Coexistence of hepatoma with mantle cell lymphoma in a hepatitis B carrier

The coexistence of hepatocellular carcinoma (HCC) and non-Hodgkin’s lymphoma (NHL) in the liver is rare. Reports show that these patients have cirrhotic livers or hepatitis virus infections before they develop HCC and NHL. We present a patient with hepatitis B virus infection who was transferred to our hospital with a newly detected liver mass; abdominal computed tomography examination showed one hypodense mass of 7 cm in diameter and multiple mesenteric and mediastinal lymph nodes. A liver tumor biopsy showed a hepatoma, and the pathologic findings from an inguinal lymph node excision showed mantle cell lymphoma. An immunohistochemical stain confirmed that the atypical lymphoid cells within the HCC were positive for the CD20, CD5 and cyclin D1 antigens. Taking these findings into account, the hepatic tumor was determined to be a HCC infiltrated by mantle cell lymphoma.

Detection of t(12;14)(p13;q32) in a patient with IGH-CCND1 negative mantle cell lymphoma resembling ultra-high risk chronic lymphocytic leukemia

T(12;14)(p13;q32) is a rare recurrent chromosomal translocation, which has only been identified in a small subgroup of mantle cell lymphoma (MCL) without typical t(11;14)(q13;q32). This rearrangement causes aberrant over-expression of cyclin D2 (CCND2), which disrupts the normal cell cycle. Here we report a subtle case of MCL with t(12;14)(p13;q32) that was initially misdiagnosed as ultra-high risk chronic lymphocytic leukemia (CLL). A 60-year-old male patient presented with obvious leukocytosis and progressive weakness. Morphology of peripheral blood and immunophenotyping by flow cytometry pointed to a diagnosis of chronic lymphocytic leukemia. Fluorescence in situ hybridization (FISH) using IGH-CCND1 probe was negative for CCND1 abnormality, but demonstrated IGH breakapart signals. The initial diagnosis of CLL was established and the patient was treated with six courses of immunochemotherpy with fludarabine, cyclophosphamide and rituximab (FCR). Complete remission (CR) was achieved at the end of treatment, but disease relapsed quickly. The patient was transferred to our hospital, flow cytometry using additional markers showed that the clonal cells were CD200+(dim), CD148+(strong), and chromosome analysis revealed a complex karyotype, 47, XY, t(12;14)(p13;q32), +12, del(9p21), which indicated over-expression of CCND2, and immunostaining showed strong positivity of SOX11 further confirming the characteristics of CCND1-negtive MCL. The final diagnosis was revised to rare subtype of MCL with CCND2 translocation and intensive regimens were employed. This confusable MCL case illustrates the importance of cytogenetic analysis and clinicopathologic diagnosis of this rare category of MCL.

18F-FDG PET/CT imaging for a gastrointestinal mantle cell lymphoma with multiple lymphomatous polyposis

Multiple lymphomatous polyposis (MLP) is an uncommon type of gastrointestinal lymphoma characterized by the presence of multiple polyps along the gastrointestinal tract. Most of this entity is in fact considered the counterpart of gastrointestinal tract involvement for mantle cell lymphoma (MCL). To our knowledge, there have been no reports on [fluorine-18]-fluorodeoxy-glucose (¹⁸F-FDG)-positron emission tomography (PET)/computed tomography (CT) imaging for gastrointestinal MCL with MLP. We present the results of ¹⁸F-FDG PET/CT imaging in a patient with gastrointestinal tract involvement of MCL showing continuous MLP from the stomach to the rectum and intestinal intussusception. FDG-PET/CT findings were false negative in typical MLP spreading widely over the gastrointestinal tract, but uptake was noted in large lesions with deep infiltration considered atypical as MLP. On FDG-PET/CT imaging, the Ki-67 proliferative index, which is a cell proliferation marker, showed neither correlation with the presence of uptake nor the maximum standardized uptake value.

A novel quantitative PCR of proliferation markers (Ki-67, topoisomerase IIalpha, and TPX2): an immunohistochemical correlation, testing, and optimizing for mantle cell lymphoma

A clinical course of patients with mantle cell lymphoma (MCL) is aggressive, and the disease is rarely curable. Proliferation rate is the most important prognostic factor. We developed a novel, reliable, rapid, and routinely applicable approach allowing a precise quantitative assessment of three proliferation markers, Ki-67, topoisomerase IIalpha, and TPX2. A total of 95 lymphoma specimens were measured in the study by real-time reverse transcription PCR (RQ-RT-PCR). We tested the reproducibility and accuracy of the assay and correlated the results with the immunohistochemical staining of the corresponding proteins. The results obtained indicated individual variability of the mRNA expression levels, reflecting heterogeneity of the proliferation rate in individual patients. In general, we observed the highest mRNA expression in the group of Burkitt lymphomas and the lowest in patients with reactive lymphadenopathies. We found increased proliferation rate in MCLs with high cyclin D1 mRNA, indicating a quantitative control of the cell cycle. We observed a correlation between mRNA expression level and the immunohistochemical staining of corresponding proteins, which significantly argues for the prognostic significance of the mRNA expression measuring. We confirmed the accuracy of the current assay for a precise quantitative examination of the proliferation activity. Real-time RT-PCR provides a novel approach applicable for clinical trials, and it represents a potent approach allowing to stratify MCL patients for entry into clinical trials according to the expression of the proliferation signature genes in their tumors. This approach may contribute to improved and individualized therapeutic options respecting the individual progression risk of patients with MCL.

Protein profiling of plasma membranes defines aberrant signaling pathways in mantle cell lymphoma

We used shotgun proteomics to identify plasma membrane and lipid raft proteins purified from B cells obtained from mantle cell lymphoma (MCL) patients in leukemic phase. Bioinformatics identified 111 transmembrane proteins, some of which were profiled in primary MCL cases, MCL-derived cell lines, and normal B cells using RT-PCR and Western blotting. Several transmembrane proteins, including CD27, CD70, and CD31 (PECAM-1), were overexpressed when compared with normal B cells. CD70 was up-regulated (>10-fold) in three of five MCL patients along with its cognate receptor CD27, which was up-regulated (4-9-fold) in five of five patients, suggesting that MCL cells may undergo autocrine stimulation via this signaling pathway. Activated calpain I and protein kinase C betaII were also detected in the plasma membranes, suggesting that these proteins are constitutively active in MCL. Protein kinase C betaII has been associated with lipid rafts, and shotgun proteomics/protein profiling revealed that key lipid raft proteins, raftlin (four of five patients) and CSK (C-terminal Src kinase)-binding protein (Cbp)/phosphoprotein associated with glycosphingolipid-enriched microdomains (PAG) (four of four patients) were down-regulated in MCL. Levels of other known lipid raft proteins, such as Lyn kinase and flotillin 1, were similar to normal B cells. However, 5-lipoxygenase (5-LO), a key enzyme in leukotriene biosynthesis, was associated with lipid rafts and was up-regulated approximately 7-fold in MCL compared with normal B cells. Significantly inhibitors of 5-LO activity (AA861) and 5-LO-activating protein (FLAP) (MK886, its activating enzyme) induced apoptosis in MCL cell lines and primary chronic lymphocytic leukemia cells, indicating an important role for the leukotriene biosynthetic pathway in MCL and other B cell malignancies. Thus, using shotgun proteomics and mRNA and protein expression profiling we identified a subset of known and unknown transmembrane proteins with aberrant expression in MCL plasma membranes. These proteins may play a role in the pathology of the disease and are potential therapeutic targets in MCL.

Sample pooling in 2-D gel electrophoresis: a new approach to reduce nonspecific expression background

Protein expression alterations unrelated to an investigated phenotype are accumulated in most cell line models during establishment. Performing a whole proteome screening of lymphoma cell lines, we established a method to reduce the influence of protein expression unrelated to the distinct investigated phenotype. In 2-D PAGE, the comprehensive analysis of a large number of protein spots would be simplified by pooling cell line samples of the investigated phenotype. Applying this pooling approach, unrelated alterations of single samples are 'muted' by dilution. Analysing two different lymphoma subtypes (follicular and mantle cell lymphoma) by this method, spots originating in only single cell lines were reduced by 72% (650/900), whereas even modestly altered expression of protein spots detected in all lines were reliably detected in the pooled protein gels. We conclude that our pooling approach is a preferable approach to reliably detect a common protein expression pattern and may even allow proteomic analysis of clinical samples with limited amounts of sample material, even with minimal cell numbers as low as 1 x 10(6).

Sequence analysis proves clonal identity in five patients with typical and blastoid mantle cell lymphoma

Mantle cell lymphoma (MCL) is typically composed of small irregular lymphoid cells. Blastoid variants, composed of lymphoblast-like (classic type) or large (pleomorphic type) cells, arise de novo or in patients with typical MCL. Although it has been assumed that blastoid variant represents histologic transformation of typical MCL, the clonal relationship between the two tumors has rarely been assessed at the molecular level. We identified five patients with typical MCL who subsequently developed the blastoid variant. There were two men and three women with a median age of 65 years (range, 34-70) at diagnosis of typical MCL involving lymph nodes. The median interval between typical and blastoid MCL was 36 months (range, 11-103). Subsequent blastoid variant MCL involved soft tissue (two), lymph node (one), ileum (one), or rectum (one). All typical and blastoid neoplasms were positive for CD20, cyclin D1, and monotypic surface immunoglobulin light chain, and all typical cases were positive for CD5. Two blastoid neoplasms lost CD5 expression, one of which aberrantly expressed CD10. Immunostaining for Ki-67 showed a median proliferative fraction of 20% in typical and 70% in blastoid neoplasms. Sequence analysis of the VDJ regions of the rearranged IgH allele proved clonal identity in each set of paired samples in all five patients. These results support the concept that blastoid MCL arising in patients with typical MCL represents histologic transformation of the original neoplastic clone.

Composite splenic marginal zone lymphoma and mantle cell lymphoma arising from 2 independent B-cell clones

We report the first case of composite lymphoma involving both mantle cell lymphoma (MCL) and splenic marginal zone lymphoma (SMZL) with circulating villous lymphocytes. Morphological, immunohistochemical, immunophenotyping, as well as detailed genetic studies (fluorescence in situ hybridization, IGVH gene sequencing), were performed and confirmed the existence of 2 independent, unrelated tumor clones. The MCL component expressed IgMD lambda, was CD5+, harbored a t(11;14)(q13;q32) involving CCND1, and showed an unmutated VH1-18 gene rearrangement. The SMZL component expressed IgMD kappa, was CD5-, showed a t(10;14)(q24;q32) and an unmutated VH3-7 gene rearrangement. Interestingly, this t(10;14) targeted the NFKB2 gene. Only a single other case of SMZL with t(10;14)/NFKB2 has been reported. Taken together, these data indicate that the MCL and SMZL arose as a consequence of independent malignant transformation events within an antigen-naive B-cell population. This case highlights the importance of a multidisciplinary approach and tissue diagnosis in these complex situations.

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.

Primary mantle cell lymphoma of the conjunctiva: a case report

Primary non-Hodgkin's lymphomas of the conjunctiva are uncommon. They are almost exclusively extranodal marginal zone B-cell lymphomas/mucosa-associated lymphoid tissue lymphomas. In this study, we report an extremely rare case of conjunctival mantle cell lymphoma in a 78-year-old man, presenting as a unilateral epibulbar mass.

From Gene Expression Analysis to Tissue Microarrays

Mantle cell lymphoma (MCL) is an aggressive lymphoid malignancy for which better treatment strategies are needed. To identify potential diagnostic and therapeutic targets, a signature consisting of MCL-associated genes was selected based on a comprehensive gene expression analysis of malignant and normal B cells. The corresponding protein epitope signature tags were identified and used to raise monospecific, polyclonal antibodies, which were subsequently analyzed on paraffin-embedded sections of malignant and normal tissue. In this study, we demonstrate that the initial selection strategy of MCL-associated genes successfully allows identification of protein antigens either uniquely expressed or overexpressed in MCL compared with normal lymphoid tissues. We propose that genome-based, affinity proteomics, using protein epitope signature tag-induced antibodies, is an efficient way to rapidly identify a number of disease-associated protein candidates of both previously known and unknown identities.

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.

CD117 expression in diffuse large B-cell lymphomas: fact or fiction?

CD117 (KIT) is expressed in a variety of hematopoietic neoplasms but there are a paucity of data regarding its expression in diffuse large B-cell lymphomas (DLBCL). The purpose of the present paper was to describe the authors' experience of two CD117+ DLBCL (one of follicle center-cell origin and one nasal Epstein-Barr virus (EBV)- plasmablastic lymphoma associated with lytic bone lesions), as determined by tissue immunohistochemistry and flow cytometry. The CD117 expression in DLBCL was further evaluated using tissue microarrays and seven additional plasmablastic lymphomas, using two commercially available anti-CD117 antibodies (Ab-1, Oncogene and A4502, DakoCytomation). Membranous +/- cytoplasmic staining was seen with Ab-1 in 24/65 (37%) DLBCL, including 21/56 microarray DLBCL, two index cases, and 1/7 additional plasmablastic lymphomas, with persistent staining in 13% of microarray DLBCL despite preincubation with KIT peptide. However, A4502 had only membranous staining of the index cases and one additional EBV- plasmablastic lymphoma with medullary disease. The present study suggests that (i) CD117 expression can be detected sporadically in DLBCL of follicle center-cell origin and a subset of plasmablastic lymphomas; (ii) staining for CD117 might help in identifying EBV- plasmablastic lymphomas associated with bone marrow involvement; and (iii) CD117 antibodies should be carefully validated prior to use, because non-specific staining, as observed with Ab-1, could lead to false-positive results.

A Simple Antigen Retrieval Method for the Optimal Demonstration of Cyclin-D1 Overexpression in Formalin-Fixed Paraffin-Embedded Cases of Mantle Cell Lymphoma

Successful diagnosis of mantle cell lymphoma (MCL) by immunohistochemistry is largely dependent on the successful demonstration of cyclin D1 overexpression in cases that fit clinical, morphologic, and immunophenotypical profiles. Accurate diagnosis in these cases is important due to the aggressive progression and poor survival times associated with this type of lymphoma. However, demonstration of cyclin D1 by immunohistochemistry on formalin-fixed, paraffin-embedded tissue is often fraught with technical difficulties, chiefly poor staining intensity largely due to insufficient antigen retrieval. The authors report a simple antigen retrieval technique that combines both heat and enzymatic treatment to demonstrate cyclin D1 overexpression. Furthermore, it appears that the antigen retrieval method is the key factor in the demonstration of cyclin D1, as detection systems with differing sensitivities (labeled streptavidin biotin [ABC] and dextran polymeric conjugate [Envision]) fail to demonstrate any significant differences in their staining intensities. This isa simple, cost-effective method that can be performed manually or can easily be adapted to suit automated staining systems.

Proteomic analysis of mantle-cell lymphoma by protein microarray

Mantle-cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma (NHL) that behaves aggressively and remains incurable. In order to understand the pathogenesis of MCL and design new therapies, it is important to accurately analyze molecular changes in pathways dysregulated in MCL. We used antibody microarrays to compare patterns of protein expression between CD19(+) purified B lymphocytes from normal tonsil and 7 cases of histologically confirmed MCL. Protein overexpression was defined as a higher than 1.3-fold or 2-fold increase in at least 67% of tumor samples compared with normal B-cell control. Of the polypeptides, 77 were overexpressed using the higher than 1.3-fold cutoff, and 13 were overexpressed using the 2-fold cutoff. These included cell cycle regulators (regulator of chromosome condensation 1 [RCC1], murine double minute 2 [MDM2]), a kinase (citron Rho-interacting kinase [CRIK]), chaperone proteins (heat shock 90-kDa protein [Hsp90], Hsp10), and phosphatase regulators (A-kinase anchor protein 1 [AKAP149], protein phosphatase 5 [PP5], and inhibitor 2). The elevated expression of some of these polypeptides was confirmed by immunoblotting and immunohistochemistry, whereas elevated expression of others could not be confirmed, illustrating the importance of confirmatory studies. This study describes a novel technique that identifies proteins dysregulated in MCL.

Acquired potential N-glycosylation sites within the tumor-specific immunoglobulin heavy chains of B-cell malignancies

BACKGROUND AND OBJECTIVES

Among B-cell malignancies, follicular lymphomas (FL) more frequently show acquired, potential N-glycosylation sites (AGS) within tumor-specific immunoglobulin. The aim of this study was to extend this observation and to evaluate the pattern of presentation of AGS within five different forms of B-cell lymphoma.

DESIGN AND METHODS

We sequenced the tumor-specific immunoglobulin heavy chain variable region fragment, including complementarity-determining regions 2 and 3, of forty-seven consecutive patients with a B-cell malignancy enrolled in idiotype vaccine clinical trials. This sequencing approach is known to allow the identification of most AGS. We then statistically analyzed differences in presentation pattern, in terms of tumor histology, immunoglobulin isotype, AGS location and amino acid composition.

RESULTS

All twenty-four FL cases presented with at least one AGS, whereas the vast majority of four B-cell lymphoma types other than FL did not. The non- FL group of tumors included four cases of Burkitt's lymphoma, six of diffuse large cell lymphoma, seven mantle cell lymphomas and six small lymphocytic lymphomas. Most IgM-bearing follicular lymphoma cases featured their AGS within complementarity-determining region 2, as opposed to those bearing an IgG, which mostly displayed the AGS within complementarity-determining region 3. The vast majority of AGS located within either complementarity-determining region ended with a serine residue, whereas those located within framework regions mostly featured threonine as the last amino acid residue.

INTERPRETATION AND CONCLUSIONS

In our series, all cases of FL had AGS within their tumor-specific immunoglobulin heavy chain variable regions. In contrast, most B-cell malignancies other than FL did not. Further studies are warranted in order to establish the possible meaning of these findings in terms of disease pathogenesis, their diagnostic value in doubtful cases and their potential implications for immunotherapy.

[Detection of cyclin D1 protein expression and t(11;14) chromosomal translocation in paraffin-embedded tissues and its clinicopathologic significance for mantle cell lymphoma]

OBJECTIVE

To investigate the feasibility of detecting cyclin D1 protein expression and t(11;14) chromosomal translocation in paraffin-embedded tissues and its diagnostic and differential diagnostic significance for mantle cell lymphoma (MCL).

METHODS

Paraffin-embedded samples of 36 cases of MCL and a control group of 71 cases of small B-cell lymphomas were retrieved from archive materials. Immunohistochemical staining for cyclin D1 and semi-nested PCR for t(11;14) were detected in all samples. House-keeping gene beta-actin was used to detect the quality of DNA.

RESULTS

(1) Cyclin D1 was expressed in 26 of the 36 MCL (72.2%). There was no cyclin D1 expression in the control group. (2) beta-actin DNA was detected in 101 of the 107 tumor cases (94.4%). t(11;14) was detected in 22 of the 36 MCL. Translocation was not found in control group. The positive rate for t(11;14) was 64.7% in MCL after exclusion of 2 cases which were negative for both t(11;14) and beta-actin. (3) 29 cases were positive for cyclin D1 and/or t(11;14), the positive rate reached 80.5%.

CONCLUSION

The combined detection of cyclin D1 and t(11;14) in paraffin-embedded tissues is found to be a specific and feasible method for diagnosis and differential diagnosis of mantle cell lymphoma.

Two-dimensional molecular profiling of mantle cell lymphoma

The present research establishes standard two-dimensional (2-D) maps for control, reactive lymph node and non-Hodgkin's lymphoma (mantle cell lymphoma, MCL). Medium sensitivity, mass spectrometry compatible colloidal Coomassie has revealed a total of ca. 750 spots in each of the maps. Comparison of 2-D maps by statistical packages, such as the PDQuest, established up- and downregulation of a total of ca. 145 spots, with positive variations of up to 10-folds and negative variations of up to 13-folds in both MCL biopsies' protein extracts. Qualitative and quantitative variations in the two lymphoma samples are consistent. More than 20 proteins have been so far identified by matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF)-mass spectrometry, with an additional five spots, which gave very good spectra but could not be matched to any of the presently available databases. Some of the spots, such as the 78 kDa glucose-regulated protein precursor and the glutathione S-transferase P, appear to be in common with other tumors, such as lung adenocarcinoma. Others may simply reflect overall changes in cellular metabolism and growth rate that occur during malignancy and thus might turn out to be in common with any cell population receiving any kind of stress. Some (notably T-cell leukemia/lymphoma protein 1A, TCL1, found to be 10-fold overexpressed) appear to be specific of the non-Hodgkin's lymphoma here studied. Western blot and immunohistochemical analyses were applied to obtain further information about stathmin (Op18) and TCL1, respectively.

Application of three-way principal component analysis to the evaluation of two-dimensional maps in proteomics

Three-way PCA has been applied to proteomic pattern images to identify the classes of samples present in the dataset. The developed method has been applied to two different datasets: a rat sera dataset, constituted by five samples of healthy Wistar rat sera and five samples of nicotine-treated Wistar rat sera; a human lymph-node dataset constituted by four healthy lymph-nodes and four lymph-nodes affected by a non-Hodgkin's lymphoma. The method proved to be successful in the identification of the classes of samples present in both of the groups of 2D-PAGE images, and it allowed us to identify the regions of the two-dimensional maps responsible for the differences occurring between the classes for both rat sera and human lymph-nodes datasets.

Mantle cell lymphoma: improved diagnostics using a combined approach of immunohistochemistry and identification of t(11;14)(q13;q32) by polymerase chain reaction and fluorescence in situ hybridization

INTRODUCTION

Mantle cell lymphoma (MCL) is a clinicopathological entity characterized by an aggressive clinical course, morphological features, and overexpression of cyclin D1 due to juxtaposition of the bcl-1 locus (and CCND1 gene coding for the cyclin D1) to the IgH gene. This phenomenon is caused by t(11;14)(q13;q32). The morphological diagnosis of MCL may pose difficulties. Ancillary methods are available to support the diagnosis.

PATIENTS AND METHODS

We studied a group of 32 patients with MCL; 24 men and 8 women. The median age at the diagnosis was 64 years. We characterized the investigated group by histology, and to analyze the immunohistochemical (IHC) profile we used a panel of antibodies including anti-cyclin D1. Polymerase chain reaction (PCR) was used to detect the rearrangement of bcl-1/IgH in 26 cases (in 11 patients, the DNA was isolated from frozen tissues or from nucleated cells of bone-marrow aspirate or peripheral blood, in 15 patients we utilized paraffin-embedded material). Dual color fluorescence in situ hybridization (FISH) on interphase nuclei detecting the t(11;14)(q13;q32) was applied in all 32 cases.

RESULTS

Cyclin D1 IHC was positive in 29 of 30 cases tested (97%). In six, the result was weak and difficult to rely on to support the diagnosis. PCR revealed the fusion gene in 14 of the 26 cases (54%). The best yield was obtained from fresh and frozen samples (8 of 11 positive). Using FISH, we identified the translocation in all 32 patients, the findings being easily interpretable in 29 patients. In three cases, the intensity of red and green signals was weaker and difficult to read though the co-hybridized signals were identified. The classical pattern of the translocation was observed in 26 patients, while in 3 we found variant patterns suggesting a loss of the V segment of the IgH gene (2x) and a shift in the breakpoint region at chromosome 11 (1x).

CONCLUSION

The diagnosis of MCL should be supported by a complex laboratory approach. Interphase FISH seems a useful complementary method to morphology and IHC. It is applicable to various tissues and cells prepared as tissue imprints or histological sections.

Establishment and characterization of a new mantle cell lymphoma cell line, Mino

Mantle cell lymphoma (MCL) is a distinct type of B-cell non-Hodgkin's lymphoma characterized by cyclin D1 overexpression and the cytogenetic abnormality, the t(11;14)(q13;q32). MCL cell lines have been difficult to establish and in vitro studies of these neoplasms are scarce. We describe the establishment and characteristics of a new MCL cell line, Mino. The cells are large, growing singly and in small clumps in vitro. By flow cytometry, the immunophenotype was compatible with MCL (i.e. CD5+CD20+CD23-FMC7+). Conventional cytogenetics showed hyperdiploidy with multiple complex karyotypic abnormalities, but no evidence of the t(11;14), proven to be present only by fluorescence in situ hybridization and polymerase chain reaction (PCR) methods. Western blots showed expression of cyclin D1 but no detectable cyclin D2 and cyclin D3; the retinoblastoma protein was predominantly phosphorylated. There was expression of tumor suppressor gene products including p53, p16(INK4a), and p21(WAF1). Sequencing of the TP53 gene revealed a mutation (codon 147(valine-->glycine)) in exon 5. Epstein Barr virus was absent. In summary, Mino is a new MCL cell line that may be useful to study the pathogenesis of MCL.

CD5- mantle cell lymphoma

Mantle cell lymphoma (MCL) typically expresses B-cell antigens and CD5 and overexpresses bcl-1 protein. However, unusual cases of bcl-1+ and CD5-MCL have been observed, posing a practical challenge for correct diagnosis and management. We identified 25 cases (48 samples) of bcl-1+ and CD5- lymphoma. CD5 expression was assessed by flow cytometric analysis alone (1 case), immunohistochemical analysis alone (17 cases), or dual flow cytometric/immunohistochemical methods (7 cases). The morphologic features were consistent with MCL with centrocytic cytomorphology in 20 cases and blastic variant in 5 cases. The t(11;14) was confirmed in 8 of 11 cases by fluorescence in situ hybridization of paraffin-embedded tissue. Cytogenetic analysis revealed the t(11;14) within a complex karyotype in 2 additional cases. These data show that MCL may lack CD5 expression. Evaluation of bcl-1 expression by immunohistochemical analysis or molecular genetics may be indicated if MCL is suspected clinically or morphologically despite a lack of CD5 expression.

Comparative study of marginal zone lymphoma involving bone marrow

Few studies have characterized or compared the pathologic features of bone marrow involvement by extranodal (EMZL), splenic (SMZL), and nodal marginal zone lymphoma (NMZL). We evaluated 45 bone marrow biopsy specimens from 39 patients with marginal zone lymphomas. As previously reported, bone marrow involvement was frequent (100%) in patients with SMZL. We also identified lymphoma involving bone marrow in 11 (44%) of 25 patients with EMZL and 1 of 2 patients with NMZL. The patterns of infiltration were mixed in all groups; however, the extent of involvement was greater in SMZL than in EMZL. In addition, germinal centers were present in bone marrow biopsy specimens involved by lymphoma in 4 patients with SMZL. Intrasinusoidal infiltration was common (10/12 [83%]) and prominent in patients with bone marrow involvement by SMZL, but was not invariably present. Intrasinusoidal infiltration of the bone marrow also was not specific for SMZL since similar infiltrates, although subtle, also were found in patients with other small B-cell lymphoproliferative disorders, including 6 (55%) of 11 patients whose bone marrow samples were infiltrated by EMZL.

CD52 expression in mantle cell lymphoma

Mantle cell lymphoma is one of the most difficult to treat of all the non-Hodgkin's lymphomas. CAMPATH-1H, a humanized monoclonal antibody against the CD52 antigen, has been used with some success in other lymphoproliferative diseases, especially chronic lymphocytic leukemia. This report demonstrates that tumor samples from patients with mantle cell lymphoma express the CD52 antigen and suggests that CAMPATH-1H should be studied in patients with mantle cell lymphoma.

The splenic form of mantle cell lymphoma

OBJECTIVES

To describe the clinical, immunophenotypic and molecular features, as well as the clinical course of patients with unusual presentation of mantle cell lymphoma (MCL) purely located to the spleen.

PATIENTS AND METHODS

We describe seven patients presented with splenomegaly and a leukemic picture without lymphadenopathy, fulfilling the diagnostic criteria of MCL. In addition to clinical and pathologic features, patients were studied with respect to surface immunophenotype, including adhesion molecule profile, immunohistochemical expression of cyclin-D1 and bcl-1 rearrangement by polymerase chain reaction.

RESULTS

Four patients were male and three female. The median palpable spleen size was 15 cm. A preliminary diagnosis of MCL was made, based on blood cell morphology and immunophenotype. All patients underwent splenectomy for therapeutic purposes. Studies done in blood and splenic lymphocytes revealed the following: 7/7 patients were CD19/CD5, CD20 and CD38 positive; CD10 negative and 6/7 CD23 negative. The adhesion molecule expression pattern was consistent in all patients: L-Selectin and CD11c were negative, CD11alpha and CD18 weakly positive and CD54 strongly positive. The median spleen weight was 1775 g. Histology disclosed a cytologic and architectural pattern consistent with MCL. Cyclin-D1 was positive in 6/6 studied patients. Bcl-1 rearrangement was found in 5/7 patients. Splenectomy was applied as the sole treatment and was beneficial in all patients, with median blood values as following: prior to splenectomy, Ht 29.5%, platelets 110 x 10(9)/l, lymphoma cells 5.0 x 10(9)/L, and at 6 months post-splenectomy, Ht 43%, platelets 311 x 10(9)/l and lymphoma cells 3.0 x 10(9)/L. Of the seven patients, two developed progressive disease 11 and 26 months post-splenectomy. The remaining five are in improving clinical and hematological condition without chemotherapy at a median follow up of 20 months.

CONCLUSIONS

We conclude that this presentation represents a separate form of MCL which requires splenectomy. It remains to be seen whether it carries a better prognosis than classical MCL.

Value of CD23 determination by flow cytometry in differentiating mantle cell lymphoma from chronic lymphocytic leukemia/small lymphocytic lymphoma

Mantle cell lymphoma (MCL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) share many morphologic and immunophenotypic features. In addition to histomorphologic examination, it is customary to use the absence of CD23 to differentiate MCL from CLL/SLL, based primarily on reported comparisons of immunohistochemical staining of tissue sections. These findings are widely extrapolated to flow cytometric analysis, although available data are contradictory and not sufficiently detailed. We compared expression of CD23 by flow cytometry in 22 cases of MCL and 25 cases of CLL/SLL. Lymphoma cells in 12 of 22 MCLs were negative for CD23, and 10 showed dim expression. In contrast, none of 25 CLL/SLLs were negative for CD23, 4 were dimly positive, and 21 were moderately or brightly positive. Thus, a significant proportion of MCL exhibited overlap of CD23 expression in the low-intensity range with CLL/SLL. Clinically, there was no correlation between the intensity of CD23 expression and clinical stage at diagnosis or survival. These findings emphasize that by flow cytometry, MCL can be differentiated reliably from CLL/SLL using CD23 if negative expression is observed. However, with dimly positive expression, interpretation should be cautious.

Cyclin D1 as an aid in the diagnosis of mantle cell lymphoma in skin biopsies: a case report

Mantle cell lymphoma (MCL), an uncommon and aggressive form of non-Hodgkin lymphoma, typically involves lymph nodes. It usually only secondarily involves extranodal sites. We describe an unusual case of a MCL that presented and relapsed in the earlobes. Light microscopic findings were initially regarded as suggestive of small lymphocytic lymphoma, although subsequent analysis of fresh tissue by flow cytometry led to the diagnosis of MCL. Retrospective application of a broad panel of recently developed markers suitable for analysis of routinely processed tissue yielded results that also permitted a diagnosis of MCL. If these results had been available at the time of initial presentation, they would have obviated the need for rebiopsy. Greater awareness not only of the phenotypic criteria by which lymphomas are classified but of the lymphoma markers available for evaluation of routinely processed tissue should facilitate the accurate diagnosis of diseases like MCL and minimize the risk of misdiagnosis as an indolent disorder.

[Interphase FISH analysis of frozen or fixed tissues for the detection of t(11;14) (q13;q32) in mantle cell lymphoma]

Cytogenetic analyses have revealed that mantle cell lymphomas (MCL) are closely associated with the t(11;14)(q13;q32). This translocation juxtaposes the immunoglobulin heavy chain gene (IGH) sequences with the BCL-1 locus, leading to up-regulation of the CCND1 gene and consequently to an overexpression of cyclin D1 protein. We studied 27 MCL with characteristic morphological and immunological (CD5+, CD10-, CD20+, CD23-) features and 2 controls (reactionnal lymphadenitis) to evaluate the feasibility and the interest of FISH analysis on interphase cells from frozen or paraffin-embedded tissues. Sections (CC) and touch preparations (EC) of frozen tissues and sections of paraffin-embedded tissues (CF) were successfully hybridized with the Vysis LSI IgH/CCND1 dual color dual fusion translocation probe. The touch preparations presented a lower cellularity than sections, therefore allowing an easier analysis. Hybridization spots intensities were found stronger in CC and EC than in CF. The percentages of t(11;14) positive cells were similar in CC, EC and CF from a same patient. The percentage of non hybridized cells, analogous in CC and EC, was higher in CF. However, the CF were directly analysed on microscope without the need of any numerical picture treatment. The t(11;14) was detected in all the cases (27/27) and positive cells percentages were always higher than the probe cut-off (5%). The FISH analysis on interphase cells appears a performing and rapid technique to detect t(11;14) in MCL on both frozen and paraffin-embedded tissue, thus extending its practical and diagnostic use.

Differential expression of chemokine receptors in B cell malignancies

Chemokines are a family of 8-10 kDa proteins with a wide range of biological activities including the regulation of leukocyte trafficking, modulation of haemopoietic cell proliferation and adhesion to extracellular matrix molecules. Using a panel of chemokine receptor-specific monoclonal antibodies (MoAb) in a multicolour flow cytometry approach we analysed the expression of the lymphocyte-associated chemokine receptors CXCR4, CXCR5, CCR5 and CCR6 in B cell acute lymphoblastic leukaemia (precursor B-ALL; six cases), B cell chronic lymphocytic leukaemia (B-CLL; 31 cases), multiple myeloma (10 cases), mantle cell lymphoma (MCL, four cases), follicular lymphoma (FL, three cases) and hairy cell leukaemia (HCL, five cases). We demonstrate that CXCR4, CXCR5 and CCR6 are differentially expressed in these B lymphoproliferative disorders depending on the maturational stage of the malignant B cell population investigated. In particular, we found that CXCR4 is strongly expressed on immature ALL blasts whereas no surface immunoreactivity for CXCR5, CCR5 and CCR6 was observed. By contrast, non-Hodgkin's lymphomas (NHLs) corresponding to more mature peripheral B cell subsets (ie B-CLL and MCL) exhibited high expression levels of CXCR4 and CXCR5. Analysis of terminally differentiated myeloma cells revealed a down-regulation of CXCR4, CXCR5 and CCR6. CCR5, which is not expressed in normal B cells, was also absent from the majority of NHLs. However, CCR5 staining was seen in three of five cases of HCL, representing the first example of cross-lineage aberrant chemokine receptor expression in malignant haemopoietic cells.

Detection of chromosome 11q13 breakpoints by interphase fluorescence in situ hybridization. A useful ancillary method for the diagnosis of mantle cell lymphoma

We assessed cytologic specimens from 11 mantle cell lymphomas (MCLs) and 32 other B-cell non-Hodgkin lymphomas (NHLs) for 11q13 breakpoints using a 2-color fluorescence in situ hybridization (FISH) assay that uses an 11q13 probe centered on the CCND1 gene and a centromeric chromosome 11 probe (CEP11). The number of nuclei in 200 cells were counted, and results were expressed as an 11q13/CEP11 ratio. All MCLs showed a high percentage of interphase nuclei with 3 or more 11q13 signals (mean, 74.8%; range 57%-90%). In contrast, in other B-cell NHLs the mean percentage of cells with 3 or more 11q13 signals was 9.2%. All MCLs had an elevated 11q13/CEP11 ratio (mean, 1.38). The mean ratio for other B-cell NHLs was 0.99. Two non-MCL cases, 1 large B-cell and 1 B-cell unclassified NHL, had high 11q13/CEP11 ratios of 1.15 and 1.30, respectively. Conventional cytogenetic analysis performed on the former case revealed a t(5;11)(q31;q13). Interphase FISH analysis using 11q13 and CEP11 probes is a convenient ancillary method for assisting in the diagnosis of MCL. This commercially available assay is simple to use on cytology or imprint specimens, and results can be obtained within 24 hours.