In situ hybridization and reverse transcription-polymerase chain reaction for cyclin D1 mRNA in the diagnosis of mantle cell lymphoma in paraffin-embedded tissues

Evidence that preimmunization with a heat-killed preparation of Mycobacterium vaccae reduces corticotropin-releasing hormone mRNA expression in the extended amygdala in a fear-potentiated startle paradigm

Posttraumatic stress disorder (PTSD) is a trauma and stressor-related disorder that is characterized by dysregulation of glucocorticoid signaling, chronic low-grade inflammation, and impairment in the ability to extinguish learned fear. Corticotropin-releasing hormone (Crh) is a stress- and immune-responsive neuropeptide secreted from the paraventricular nucleus of the hypothalamus (PVN) to stimulate the hypothalamic-pituitary-adrenal (HPA) axis; however, extra-hypothalamic sources of Crh from the central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST) govern specific fear- and anxiety-related defensive behavioral responses. We previously reported that preimmunization with a heat-killed preparation of the immunoregulatory environmental bacterium Mycobacterium vaccae NCTC 11659 enhances fear extinction in a fear-potentiated startle (FPS) paradigm. In this follow-up study, we utilized an in situ hybridization histochemistry technique to investigate Crh, Crhr1, and Crhr2 mRNA expression in the CeA, BNST, and PVN of the same rats from the original study [Fox et al., 2017, Brain, Behavior, and Immunity, 66: 70-84]. Here, we demonstrate that preimmunization with M. vaccae NCTC 11659 decreases Crh mRNA expression in the CeA and BNST of rats exposed to the FPS paradigm, and, further, that Crh mRNA expression in these regions is correlated with fear behavior during extinction training. These data are consistent with the hypothesis that M. vaccae promotes stress-resilience by attenuating Crh production in fear- and anxiety-related circuits. These data suggest that immunization with M. vaccae may be an effective strategy for prevention of fear- and anxiety-related disorders.

Cyclin D1 expression by histiocytes may mimic cyclin D1-positive proliferation centres of chronic lymphocytic leukaemia/small lymphocytic lymphoma

AIMS

Cyclin D1, generally considered to be absent in chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL), has been reported in the proliferation centres (PCs) of recent CLL/SLL cases. Cyclin D1 immunostaining in CLL/SLL may lead to diagnostic confusion. The objective of this study was to identify the types of stained cells and the impact on diagnosis.

METHODS

Cyclin D1 expression was assessed by immunostaining samples from 46 cases of CLL/SLL. CD68 and double immunostaining with CD20/CyclinD1, CD68/CyclinD1, and CD163/CyclinD1 were then performed in cases of CLL/SLL positive for cyclinD1 in the PCs.

RESULTS

Dim-positive cyclin D1 staining in randomly scattered cells in the CLL/SLLs were observed in 38/46 cases (82.6%). In five (10.9%) cases, more than 50 cyclin D1-positive cells per high-power field were detected within the PCs in CLL/SLL with weak to moderate intensity. Double immunochemical staining in these cases showed that cyclin D1 in these positive cells was mostly co-expressed with CD68 and CD163 and the cells were negative for CD20.

CONCLUSIONS

The cyclin D1-positive CLL/SLL cells in this study were mostly histiocytes. The expression of cyclin D1 by histiocytes may mimic cyclin D1+ CLL/SLL; thus, the recognition of cyclin D1 expression by non-lymphoid cells in lymphoma is important.

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.

Tumor Cell Nuclei Extraction From Paraffin-Embedded Lymphoid Tissue for Fluorescence In Situ Hybridization

In this study the authors evaluated a technique for isolating intact tumor nuclei from paraffin-embedded lymphoma samples before performing FISH testing to detect the lymphoma-specific trans-location t(11;14) that defines mantle cell lymphoma. Well-characterized surgical pathology cases of mantle cell lymphoma were identified from pathology archives. Thin sections were cut from the paraffin-embedded tissue blocks. One section was stained using hematoxylin and eosin and an area composed exclusively of malignant cells was identified and marked on the slide. The corresponding area of the tissue block corresponding to this region underwent needle core biopsy, and the tissue was processed to isolate tumor cell nuclei and deposited onto a glass slide. The paired sample preparations underwent routine FISH testing for detection of the t(11;14)(q13;q32) chromosomal trans-location. DNA probe hybridization quality was compared between the tissue and isolated nuclei. Individual tumor cell nuclei were successfully extracted from each of the tissue blocks. The t(11;14) trans-location was detected by FISH in all of the samples diagnosed as mantle cell lymphoma. The hybridization signals found in the nuclei of extracted tumor cells were bright, planar, and easily identified. Detection of signal was superior to that on whole tissue samples, where signals often overlapped or were truncated. This technique produces intact nuclei for analysis, preserves the tissue block for additional studies, and allows sampling of a specific area of the tissue block. This approach may be particularly useful when the amount of diagnostic tissue is limited.

SP4, a Novel Anti-Cyclin D1 Rabbit Monoclonal Antibody, Is a Highly Sensitive Probe for Identifying Mantle Cell Lymphomas Bearing the t(11;14)(q13;q32) Translocation

Immunohistochemistry is the most widely used approach in the diagnosis of mantle cell lymphoma (MCL). However, its reliability may be hampered by several technical reasons, necessitating the use of alternative techniques such as the identification of the t(11;14)(q13;q32) translocation to characterize such lesions. The authors compared two monoclonal antibodies (DCS-6 and SP4) for assessing cyclin D1 immunoreactivity in a series of 22 MCLs. Their results documented that SP4, a novel rabbit monoclonal antibody, is more effective than the mouse monoclonal antibody DCS-6, one of the most commonly used reagents in daily practice. Although DCS-6 and SP4 were capable of identifying cyclin D1 immunoreactivity in 95.4% and 100% of the cases analyzed, respectively, the prevalence of cyclin D1 immunoreactive neoplastic cells was significantly (P < 0.0001) higher with SP4 (86.6 +/- 13.1%) than with DCS-6 (39.8 +/- 32%). Moreover, the staining intensity was faint in 16 (76.2%) cases and moderate to strong in 5 (23.8%) cases immunostained with DCS- 6, while all the cases showed a moderate to strong immunoreactivity with SP4 (P < 0.0001). According to an arbitrary score based on the percentage of immunoreactive neoplastic cells and staining intensity, only 10 (45.4%) cases were considered high cyclin D1 expressors after staining with DCS-6, whereas all the cases were high expressors with SP4 (P < 0.0001). These data provide evidence that the SP4 monoclonal antibody may be a fast, easy-to-interpret, and reliable surrogate for the detection of the (11;14) translocation by molecular techniques.

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.

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.

Rapid detection of the t(11;14) translocation in mantle cell lymphoma by interphase fluorescence in situ hybridization on archival cytopathologic material

BACKGROUND

The cytomorphologic diagnosis of mantle cell lymphoma (MCL) can be difficult and requires ancillary studies for accurate subclassification. More than 95% of MCLs are known to carry the t(11;14) chromosomal translocation. However, traditional cytogenetic studies on cytologic material can be both difficult technically and time consuming. Interphase fluorescence in situ hybridization (FISH) can be a powerful tool for detecting chromosomal changes in individual tumor cells. The authors evaluated the utility of interphase FISH for the rapid detection of t(11;14) in archival cytologic material.

METHODS

The cytopathology data bases at two institutions were searched for patients with well characterized MCL (biopsy, immunophenotyping). Ten patients with MCL (8 fine-needle aspiration samples and 2 body cavity fluid samples) were identified. The area of interest on the cytology slides was marked and hybridized with two-color, locus-specific identifier DNA probes. A dual-fusion probe signal was used to detect the juxtaposition of the immunoglobulin heavy-chain (IgH) (14q32) locus with cyclin D1 (CCND1) gene sequences (11q13). Samples with tumor cell nuclei that showed at least one yellow fusion signal in addition one green signal (IgH) and one orange signal (CCND1) were interpreted as positive. Positive and negative controls were used.

RESULTS

The t(11;14) translocation was detected by FISH in 10 of 10 patients (100%) with MCL.

CONCLUSIONS

The cytomorphology of small-to-intermediate cell lymphomas, including MCL, follicular lymphoma, and marginal zone/mucosa-associated lymphoid tissue lymphoma, can show overlapping cytomorphologic features with one another as well as with reactive lymphoid proliferations. In selected samples in which specific classification is not possible or when confirmation is required on a small sample size, molecular analysis and cytogenetics may be helpful in arriving at an unambiguous cytodiagnosis and subclassification. Distinction of MCL from other lymphomas is important, because the clinical course is aggressive, and response to conventional chemotherapy is poor. This study showed that the detection of t(11;14) by FISH can be performed rapidly and easily on archival cytologic material for the molecular diagnosis of MCL.

Fluorescence in situ hybridization: method of choice for a definitive diagnosis of mantle cell lymphoma

Fluorescence in situ hybridization (FISH) using IGH/CCND1 probes was used to analyze 35 specimens including 27 paraffin sections, 3 bone marrow aspirates, and 5 peripheral blood smears. The 27 paraffin sections included 7 bone marrows, 10 lymph nodes, 3 spleens, 3 tonsils, 3 gastrointestinal biopsies, and 1 skin biopsy. Among these cases, 23 specimens were from 20 patients with mantle cell lymphoma (MCL) and 12 specimens were from 12 patients with non-MCL lymphomas/lymphoid hyperplasia. Specimens from all MCL patients showed positive results with FISH. In one patient, the archived paraffin sections were negative with FISH, but a fresh peripheral blood specimen showed a positive result. Negative results were obtained in all specimens from non-MCL cases. Flow cytometric analysis revealed that all cases of MCL showed CD19/CD5 staining, but the percentages of cells positive for CD23 and FMC-7 were variable, thus they cannot be depended upon for a definitive diagnosis of MCL. Immunohistochemical stains demonstrated positive staining for CD5 and CD20 and negative staining for CD23 in MCL cases but cyclin D1 was positive in only 10 of 13 MCL cases studied. Therefore, it appears that immunophenotyping alone is not sufficient to establish a definitive diagnosis of MCL. FISH should be routinely used when the diagnosis needs confirmation. FISH can be performed in a routine clinical laboratory, and it is applicable to archived material for retrospective studies. Other molecular cytogenetic techniques in comparison with FISH are discussed.

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.

Value of interphase FISH for the diagnosis of t(11:14)(q13;q32) on skin lesions of mantle cell lymphoma

The diagnosis of skin lesions of mantle cell lymphoma (MCL) may be difficult at the onset of the disease. We observed 2 patients with papules of the trunk and 1 with diffuse infiltration of the trunk and the face and 2 subcutaneous nodules. Skin samples showed diffuse infiltration of the dermis (n = 1) or perivascular infiltration (n = 2). The infiltrate corresponded to centrocytic cells (n = 2) or pleomorphic blastoid cells (n = 1) with a B-cell phenotype: CD3-, CD5+ (2/3), CD20+, CD23-, and CD43+. In only 1 case was cyclin D1 immunoreactivity detected, and the t(11;l4)(q13;q32) breakpoint was amplified from both lymph node and skin DNA. Competitive reverse transcriptase-polymerase chain reaction was not contributive for skin specimens. In all 3 cases, interphase fluorescence in situ hybridization (FISH) demonstrated t(11;14) fusion signals either on paraffin sections or on fresh frozen touch preparations of skin biopsies. The recognition of skin lesions of MCL from other B-cell infiltrates can be established by interphase FISH.

Determination of cyclin D1 and CD20 mRNA levels by real-time quantitative RT-PCR from archival tissue sections of mantle cell lymphoma and other non-Hodgkin's lymphomas

Cyclin D1 overexpression is a valuable marker for the diagnosis of mantle cell lymphoma (MCL). We used a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) method to quantify levels of cyclin D1, CD20, and cyclophilin A mRNA in manually microdissected, paraffin-embedded tissue sections using an ABI 7700 qRT-PCR system. The study group included 21 cases of MCL and 37 cases of other types of B-cell non-Hodgkin's lymphoma. Cyclin D1 mRNA copy number was normalized to CD20 and cyclophilin A mRNA and evaluated statistically by analysis of variance. The relative cyclin D1 levels were similar whether normalized to CD20 or cyclophilin A, indicating that CD20 levels are stable and can be used as a B-cell-specific normalizer. Statistically significant differences were found in the median levels of cyclin D1 mRNA (expressed as % CD20 mRNA) among cases of MCL (87.6), small lymphocytic lymphoma (9.9), follicular lymphoma (2.4), diffuse large B-cell lymphoma (5.9), marginal zone B-cell lymphoma (39.8), and Burkitt lymphoma (7.1) (P < 0.05). We conclude that qRT-PCR can be used to quantify cyclin D1 mRNA levels in archival tissue sections. Normalization of cyclin D1 to a B-cell-specific marker more accurately reflects overexpression by MCL than other methods that normalize using constitutively expressed mRNA species.

Banded chromosomes versus fluorescence in situ hybridization in the diagnosis of mantle cell lymphoma: a lesson from three cases

We present three cases with presumptive evidence of mantle cell lymphoma (MCL) that were submitted for cytogenetic evaluation. Chromosome analysis showed a normal karyotype in two cases, while the third case showed the composite karyotype; 45,XY,t(1;22)(p13;q13),23,del(10)(q22),add(15)(q22),add(17)(p13). The characteristic t(11;14)(q13;q32) for MCL was not observed by conventional karyotyping in any of the cases. We furthermore evaluated the specimens by fluorescence in situ hybridization (FISH) using the dual-color LSI IgH/CCND1 DNA probe. Fusion signals, consistent with t(11;14)(q13;q32), were observed in 65% and 85% of interphase cells in cases 1 and 2, respectively, while the metaphases from both cases revealed a normal pattern. All abnormal metaphases as well as 57% of interphase cells from case 3 displayed a fusion signal. In the abnormal metaphase cells, the fused signal was located on the normally looking 14q32, suggesting that the IgH/CCND1 fusion resulted from the insertion of the CCND1 gene into 14q32 adjacent to the IgH gene. Thus, FISH confirmed the diagnosis of MCL by showing the IgH/CCND1 fusion. In addition, these findings indicate that the sensitivity of FISH is superior to that of conventional cytogenetics in detecting t(11;14)(q13;q32) associated with MCL.

A comparative analysis of FISH, RT-PCR, PCR, and immunohistochemistry for the diagnosis of mantle cell lymphomas

Mantle cell lymphoma (MCL) diagnosis first relies on morphology and phenotype that may overlap with other B-cell lymphomas. Therefore, the demonstration of t(11;14)(q13;q32), the cytogenetic hallmark of MCL, is considered of diagnostic value. By studying a series of 35 MCL with characteristic morphology and phenotype (CD5+, CD10-, CD20+, CD23-), we have evaluated the applicability and the sensitivity of interphase fluorescence in situ hybridization (FISH) for t(11;14) detection and other techniques: (1) polymerase chain reaction (PCR) for amplification of t(11;14) genomic breakpoint, (2) competitive RT-PCR for the detection of cyclin D1 transcripts overexpression, and (3) immunohistochemistry (IHC) for cyclin D1 protein detection. Tissues from different origins were analyzed: lymph nodes (n = 24), spleen (n = 3), digestive biopsy (n = 3), tonsils (n = 3), and skin (n = 2). Interphase FISH was performed either on touch preparations (n = 11) and frozen (n = 9) or paraffin sections (n = 15). FISH analysis detected t(11;14) in 34/35 cases (97%) and demonstrated a recurrent CCND1 amplification in t(11;14)+ nuclei of the three blastoid MCL variants of our series. Genomic PCR analysis, hampered by the scattering of 11q13 breakpoints, was positive in only 13/35 cases (37%). RT-PCR analysis was applicable on nonepithelial tissues (27/35) and showed cyclin D1 transcript overexpression in all tested cases (27/35). IHC for cyclin D1 protein was performed either on frozen (n = 12) or on paraffin sections (n = 23), and its sensitivity was higher on paraffin sections (91%) than on frozen sections (25%). A cyclin D1 protein immunoreactivity was observed in 24/35 cases (69%). Our study emphasizes on the use of FISH analysis for the direct detection of t(11;14) because its applicability and sensitivity largely exceeded those of other techniques. It may also provide some informations on secondary cytogenetic changes of potential clinical relevance.

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.

Cyclin D1 overexpression in multiple myeloma. A morphologic, immunohistochemical, and in situ hybridization study of 71 paraffin-embedded bone marrow biopsy specimens

Cyclin D1 expression was evaluated by immunohistochemical analysis and biotin-labeled in situ hybridization (ISH) in a series of 71 decalcified, paraffin-embedded bone marrow biopsy specimens from patients with multiple myeloma (MM). Cyclin D1 messenger RNA (mRNA) overexpression was detected by ISH in 23 (32%) of 71 cases, whereas cyclin D1 protein was identified by immunohistochemical analysis in 17 (24%) of 71 specimens. All cases that were positive by immunohistochemical analysis also were positive by ISH. Statistically significant associations were found between cyclin D1 overexpression and grade of plasma cell differentiation and between cyclin D1 overexpression and extent of bone marrow infiltration. Our findings demonstrate the following: (1) ISH for cyclin D1 mRNA is a sensitive method for the evaluation of cyclin D1 overexpression in paraffin-embedded bone marrow biopsy specimens with MM. (2) ISH is more sensitive than immunohistochemical analysis in the assessment of cyclin D1 expression. (3) Cyclin D1 overexpression in MM is correlated positively with higher histologic grade and stage.

Biology and management of mantle cell lymphoma

Mantle cell lymphoma is a distinct subtype and accounts for approximately 5 to 10% of non-Hodgkin lymphomas. The malignant cells express pan B-cell markers, including CD19, CD20 and CD22, and the T-cell marker CD5, whereas CD10 and CD23 expression are usually absent. By cytogenetic analysis, the t(11;14)(q13;q32) translocation is commonly observed, resulting in overexpression of cyclin D1. This entity often combines some unfavorable clinical features of the indolent and aggressive lymphoma subtypes, as it is generally incurable and relatively aggressive. It is most commonly observed in men 50 to 70 years of age and is characterized by disseminated disease, usually involving lymph nodes, bone marrow, and spleen. Frequently, there is extranodal involvement including the gastrointestinal tract. These tumors are incurable with the currently available therapeutic options, with usual time to progression after chemotherapy of approximately 1 year. Newer chemotherapy regimens (including stem cell transplantation) and monoclonal antibody-based therapies have shown limited evidence of additional benefit. Overall, the prognosis for patients with mantle cell lymphoma remains poor, and novel strategies are needed.