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.     

An uncommon case of de novo CD10+ CD5? mantle cell lymphoma mimics follicle center B cell lymphoma

Mantle cell lymphoma (MCL) is a mature B-cell lymphoma characterized by expression of CD5, overexpres-sion of Cyclin D1 as a result of chromosomal translocation t(11;14)(q13;q32), and poor prognosis. Cases of MCL lacking CD5 expression as well as cases with coexpression of CD5 and CD10 have also been reported. Here we describe an uncommon case of de novo MCL with expression of CD10, but not CD5, mimicking lymphoma of germinal center-derived B cells. The lymphoma cells in this case demonstrated a diffuse pattern of proliferation, and were strongly positive for Cyclin D1 by immunohistochemical stain. Fluorescence in situ hybridization studies demonstrated the presence of t(11;14)(q13;q32) involving BCL1, but not chromosomal translocations involving C-MYC or BCL2, confirming the diagnosis of MCL. This case further highlights the importance of comprehensive immunopheno-typic and genetic characterization in the diagnosis and classification of B-cell lymphomas.     

Cyclin D1 over expression in malignant lymphomas

Cyclin D1, the regulatory subunit of certain protein kinases thought to advance the G₁ phase of the cell cycle, is now established as a protooncogene, with evidence indicating that its derangement may contribute to the uncontrolled cell growth characteristic of tumors. The chromosomal translocation t(11;14)(q 13 :q32), Involving rearrangement of the BCL-1 locus, is closely associated wlth human lymphoid neoplasia affecting mantle cell lymphomas (MCL). Recently, the putative BCL-1 protosncogene turned out to be none other than the cydin D1 gene. Although the observed break points In the BCL-7 locus are not tightly clustered, Its rearrangement has been documented In 40–70% of cases of mantle cell lymphoma, whereas it only rarely occurs in other B cell lymphomas. Of note, all of the known break points leave the cyclin D1 coding region structurally Intact and result In increased protein expression, implying that this may provide a highly sensitive and specific marker for MCL. Recent studies demonstrated that immunohistochemical detection In paraffin-embedded material, using a mone clonal antibody, Is very useful for routine diagnosis. Current knowledge of cydin D1 over expression In malignant lymphomas, with emphasis on its clinic pathologic significance, is reviewed.     

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.     

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.     

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).     

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.     

套细胞淋巴瘤石蜡包埋组织中细胞周期蛋白D1和t(11;14)易位检测的临床病理意义

目的 探讨套细胞淋巴瘤石蜡包埋组织中细胞周期蛋白(cyclin)D1和t(11;14)易位检测的可行性及其诊断和鉴别诊断价值。方法 收集套细胞淋巴瘤36例,对照组小B细胞恶性淋巴瘤71例,均为石蜡包埋组织,运用免疫组织化学方法观察cyclin D1的表达;用半巢式聚合酶链反应(PCR)法检测t(11;14)易位,以看家基因β-肌动蛋白(actin)作为内对照检测DNA质量。结果 (1)36例套细胞淋巴瘤中26例(72．2％)表达cyclin D1,对照组无1例表达。(2)107例标本中101例(94．4％)可检出β-actin DNA表达。36例套细胞淋巴瘤中22例检出t(11;14)易位,对照组无1例检出。去除B-actin和t(11;14)易位均阴性2例,套细胞淋巴瘤中t(11;14)易位检出率为64．7％。(3)36例套细胞淋巴瘤中cyclin D1染色和(或)t(11;14)易位检测阳性病例为29例,总阳性率为80．5％。结论套细胞淋巴瘤石蜡包埋组织中cyclin D1和t(11;14)易位的检测具较高的特异性和可行性,两者的综合应用有助于正确的诊断和鉴别诊断。     

Mantle cell lymphoma: recent insights into pathogenesis, clinical variability, and new diagnostic markers

Mantle cell lymphoma (MCL; previously called centrocytic lymphoma or lymphocytic lymphoma of intermediate differentiation) is a distinct subtype of B-cell lymphoma, accounting for approximately 3%-10% of all lymphoma diagnoses. The name refers to the growth pattern in early disease presentation resembling the normal mantle zone that surrounds the germinal center of the B-cell follicle. The hallmark of MCL is the t(11;14)(q13;q32), resulting in aberrant expression of the CCND1 gene and expression of cyclin D1 in the tumor cells. Expression and genomic profiling of MCL have provided new insight into the pathogenesis and will be summarized in this review. Pitfalls in the differential diagnosis versus B-cell chronic lymphocytic leukemia, B-cell prolymphocytic leukemia, cyclin D1-positive diffuse large B-cell lymphoma, hairy cell leukemia, and plasma cell tumors will be discussed, including the usefulness new diagnostic markers SOX11 and CD200. In situ MCL, MCL with an indolent clinical course, and cyclin D1-negative MCL are other topics of this review.     

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.     

Mantle cell lymphoma in Taiwan: clinicopathological and molecular study of 21 cases including one cyclin D1-negative tumor expressing cyclin D2

Mantle cell lymphoma (MCL) is a rare B-cell lymphoma that has never been characterized in Taiwan. The purpose of the present paper was to retrospectively identify 21 cases in male patients, with a median age of 61, involving lymph node (91%), marrow (71%), and peripheral blood (23%). Eighteen (86%) were in stages III/IV with 1 and 5 year survival rates of 78% and 17%, respectively. Mixed nodular and diffuse pattern (45%) was most common while interstitial pattern (92%) predominated in marrow. Eighteen (86%) were of classical morphology, two were pleomorphic and one was blastic. The tumors expressed IgM and bcl-2 (100%), cyclin D1 (95%), CD5 (86%), CD43 and IgD (62%), CD52 (60%), and bcl-6 (5%). Ki-67 index>or=30% (P=0.1834) was associated with a trend toward poorer survival while p21, p27, or p53 expression was not statistically significant for survival. Real-time polymerase chain reaction for cyclin D1 (CCND1) gene mRNA expression showed high levels in nine cyclin D1-positive patients and a low level in the single cyclin D1-negative patient. The latter patient was cyclin D2 positive and negative for immunoglubuin heavy chain gene and CCND1 gene translocation by locus-specific interphase fluorescent in situ hybridization. In conclusion, it is confirmed that the usual morphological variants and aberrant immunophenotype of MCL in the West occur in Taiwan and that this disease carries a poor prognosis.     

Immunohistochemical analysis of cyclin D1 shows deregulated expression in multiple myeloma with the t(11;14)

The t(11;14)(q13;q32) chromosomal translocation, the hallmark of mantle cell lymphoma (MCL), is recurrently found in multiple myelomas (MM) by means of conventional cytogenetics. Unlike MCL, recent molecular studies of MM-derived cell lines with t(11;14) have indicated that the breakpoints are highly dispersed over the 11q13 region; however, the fact that cyclin D1 is generally overexpressed in these cell lines suggests that this gene is the target of the translocation. To evaluate further the involvement of cyclin D1 in MM, we used immunohistochemistry and fluorescence in situ hybridization to investigate cyclin D1 expression and the presence of chromosome 11 abnormalities in a representative panel of 48 MM patients (40 at diagnosis and 8 at relapse). Cyclin D1 overexpression occurred in 12/48 (25%) of cases; combined immunohistochemistry and fluorescence in situ hybridization analyses in 39 patients showed cyclin D1 positivity in all of the cases (7/7) bearing the t(11;14), in two of the 13 cases with trisomy 11, and in one of the 19 cases with no apparent abnormalities of chromosome 11. Our data indicate that the t(11;14) translocation in MM leads to cyclin D1 overexpression and that immunohistochemical analysis may represent a reliable means of identifying this lesion in MM.     

CD5-undetected by immunohistochemistry, t(11;14)(q13;q32)-positive conjunctival mantle cell lymphoma: a case report

Most primary ocular adnexal lymphomas are extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT). A few cases of ocular adnexal mantle cell lymphomas have been reported in the literature. We present a case of mantle cell lymphoma presenting as conjunctival mass. A 58-year-old man presented with a palpable mass in the left lower tarsal conjunctiva incidentally detected one month previously. Histopathologic examination showed proliferation of monomorphous small-to-medium sized lymphoid cells. On immunohistochemistry, tumor cells were positive for CD20, bcl-2, and cyclin D1, and negative for CD5. PCR analysis for immunoglobulin heavy chain gene rearrangement showed monoclonal B-cell proliferation. t(11;14)(q13;q32), involving the CCND1 and IGH genes, was detected in interphase fluorescent in situ hybridization using formalin-fixed, paraffin-embedded tissue; however, MALT1 gene translocation was not observed. The final diagnosis was mantle cell lymphoma. There was no lymphadenopathy; however, bone marrow involvement of the lymphoma was suspected. The patient has been receiving systemic chemotherapy. This case emphasizes the differential diagnosis of conjunctival mantle cell lymphoma from extranodal marginal zone B-cell lymphomas of MALT regarding the clinical and pathological aspects.     

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.     

Gene rearrangement of bcl-1 and bcl-2 is confined to distinct subgroups of high-grade malignant B-cell lymphomas

The occurrence of bcl-1 and bcl-2 gene rearrangements was investigated in 37 cases of high-grade B-cell lymphomas. Bcl-2 rearrangement was detectable only in single cases of primary centroblastic lymphoma with a follicular growth pattern, whereas secondary centroblastic lymphomas evolving from a centroblastic–centrocytic lymphoma were positive in up to 60 per cent of the cases analysed. Bcl-1 rearrangement was found only in one case of immunoblastic B-cell lymphoma with a history of a pre-existing lymphoplasmacytoid immunocytoma. It is concluded that there may be a subgroup of centroblastic lymphomas with a biology similar to that of centroblastic–centrocytic lymphomas. The detection of bcl-1 rearrangement in high-grade lymphomas may indicate a secondary high-grade lymphoma.