible for the suppression of responses of peripheral blood lymphocytes stimulated by anti-CD3. These effects were mediated by activation of regulatory T cells to produce interleukin (IL)-10. In the present study, we examined whether a similar relation might exist between levels of H-Ferritin and activation of regulatory T cells in patients with melanoma. Ferritin levels were evaluated by ELISA and regulatory T-cell numbers were assessed by three-color flow cytometry to identify CD4(+) CD25(+) CD69(-) T cells. CD69 positive cells were excluded to avoid inclusion of normal activated CD4, CD25 expressing T cells. Measurements of H- and light-chain (L)-Ferritin by ELISA revealed that H- but not L-Ferritin was elevated in the circulation of melanoma patients. In addition, these studies revealed a marked increase in the number of CD4(+) CD25(+) CD69(-) T cells in such patients, compared with age-matched controls. The ratio of H-Ferritin:L-Ferritin correlated with the levels of regulatory T cells consistent with a causal relation between unbound H-Ferritin levels and the activation of regulatory T cells. H-Ferritin or regulatory T cells did not, however, correlate with the stage of the melanoma. These results provide evidence for the importance of H-Ferritin in the induction of regulatory T cells in patients with melanoma and provide additional insight into the suppression of immune responses in such patients.     

Sequential cyclophosphamide-bortezomib-dexamethasone unmasks the harmful cardiac effect of dexamethasone in primary light-chain cardiac amyloidosis

Chemotherapy combining cyclophosphamide, bortezomib and dexamethasone is widely used in light-chain amyloidosis. The benefit is limited in patients with cardiac amyloidosis mainly because of adverse cardiac events. Retrospective analysis of our cohort showed that 39 patients died with 42% during the first month. A new escalation-sequential regimen was set to improve the outcomes. Nine newly-diagnosed patients were prospectively treated with close monitoring of serum N-terminal pro-brain natriuretic peptide, troponin-T and free light chains. The results show that corticoids may destabilise the heart through fluid retention. Thus, a sequential protocol may be a promising approach to treat these patients.     

Microsatellite Instability Is a Common Finding in Multiple Myeloma

PurposeMicrosatellite instability (MSI) occurs as a result of sliding in the DNA sequences from shortening or elongation of the repeat zones of DNA during replication. Such abnormalities can normally be corrected by the enzymes coded by the DNA mismatch repair (MMR) genes. Therefore, detection of MSI is considered to be a sign of disorder of the MMR genes and is interpreted as a replication error phenotype.Patients and MethodsWe evaluated the MSI in 5 different loci in the 14q32 region of immunoglobulin heavy chain IgH gene in 26 newly diagnosed patients with multiple myeloma (MM).ResultsFifty-four percent of the patients disclosed MSI and at least 1 locus but no significant association of MSI was found between different clinical stages and the MM subtype. MSI was not found in 5 light-chain myeloma patients.ConclusionAlthough our case number is small, probably the genomic instability in heavy-chain MM may be a common finding and probably plays a critical role in the MM pathogenesis.     

Cytogenetic 2; 18 and 18; 22 translocation in chronic lymphocytic leukemia with juxtaposition of bcl-2 and immunoglobulin light chain genes.

The majority of follicular lymphoma cells carry the typical chromosome translocation 14;18, which juxtaposes the bcl-2 gene to the immunoglobulin heavy-chain (IgH) gene. Variant translocations of the bcl-2 gene to the Ig lambda or Ig kappa gene have been found by molecular biological techniques in a significant fraction (approximately 10%) of chronic lymphocytic leukemia (CLL). However, there have been no reports describing the presence of cytogenetic 18;22 and 2;18 translocations in CLL, in spite of extensive karyotypic studies. We present here two cases of CLL, one with cytogenetically detected t(2;18)(p11;q21) and the other with the t(18;22)(q21;q11). The molecular analysis revealed that these translocations juxtaposed the bcl-2 and immunoglobulin light-chain (IgL) genes. The t(18;22) broke the 5' flanking region of the bcl-2 gene and juxtaposed to the immunoglobulin lambda light-chain (Ig lambda) gene in a head-to-head configuration, as in the cases previously described. In the case of the t(2;18), the bcl-2 gene and immunoglobulin kappa light-chain (Ig kappa) gene were juxtaposed in a head-to-tail configuration, which is opposite to that expected from the orientation of the genes on chromosomes. The breakpoint was located within the 5' untranslated region of the bcl-2 gene. The results presented here indicate that the bcl-2/immunoglobulin light-chain (IgL) gene juxtaposition seen in a fraction of CLL is the result of cytogenetically detectable reciprocal chromosome translocations 2;18 and 18;22.     

Clinicopathologic and genetic profile of intracranial marginal zone lymphoma: a primary low-grade CNS lymphoma that mimics meningioma.

PURPOSE: Although rare overall, marginal zone B-cell lymphoma (MZBCL) is the most common primary low-grade CNS lymphoma reported in the literature. The aim of this study is to elucidate the biology and genetic features of this unusual tumor. PATIENTS AND METHODS: Fifteen CNS MZBCLs were studied clinically, pathologically, and genetically, including fluorescent in situ hybridization analyses with commercially available MALT1 and IgH break-apart and centromere 3, 7, 12, and 18 probes. RESULTS: CNS MZBCLs preferentially affect middle-aged women (female-to-male ratio, 4:1), with 93% presenting as dural-based masses mimicking meningioma. Ten patients with 1 to 7.6 years of follow-up after diagnosis showed no evidence of disease after radiation and/or chemotherapy. Like MZBCLs outside of the CNS, they consisted of CD20+, CD3- small B lymphocytes with varying degrees of plasmacytic differentiation and predominantly kappa light-chain restriction (78%). Lymphoid follicles with follicular colonization were seen in three patients and deposition of amyloid was noted in samples from two patients, one of which was tumefactive. Neither Bcl-6 protein nor Epstein-Barr virus-encoded RNA was expressed. Trisomy 3 was detected in six of 12 patients, with no rearrangements of MALT1 or IgH and no trisomies of 7, 12, or 18 detected. CONCLUSION: Our data suggest that intracranial MZBCL is an indolent primary CNS lymphoma that typically presents as a meningioma-like dural-based mass. Trisomy 3, but not MALT1 or IgH translocation, is a common genetic abnormality that may contribute to the pathogenesis of this CNS lymphoma.