Detection of the bcl-1 rearrangement at the major translocation cluster in frozen and paraffin-embedded tissues of mantle cell lymphomas by polymerase chain reaction

Leukemic involvement is a common feature in mantle cell lymphoma

BACKGROUND

The reported incidence of peripheral blood involvement in patients with mantle cell lymphoma (MCL) ranges from 13% to 77%. The aim of the study was to analyze the prevalence and the biologic and clinical significance of leukemic involvement in a series of patients with MCL.

METHODS

Leukemic expression was assessed by conventional morphology and flow cytometry (FC) in 48 patients. In addition, comparative genomic hybridization (CGH) was performed in 27 patients.

RESULTS

At diagnosis, 44 patients (92%) had evidence of leukemic expression by FC, including 8 patients (17%) without morphologically apparent leukemic involvement. Moreover, a lymphocyte count > or =5 x 10(9)/L was observed in 25 cases (52%). The most frequent imbalances detected by CGH were gains of 3q, 7p, 8q, 9q, 12q, and 13q, and losses of 13q, 1p, 9p, 11q, 10p, 17p, 6q, 8p, and 9q. Using a cutoff of 5 x 10(9)/L lymphocytes, cases with lymphocytosis more frequently presented with gains of 3q (P = .02), losses of 10p (P = .05), a low response rate (P = .04), and a short survival (P = .05).

CONCLUSIONS

Leukemic expression at diagnosis detected by FC was found to be highly frequent in this series of patients with MCL. Although morphologically apparent leukemic expression was not associated with specific chromosomal alterations detected by CGH, a lymphocyte count > or =5 x 10(9)/L was correlated with particular genetic abnormalities and a poor outcome.

Gastrointestinal involvement in mantle cell lymphoma: a prospective clinic, endoscopic, and pathologic study

The frequency of gastrointestinal (GI) tract involvement in mantle cell lymphoma (MCL) at diagnosis is reported to be below 30%. To investigate the actual frequency of GI involvement by MCL, upper and lower endoscopy was prospectively performed on 13 untreated MCL patients at diagnosis. Multiple biopsies from endoscopically normal and abnormal gastric and colonic mucosa were studied with immunohistochemistry (IHC) for CD20, CD5, and cyclin D1, as well as fluorescence in situ hybridization (FISH) for t(11;14) and polymerase chain reaction (PCR) for immunoglobulin heavy chain gene. Abnormal mucosa was identified in 38% of cases by upper endoscopy (mainly mild nonspecific gastritis) and in 54% of cases by lower endoscopy (mostly micropolyps). Histologically, infiltration by MCL was demonstrated in the stomach in 77% of cases and in the colon in 77% of cases. As a whole, 92% of patients showed upper or lower GI tract infiltration by MCL. Histologic evidence of MCL involvement was present in all cases with endoscopically abnormal mucosa, but it was also observed in two-thirds of cases with endoscopically unremarkable mucosa. Positive cyclin D1 IHC was seen in all instances displaying CD20 and CD5-positive lymphoid infiltrates, whereas t(11;14) was demonstrated by FISH in 63.5% and PCR was clonal in 64% of those instances. In conclusion, the great majority of MCL patients showed GI tract involvement at the time of diagnosis, not uncommonly in the form of minute lymphoid infiltrates. IHC for cyclin D1 was significantly more sensitive than FISH t(11;14) or PCR for immunoglobulin heavy chain gene to confirm MCL in this setting.

Richterʼs Syndrome

Richter's syndrome, that is, transformation of chronic lymphocytic leukemia to a large cell or immunoblastic lymphoma, occurs in up to 10% of patients with chronic lymphocytic leukemia. The onset of Richter's syndrome is characterized by worsening systemic symptoms, rapid tumor growth, and/or extranodal involvement. Median survival with conventional chemotherapy is less than 6 months. Therapy with more recent therapeutic regimens, such as hyperCVXD (fractionated cyclophosphamide, vincristine, liposomal daunorubicin, and dexamethasone), augmented hyperCVXD, and yttrium-90 ibritumomab tiuxetan, has not produced major improvements in response rates or overall survival. Improvement in the outcome of patients with Richter's syndrome may be aided by a more comprehensive understanding of the pathogenesis of Richter's syndrome; therapy could then be targeted against specific abnormalities. Current data indicate that the transformation of chronic lymphocytic leukemia to a large-cell or immunoblastic lymphoma is associated with abnormalities in cell cycle regulation (e.g., loss of the cell cycle inhibitors p16(INK4a) and p27(KIP1) ) and DNA repair (e.g., mutations and/or deletions of the p53, ATM, and p14(ARF) genes and epigenetic silencing of the MLH1 gene). However, the critical event leading to transformation is unclear. Given the poor prognosis of patients with Richter's syndrome, every effort should be made to enroll these patients into clinical trials evaluating novel agents with the appropriate correlative studies.

IgVH mutations in blastoid mantle cell lymphoma characterize a subgroup with a tendency to more favourable clinical outcome

Mantle cell lymphoma (MCL) is associated with a very unfavourable clinical course. This is particularly true for mantle cell lymphoma of the blastoid subtype (MCL-b). In order to define prognostic factors, we analysed the impact of immunoglobulin heavy chain variable (IgV H) gene somatic hypermutations on clinical outcome in a series of 21 cases of morphologically, phenotypically, and genotypically well-characterized MCL-b. Testing and estimation were performed using log-rank statistics and displayed on Kaplan-Meier graphs. Thirteen of 21 cases of MCL-b revealed a homology rate of > or = 99% compared to IgV H germ-line sequences in the databases and were scored as non-mutated. Eight of 21 cases (38%) of MCL-b were mutated. In MCL-b the mutation frequency was usually low and the mutation pattern was only rarely antigen-selected, in contrast to a control group of 11 cases with morphologically almost identical, but phenotypically and genotypically clearly distinguishable, diffuse large B cell lymphoma, derived, most likely, from germinal centre B cells. In our series of 21 MCL-b, positive IgV H mutational status, irrespective of varying homology thresholds, had no statistically significant prognostic impact on event-free or overall survival. However, mutated MCL-b tended to present more frequently at an earlier stage and without bone marrow involvement and to show lower rates of relapse and death, resulting in a more favourable clinical outcome.

Rituximab consolidation after high-dose chemotherapy and autologous blood stem cell transplantation in follicular and mantle cell lymphoma: a prospective, multicenter phase II study

BACKGROUND

Patients with follicular (FL) or mantle cell lymphoma (MCL) are incurable with conventional therapy. We investigated the safety and efficacy of rituximab consolidation after autologous stem cell transplantation (ASCT) in order to prevent relapse by clearance of minimal residual disease (MRD).

METHODS

Rituximab was given approximately 8 weeks after CD34+ cell enriched ASCT at 375 mg/m2, weekly for 4 weeks. Monitoring of MRD was performed by repetitive PCR analyses.

RESULTS

Thirty-one patients were included; one died early after ASCT before rituximab administration. Thirty patients (20 FL, 10 MCL) were evaluable after rituximab consolidation, and 27 of these were assessable for MRD detection. Rituximab consolidation post-ASCT was safe, the most common toxicity being infection. At a median follow-up of 42 months (range 13-96) after ASCT, 25 patients were censored with an actuarial event-free survival (EFS) of 81% at 4 and 5 years. Four patients (two FL, two MCL) relapsed, and one additional MCL patient died unexpectedly in complete remission. PCR-negativity was observed in 22% of the patients before ASCT, 53% post-ASCT (P=0.0547), 72% after rituximab (P=0.0018) and 100% at 6 months post-transplant (P < 0.001).

CONCLUSIONS

One single course of rituximab consolidation given after ASCT is safe, may help to eliminate MRD and may translate into improved EFS in both FL and MCL patients.

The role of molecular studies in lymphoma diagnosis: a review

Lymphoma classification is based on a multiparametric approach to diagnosis, in which clinical features, morphology, immunophenotype, karyotype and molecular characteristics are important to varying degrees. While in most cases, a diagnosis can be confidently established on the basis of morphology and immunophenotype alone, a small proportion of diagnostically difficult cases will rely on molecular studies to enable a definitive diagnosis. This review discusses the various molecular techniques available including Southern blotting (SB), polymerase chain reaction (PCR), fluorescence in situ hybridisation (FISH)--including multicolour-FISH/spectral karyotyping and comparative genomic hybridisation--and also gene expression profiling using cDNA microarray technology. Emphasis is given to the analysis of antigen receptor gene rearrangements and chromosomal translocations as they relate to lymphoma diagnosis and also in the setting of minimal residual disease (MRD) detection and monitoring. Laboratories performing these tests need to have expertise in these areas of testing, and there is a need for greater standardisation of molecular tests. It is important to know the sensitivity and specificity of each test as well as its limitations and the pitfalls in the interpretation of results. Above all, results of molecular testing should never be considered in isolation, and must always be interpreted in the context of clinical and other laboratory data.

CCL19 and CXCL12 Trigger in Vitro Chemotaxis of Human Mantle Cell Lymphoma B Cells

PURPOSE

Few data are available in the literature on chemokine receptor expression and migratory capability of mantle cell lymphoma (MCL) B cells. Information on these issues may allow us to identify novel mechanisms of chemokine-driven tumor cell migration.

EXPERIMENTAL DESIGN

The research was designed to investigate: (a) expression of CCR1 to CCR7 and CXCR1 to CXCR5 chemokine receptors; and (b) chemotaxis to the respective ligands in MCL B cells and in their normal counterparts, i.e., CD5+ B cells.

RESULTS

Malignant B cells from MCL patients and normal counterparts displayed similar chemokine receptor profiles. MCL B cells were induced to migrate by CXCL12 and CCL19, whereas normal CD5+ B cells migrated to the former, but not the latter chemokine. Overnight culture of MCL B cells and their normal counterparts with CXCL12 cross-sensitized other chemokine receptors to their ligands in some tumor samples but not in CD5+ B cells.

CONCLUSIONS

CCR7 and CXCR4 ligands may play a key role in tumor cell migration and spreading in vivo. CXCL12 may additionally contribute by sensitizing MCL B cells to respond to the ligands of other chemokine receptors.

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.

CD34+-enriched-CD19+-depleted autologous peripheral blood stem cell transplantation for chronic lymphoproliferative disorders: high purging efficiency but increased risk of severe infections

OBJECTIVE

The main objective of this work was to decrease the incidence of relapse after autologous stem cell transplantation with a "double purging" procedure.

METHODS

We used a "positive" (CD34) and "negative" (CD19) double selection method to improve the efficacy of "single purging" of hematopoietic harvests in poor-prognosis lymphoproliferative disorders. All patients included in the study had a positive molecular marker of their disease. Minimal residual disease (MRD) was studied by flow cytometry and PCR techniques during the purging procedure and after transplantation.

RESULTS

Twenty-six patients fulfilled entry criteria. Median age of patients was 50 years (range: 33-66); 17 were male and 9 female. Thirteen (50%) of the patients mobilized an adequate number of CD34+ cells (>or=3 x 10(6)/kg) to proceed with the double-selection protocol. Twelve of the 13 harvests became PCR negative after purging. Ten patients were grafted with the selected products and all but one engrafted without delay. After a median follow-up of 30 months, 2 of 10 patients suffered a molecular relapse at 7 and 19 months respectively. The earlier relapse was observed in the patient who received a MRD+ product. Only one patient experienced a clinical relapse. Three patients died due to obliterans bronchiolitis, pneumococcal sepsis, and septic shock of unknown origin, respectively, and three others presented life-threatening infections.

CONCLUSION

Therefore, CD34+/CD19+ positive/negative selection is an effective purging approach in patients with chronic lymphoproliferative disorders. This favorable effect is, however, counterbalanced by the high frequency of life-threatening infections.

Multiple cell cycle regulator alterations in Richter's transformation of chronic lymphocytic leukemia

To investigate the role of the cell cycle regulators p21(Waf1), p27(Kip1), retinoblastoma (Rb), and cyclin D1 in Richter's transformation of chronic lymphocytic leukemia (CLL), we analyzed 19 CLL and eight Richter's syndrome (RS) tumors, previously characterized for p53 and ARF/INK4a abnormalities. p21(Waf1)immunohistochemical expression was negative in 12 of 15 CLL (80%), whereas it was moderate or strong in three of seven RS (43%). p21(Waf1) gene was in germline configuration in all the tumors analyzed. Four immunohistochemical patterns of p53 and p21(Waf1) expression were observed: (1) p53-/p21- in 10 of 15 CLL (67%), but only in two of six RS (33%); (2) p53+/p21+ in three CLL (20%) and two RS (33%); (3) p53-/p21+ in one RS; and (4) p53++/p21- in two CLL and one RS. Two p53+/p21+ CLL evolved into RS. p53 mutations clustered around the p53++/p21- (two CLL and one RS) and p53-/p21- (one CLL and one RS) tumors. While the majority of CLL displayed strong p27 immunoreactivity, RS tumors were constantly p27-negative. p27(Kip1) gene was in germline configuration in all the tumors analyzed. Most CLL cases were negative for Rb expression. In contrast, all RS exhibited strong Rb expression. Cyclin D1 overexpression was only detected in one CLL evolving into RS and one RS. In conclusion, a p53+/p21- immunohistochemical pattern is shown exclusively by p53-mutated CLL/RS. Additionally, our results suggest a possible implication of moderate/strong p21(Waf1) expression, loss of p27 expression, and cyclin D1 overexpression in the Richter's transformation of CLL.

Fluorescence PCR quantification of cyclin D1 expression

We have used a continuous fluorescence monitoring method to assess cyclin D1 mRNA expression in a variety of hematological and non-hematological processes. We examined 14 cell lines, 11 reactive lymphoid tissues, and 57 primary hematopoietic neoplasms including mantle cell lymphoma (MCL) (n = 10), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n = 11), acute lymphoblastic leukemia/lymphoma (n = 15), follicular lymphoma (n = 6), peripheral T-cell lymphoma (PTCL) (n = 3), anaplastic large cell lymphoma (n = 3), hairy cell leukemia (n = 3), Burkitt lymphoma (n = 1), Burkitt-like lymphoma (n = 4), and plasmacytoma (n = 1) for the expression of cyclin D1 mRNA using fluorescently labeled sequence-specific hybridization probes. Fluorescence (F) was plotted against cycle (C) number over 45 cycles. The log-linear portion of the F versus C graph identified a fractional cycle number for threshold fluorescence. A beta-globin mRNA transcript with equivalent amplification efficiency to that of cyclin D1 was used for assessment of RNA integrity and normalization. In general, the MCLs demonstrated substantially higher levels of cyclin D1 mRNA than the other lymphoproliferative processes. Moderately high levels of cyclin D1 mRNA were detected in one PTCL. On average, the CLL/SLL cases showed cyclin D1 mRNA levels two to three orders of magnitude lower than observed in the MCLs. Cell lines derived from non-hematopoietic neoplasms such as fibrosarcoma, small cell carcinoma, and neuroblastoma showed comparable or higher levels of cyclin D1 mRNA than the MCLs. Our results indicate that quantitative real-time reverse transcription (RT) polymerase chain reaction is a simple, rapid, and accurate technique for assessing cyclin D1 expression, and while it is not specific, it can reliably be used in the distinction of MCL from CLL/SLL.

Real-time RT-PCR assay for quantifying cyclin D1 mRNA in B-cell non-Hodgkin's lymphomas

Mantle cell lymphoma (MCL) is a distinct type of non-Hodgkin's lymphoma (NHL) characterized by the t(11;14)(q13;q32), in which the ccnd1 gene is juxtaposed with the immunoglobulin heavy chain gene, resulting in up-regulation of cyclin D1. Cyclin D1 overexpression is a useful finding that supports the diagnosis of MCL. In this study, we used a 5' --> 3' exonuclease-based real-time reverse-transcriptase polymerase chain reaction (RT-PCR) method to quantify cyclin D1 mRNA in 108 B-cell NHL and nonneoplastic specimens, including 25 cases of MCL. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was also quantified to normalize cyclin D1 mRNA levels, and the data were expressed as a cyclin D1 to GAPDH ratio. At each anatomic site, MCL cases had higher cyclin D1 levels than other types of NHL or nonneoplastic specimens, without overlap. For example, in lymph node specimens, the median cyclin D1/GAPDH ratio was 147 (range, 94-160) in MCL, compared with 8.6 (range, 4-18) in chronic lymphocytic leukemia/small lymphocytic lymphoma; 5.8 (range, 1.8-24) in follicular lymphoma; 4.8 in one case of marginal zone lymphoma; and 20.2 (range, 5.8-44) in reactive specimens. Statistical analysis using one-way analysis of variance (ANOVA) showed that MCL cases had significantly higher cyclin D1 levels than other groups (P <.05). In peripheral blood specimens involved by MCL, cyclin D1 levels correlated with extent of involvement. We conclude that this real-time RT-PCR method to quantify cyclin D1 expression is helpful in distinguishing MCL from other types of B-cell NHL and from nonneoplastic specimens. This method is rapid, can be applied to the analysis of fluid specimens, and obviates the need for time-consuming and laborious detection methods that are required by traditional semi-quantitative RT-PCR methods.

Identification of novel regions of amplification and deletion within mantle cell lymphoma DNA by comparative genomic hybridization

We have carried out comparative genomic hybridization (CGH) analysis on archival biopsy material from a series of 30 UK mantle cell lymphomas. The most frequent aberrations were gains of 3q (21 cases), 6p (19 cases), 7q (8 cases), 12p (8 cases), 12q (9 cases) and 17q11q21 (8 cases), and losses of 1p13p32 (10 cases), 5p13p15.3 (9 cases), 6q14q27 (11 cases), 8p (7 cases), 11q13q23 (8 cases) and 13q (18 cases). Nineteen cases (63%) had a common region of amplification at 3q28q29, which was highly amplified in three cases, suggesting the presence of a mantle cell lymphoma (MCL)-related oncogene in this region. There was a minimal common region of deletion at 6q25q26 in nine cases (30%). No MCL-specific locus has previously been identified on chromosome 6 and this region may contain a tumour suppressor gene specifically implicated in the development of this subtype of lymphoma. An increased number of chromosome aberrations, gain of Xq and loss of 17p were all significantly associated with a worse prognosis. A greater understanding of the genetics of mantle cell lymphoma may allow the identification of prognostic factors which will aid the identification of appropriate treatment regimens.

ATM gene inactivation in mantle cell lymphoma mainly occurs by truncating mutations and missense mutations involving the phosphatidylinositol-3 kinase domain and is associated with increasing numbers of chromosomal imbalances

The ataxia-telangiectasia mutated (ATM) gene codifies for a protein critically involved in the cellular response to DNA damage. ATM alterations have been observed in some sporadic lymphoproliferative disorders. The recurrent 11q22-23 deletions found in mantle cell lymphoma (MCL) suggest that ATM could be inactivated in these lymphomas. In this study, ATM gene alterations and protein expression were examined in 20 and 17 MCL tumor specimens, respectively. Previously, these patients had been examined for p53 and p14(ARF) gene status and analyzed by comparative genomic hybridization. Nine patients had 11q22-23 losses. Eight ATM gene mutations were detected in 7 patients. These alterations were 3 missense mutations in the phosphatidylinositol-3 kinase (PI-3K) domain and 5 truncating mutations, including 3 frameshifts, a nonsense mutation, and a substitution of the initial methionine. All truncating mutations were associated with lack of protein expression. Somatic origin was demonstrated in 3 mutations, whereas one mutation was carried heterozygously in the patient germ line. Chromosomal imbalances were significantly higher in typical MCL with ATM inactivation (7.8 +/- 1.3) than in tumors with the wild-type gene (3 +/- 1.1) (P =.001). Moreover, tumors with bi-allelic ATM alteration were associated with 3q gains (P =.015) and frequent extranodal involvement (P =.049). ATM gene alterations were not related to the histologic variant of the tumors, p53/p14(ARF) gene status, survival, or other clinicopathologic features of the patients. These findings indicate that ATM gene mutations in MCL are mainly truncating or missense mutations involving the PI-3K domain, and that may play a role in the pathogenesis of a subset of these tumors with increased numbers of chromosomal imbalances.

Cutaneous lymphocyte-associated antigen (CLA) expression in a lymphoblastoid mantle cell lymphoma presenting with skin lesions. Comparison with other clinicopathologic presentations of mantle cell lymphoma

BACKGROUND

Cutaneous lymphocyte-associated antigen (CLA) is a lymphocyte homing receptor selectively expressed by T cells of the cutaneous immune system and their malignant counterpart, that is to say, cutaneous T-cell lymphomas. However it is absent in the vast mayority of other T-cell malignancies and B-cell lineage lymphomas irrespective on primary tumor site.

METHODS

Expression of CLA was investigated on six cases of mantle cell lymphoma (MCL) which differed in their histopathological subtype (typical or blastic) and their tendency to infiltrate skin and/or central nervous system (CNS).

RESULTS

CLA immunostaining on neoplastic cells was only observed in a 61-year-old female suffering from a lymphoblastoid MCL which clinically presented with specific skin lesions and further developped CNS disease. In this patient, coexpression of CLA with MCL markers (CD20 and CD5) was confirmed by conventional immunohistochemistry and double immunofluorescence studies.

CONCLUSIONS

To our knowledge, CLA immunoreactivity on B-cell lymphomas has not beeen previously reported. The expression of this skin-related adhesion molecule on malignant MCL cells could explain the clinical behavior of our case which presented and relapsed with cutaneous lesions. However, CLA seems not to be a MCL marker nor a CNS-related adhesion molecule. The authors review the clinical and histopathological characteristics of MCL-specific skin lesions and their diagnostic clues based on cell morphology, immunohistochemistry and molecular investigations.

Quantitative Real-Time Reverse Transcription-PCR Assay for Cyclin D1 Expression: Utility in the Diagnosis of Mantle Cell Lymphoma

Background: The t(11;14)(q13;q32) translocation present in the majority of mantle cell lymphomas (MCLs) places the cyclin D1 gene under the control of immunoglobulin transcriptional regulatory elements, causing overexpression of cyclin D1. Quantification of cyclin D1 expression can distinguish MCL from other lymphomas.

Methods: A quantitative real-time reverse transcription (RT)-PCR assay was developed for cyclin D1 mRNA suitable for use with RNA extracted from fresh and formalin-fixed, paraffin-embedded tissues. Specimens were amplified in an Applied Biosystems Model 7700 Sequence Detection System in reactions containing primers and probes for cyclin D1 and a control gene, β2-microglobulin. Relative expression of the two genes was standardized against a control MCL cell line, M02058.

Results: The range of cyclin D1 expression among 20 MCLs was substantially higher than that in other lymphomas and reactive lymph nodes. By choosing an optimal cutoff point for assessing overexpression, the sensitivity and specificity of the assay for the diagnosis of MCL in lymph node specimens both approached 100%: Overexpression was detected in 20 of 20 MCLs, but in none of 21 non-mantle-cell lymphomas or 10 reactive lymph nodes.

Conclusions: Quantitative real-time RT-PCR for cyclin D1 overexpression provides a rapid diagnostic test with clinical utility in the diagnosis of MCL.

Primary spinal epidural mantle cell lymphoma: case report

OBJECTIVE AND IMPORTANCE

Mantle cell lymphoma is a distinct clinicopathological type of non-Hodgkin's lymphoma that often presents at an advanced stage, with systemic spread. Spinal involvement is uncommon and generally occurs as part of advanced disease or generalized relapses. Primary spinal epidural lymphoma is a rare initial manifestation of non-Hodgkin's lymphoma, and mantle cell lymphoma with initial presentation in the spinal epidural space is extremely rare, having been previously reported in only two cases.

CLINICAL PRESENTATION

We report a case of a 71-year-old man who presented with increasing weakness and numbness of the legs. Magnetic resonance imaging revealed a spinal epidural mass in the lumbosacral region.

INTERVENTION

The patient underwent a partial L4 and L5-S1 laminectomy, with incomplete resection of the mass for spinal decompression and tissue diagnosis. Mantle cell lymphoma was diagnosed in the pathological examination.

CONCLUSION

After radiotherapy, the disease recurred with a soft-tissue mass in the anterior maxillary area of the face. The patient underwent restaging and was treated with chemotherapy, with only a partial response. Mantle cell lymphoma with primary spinal epidural presentation is rare. This diagnosis can be established and other causes of spinal cord compression can be ruled out by obtaining tissue for proper histopathological examinations. Because of its aggressive behavior and poor prognosis, mantle cell lymphoma should be treated using a combined-modality approach.

Blastic mantle cell leukemia: an unusual presentation of blastic mantle cell lymphoma

Six patients had blood and bone marrow manifestations characterized by the presence of morphologically immature or blastic B-lineage lymphoid cells expressing CD5 antigen. The median patient age was 70 years, and the male-to-female ratio was 5:1. The presence or degree of lymphadenopathy and splenomegaly was variable among this group at staging evaluation, although two patients did not have these features. One patient had an antecedent diagnosis of classical nodal mantle cell lymphoma, without prior morphologic blood or bone marrow involvement. Other patients lacked a history of underlying lymphoproliferative disorders. The median white blood cell count was 120 x 10(9)/L. Most patients had thrombocytopenia, whereas only one patient had neutropenia at presentation. Leukemic peripheral blood cells in these six cases were small to medium in size with fine or granular nuclear chromatin and small or inconspicuous nucleoli. The pattern of marrow involvement was interstitial or diffuse, with cells showing immature nuclear features resembling acute leukemia or blastic lymphoma. All tumors demonstrated a consistent immunophenotype of B-cell lineage, surface immunoglobulin positivity, and CD5 antigen expression. The progenitor cell-associated markers CD34 and TdT were not expressed, and CD23 antigen was either negative (three of four cases) or only weakly present (one of four cases). The presence of a karyotypic t(11;14)(q13;q32) was documented in one tumor, whereas two other cases had BCL-1 gene rearrangements by either polymerase chain reaction or Southern blot analysis. Cyclin D1 mRNA overexpression was noted in three of four cases tested. This patient group was characterized by very poor overall survival (median, 3 months; range, 0.5 to 6 months). The aggregate clinical, pathologic, and genetic data in these unusual cases are consistent with de novo or predominant leukemic presentations of blastic mantle cell lymphoma. Accurate diagnosis in such cases is greatly facilitated by cytogenetic studies or the demonstration of BCL-1/cyclin D1 abnormalities.

Mantle cell lymphoma

OBJECTIVE

This article summarizes the most useful ancillary immunohistochemical and molecular assays for use in the diagnosis of mantle cell lymphoma.

DATA SOURCES

The English language literature was surveyed, with an emphasis on recent publications, for articles presenting key advances in the molecular characterization of mantle cell lymphomas and for series of cases testing the utility of molecular diagnostic tests. The authors' series of 26 small B-cell lymphomas, analyzed for the cyclin D1 protein by paraffin immunohistochemistry and for t(11;14) by polymerase chain reaction, is included.

CONCLUSIONS

Mantle cell lymphoma, a B-cell lymphoma now recognized in the 1994 Revised European-American Classification of Lymphoid Neoplasms (REAL) classification, is a relatively aggressive lymphoma with a poor prognosis. Its characteristic t(11;14)(q13;q32) translocation has a role in oncogenesis and has been exploited for molecular diagnostic tests, but these tests vary in sensitivity, specificity, and ease of use. Improved immunohistochemical tests are sufficient to confirm the diagnosis in most cases. Conventional cytogenetics and molecular diagnostic tests for t(11;14)-Southern blot and polymerase chain reaction analysis-may be helpful in selected cases, but are laborious or of limited sensitivity. Other methods, such as fluorescence in situ hybridization, need further development to provide faster, more sensitive diagnosis.

Clonality assessment in blood of patients with mantle cell lymphoma

The presence of circulating neoplastic cells at diagnosis was assessed in the blood of patients presenting with mantle cell lymphoma (MCL) to determine the feasibility of a diagnostic molecular assay. Blood samples from 16 patients with pathologically reviewed MCL were analysed for the t(11;14)(q13;q32) translocation by the polymerase chain reaction (PCR): 7 (44%) were found positive. The remaining cases were examined by PCR for the presence of circulating neoplastic B-cells by amplifying the third complementarity region (CDR3) of immunoglobulin heavy chain genes and the immunoglobulin light kappa chain deletion rearrangements. A further 7 (44%) patients showed the presence of clonal lymphoma cells, leaving only 2 (12%) of cases negative for circulating lymphomatous cells. This study suggests that there is a high incidence of lymphoma cells in the blood of patients presenting with MCL. PCR for these clonal cells may be diagnostically useful.

Differential expression of cyclin D1 in mantle cell lymphoma and other non-Hodgkin's lymphomas

Mantle-cell lymphomas are associated with a characteristic chromosomal translocation, t(11;14)(q13;q32). This translocation involves rearrangement of the bcl-1 proto-oncogene from chromosome 11 to the immunoglobulin heavy chain gene on chromosome 14, resulting in an overexpression of cyclin D1 mRNA (also known as bcl-1 and PRAD1). In the current study performed on paraffin-embedded tissue, cyclin D1 mRNA could be detected in 23 of 24 mantle-cell lymphomas by reverse transcription polymerase chain reaction (RT-PCR) whereas only 9 of 24 demonstrated a t(11;14) by PCR. However, we also found that cyclin D1 mRNA could be detected in the majority (11 of 17, 65%) of non-mantle-cell lymphomas and in a minority of atypical lymphoid hyperplasias (3 of 7, 43%). Cyclin D1 mRNA expression was not observed in floridly reactive lymph nodes (0 of 9) or in unstimulated lymph nodes (0 of 20), suggesting that it is a sensitive adjunct marker for malignant lymphoproliferative processes, but not specific for mantle-cell lymphoma. A semiquantitative RT-PCR assay was developed that compared the ratio of cyclin D1 to the constitutively expressed gene beta2-microglobulin. Using this assay on a limited number of our specimens, cyclin D1 overexpression in mantle-cell lymphoma could be reliably distinguished from its expression in other non-Hodgkin's lymphomas. This assay for cyclin D1 expression, designed for formalin-fixed, paraffin-embedded tissue, was a very sensitive and specific marker for mantle-cell lymphoma.

Molecular methods for detecting t(11;14) translocations in mantle-cell lymphomas

The t(11;14)(q13;q32) and its molecular counterpart, bcl1/JH, are characteristic of mantle-cell lymphomas (MCL). Molecular detection of the translocation is useful in diagnosis and classification, and also shows promise in detecting minimal residual disease. The purpose of this study was to determine the frequency of detecting bcl1/JH by polymerase chain reaction (PCR) compared with Southern blot analysis in cases proven by cytogenetic analysis to harbor t(11;14). Southern blot analysis using two probes targeting the major translocation cluster (MTC) and a third probe targeting the p94 region was performed, along with PCR using two different bcl1 MTC primers, on 18 cases of MCL known to have t(11;14). Southern blot analysis revealed bcl1 rearrangement in 13 of 18 cases (72%), 12 with MTC breakpoints and 1 with a p94 breakpoint. The 2.1-kb MTC probe "b" was superior to the smaller 700-bp probe "a" in detecting these rearrangements. The MTC translocation was identified by PCR in 10 of 12 cases, and both primer sets that were tested performed equally well. This study illustrates the frequency with which molecular methods detect known t(11;14) translocations in MCLs. These results may help clinical laboratory scientists optimize their procedure for detecting bcl1 translocations by molecular methods at initial diagnosis and for purposes of detecting minimal residual disease.

Bone marrow and peripheral blood involvement in mantle cell lymphoma

The peripheral blood smears, bone marrow aspirates and biopsies of 46 patients with mantle cell lymphoma were reviewed. The diagnosis of mantle cell lymphoma was established in all cases on extramedullary tissue samples using standard morphologic, phenotypic and molecular genetic criteria. 27/35 patients (77%) had circulating lymphoma cells (median 200%m of all circulating white blood cells; range 5-90%) identified by morphology at some point during the course of their disease. No statistical difference in survival was detected in patients with or without peripheral blood involvement. Lymphoma was identified in bone marrow aspirate specimens from 33/40 patients (83%) and in bone marrow biopsy specimens from 39/43 patients (91%). The pattern of marrow biopsy involvement was nodular (31 cases; 82%), interstitial (19 cases; 50%), paratrabecular (17 cases, 45%) and diffuse (12 cases; 32%). Although the median survival of patients with > or = 50% bone marrow involvement was 13 months, and the median survival of patients with < or = 50% was 49 months; no statistically significant differences between these small subgroups were observed. Mantle cell lymphoma frequently involves the peripheral blood and bone marrow. Its appearance is distinctive but variable, and immunophenotypic studies as well as morphologic confirmation by a biopsy of tissue other than bone marrow is still required for diagnosis.

Mantle cell lymphoma: presenting features, response to therapy, and prognostic factors

BACKGROUND

The goal of this study was to analyze the presenting features, natural history, and prognostic factors in 59 patients with well characterized mantle cell lymphoma (MCL).

METHODS

Cases were classified as nodular or diffuse and as typical or blastic variants. Age, performance status (PS), histologic variants, mitotic index (MI), hematologic parameters, tumor extension data, and International Prognostic Index (IPI) were recorded and evaluated for prognosis.

RESULTS

The median age of the patients was 63 years (range, 39-83 years), and the male to female ratio was 3:1. Fifty-three patients had typical histology (3 nodular and 50 diffuse), and 6 had the blastic variant. Approximately 95% of patients presented with advanced stage disease (Ann Arbor Stage III-IV). Leukemic expression was observed in 58%. Complete and partial response rates were 19% and 46%, respectively. Parameters associated with lower response rate were Stage IV, high/intermediate or high risk IPI, and increased lactate dehydrogenase (LDH) level. In the logistic regression analysis, high LDH level and Stage IV disease were associated independently with lower response rate. Median survival was 49 months. Parameters associated with a short survival were: poor PS, splenomegaly, B-symptoms, MI > 2.5, leukocyte count > 10 x 10(9)/L, high LDH level, blastic variant, and high/intermediate or high risk IPI. In the Cox proportional hazards regression model, only poor PS (relative risk [RR] = 3.3; P = 0.002), splenomegaly (RR = 2.8; P = 0.007), and MI > 2.5 (RR = 2.4; P = 0.012) were associated with short survival.

CONCLUSIONS

In this series, patients with MCL presented with advanced stage and extranodal involvement. Only a minority of patients achieved a complete response. The median survival was 4 years, with PS, splenomegaly, and MI being the most important factors predicting survival. These results show clearly that more effective therapies for MCL are needed.

Low-grade, malt-type, primary B-cell lymphoma of the conjunctiva

Although primary ocular lymphomas may be found in the conjunctiva, eye lids and lacrimal glands, the majority nevertheless occur in the orbit. Only a few cases of primary conjunctival lymphoma have been described in the literature. A 68-year-old man presented with a painless swelling of the epibulbar conjunctiva of the right eye. A diffuse lymphoid infiltrate consisting of small-sized lymphoid cells with the morphology and distribution characteristics of mucosa-associated lymphoid tissue was observed. Immunohistological study demonstrated the B lymphocyte lineage of tumor cells and Bcl-1 and bcl-2 rearrangements were negative. After clinical staging including thoracic, abdominal, brain and orbital CT scans, fiberoptic gastroscopy and bone marrow biopsy, no other foci of this lymphoma were found. Radiation therapy was given and the patient currently remains free of lymphoma 30 months after diagnosis.

Molecular diagnosis of B- and T-cell lymphomas: fundamental principles and clinical applications

Molecular diagnostic assays have become routine in the evaluation of lymphoid malignancies. Both Southern transfer and polymerase chain reaction (PCR) technologies are used to assess for B- and T-cell clonality, the presence of rearrangements involving protooncogenes such as bcl-1 and bcl-2, and the monitoring of minimal residual disease. We review the fundamentals of B- and T-cell ontogeny as well as the basic principles of the Southern transfer and PCR assays and their applications to the diagnosis of lymphoid malignancies.

Deletions and Loss of Expression of P16INK4a and P21Waf1 Genes Are Associated With Aggressive Variants of Mantle Cell Lymphomas

Mantle cell lymphoma (MCL) is molecularly characterized by bcl-1 rearrangement and cyclin D1 gene overexpression. Some aggressive variants of MCL have been described with blastic or large cell morphology, higher proliferative activity, and shorter survival. The cyclin-dependent kinase inhibitors (CDKIs) p21Waf1 and p16INK4a have been suggested as candidates for tumor-suppressor genes. To determine the role of p21Waf1 and p16INK4a gene alterations in MCLs, we examined the expression, deletions, and mutations of these genes in a series of 24 MCLs, 18 typical, and 6 aggressive variants. Loss of expression and/or deletions of p21Waf1 and p16INK4a genes were detected in 4 (67%) aggressive MCLs but in none of the typical variants. Two aggressive MCLs showed a loss of p16INK4a expression. These cases showed homozygous deletions of p16INK4a gene by Southern blot analysis. An additional aggressive MCL in which expression could not be examined showed a hemizygous 9p12 deletion. Loss of p21Waf1 expression at both protein and mRNA levels was detected in an additional aggressive MCL. No p21Waf1 gene deletions or mutations were found in this case. The p21Waf1 expression in MCLs was independent of p53 mutations. The two cases with p53 mutations showed p21Waf1 and p16INK4a expression whereas the 4 aggressive MCLs with p16INK4a and p21Waf1 gene alterations had a wild-type p53. p21Waf1 and p16INK4a were expressed at mRNA and protein levels in all typical MCLs examined. No gene deletions or point mutations were found in typical variants. Two typical MCLs showed an anomalous single-stranded conformation polymorphism corresponding to the known polymorphisms at codon 148 of p16INK4a gene and codon 31 of p21Waf1 gene. These findings indicate that p21Waf1 and p16INK4a alterations are rare in typical MCLs but the loss of p21Waf1 and p16INK4a expression, and deletions of p16INK4a gene are associated with aggressive variants of MCLs, and they occur in a subset of tumors with a wild-type p53 gene.

Deletions and Loss of Expression of P16INK4a and P21Waf1 Genes Are Associated With Aggressive Variants of Mantle Cell Lymphomas

Mantle cell lymphoma (MCL) is molecularly characterized by bcl-1 rearrangement and cyclin D1 gene overexpression. Some aggressive variants of MCL have been described with blastic or large cell morphology, higher proliferative activity, and shorter survival. The cyclin-dependent kinase inhibitors (CDKIs) p21Waf1 and p16INK4a have been suggested as candidates for tumor-suppressor genes. To determine the role of p21Waf1 and p16INK4a gene alterations in MCLs, we examined the expression, deletions, and mutations of these genes in a series of 24 MCLs, 18 typical, and 6 aggressive variants. Loss of expression and/or deletions of p21Waf1 and p16INK4a genes were detected in 4 (67%) aggressive MCLs but in none of the typical variants. Two aggressive MCLs showed a loss of p16INK4a expression. These cases showed homozygous deletions of p16INK4a gene by Southern blot analysis. An additional aggressive MCL in which expression could not be examined showed a hemizygous 9p12 deletion. Loss of p21Waf1 expression at both protein and mRNA levels was detected in an additional aggressive MCL. No p21Waf1 gene deletions or mutations were found in this case. The p21Waf1 expression in MCLs was independent of p53 mutations. The two cases with p53 mutations showed p21Waf1 and p16INK4a expression whereas the 4 aggressive MCLs with p16INK4a and p21Waf1 gene alterations had a wild-type p53. p21Waf1 and p16INK4a were expressed at mRNA and protein levels in all typical MCLs examined. No gene deletions or point mutations were found in typical variants. Two typical MCLs showed an anomalous single-stranded conformation polymorphism corresponding to the known polymorphisms at codon 148 of p16INK4a gene and codon 31 of p21Waf1 gene. These findings indicate that p21Waf1 and p16INK4a alterations are rare in typical MCLs but the loss of p21Waf1 and p16INK4a expression, and deletions of p16INK4a gene are associated with aggressive variants of MCLs, and they occur in a subset of tumors with a wild-type p53 gene.