Cyclin D1-negative Mantle Cell Lymphoma Research Articles

Clinicopathological and molecular genetic features of cyclin D1-negative mantle cell lymphoma

Objective: To investigate the clinicopathological features and molecular genetics of cyclin D1-negative mantle cell lymphoma (MCL). Methods: The clinicopathological features and molecular genetics of CyclinD1-negative MCL diagnosed between January 2016 and July 2021 at the First Affiliated Hospital of Zhengzhou University were analyzed using immunohistochemistry and fluorescence in situ hybridization. Clinical information was collected and analyzed. Results: A total of five Cyclin D1-negative MCL cases from all 212 MCL patients (5/212, 2.4%)were included. There were three male and two female patients,age ranged from 59 to 70 years (median 64 years). All patients presented with nodal lesions. None of the patients had B symptoms but four had bone marrow involvement. Histopathologically, four cases were classic MCL and one case was pleomorphic variant type. All five cases were negative for Cyclin D1 but SOX-11 were positive in all cases. CD5 was positive in four cases and one case was weakly positive for CD23. CD10 and bcl-6 were negative in all cases. CCND1 translocation was identified in three cases and CCND2 translocation in one case by FISH analysis. However,CCND3 translocations were not found in the five cases. Conclusions: Cyclin D1-negative MCL are uncommon, its accurate diagnosis needs combined analysis with morphologic and immunophenotypic characteristics and genetic changes. It may be particularly difficult to distinguish from other small cell type B cell lymphomas. FISH analyses for CCND1/CCND2/CCND3 translocations and immunohistochemistry for SOX-11 are helpful to resolve such a difficult distinction.

Mantle cell lymphoma in 2022-A comprehensive update on molecular pathogenesis, risk stratification, clinical approach, and current and novel treatments.

The field of mantle cell lymphoma (MCL) has witnessed remarkable progress due to relentless advances in molecular pathogenesis, prognostication, and newer treatments. MCL consists of a spectrum of clinical subtypes. Rarely, atypical cyclin D1-negative MCL and in situ MCL neoplasia are identified. Prognostication of MCL is further refined by identifying somatic mutations (such as TP53, NSD2, KMT2D), methylation status, chromatin organization pattern, SOX-11 expression, minimal residual disease (MRD), and genomic clusters. Lymphoid tissue microenvironment studies demonstrated the role of B-cell receptor signaling, nuclear factor kappa B (NF-kB), colony-stimulating factor (CSF)-1, the CD70-SOX-11 axis. Molecular mechanism of resistance, mutation dynamics, and pathogenic pathways (B-cell receptor (BCR), oxidative phosphorylation, and MYC) were identified in mediating resistance to various treatments (bruton tyrosine kinase (BTK) inhibitors [ibrutinib, acalabrutinib]. Treatment options range from conventional chemoimmunotherapy and stem cell transplantation (SCT) to targeted therapies against BTK (covalent and noncovalent), Bcl2, ROR1, cellular therapy such as anti-CD19 chimeric antigen receptor therapy (CAR-T), and most recently bispecific antibodies against CD19 and CD20. MCL patients frequently relapse. Complex pathogenesis and the management of patients with progression after treatment with BTK/Bcl2 inhibitors and CAR-T (triple-resistant MCL) remain a challenge. Next-generation clinical trials incorporating newer agents and concurrent translational and molecular investigations are ongoing.

Diagnostic accuracy of SOX11 immunohistochemistry in mantle cell lymphoma: Ameta-analysis.

SOX11 is a transcription factor that is normally expressed in the fetal brain and has also been detected in some malignant tumors, including mantle cell lymphoma (MCL). MCL is a mature B-cell lymphoma that characteristically expresses cyclin D1, which has been used as a diagnostic tumor marker. SOX11 has also recently emerged as a tumor marker for MCL, particularly in cyclin D1-negative MCLs and to distinguish between MCLs and other cyclin D1-positive lymphomas. In this study, we evaluated the diagnostic accuracy of SOX11 immunohistochemistry for the diagnosis of MCL using a meta-analysis. A comprehensive literature search was performed using the PubMED, EMBASE, and Cochrane library through May 9, 2018. In total, 14 studies were included in our meta-analysis. The sensitivity, specificity, and area under the curve calculated from the summary receiver operator characteristic were 0.9, 0.95, and 0.934, respectively. Effect sizes of log positive likelihood ratios, log negative likelihood ratios, and log diagnostic odds ratios were 2.67, -2.12, and 5.27, respectively. Statistically significant substantial heterogeneity was observed for specificity (I2 = 95%), but not for sensitivity. Subgroup analysis and meta-regression were performed to explain the heterogeneity in specificity and showed that the proportions of Burkitt's lymphoma, lymphoblastic lymphoma, and hairy cell leukemia were significant covariates among studies using rabbit polyclonal antibodies. Overall, this meta-analysis showed that SOX11 was a useful diagnostic marker for MCL, with the clone MRQ-58 mouse monoclonal antibody showing particularly robust performance.

Mantle cell lymphoma: 2019 update on the diagnosis, pathogenesis, prognostication, and management.

Unprecedented advances in our understanding of the pathobiology, prognostication, and therapeutic options in mantle cell lymphoma (MCL) have taken place in the last few years. Heterogeneity in the clinical course of MCL-indolent vs aggressive-is further delineated by a correlation with the mutational status of the variable region of immunoglobulin heavy chain, methylation status, and SOX-11 expression. Cyclin-D1 negative MCL, in situ MCL neoplasia, and impact of the karyotype on prognosis are distinguished. Apart from Ki-67% and morphology pattern (classic vs blastoid/pleomorphic), the proliferation gene signature has helped to further refine prognostication. Studies focusing on mutational dynamics and clonal evolution on Bruton's tyrosine kinase (BTK) inhibitors (ibrutinib, acalabrutinib) and/or Bcl2 antagonists (venetoclax) have further clarified the prognostic impact of somatic mutations in TP53, BIRC3, CDKN2A, MAP3K14, NOTCH2, NSD2, and SMARCA4 genes. In therapy, long-term follow-up on chemo-immunotherapy studies has demonstrated durable remissions in some patients; however, long-term toxicities, especially from second cancers, are a serious concern with chemotherapy. The therapeutic options in MCL are constantly evolving, with dramatic responses from nonchemotherapeutic agents (ibrutinib, acalabrutinib, and venetoclax). Chimeric antigen receptor therapy and combinations of nonchemotherapeutic agents are actively being studied and our focus is shifting toward making the treatment of MCL chemotherapy-free. Still, MCL remains incurable. The following aspects of MCL continue to pose a challenge: disease transformation, role of the cytokine-microenvironmental milieu, incorporation of positron emission tomography-computerized tomography imaging, minimal residual disease in the prognosis, circulating tumor DNA testing for clonal evolution, predicting resistance to BTK inhibitors, and optimal management of patients who progress on BTK/Bcl2 inhibitors. Next-generation clinical trials should incorporate nonchemotherapeutic agents and personalize the treatment based upon the genomic profile of individual patient. Recent advances in the field of MCL are reviewed.

Mantle cell lymphoma pathology update in the 2016 WHO classification

Mantle cell lymphoma (MCL) is an aggressive mature B-cell neoplasm genetically characterized by the presence of the t(11;14)(q13;q32) that leads to the constitutive overexpression of cyclin D1. The pathological and biological spectrum of this neoplasm has been expanded in recent years. This improvement in the knowledge of the disease has provided a better understanding of the diverse clinical evolution of the patients. The characterization of cyclin D1-negative MCL has led to the identification of cyclin D2 and D3 translocations as alternative mechanisms in this variant. Two major biological and clinical subtypes of the disease have been recognized, conventional and leukemic non-nodal MCL (nnMCL). MCL derives from CD5+ mature B-cells that have bypassed or experienced the germinal center microenvironment, retain a naive or memory-like epigenetic signature and carry a variable load of somatic mutations in the IGHV region; from truly unmutated to highly mutated, respectively. These two subtypes of tumors also differ in their genomic alterations, and clinical behavior, the conventional MCL (cMCL) being more aggressive than the leukemic nnMCL. This review will focus on the new aspects of the pathology of MCL in the updated 2016 WHO classification and its relevance for the clinical practice.

Are we making progress?

This editorial is written a few days before the EAHP/SH meeting in Uppsala, when you read it, the meeting will be over. Although successes of the past do not guarantee success in the future, I am confident that the workshops and symposia will be very good, and that I will learn a lot. Preparing myself for the meeting brings several thoughts: is it worth the hassle? The days before leaving the laboratory for a week are very busy: I have to finish my cases as much as possible, arrange for handling upcoming results from molecular tests, want to finish all kinds of other issues, want to read the latest literature to be prepared for discussions, prepare the workshop, etc. And I know that after my return, my desk will be full of all kinds of pressing matters. There will soon be an excellent workshop report and the best papers will be published fast too, so why go? In the first place, it is fun: it is great to meet my colleagues, to hear what they try to find out, the thoughts they have on cases and concepts, and to see Uppsala for the first time and enjoy its culture (including culinary). In the second place, it is good to experience in person the progress of hematopathology. We will discuss difficult cases with many experts, and this cannot be replaced by reading journals, not even the Journal of Hematopathology. And thirdly, and maybe the most important, to be in another environment outside the lab and daily life and to be immersed in hematopathology makes it possible to really think about our profession: something that is important to do regularly. One thought comes up when reading the recent literature: are we making progress? Of course we know much more than years ago—on proteins, genes, and miRNAs that are important for lymphoma development; we have many more (sub)entities that we can diagnose; and we all use more tools tomake a diagnosis in our routine practice. But does it help the patient at all? What good is it to know that there is activated B cell type of diffuse large B cell lymphoma? That there is such a thing as cyclinD1 negative mantle cell lymphoma or EBVassociated diffuse large B cell lymphoma of the elderly? And to be honest, didn’t Prof. Lennert recognize all these new things already in a Giemsa stain? Some epidemiologists report that we are not making progress in cancer treatment, that we are treating earlier precursors or less aggressive forms which only suggests that survival is better, but that the same amount or even more persons die of cancer. Well, this might be true for prostate cancer and breast cancer, but I believe that in lymphomas, real progress can be shown, with mantle cell lymphoma as a prime example. We hematopathologists can be really proud that we were able to recognize this entity and made it possible that it is diagnosed reliably. This has resulted in large multicenter studies, with serious improvement of the survival. So, yes, I really look forward to a great meeting, which will be enjoyable, and also will give me the feeling that I do something good for my patients; what more can you want!

SOX11 is a biomarker for cyclin D1-negative mantle cell lymphoma.

Cyclin D1 (CCND1) protein overexpression and/or the t(11;14)(q13;q32) translocation are the pathognomonic hallmarks of mantle cell lymphoma (MCL). However, there have been cases that lacked both t(11;14) and cyclin D1 protein but still had a gene expression profile suggesting a diagnosis of MCL. SOX11 expression was detected in most cyclin D1- negative MCL and can serve as a specific biomarker for the diagnosis of this subset of MCL. Lack of SOX11 expression in MCL was associated with an indolent subset and favorable prognosis.

Mantle cell lymphoma--a spectrum from indolent to aggressive disease.

Mantle cell lymphoma (MCL) is a distinctive lymphoma type generally characterized by the presence of CCND1 translocation and overexpression of cyclin D1. MCL usually presents with advanced stage and rapid clinical progression. The diagnosis is in most instances uncomplicated but cases with variant morphologies or immunophenotypes, especially cyclin D1-negative cases, may cause diagnostic difficulties. During the mantle cell lymphoma (MCL) session at the European Association of Haematopathology/Society for Hematopathology workshop 2014 held in Istanbul, Turkey, submitted cases illustrated interesting features such as unusual morphology or immunophenotypes. In several submitted cases of cyclin D1-positive MCL, CCND1 rearrangement could not be detected by t(11;14)(q13;q32) dual-color dual-fusion FISH but was suggested by CCND1 break-apart probes, and advantages and disadvantages of different FISH probes were highlighted. Three cyclin D1-negative MCL cases were submitted. These were identified by SOX11 immunohistochemistry and found to carry CCND2 translocations and/or to express high levels of cyclin D2 mRNA. Features associated with aggressive clinical course were presented including high expression of p53 protein and MYC aberrations. The need to integrate histological, immunophenotypic, genetic, and clinical data to arrive at the correct diagnosis was emphasized.

Utility and diagnostic pitfalls of SOX11 monoclonal antibodies in mantle cell lymphoma and other lymphoproliferative disorders.

Mantle cell lymphoma (MCL) is classically characterized by t(11;14) leading to cyclin D1 overexpression. Recently the transcription factor SOX11 has been discovered to be expressed in most MCL, including cyclin D1-negative cases. In this study we assess the performance of 2 commercially available monoclonal antibodies, Atlas Antibodies (Stockholm, Sweden) clone CLO142 and Cell Marque (Rocklin, CA) clone MRQ-58, for SOX11 immunohistochemistry in MCL, both cyclin D1 positive and cyclin D1 negative, as well as in cases of other small B-cell lymphoproliferative disorders, diffuse large B-cell lymphomas (DLBCLs), Burkitt lymphomas, and lymphoblastic leukemia/lymphomas. We also performed Western blots to further characterize the antibody specificity. Both antibodies show reliable, clear nuclear staining in MCL with variable specificity. However, the MRQ-58 antibody was more specific for MCL than CLO142, which showed considerably more nonspecific staining, especially in DLBCLs (59% positive vs. 4% positive with MRQ-58). In addition we reconfirmed the utility of SOX11 IHC for identifying cases of cyclin D1-negative blastoid MCL. However, we also identified cases of SOX11-positive DLBCL and splenic marginal zone lymphoma. Although SOX11 IHC is a powerful, and relatively accessible, tool to identify MCLs with variant immunophenotypes and/or morphology, these latter 2 cases highlight the need for strict criteria for interpreting SOX11 staining.

Flow cytometric analysis of SOX11: a new diagnostic method for distinguishing B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma from mantle cell lymphoma

The differential diagnosis between mantle cell lymphoma (MCL) and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (B-CLL/SLL) is essential, since MCL usually has a more aggressive clinical course. By flow cytometry both MCL and B-CLL are CD19, CD20 and usually CD5 positive. However, ambiguities in other immune phenotypic markers of these lymphoma entities sometimes complicate the flow cytometric differential diagnosis. We here demonstrate that the transcription factor SOX11, which is highly up-regulated in most MCL, can be analyzed by flow cytometry. SOX11 protein could be consistently detected in ex vivo isolated MCL but not in B-CLL/SLL. Flow cytometry also enabled protein quantification, and SOX11 protein levels correlated with mRNA expression. We suggest that implementing detection of SOX11 in diagnostic flow cytometry would be beneficial for accurate and reliable diagnosis of MCL, especially for distinguishing cases of MCL and B-CLL/SLL with aberrant immune phenotypes, and for cases of rare cyclin D1 negative MCL.

Assessment of SOX11 Expression in Routine Lymphoma Tissue Sections

The diagnosis of mantle cell lymphoma (MCL) can be difficult, especially when no t(11;14) translocation and cyclin D1 overexpression can be detected. In such cases, the transcription factor SOX11 represents an important diagnostic marker, as it is expressed in most MCLs and, in particular, in all cyclin D1-negative MCLs reported so far. A reliable anti-SOX11 antibody is therefore a very useful tool for routine diagnosis. Here, we characterize the new monoclonal anti-SOX11 antibodies, suitable for Western blot assay and immunohistochemistry (IHC) on formalin-fixed paraffin-embedded tissue; we tested them on a large series of primary lymphoid tumors and compared these results with those of other routinely used antibodies. Moreover, we show that IHC results depend on transcription levels of SOX11, which suggests that posttranscriptional and posttranslational modifications do not significantly affect cutoff levels for IHC detection of SOX11.

Genome-wide miRNA profiling of mantle cell lymphoma reveals a distinct subgroup with poor prognosis

AbstractmiRNA deregulation has been implicated in the pathogenesis of mantle cell lymphoma (MCL). Using a high-throughput quantitative real-time PCR platform, we performed miRNA profiling on cyclin D1–positive MCL (n = 30) and cyclin D1–negative MCL (n = 7) and compared them with small lymphocytic leukemia/lymphoma (n = 12), aggressive B-cell lymphomas (n = 138), normal B-cell subsets, and stromal cells. We identified a 19-miRNA classifier that included 6 up-regulated miRNAs and 13 down regulated miRNA that was able to distinguish MCL from other aggressive lymphomas. Some of the up-regulated miRNAs are highly expressed in naive B cells. This miRNA classifier showed consistent results in formalin-fixed paraffin-embedded tissues and was able to distinguish cyclin D1–negative MCL from other lymphomas. A 26-miRNA classifier could distinguish MCL from small lymphocytic leukemia/lymphoma, dominated by 23 up-regulated miRNAs in MCL. Unsupervised hierarchical clustering of MCL patients demonstrated a cluster characterized by high expression of miRNAs from the polycistronic miR17-92 cluster and its paralogs, miR-106a-363 and miR-106b-25, and associated with high proliferation gene signature. The other clusters showed enrichment of stroma-associated miRNAs, and also had higher expression of stroma-associated genes. Our clinical outcome analysis in the present study suggested that miRNAs can serve as prognosticators.

Cyclin D1-negative Blastoid Mantle Cell Lymphoma Identified by SOX11 Expression

SOX11 expression has been recently shown to be useful in the diagnosis of mantle cell lymphoma (MCL), including cyclin D1-negative MCL with typical morphology. We evaluated SOX11 expression pattern in B-cell non-Hodgkin lymphoma (B-NHL) subtypes to confirm specificity and used it as a feature to identify the first reported cases of cyclin D1-negative blastoid MCL. SOX11 expression was evaluated by immunohistochemistry in 140 cases of mature B-NHL, including 4 cases of suspected blastoid MCL that lacked cyclin D1 expression and 8 cases of CD5-positive diffuse large B-cell lymphoma (DLBL). In addition, 5 cases of B or T lymphoblastic lymphoma were included. Nuclear expression of SOX11 was found in cyclin D1-positive MCL (30/30, 100%) and in a case of cyclin D1-negative MCL with typical morphology. SOX11 was also expressed in Burkitt lymphoma (1/5, 20%) and lymphoblastic lymphoma (2/3 T-LBLs, 2/2 B-LBLs, overall 4/5, 80%), whereas all cases of DLBL (including CD5 DLBL) and other small B-NHL were negative. The 4 suspected cases of blastoid MCL were also SOX11. These cases had a complex karyotype that included 12p abnormalities. We confirmed prior reports that stated that SOX11 nuclear expression was a specific marker for MCL, including cyclin D1-negative MCL with typical morphology. To our knowledge, this is the first report regarding its use in identifying cases of cyclin D1-negative blastoid MCL. Routine use of SOX11 in cases of suspected CD5 DLBL might help identify additional cases of cyclin D1-negative blastoid MCL.

Histopathology of Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a relatively rare lymphoma, accounting for less than 10% only of all lymphomas. Its morphology is quite homogeneous, but it varies strikingly in about 10% of the cases, making the diagnosis of MCL challenging for histopathologists. The definition of the disease was greatly influenced by the discovery of the translocation t(11;14)(q13,q32), which juxtaposes the cyclin D1 and the immunoglobulin heavy chain genes and is present in the vast majority of MCL cases. The introduction of monoclonal antibodies for the detection of cyclin D1 expression into the diagnostic procedure substantially improved the reproducibility and reliability of the pathological diagnosis. However, new challenges for histopathologists have arisen over the last years, among which are the detection of cyclin D1-negative MCL cases and clinically relevant prognostic subgroups.

CD5-positive, cyclinD1-negative mantle cell lymphoma with a translocation involving the CCND2 gene and the IGL locus

Distinguishing mantle cell lymphoma (MCL), from low-grade B-cell lymphoma is important because MCL is clinically more aggressive and is treated differently. Though most MCL overexpress cyclinD1 (CCND1) and have a t(11;14)(q13;q32), MCL that are negative for CCND1 exist. Some have translocations involving cyclinD2 (CCND2) and either the immunoglobulin heavy chain or kappa light chain locus. We present a CD5-positive, CCND1-negative B-cell lymphoma with a novel translocation involving CCND2 and the immunoglobulin lambda (IGL) gene. A 64-year-old male underwent resection of a polypoid mass of the ileum. Histology showed atypical, medium-sized lymphoid cells positive for CD20, CD5, CD43, and CCND2 by immunohistochemistry, and negative for CCND1, CCND3, and p27. Fluorescence in situ hybridization was negative for CCND1 abnormalities, but demonstrated a CCND2/IGL fusion. Clinical workup revealed stage IV disease. Current diagnostic criteria are insufficient for subclassifying this case, highlighting the need for additional studies on CCND2-translocated B-cell lymphomas to guide therapy appropriately.

Are we making progress?

This editorial is written a few days before the EAHP/SH meeting in Uppsala, when you read it, the meeting will be over. Although successes of the past do not guarantee success in the future, I am confident that the workshops and symposia will be very good, and that I will learn a lot. Preparing myself for the meeting brings several thoughts: is it worth the hassle? The days before leaving the laboratory for a week are very busy: I have to finish my cases as much as possible, arrange for handling upcoming results from molecular tests, want to finish all kinds of other issues, want to read the latest literature to be prepared for discussions, prepare the workshop, etc. And I know that after my return, my desk will be full of all kinds of pressing matters. There will soon be an excellent workshop report and the best papers will be published fast too, so why go? In the first place, it is fun: it is great to meet my colleagues, to hear what they try to find out, the thoughts they have on cases and concepts, and to see Uppsala for the first time and enjoy its culture (including culinary). In the second place, it is good to experience in person the progress of hematopathology. We will discuss difficult cases with many experts, and this cannot be replaced by reading journals, not even the Journal of Hematopathology. And thirdly, and maybe the most important, to be in another environment outside the lab and daily life and to be immersed in hematopathology makes it possible to really think about our profession: something that is important to do regularly. One thought comes up when reading the recent literature: are we making progress? Of course we know much more than years ago—on proteins, genes, and miRNAs that are important for lymphoma development; we have many more (sub)entities that we can diagnose; and we all use more tools tomake a diagnosis in our routine practice. But does it help the patient at all? What good is it to know that there is activated B cell type of diffuse large B cell lymphoma? That there is such a thing as cyclinD1 negative mantle cell lymphoma or EBVassociated diffuse large B cell lymphoma of the elderly? And to be honest, didn’t Prof. Lennert recognize all these new things already in a Giemsa stain? Some epidemiologists report that we are not making progress in cancer treatment, that we are treating earlier precursors or less aggressive forms which only suggests that survival is better, but that the same amount or even more persons die of cancer. Well, this might be true for prostate cancer and breast cancer, but I believe that in lymphomas, real progress can be shown, with mantle cell lymphoma as a prime example. We hematopathologists can be really proud that we were able to recognize this entity and made it possible that it is diagnosed reliably. This has resulted in large multicenter studies, with serious improvement of the survival. So, yes, I really look forward to a great meeting, which will be enjoyable, and also will give me the feeling that I do something good for my patients; what more can you want!

Expression of sphingosine-1-phosphate receptor 1 in mantle cell lymphoma

The distribution and pathological significance of sphingosine-1-phosphate receptor 1 expression are still unclear. In this study, we evaluated sphingosine-1-phosphate receptor 1's suitability as a diagnostic marker for malignant lymphoma by immunostaining formalin-fixed paraffin-embedded sections using a well-defined commercial anti-sphingosine-1-phosphate receptor 1 antibody. Sphingosine-1-phosphate receptor 1 was strongly expressed on the surface of small lymphocytes forming primary lymphoid follicles and in the mantle zone of secondary lymphoid follicles. Microarray-based immunohistochemistry with tissue samples from 85 lymphoid malignancy cases demonstrated that sphingosine-1-phosphate receptor 1 was expressed on the surface of mantle cell lymphoma cells. Strong expression was observed in all classical mantle cell lymphoma cases involving the lymph node (19 out of 19), gastrointestinal tract (10 out of 10), bone marrow (9 out of 9), and orbita (1 out of 1). Good results were obtained even in sections where cyclin D1 signals were lost because of over-fixation and/or decalcification. One aggressive variant of mantle cell lymphoma displayed a weaker membranous staining than classical mantle cell lymphoma in the lymph node and bone marrow. In a cyclin D1-negative mantle cell lymphoma of the orbita, no conclusive result was obtained. No cases of follicular lymphoma, marginal zone lymphoma, B lymphoblastic leukemia/lymphoma, or Burkitt's lymphoma showed any significant expression, whereas 2 out of 6 chronic lymphocytic leukemia/small lymphocytic lymphomas in bone marrow, 1 out of 3 lymphoplasmacytic lymphomas in the lymph node, and 2 out of 37 diffuse large B-cell lymphomas exhibited staining. A quantitative reverse transcription polymerase chain reaction-based analysis of mantle cell lymphoma lines revealed the sphingosine-1-phosphate receptor 1 mRNA expression level to be well correlated with the results of immunocytochemistry, flow cytometry, and western blotting. Thus, sphingosine-1-phosphate receptor 1 immunohistochemistry may be useful in the histological diagnosis of mantle cell lymphoma with formalin-fixed and paraffin-embedded sections. The antigen may be particularly valuable in cases where cyclin D1 immunostaining is not successful.

SOX11 expression is highly specific for mantle cell lymphoma and identifies the cyclin D1-negative subtype

Cyclin D1-negative mantle cell lymphoma is difficult to distinguish from other small B-cell lymphomas. The clinical and pathological characteristics of patients with this form of lymphoma have not been well defined. Overexpression of the transcription factor SOX11 has been observed in conventional mantle cell lymphoma. The aim of this study was to determine whether this gene is expressed in cyclin D1-negative mantle cell lymphoma and whether its detection may be useful to identify these tumors. The microarray database of 238 mature B-cell neoplasms was re-examined. SOX11 protein expression was investigated immunohistochemically in 12 cases of cyclin D1-negative mantle cell lymphoma, 54 cases of conventional mantle cell lymphoma, and 209 additional lymphoid neoplasms. SOX11 mRNA was highly expressed in conventional and cyclin D1-negative mantle cell lymphoma and in 33% of the cases of Burkitt's lymphoma but not in any other mature lymphoid neoplasm. SOX11 nuclear protein was detected in 50 cases (93%) of conventional mantle cell lymphoma and also in the 12 cyclin D1-negative cases of mantle cell lymphoma, the six cases of lymphoblastic lymphomas, in two of eight cases of Burkitt's lymphoma, and in two of three T-prolymphocytic leukemias but was negative in the remaining lymphoid neoplasms. Cyclin D2 and D3 mRNA levels were significantly higher in cyclin D1-negative mantle cell lymphoma than in conventional mantle cell lymphoma but the protein expression was not discriminative. The clinico-pathological features and outcomes of the patients with cyclin D1-negative mantle cell lymphoma identified by SOX11 expression were similar to those of patients with conventional mantle cell lymphoma. SOX11 mRNA and nuclear protein expression is a highly specific marker for both cyclin D1-positive and negative mantle cell lymphoma.

Translocations targeting CCND2, CCND3, and MYCN do occur in t(11;14)-negative mantle cell lymphomas

AbstractThe genetics of t(11;14)(q13;q32)/cyclin D1–negative mantle cell lymphoma (MCL) is poorly understood. We report here 8 MCL cases lacking t(11;14) or variant CCND1 rearrangement that showed expression of cyclin D1 (2 cases), D2 (2 cases), and D3 (3 cases). One case was cyclin D negative. Cytogenetics and fluorescence in situ hybridization detected t(2;12)(p11;p13)/IGK-CCND2 in one of the cyclin D2-positive cases and t(6;14)(p21;q32)/IGH-CCND3 in one of the cyclin D3-positive cases. Moreover, we identified a novel cryptic t(2;14)(p24;q32) targeting MYCN in 2 blastoid MCLs: one negative for cyclin D and one expressing cyclin D3. Interestingly, both cases showed expression of cyclin E. Notably, all 3 blastoid MCLs showed a monoallelic deletion of RB1 associated with a lack of expression of RB1 protein and monoallelic loss of p16. In sum-mary, this study confirms frequent aberrant expression of cyclin D2 and D3 in t(11;14)-negative MCLs and shows a t(11;14)-independent expression of cy-clin D1 in 25% of present cases. Novel findings include cyclin E expression in 2 t(11;14)-negative MCLs characterized by a cryptic t(2;14)(p24;q32) and identification of MYCN as a new lymphoma oncogene associated with a blastoid MCL. Clinically important is a predisposition of t(11;14)-negative MCLs to the central nervous system involvement.

CD5‐positive mucosa‐associated lymphoid tissue (MALT) lymphoma of ocular adnexal origin: Usefulness of fluorescence in situ hybridization for distinction between mantle cell lymphoma and MALT lymphoma

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma) usually lacks CD5 expression. Herein is described two cases of CD5-positive MALT lymphoma of ocular adnexal origin. The differential diagnosis between CD5-positive MALT lymphoma and mantle cell lymphoma (MCL), notably cyclin D1-negative MCL, was difficult because both cases consisted histologically of small to medium-sized cells with diffuse or vaguely nodular growth pattern, and the neoplastic cells were positive for CD5 and negative for cyclin D1. Somatic mutation analysis of the immunoglobulin heavy chain variable region (VH) gene in case 1 found a relatively higher mutation frequency (5.0%), which was not definitive to rule out MCL. Interphase fluorescence in situ hybridization (FISH) on paraffin-embedded section using IgH/cyclin D1 (CCND1) probe showed that in both cases there was no molecular evidence of t(11;14), finally leading to the diagnosis of CD5-positive MALT lymphoma. Although the present two patients had no recurrence over 34 months after initial diagnosis, careful observation is needed because the clinicopathological significance of MALT lymphoma with this rare phenotype remains obscure.