Immunohistochemical detection of cyclin D1 using optimized conditions is highly specific for mantle cell lymphoma and hairy cell leukemia.

Mantle cell lymphoma (MCL) is more aggressive when compared with other lymphomas composed of small, mature B lymphocytes. Cyclin D1 is overexpressed in MCL as a result of the translocation t(11;14)(q13;q32). Cyclin D1 immunohistochemistry in fixed, paraffin-embedded tissue contributes to the precise and reproducible diagnosis of MCL without the requirement of fresh tissue. However, its use in bone marrow biopsies is not well established. In addition, increased levels of cyclin D1 mRNA have been found in hairy cell leukemia but have not consistently been detected by immunohistochemistry. We used a polyclonal antibody and heat-induced antigen retrieval conditions to evaluate 73 fixed, paraffin-embedded bone marrow, spleen, and lymph node specimens with small B-cell infiltrates, obtained from 55 patients. Cyclin D1 was overexpressed in 13/13 specimens of MCL (usually strong, diffuse reactivity in most tumor cells) and in 14/14 specimens of hairy cell leukemia (usually weak, in a subpopulation of tumor cells). No reactivity was detected in five cases of B-chronic lymphocytic leukemia; five cases of splenic marginal zone lymphoma; six cases of nodal marginal zone cell lymphoma; two cases of gastric marginal zone cell lymphoma; or ten benign lymphoid infiltrates in bone marrow, spleen, or lymph nodes. In summary, although the total number of studied cases is small and a larger series of cases may be required to confirm our data, we present optimized immunohistochemical conditions for cyclin D1 in fixed, paraffin-embedded tissue that can be useful in distinguishing MCL and hairy cell leukemia from other small B-cell neoplasms and reactive lymphoid infiltrates.     

D cyclins in CD5+ B-cell lymphoproliferative disorders: cyclin D1 and cyclin D2 identify diagnostic groups and cyclin D1 correlates with ZAP-70 expression in chronic lymphocytic leukemia

We analyzed protein expression of cyclin D1, cyclin D2, and cyclin D3 using high-resolution enzymatic amplification staining and flow cytometry in the neoplastic cells from 80 patients with CD5+ B-cell lymphoproliferative disorders. The D cyclins were expressed differentially in chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), and mantle cell lymphoma (MCL) with strong staining of cyclin D1 and D2 in MCL, strong staining of cyclin D1 but weak staining of cyclin D2 in 4 of 5 PLLs, and low-level staining for both cyclins in most CLLs. No correlation between cyclin D1 and D2 and growth rates or CD38 expression was observed. However, cyclin D1 levels were significantly higher in ZAP-70+ CLL cases, although no association between ZAP-70 and cyclin D2 was detected. The results indicate that flow cytometric analysis of D cyclins may help in classification of CD5+ B-cell lymphoproliferative disorders.     

Indolent mantle cell lymphoma with nodal involvement and mutated immunoglobulin heavy chain genes

Mantle cell lymphoma (MCL) is typically considered an aggressive but incurable neoplasm composed of cyclin D1+ monoclonal B-cells with a t(11;14)(q13;q32) and usually unmutated immunoglobulin (Ig) genes. Although it has been suggested that a more indolent leukemic disorder exists with the same phenotype and genotype but with mutated Ig genes, others have considered these cases to be variants of chronic lymphocytic leukemia. We present a case of an indolent MCL that was documented with cyclin D1 expression in a lymph node biopsy performed more than 12 years ago. The patient has peripheral blood involvement with a lymphocyte count in the reference range, variable thrombocytopenia, and minimal adenopathy but is otherwise well, never having received any antineoplastic therapy. Study of peripheral blood samples from 2002 revealed a CD5-variable B-cell monoclonal proliferation with a t(11;14)(q13;q32) plus other karyotypic abnormalities, positive fluorescence in situ hybridization studies for the CCND1/IgH translocation, and clonal Ig gene rearrangement with mutated Ig genes (95.7% homology to VH 4-31). The subtle but diagnostic lymph node biopsy in this case helps to further support that an indolent t(11;14) monoclonal lymphocytosis with mutated Ig genes can represent an MCL variant rather than chronic lymphocytic leukemia.     

p27(Kip1) immunostaining for the differential diagnosis of small b-cell neoplasms in trephine bone marrow biopsies.

The distinction between mantle cell lymphoma (MCL) and other small B-cell non-Hodgkin lymphomas (NHL) is important because MCL has a more aggressive clinical course. In bone marrow (BM) biopsy specimens, this distinction can be particularly difficult. Although cyclin D1 immunostaining and molecular detection of the t(11;14) translocation are highly specific markers for MCL, they fail to detect a proportion of cases. We have recently described that MCL typically lacks detectable expression of the cyclin-dependent kinase inhibitor p27(kip1) protein by immunostaining, which is expressed at high levels in most small B-cell NHL inversely correlated to the proliferation rate. We therefore examined whether p27(kip1) immunostaining could be a useful adjunct for the differential diagnosis of small B-cell NHL infiltrates in the BM. Trephine BM biopsy specimens of 96 patients, including well-characterized MCL (19 cases), B-cell chronic lymphocytic leukemia (27 cases), follicular lymphoma (18 cases), hairy cell leukemia (22 cases), and marginal zone lymphoma (10 cases) as well as 10 reactive BM, including five with benign lymphoid aggregates were investigated. In addition, the presence of a t(11;14) translocation involving the major translocation cluster was studied by PCR in all MCL. All cases of B-cell chronic lymphocytic leukemia, follicular lymphoma, and marginal zone lymphoma revealed a strong p27(kip1) nuclear staining in the majority of neoplastic cells. Fourteen (78%) cases of MCL were p27(kip1)-negative in the tumor cells, whereas four cases revealed a weak nuclear positivity. Seventeen (77%) cases of hairy cell leukemia were also either completely negative for p27(kip1) or showed a faint positive staining in a minority of the neoplastic cells. Nine of 19 cases (47%) of MCL showed a bcl1 rearrangement involving the major translocation cluster region. These findings demonstrate that p27(kip1) immunostaining is a valuable additional marker for the differential diagnosis of small B-cell NHL infiltrates in BM biopsies. The reduction or lack of p27(kip1) protein expression in MCL, as well as in hairy cell leukemia, might be an important event in the pathogenesis of these disorders.     

bcl-1 REARRANGEMENT AND CYCLIN D1 PROTEIN EXPRESSION IN MANTLE CELL LYMPHOMA

Centrocytic lymphoma, or mantle cell lymphoma (MCL), is characterized by a chromosomal translocation t(11;14) (q13;q32) involving the bcl-1 locus on chromosome 11. Cyclin D1 is a cell-cycle regulatory protein essential for G1–S transition and has been identified as a potential transforming gene affected by the translocation. In this study, 32 cases of MCL were analysed for the bcl-1 rearrangement and cyclin D1 protein expression. In 17 cases, a rearrangement at the major translocation cluster of bcl-1 could be detected. Twenty-four cases exhibited nuclear cyclin D1 expression that was not detectable in other B-cell lymphomas ( n =40) or in normal B-cells. In nine MCL samples, cyclin D1 was expressed without a detectable bcl-1 rearrangement. The detection of a t(11;14) by means of classical cytogenetics in one of these cases, however, may suggest that this discrepancy could be due to chromosomal breakages outside the typical translocation cluster region. In two cases, a bcl-1 rearrangement was not accompanied by cyclin D1 expression. This study provides further evidence that cyclin D1 is involved in the pathogenesis of MCL and can be exploited as a diagnostic marker in the differential diagnosis of B-cell lymphomas and in the identification of MCL.     

Therapy-related B lymphoblastic leukemia with t(4;11)(q21;q23)/AF4-MLL in a patient with mantle cell lymphoma after recent aggressive chemotherapy - a unique case report

Mantle cell lymphoma (MCL) is a mature B-cell lymphoma associated with the hallmark translocation t(11;14)(q13;32), which involves the cyclin D1 (CCND1) and immunoglobin heavy chain (IgH) genes. It may transform to a more aggressive blastoid or pleomorphic variant, with or without acquisition of chromosomal abnormalities. MCL could also present with a leukemic phase with marked lymphocytosis. A literature search did not reveal any prior reports of MCL transforming to or followed by a B-cell lymphoblastic leukemia (B-ALL).     

Mantle cell lymphoma with a unique pattern of CD5 expression: a case report with review of the literatures

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin’s lymphoma characterized by chromosomal translocation t(11;14)(q13;q32), positive CD5, and nuclear cyclin D1 overexpression with unfavorable prognosis. We report herein a case of MCL in a 73-year-old male diagnosed with diffuse large B-cell lymphoma (ileal tumor) at another hospital, who subsequently relapsed with CD5-negative MCL. At the 1st relapse, he developed neck lymph node swelling, of which biopsy showed proliferation of atypical large pleomorphic cells with CD5-negativity by both immunohistochemistry and flow cytometry. At the 2nd relapse, he again developed an ileal tumor, of which biopsy showed positivity for CD5, CD20, and cyclin D1. In MCL, CD5-negative expression has sometimes been reported as having pleomorphic and blastoid variants. The present case was also histologically the pleomorphic type, but the CD5 expression changed from negative at the onset and the 1st relapse to positive at the 2nd relapse. This is a rare and interesting case because of the different expression of CD5 at all stage. This phenomenon made the diagnosis of MCL difficult.     

Morphological spectrum of cyclin D1-positive mantle cell lymphoma: study of 168 cases

Immunostaining for cyclin D1 is essential for reliable diagnosis of mantle cell lymphoma (MCL). However, a small number of cyclin D1-positive lymphomas other than MCL have been encountered. Our goal was to investigate the morphological spectrum of MCL as a disease entity, based on cyclin D1 overexpression. We reviewed 181 biopsy specimens obtained from 168 cases of cyclin D1-positive MCL. Typical findings were the presence of nodular (53.9% of cases) or diffuse (46.1%) histological patterns, containing mantle zone patterns (16.8%), naked germinal centers (33.5%) and perivascular hyaline deposition (83.2%). Unusual findings of residual germinal centers with a mantle cuff (four cases) and follicular colonization (two cases) were seen. High magnification showed a monotonous proliferation of tumor cells with cytological diversity including small (3.0%), intermediate (43.1%), medium (34.1%), medium-large (13.2%) and large (6.6%) cells. Pleomorphic and blastic/blastoid variants were encountered in 9.6 and 7.2% of cases, respectively. Three cases had foci of cells of considerable size, with a moderately abundant pale cytoplasm resembling marginal zone B cells. Two cases showed an admixture of cells which appeared transformed and mimicked the histology of chronic lymphocytic leukemia/small lymphocytic leukemia. In one, neoplastic mantle zones were surrounded by sheets of mature plasma cells, resembling the plasma cell type of Castleman's disease. An admixture of areas characteristic of MCL and of other larger cells, indicating histological progression or a composite lymphoma, were observed in seven cases. In high-grade lesions of five cases, nuclear staining of cyclin D1 was rarely detected. In our experience, cyclin D1 expression was also found in nine lymphomas other than MCL (five plasma cell myelomas, three Hodgkin's disease and one anaplastic large cell lymphoma). The application of cyclin D1 staining prompted us to recognize the broad morphological spectrum of MCL. MCL can be diagnosed with the application of cyclin D1 immunostaining, if careful attention is given to architectural and cytological features.     

From the archives of MD Anderson Cancer Center: Untreated leukemic non-nodal mantle cell lymphoma with relapse as pleomorphic variant mantle cell lymphoma 21 years later

Leukemic, non-nodal mantle cell lymphoma (MCL) is a distinct, rare, indolent variant of mantle cell lymphoma, but can relapse aggressively. It can present with lymphocytosis with chronic lymphocytic leukemia (CLL)-like morphologic and immunophenotypic features as was initially considered in the index case. However, at time of splenectomy, two years later cyclin D1 overexpression was shown and the disease was realized to be leukemic non-nodal MCL. The patient was followed for 21 years, without therapy, before he developed clinically aggressive MCL with lymphadenopathy. Lymph node biopsy showed MCL, pleomorphic variant. We review the literature and discuss the features of leukemic non-nodal MCL as well as the potential pitfalls in diagnosis. Furthermore, we are not aware of another cases reported with a 21 year interval from initial diagnosis of leukemic non-nodal MCL to aggressive MCL.     

Expression of Mcl-1 in mantle cell lymphoma is associated with high-grade morphology,a high proliferative state,and p53 overexpression

Mantle cell lymphoma (MCL) is a distinct type of B-cell non-Hodgkin's lymphoma characterized by the t(11;14)(q13;q32) and cyclin D1 overexpression. Defects in apoptosis may contribute to pathogenesis. This study evaluated the expression of the anti-apoptotic protein Mcl-1 in two MCL cell lines and five frozen MCL tumours (four small-cell, one blastoid/large-cell) using western blot analysis. Mcl-1 expression was also assessed in 36 formalin-fixed, paraffin wax-embedded MCL tumours (24 small-cell, 12 blastoid/large-cell) by immunohistochemistry. Western blot analysis revealed the expected 37 kD protein product in both MCL cell lines and in five frozen tumours, with the blastoid case having the highest expression level. Using a cut-off of >10% immunolabelled cells for Mcl-1, it was found that 12 of 36 MCL tumours were positive. Mcl-1-positive tumours had a higher frequency of blastoid/large-cell morphology (8/12 versus 4/24, p = 0.009), p53 overexpression (3/10 versus 1/23, p = 0.04), and higher Ki67 immuno-labelling (p = 0.002). It is concluded that expression of Mcl-1 in MCL is heterogeneous. A relatively high level of Mcl-1 expression correlates with high-grade morphology, a high proliferative state, and p53 overexpression.     

Combined translocation with ZNF198-FGFR1 gene fusion and deletion of potential tumor suppressors in a myeloproliferative disorder

Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32) translocation, which leads to overexpression of the cyclin D1 (CCND1) gene. This translocation is observed in almost all cases of MCL. In this alteration, the involvement of immunoglobulin heavy chain (IGH) locus plays a key role in the activation of the CCND1 oncogene. Translocations affecting IGH loci are mostly prevalent in B-cell lymphomas, but variant translocations involving immunoglobulin kappa (IGK) or lambda (IGL) light chain loci have been observed in a minority of B-lymphoid malignancies. Variant translocations have been reported in only a few cases of MCL, however. This report presents a case of MCL with a variant t(2;11)(p11.2;q13), rearrangement of the CCND1 gene, and overexpression of cyclin D1. To characterize this rearrangement, specific noncommercial probes were used. This set of probes comprises IGK and REL flanking probes and 12 bacterial artificial chromosome (BAC) probes covering the region to be investigated. The results indicated that this alteration has not affected the IGK locus, and the breakpoint was within a 260-kb region located approximately 1 Mb telomerically to the IGK gene. It is probable that the KV3J gene localized in this region could deregulate the expression of cyclin D1.     

Mantle cell lymphoma, in leukaemic phase with prominent splenomegaly. A report of eight cases with similar clinical presentation and aggressive outcome

Mantle cell lymphoma (MCL) is a well-defined peripheral B-cell lymphoma usually diagnosed upon peripheral lymph node biopsy. We report eight cases of peripheral B-cell leukaemia that demonstrate presumptive evidence of mantle cell characteristics. The patients had a median age of 68.5 years, and five were male. All presented with an enlarged spleen without any peripheral lymphadenopathies, and they were leukaemic at presentation (median lymphocytosis, 38x10(9)/l). Morphological diagnosis of MCL was very difficult in five cases but easier in three because we were able to analyse either pre- or post-mortem lymph nodes and spleen. The immunophenotype of blood lymphocytosis using flow cytometry, the presence of a t(11;14)(q13;q32) and a cyclin D1 expression by leukaemic cells all fit with the diagnosis of MCL. All patients progressed and died with a median overall survival of 8 months. Multifocal areas of transformation in blastoid or large cell variants were observed in the three autopsied patients. In summary, one should consider the diagnosis of MCL at presentation in leukaemic phase even in the absence of peripheral adenopathies.     

De novo CD5 positive diffuse large B-cell lymphomas with bone marrow involvement in Korean

In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lymphoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immunoglobulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.     

逆转录聚合酶链反应检测石蜡包埋组织中细胞周期蛋白D1 mRNA对套细胞淋巴瘤的诊断价值

目的 探讨用逆转录聚合酶链反应（RT-PCR）法和竞争性RT-PCR法检测套细胞淋巴瘤（MCL）石蜡包埋组织中细胞周期蛋白D1（cyclin D1）蛋白和mRNA在常规病理工作中的可行性及其诊断和鉴别诊断价值。方法 收集淋巴结内MCL38例、对照组包括结内小B细胞淋巴瘤58例（B小淋巴细胞性淋巴瘤14例,淋巴浆细胞性淋巴瘤3例,滤泡性淋巴34例,淋巴结边缘区B细胞淋巴瘤7例）和淋巴结反应性增生病例20例,用免疫组织化学EnVision法和RT-PCR法、竞争性RT-PCR法检测cyclin D1蛋白及其mRNA的表达,以看家基因PGK作为内对照检测RNA。结果 （1）38例结内MCL中,cyclin D1蛋白阳性率为71．1％（27／38）,对照组均为阴性。（2）116例标本中,可检出内对照PGK基因mRNA表达103例（88．8％）。38例MCL中PGK阳性36例（94．7％）。（3）38例结内MCL中,34例可检出cyclin D1 mRNA表达,去除PGK和cyclin D1 mRNA均阴性的2例,MCL中cyclin D1 mRNA表达的阳性率为94．4％（34／36）。对照组中B小淋巴细胞性淋巴瘤1例检出cyclin D1 mRNA表达,其余病例均未检出cyclin D1 mRNA表达。PCR结果全部经测序证实。（4）用竞争性RT-PCR,38例结内MCL中27例可检出cyclin D1 mRNA高表达,去除2例PGK也为阴性的病例,MCL中cyclin D1 mRNA高表达率为75．0％（27／36）。对照组小B细胞恶性淋巴瘤及淋巴结反应性增生无1例有cyclin D1 mRNA高表达。结论 RT-PCR方法和竞争性RT-PCR方法可在石蜡包埋组织中检测cyclin D1 mRNA的表达,均可用于MCL的诊断。     

CD5(-) diffuse large B-cell lymphoma with peculiar cyclin D1+ phenotype. Pathologic and molecular characterization of a single case

Increased expression of cyclin D1 is notoriously associated with mantle cell lymphoma because of translocation t(11;14)(q13;q32) or variants involving the cyclin D1 gene. We present an unusual case of CD5-negative diffuse large B-cell lymphoma expressing cyclin D1 in the absence of translocation by fluorescence in situ hybridization analysis. Using array-comparative genomic hybridization, we found a complex karyotype without the characteristic chromosomal aberrations accompanying cyclin D1 translocation in mantle cell lymphoma; instead, there was monoallelic deletion of AKT interacting protein and glycogen synthase kinase-3 β genes, both involved in the AKT/glycogen synthase kinase-3 β cascade-controlling nuclear levels of cyclin D1. These findings suggest that posttranslational events regulating cyclin D1 activity may take place also in a subset of diffuse large B-cell lymphomas and contribute to lymphomagenesis. As a consequence, the sole cyclin D1 positivity by immunohistochemistry may not be enough to distinguish pleomorphic/blastoid mantle cell lymphoma from diffuse large B-cell lymphoma. Search for t(11;14) with fluorescence in situ hybridization probes should always be performed in doubtful cases.