Immunohistochemical analysis of cyclin D1 protein in hematopoietic neoplasms with special reference to mantle cell lymphoma

The critical role of histology in an era of genomics and proteomics: a commentary and reflection

The role of histologic examination in lymphoma diagnosis has been called into question by proponents of new technologies, such as genomics and proteomics. We review the history and salient features of morphologic evaluation in lymphoid diseases, and discuss the general and specific limitations of mature ancillary techniques, such as immunohistochemistry, flow cytometry, and molecular studies. We then speculate on the future relationship between morphology and the new genomic and proteomic technologies as they become integrated into clinical practice.

Durable response but prolonged cytopenia after cladribine treatment in relapsed patients with indolent non-Hodgkin's lymphomas: results of a Japanese phase II study

We conducted a phase II study to evaluate the efficacy and safety of cladribine (2-chlorodeoxyadenosine [2-CdA]) for patients with refractory or relapsed indolent B-cell lymphoma or mycosis fungoides. Forty-five patients were enrolled, and 43 patients, including 34 with follicular lymphoma, were eligible. 2-CdA was given by continuous intravenous infusion at a dose of 0.09 mg/kg daily for 7 consecutive days, and this schedule was repeated every 4 weeks up to a maximum of 6 cycles. The overall and complete response rates were 58.1% (25/43; 90% confidence interval, 44.5%-70.9%) and 14.0% (6/43), respectively. The disease progression-free proportions of all 43 eligible and all 25 responding patients at 2 years were 30.3% and 48.1%, respectively. Neutropenia and thrombocytopenia of grade 3 or 4 were observed in 53.3% and 37.8% of patients, respectively, with prolonged cytopenia observed in patients with increased numbers of treatment cycles. Nonhematologic toxicities of grade 3 or greater included diarrhea, arrhythmia, malaise, and gastrointestinal bleeding in 1 patient each, an increase in glutamic-pyruvic transaminase level in 2 patients, and infection in 5 patients. Two treatment-related deaths were observed. Four patients developed myelodysplastic syndrome (MDS) at 13 months to 2 years after completion of the 2-CdA treatments. 2-CdA is an active agent with acceptable toxicity for refractory or relapsed indolent lymphoma; however, prolonged myelosuppression and the potential development of MDS should be carefully monitored.

Japanese multicenter phase II and pharmacokinetic study of rituximab in relapsed or refractory patients with aggressive B-cell lymphoma

BACKGROUND

To evaluate the efficacy and feasibility of rituximab monotherapy in Japanese patients with relapsed or refractory aggressive B-cell lymphoma.

PATIENTS AND METHODS

Sixty-eight patients were treated with rituximab at 375 mg/m(2) by eight consecutive weekly infusions. Pretreatment variables affecting overall response rate (ORR) and progression-free survival (PFS) and the relationship between pharmacokinetic parameters and efficacy were analyzed.

RESULTS

The ORRs of 68 enrolled patients and 57 eligible patients were 35% [95% confidence interval (CI) 24% to 48%] and 37% (95% CI 25% to 51%), respectively. Median PFS of 53 evaluable patients was 52 days, whereas time to progression of 21 eligible responders was 245 days. Mild to moderate infusion-related toxicities were observed frequently at the first infusion, but all of them were reversible. Elevated lactate dehydrogenase (LDH) and refractoriness to prior chemotherapy were unfavorable factors affecting ORR and PFS (P <0.01). Serum trough levels of rituximab and area under the concentration-time curve for responders were higher than for non-responders (P <0.05).

CONCLUSIONS

Eight consecutive weekly infusions of rituximab have significant anti-lymphoma activity for relapsed or refractory aggressive B-cell lymphoma. Several pretreatment variables and serum rituximab levels are useful for predicting its efficacy.

Routine use of immunophenotype by flow cytometry in tissues with suspected hematological malignancies

BACKGROUND

Immunophenotype is an essential parameter in the diagnosis of hematological malignancies. Flow cytometry (FCM) is used in the analysis of bone marrow or peripheral blood samples but is less frequently used in the evaluation of tissue biopsies with suspected hematological malignancies. The aim of this study was to analyze the role of FCM in the diagnosis of biopsies from patients with a suspected hematological disorder.

METHODS

A total of 422 consecutive biopsies were studied using standard morphology, immunohistochemistry (IHC), and FCM. Results of FCM were obtained in less than 3 h and were interpreted independently from morphology and IHC.

RESULTS

A strong correlation between malignant disease and abnormal pattern of FCM was observed (218 of 250) with the exception of Hodgkin disease (P < 0.001). Overall, negative predictive value was 0.52 and positive predictive value was 1. Light chain restriction was observed in 182 of 201 B-cell lymphoma and in 0 of 142 non-B-cell disorders by FCM. In contrast, light chain pattern could only be evaluated in 38 of 91 cases by IHC. FCM allowed a rapid diagnosis of infrequent or high-grade malignancies such as histiocytic sarcoma or T-lymphoblastic lymphoma. The addition of FCM in the routine study of tissue biopsies facilitates the diagnosis of double pathology in five (1%) patients.

CONCLUSIONS

FCM is a fast and reliable methodology for phenotyping tissue samples, which easily detects infrequent hematological malignancies, disease-specific phenotypes and clonality in B-cell lymphomas. Moreover, the simultaneous recognition of different cell populations allows the diagnosis of composite cell lymphomas, or double pathologies.

Case of Epstein-Barr virus-associated transformation of mantle cell lymphoma

We report here a case of mantle cell lymphoma (MCL) in a patient who, following Epstein-Barr virus (EBV) infection, developed diffuse large B-cell lymphoma (DLBCL). A 47-year-old woman was diagnosed as having MCL with clinical stage IIIA in July 1990. After treatment with a third-generation chemotherapy without response, she was kept under observation for 8 years. In January 1999, fever and night sweats appeared with laboratory evidence for EBV infection, and acute swelling of lymph nodes and hepatosplenomegaly developed in May 1999. Histopathological examination confirmed the diagnosis of DLBCL. Sequence analysis of the complementarity-determining region (CDR)-III of the immunoglobulin heavy chain gene demonstrated clonal identity between the initial MCL and the subsequent DLBCL. Immunohistochemistry revealed that cyclin D1, CD5, and CD20 were expressed in the MCL but lost in the DLBCL cells, and EBER-ISH confirmed that EBV infection was absent in the former but present in the latter. Southern hybridization with the EBV terminal repeat probe showed a clear monoclonal pattern in the DLBCL specimen. All these results suggest that EBV infection may have been the molecular event that caused transformation of MCL cell(s) to DLBCL in this case. This is, to the best of our knowledge, the first well-documented case of EBV-associated transformation of MCL.

Detection of cyclin D1 in B cell lymphoproliferative disorders by flow cytometry

AIMS

To describe and revise a flow cytometric assay for evaluating cyclin D1 overexpression in B cell lymphoproliferative disorders (B-LPDs).

METHODS

Cyclin D1 expression was evaluated in 11 healthy controls and 51 patients with B-LPD by flow cytometry using the 5D4 monoclonal antibody. In 25 cases, experiments were repeated up to four times with mononuclear cells (MNC) fixed in ethanol for 1-120 days to evaluate the consistency of cyclin D1 expression. Flow cytometry results were compared with fluorescence in situ hybridisation (FISH) for the t(11;14) translocation in 19 patients and with immunohistochemistry (IHC) using the DCS-6 monoclonal antibody in nine patients.

RESULTS

A mean fluorescence intensity ratio (MFIR) of 4.8 was defined as the cut off point for positivity based on cyclin D1 expression in healthy controls (mean + 3 SD). Ten patients overexpressed cyclin D1 by flow cytometry. These included five of eight patients with mantle cell lymphoma, four of 19 with chronic lymphocytic leukaemia, and one with follicular lymphoma. MFIR in the repeat experiments differed less than 25% in 20 of 25 patients and in no cases did it cross the cut off point. There was a good correlation between cyclin D1 expression by flow cytometry and FISH for t(11;14) in 15 of 19 patients and six of nine had concordant results with flow cytometry, FISH, and IHC.

CONCLUSION

Cyclin D1 expression remains fairly stable once MNC are fixed in ethanol and the flow cytometric assay can be used for the routine screening of B-LPD. Further comparisons between flow cytometry, IHC, and FISH may be needed to ascertain the diagnostic value of the flow cytometric assay.

Factors affecting toxicity, response and progression-free survival in relapsed patients with indolent B-cell lymphoma and mantle cell lymphoma treated with rituximab: a Japanese phase II study

BACKGROUND

The aim of the study was to determine factors affecting the toxicity and efficacy of rituximab monotherapy in relapsed patients with indolent B-cell lymphoma and mantle cell lymphoma (MCL).

PATIENTS AND METHODS

A total of 90 patients were enrolled and treated with rituximab infusions at 375 mg/m2 once weekly for 4 weeks. Central pathology review revealed that histologically, 81 patients had indolent B-cell lymphoma or MCL: 59 with follicular lymphoma, 17 with MCL, four with marginal zone lymphoma and one with lymphoplasmacytoid lymphoma. Of these, four were ineligible due to violation of other eligibility criteria. Pre-treatment variables affecting toxicities were analyzed for all 90 patients, and those affecting response and progression-free survival (PFS) were analyzed for 77 eligible patients with confirmed indolent B-cell lymphoma or MCL. The relationship between serum rituximab levels and efficacy was also analyzed for 66 eligible patients.

RESULTS

Hematological toxicities (grade > or =3) occurred more frequently in females (P <0.05), and thrombocytopenia and leukopenia were more frequent in patients with high lactate dehydrogenase (LDH) levels (P <0.05). Non-hematological toxicities (grade > or =2) were more frequent in patients with extranodal disease or bone marrow involvement. The overall response rate (ORR) in patients receiving one prior chemotherapy regimen was higher than those receiving two or more regimens (P <0.05). The median PFS was shorter in MCL patients, in those with extranodal disease, or in those receiving two or more prior chemotherapy regimens (P <0.01). The PFS intervals of patients with higher serum rituximab levels (> or =70 microg/ml) immediately before the third infusion were longer than in other patients (P <0.01).

CONCLUSIONS

Several prognostic factors and serum rituximab levels are useful for predicting the toxicity and efficacy of rituximab monotherapy.

The evaluation of the biological behavior and grade among cases with mantle cell lymphoma

We have studied the expression of MIB-1 and prognosis in cyclin D1(CyD1)+ and CyD1- mantle cell lymphoma (MCL), and compared them to B-CLL/SLL. All cases were assigned to four groups by immunoreactivity and primary sites: (1) CyD1+ nodal MCL, 11 cases: (2) CyD1+ extranodal MCL (multiple lymphomatous polyposis, (MLP)) three cases: (3) CyD1- nodal MCL, three cases: and (4) CyD1- B-CLL/SLL, seven cases. The average of MIB-1 labeling indexes of the four groups were 30.66, 8.70, 9.30 and 4.66, respectively. The CyD1- group consisting of nodal MCL and CLL/SLL had a significantly longer median survival time (69 months) than the CyD1+ group consisting of nodal MCL and MLP (22 months, P = 0.01). These data indicate that CyD1- nodal MCL may show a lower MIB-1 labeling index, and has a better prognosis, than CyD1+ nodal MCL. In addition, a large difference in the average of MIB-1 labeling indexes between nodal MCL and MLP in the CyD1+ group was found.

Morphological spectrum of cyclin D1-positive mantle cell lymphoma: study of 168 cases

Immunostaining for cyclin D1 is essential for reliable diagnosis of mantle cell lymphoma (MCL). However, a small number of cyclin D1-positive lymphomas other than MCL have been encountered. Our goal was to investigate the morphological spectrum of MCL as a disease entity, based on cyclin D1 overexpression. We reviewed 181 biopsy specimens obtained from 168 cases of cyclin D1-positive MCL. Typical findings were the presence of nodular (53.9% of cases) or diffuse (46.1%) histological patterns, containing mantle zone patterns (16.8%), naked germinal centers (33.5%) and perivascular hyaline deposition (83.2%). Unusual findings of residual germinal centers with a mantle cuff (four cases) and follicular colonization (two cases) were seen. High magnification showed a monotonous proliferation of tumor cells with cytological diversity including small (3.0%), intermediate (43.1%), medium (34.1%), medium-large (13.2%) and large (6.6%) cells. Pleomorphic and blastic/blastoid variants were encountered in 9.6 and 7.2% of cases, respectively. Three cases had foci of cells of considerable size, with a moderately abundant pale cytoplasm resembling marginal zone B cells. Two cases showed an admixture of cells which appeared transformed and mimicked the histology of chronic lymphocytic leukemia/small lymphocytic leukemia. In one, neoplastic mantle zones were surrounded by sheets of mature plasma cells, resembling the plasma cell type of Castleman's disease. An admixture of areas characteristic of MCL and of other larger cells, indicating histological progression or a composite lymphoma, were observed in seven cases. In high-grade lesions of five cases, nuclear staining of cyclin D1 was rarely detected. In our experience, cyclin D1 expression was also found in nine lymphomas other than MCL (five plasma cell myelomas, three Hodgkin's disease and one anaplastic large cell lymphoma). The application of cyclin D1 staining prompted us to recognize the broad morphological spectrum of MCL. MCL can be diagnosed with the application of cyclin D1 immunostaining, if careful attention is given to architectural and cytological features.

Primary hyperparathyroidism caused by parathyroid-targeted overexpression of cyclin D1 in transgenic mice

The relationship between abnormal cell proliferation and aberrant control of hormonal secretion is a fundamental and poorly understood issue in endocrine cell neoplasia. Transgenic mice with parathyroid-targeted overexpression of the cyclin D1 oncogene, modeling a gene rearrangement found in human tumors, were created to determine whether a primary defect in this cell-cycle regulator can cause an abnormal relationship between serum calcium and parathyroid hormone response, as is typical of human primary hyperparathyroidism. We also sought to develop an animal model of hyperparathyroidism and to examine directly cyclin D1's role in parathyroid tumorigenesis. Parathyroid hormone gene regulatory region--cyclin D1 (PTH--cyclin D1) mice not only developed abnormal parathyroid cell proliferation, but also developed chronic biochemical hyperparathyroidism with characteristic abnormalities in bone and, notably, a shift in the relationship between serum calcium and PTH. Thus, this animal model of human primary hyperparathyroidism provides direct experimental evidence that overexpression of the cyclin D1 oncogene can drive excessive parathyroid cell proliferation and that this proliferative defect need not occur solely as a downstream consequence of a defect in parathyroid hormone secretory control by serum calcium, as had been hypothesized. Instead, primary deregulation of cell-growth pathways can cause both the hypercellularity and abnormal control of hormonal secretion that are almost inevitably linked together in this common disorder.

Classification of small B-cell lymphoid neoplasms using a paraffin section immunohistochemical panel

Immunophenotypic analysis is critical in categorizing small B-cell neoplasms; however, many recommended antibody panels have required fresh or frozen tissue. Many paraffin-reactive antibodies are now available but have been studied mostly in isolation. Therefore, the utility of a panel of paraffin-reactive antibodies in differentiating small B-cell neoplasms was investigated. Paraffin-embedded sections of small lymphocytic lymphoma/B-chronic lymphocytic leukemia (SLL/B-CLL; 12), mantle cell (MCL; 15), follicular (FL; 11), and marginal zone B-cell (MZL; eight) lymphomas were stained with CD20/L26, CD3, CD43/DF-T1 or Leu22, CD5/4C7, CD23/BU38, cyclin D1/H295, and CD10/56C6 antibodies. For select antibodies, results were compared to flow cytometric data (FC). Formalin and B5 fixation were also compared. Seven of 11 SLL/B-CLL were CD43+ CD5+ CD23+ cyclin D1- CD10-; seven of 11 MCL were CD43+ CD5+ CD23- cyclin D1+ CD10-; nine of 10 FL were CD43- CD5- CD23- cyclin D1- CD10+; and five of six MZL were CD43+ CD5- CD23- cyclin D1- CD10-. CD5, CD23, and CD10 stains showed sensitivities of 81, 88, and 100%, respectively, compared to FC. With B5 fixation, cyclin D1 was more often negative and CD5 more often equivocal. A panel of paraffin-reactive antibodies aids in classification of small B-cell neoplasms, although a small number of cases have indeterminate phenotypes and MZL have no defining features. CD5 separates most SLL/B-CLL and MCL from FL and MZL. CD23 separates SLL/B-CLL from most MCL, but cyclin D1 is most important for identifying MCL. CD10 positivity distinguishes most FL from other small B-cell lymphoid neoplasms.

Optimized cyclin D1 immunoperoxidase staining in mantle cell lymphoma

Mantle cell lymphoma (MCL) has a worse prognosis than MALT lymphoma (MALTL). Distinction between MCL and MALTL on purely morphologic grounds can be difficult. Cyclin D1 (PRAD1/bcl1) is overexpressed in MCL as a result of a t(11:14) gene rearrangement, which leads to overexpression of cyclin D1 mRNA and protein. The immunohistochemical detection of cyclin D1 in MCL has been reported by several authors to be highly specific with sensitivity ranging from 70%-100%, but diagnostic laboratories have reported difficulty in finding a reliable method for cyclin D1 immunostaining. The aim of this study was to evaluate and optimize a method for detection of cyclin D1 by paraffin section immunoperoxidase staining. Sections of routinely processed tissue from five MCL and one splenic marginal zone lymphoma (MZL) were immunostained using a mixture of two primary monoclonal antibodies and a standard avidin-streptavidin method. Antigen retrieval was performed using 1) steam heat in citrate buffer, 2) as in "1" followed by sonication for one minute, and 3) as in "2" followed by enzymatic digestion. All the above were repeated, with the additional use of catalyzed signal amplification (CSA). Later, sections of the same cases, plus three MALTL were immunostained as in "2". Steam heat antigen retrieval alone produced the best results. All MCL showed positive nuclear staining while the MZL and all MALTL were negative. Sonication did not enhance staining noticeably, whereas enzymatic digestion produced cytoplasmic staining. CSA increased background staining with no significant gain in nuclear stain intensity. We conclude that cyclin D1 immunostaining of formalin-fixed, paraffin-embedded tissue can be reliably achieved by heat induces antigen retrieval and a cocktail of two monoclonal antibodies.

Expression and subcellular localization of cyclin D1 protein in epithelial ovarian tumour cells

The expression of cyclin D1 protein in tumour sections from 81 patients with epithelial ovarian cancer was analysed using immunohistochemistry. The tumours that overexpressed cyclin D1 in more than 10% of neoplastic cells were considered positive. Thus overexpression of cyclin D1 was observed in 72/81 (89%) of the cases examined. Protein was detected in both the nucleus and the cytoplasm in 24/81 (30%) and localized exclusively in the cytoplasm in 48/81 (59%) of the tumours. Cyclin D1 was overexpressed in both borderline and invasive tumours. There was no association between protein overexpression and tumour stage and differentiation. Furthermore, no correlation between cyclin D1 expression and clinical outcome was observed. However, in tumours overexpressing cyclin D1 (n = 72), the proportion displaying exclusively cytoplasmic localization of protein was higher in those with serous compared with non-serous histology (P = 0.004, odds ratio 4.8, 95% confidence interval 1.4-19.1). Western analysis using a monoclonal antibody to cyclin D1 identified a 36 kDa protein in homogenates from seven tumours displaying cytoplasmic only and one tumour demonstrating both nuclear and cytoplasmic immunostaining. Using restriction fragment length polymorphism polymerase chain reaction and PCR-multiplex analysis, amplification of the cyclin D1 gene (CCND1 was detected in 1/29 of the tumours demonstrating overexpression of cyclin D1 protein. We conclude that deregulation of CCND1 expression leading to both cytoplasmic and nuclear protein localization is a frequent event in ovarian cancer and occurs mainly in the absence of gene amplification.

Clinicopathological evaluation of the Revised European-American Classification of Lymphoid Neoplasms (REAL) in Japan

After the publication of a Revised European-American Classification of Lymphoid Neoplasms (REAL classification) in 1994, there have been reports from Europe and America regarding its practical utility and clinical significance. However, no studies have been published from Eastern countries including Japan. It has been well recognized that the distribution of malignant lymphoma in Japan is quite different from that seen in Western countries. In addition, some new entities have also been described in the REAL classification. Therefore, it seems important to examine its practical utility and clinical significance in Japan. Of the 579 cases reviewed, approximately 68% were B-cell non-Hodgkin's lymphoma (NHL) followed by 27% T-cell lymphomas. Hodgkin's disease (HD) comprised only 5% of all cases, making the ratio of NHL to HD 20.6. The most common type was diffuse large B-cell lymphoma which represented about 37% of all cases. Peripheral T-cell lymphomas, unspecified (PTCL), occurred in 15% whereas marginal zone B-cell lymphoma followed (14.9%). However, follicle center lymphoma (FCL) was less common (4.4%) as has been previously reported. We evaluated the clinical significance of the new REAL classification in 244 cases. International Prognostic Index (IPI) was a powerful predictor of survival (p<0.0001), and the immunophenotype was significant (p<0.05). Furthermore, here, we also attempt to establish a prognostic scheme based on the histologic type. In conclusion, the REAL classification appears to be useful and clinically significant in Japan.

An Asian variant of intravascular lymphomatosis: an updated review of malignant histiocytosis-like B-cell lymphoma

Malignant histiocytosis-like B-cell lymphoma (MH-like BCL) is characterized clinically by hemophagocytic syndrome (HPS), bone marrow involvement at presentation, and an aggressive clinical course. Yet, it remains an ill-defined disease entity. We recently described five cases of MH-like BCL and suggested that these may be regarded as a peculiar variant of intravascular lymphomatosis (IVL), based on clinical and pathological observation. Interestingly, this type of lymphoma has been reported exclusively among Asians, with few reports from Western countries, and therefore we propose that this variant be noted as an Asian variant of IVL(AIVL). To evaluate the incidence of this variant, we performed a literature search for English or Japanese studies dealing with MH-like BCL or B-cell IVL associated with HPS (IVL with HPS). We found 18 reports of MH-like BCL and 16 reports of IVL with HPS and re-evaluated the clinicopathologic aspects of each study with respect to AIVL. Although several differences were noted, such as gender, presence of respiratory changes, bone marrow invasion and disseminated intravascular coagulopathy, there were also overlapping profiles and they appeared to be consistent with the AIVL single disease entity. Of particular note was the absence of peripheral lymphadenopathy and tumor formation which posed diagnostic problems in the initial phase of the presentations. Thus, based on analysis of the clinical findings of these 34 cases, the diagnostic criteria for AIVL consists primarily of cytopenia (anemia and/or thrombocytopenia), hepatosplenomegaly, absence of peripheral lymphadenopathy and tumor formation, and erythrocyte-hemophagocytosis along with intravascular proliferation of the neoplastic B cells. The pathologic findings of the 19 autopsied cases which fulfilled the criteria are also summarized, and they reveal morphologic, immunologic, and genotypic features of typical IVL.

Histology according to the Revised European-American Lymphoma Classification significantly predicts the prognosis of ocular adnexal lymphoma

Lymphoid infiltrates in the ocular adnexa are mostly low-grade B-cell lymphoma, but their clinicopathologic characteristics and prognostic factors have not been extensively analyzed according to the Revised European-American Lymphoma (REAL) Classification. We reviewed histopathologic sections from 77 patients with primary ocular adnexal lymphoid infiltrates, and conducted univariate and multivariate analyses of possible prognostic factors. Fifty-seven of the 77 patients were confirmed to have malignant lymphoma. Histopathologic sections from 44 of the 57 patients were reclassified into the following categories; marginal zone lymphoma (MZL) in 35, mantle cell lymphoma (MCL) in two, diffuse large cell lymphoma (DLCL) in six, and lymphoplasmacytoid lymphoma (LPL) in one. In the remaining 13 patients, biopsied specimens were inadequate for further subclassification. The cause-specific survival rates of the 57 patients with primary ocular adnexal lymphoma at 5, 10, and 15 years were 90.1%, 84.8% and 84.8%, respectively. The univariate analysis showed that the clinical stage, serum lactate dehydrogenase (LDH) value and histopathologic subtype were significant. The 5-year cause-specific survival rate of the 35 patients with MZL was 100%, whereas that of the eight patients with non-MZL (DLCL and MCL) was 25% (p<0.0001). The multivariate analysis revealed that the histologic subtype (p=0.010) and serum LDH value (p=0.015) were independent significant predictors of survival. We conclude that malignant lymphomas occurring in the ocular adnexa histologically consist mostly of MZL. The histologic subtype according to the REAL Classification significantly predicts the prognosis of ocular adnexal lymphoma.

Cyclin D1 and human neoplasia

Neoplasia is characterised by abnormal regulation of the cell cycle. Cyclin D1 is a protein derived from the PRAD1, CCND1 or bcl-1 gene on chromosome 11q13, which is involved in both normal regulation of the cell cycle and neoplasia. In the G1 (resting) phase of the cell cycle, cyclin D1 together with its cyclin dependent kinase (cdk) partner, is responsible for transition to the S (DNA synthesis) phase by phosphorylating the product of the retinoblastoma gene (pRB), which then releases transcription factors important in the initiation of DNA replication. Amplification of the CCND1 gene or overexpression of the cyclin D1 protein releases a cell from its normal controls and causes transformation to a malignant phenotype. Analysis of these changes provides important diagnostic information in mantle cell (and related) lymphomas, and is of prognostic value in many cancers. Knowledge of cyclin D1's role in malignancy at the various sites, provides a basis on which future treatment directed against this molecule can proceed.

Cyclin D1 overexpression detected by a simple competitive reverse transcription-polymerase chain reaction assay for lymphoid malignancies

t(11;14)(q13;q32) observed in B-cell malignancies is associated with cyclin D1 (bcl-1, PRAD1, CCND1) overexpression. We devised a simple competitive reverse transcription-polymerase chain reaction (RT-PCR) assay for rapid detection of cyclin D1 overexpression. Sharing a single upstream primer derived from a homologous sequence in cyclins D1, D2 and D3, each PCR product serves as a competitor and cyclin D1 overexpression is determined by comparing the intensities of the three amplified products. We analyzed cyclin D1 in clinical specimens from 104 patients with lymphoid malignancies. Cyclin D1 overexpression was evident in 13 of 104 (7/72 non-Hodgkin's lymphomas, 0/6 adult T-cell lymphoma/leukemias, 0/4 Hodgkin's diseases, 0/11 acute lymphoblastic leukemias, 3/4 multiple myelomas, 1/2 Waldenström's macroglobulinemias, 1/2 prolymphocytic leukemias and 1/3 chronic lymphocytic leukemias). Among 72 patients for whom cytogenetic studies had been done, all 7 patients with t(11;14) were positive. The relative expression levels of D-type cyclins altered dramatically in the presence of t(11;14). Thus, this RT-PCR assay can identify tumors with cyclin D1 overexpression. Cyclin D1 overexpression was frequent in extranodal specimens (11 out of 32 vs. 2 of 72 lymph nodes) and was restricted to specific types of lymphoid malignancies, as observed using other methods. This reliable assay should be suitable to provide clinical guidance for the diagnosis and management of lymphoid malignancies, especially in the case of extranodal involvement.

Immunological abnormalities in splenic marginal zone cell lymphoma

The clinical features of patients with splenic marginal zone cell lymphoma (SMZCL) have rarely been reported. In the present study, immunological abnormalities, particularly hematological abnormalities, observed in SMZCL were described. Autoimmune hemolytic anemia, immune thrombocytopenia, and appearance of lupus anticoagulant were observed in 2 of 3 patients with SMZCL. Other abnormal data including monoclonal gammopathy and cold agglutinin were also observed in 2 of the 3 patients. Immunological abnormalities may be characteristic complications in patients with SMZCL and must be followed carefully, since they may be a reliable marker of this type of lymphoma activity.

Somatic hypermutations in the VH segment of immunoglobulin genes of CD5-positive diffuse large B-cell lymphomas

De novo CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBL) has recently been identified as constituting a homogeneous subgroup with distinct clinicopathologic and genotypic characteristics, but its origin remains to be elucidated. Previous studies by sequence analysis of the variable region of the immunoglobulin heavy chain (VH) have shown that CD5+ B-cell malignancies such as mantle cell lymphoma (MCL) and B-cell chronic lymphocytic leukemia (B-CLL) cells represent pre-germinal center (pre-GC) stage B cells in contrast with the post-GC stage of most DLBLs, which show somatic hypermutations in VH genes. In the present study, we investigated the VH sequence of de novo CD5+ DLBL to clarify whether CD5+ DLBL represents the pre-GC stage, as do other CD5+ B-cell malignancies, or the post-GC stage, as is typical of DLBL. All eight cases (four CD5+ DLBL and four CD5-negative (CD5-) DLBL) examined by us showed somatic hypermutations in the VH segment and two of the CD5- DLBL cases showed intra-clonal diversity, suggesting that CD5+ DLBLs were derived from the same maturation stage as CD5- DLBL, but were distinct from the other indolent CD5+ B-cell lymphomas of B-CLL and MCL. These data suggest that de novo CD5+ DLBLs do not merely lie within a continuous spectrum with B-CLL and MCL, but represent a biologically distinct variant within the diagnostic framework of diffuse large B-cell lymphoma.

Lymph node involvement by splenic marginal zone lymphoma: morphological and immunohistochemical features

Splenic marginal zone lymphoma (SMZL) has recently been proposed as a distinctive type of low-grade B-cell lymphoma. Although there is general agreement that this entity exists, its precise definition is blurred by uncertainty in differential diagnosis from other low-grade B-cell lymphomas. There is even more uncertainty as to the histology of splenic hilar and peripheral lymph nodes involved by SMZL. We therefore reviewed the histological and immunohistochemical features of 19 of these lymph nodes (14 hilar and five peripheral) from 14 cases of classical SMZL and compared them with the features of lymph nodes involved by other B-cell lymphomas. The morphology and immunohistology of the lymph nodes resemble those found in the white pulp of the spleen, showing a distinctive pattern, different from that which is observed in other B-cell lymphomas. In these cases, the overall architecture of the lymph nodes is effaced and replaced by a nodular infiltrate, although the sinuses are preserved in most hilar lymph nodes. Some of the nodules contain a central reactive follicular center, around which there is a broad zone of small lymphocytes. In other cases, the central area is partially infiltrated or, more commonly, totally replaced by these small lymphocytes, which in the periphery of the nodules showed a pale, slightly larger cytoplasm. Scattered nucleolated blasts are present, largely confined to the periphery of the nodules. The tumoral cells express immunoglobulin (Ig)D, IgM, and Ig light chain restriction and show a low proliferation fraction. These findings confirm that SMZL is a real entity, and not merely a morphological pattern of splenic infiltration by different types of low-grade B-cell lymphoma.

Detection of Cyclin D1 (bcl-1, PRAD1) Overexpression by a Simple Competitive Reverse Transcription-Polymerase Chain Reaction Assay in t(11; 14)(q13; q32)-Bearing B-Cell Malignancies and/or Mantle Cell Lymphoma

In mantle cell lymphoma, the t(11; 14)(q13; q32) and its molecular counterpart, bcl-1 rearrangement, are consistent features and lead to cyclin D1 (bcl-1, PRAD1) proto-oncogene overexpression. In order to detect cyclin D1 overexpression, we developed a simple assay involving a reverse transcription followed by competitive polymerase chain reaction (PCR). A single upstream primer was derived from a homologous region between cyclin D1 and the other D-type cyclins, cyclins D2 and D3, while three downstream primers were specific to their respective D-type cyclins. Because the upstream primer was shared in PCR amplification of the three sequences, each PCR product served as a competitor and the quantification of the target was made by comparison of the intensity of the three products. With this assay we analyzed 45 hematopoietic cell lines and 40 clinical specimens. Cyclin D1 was rarely expressed in lymphoid cell lines except in t(11; 14)(q13; q32)-bearing B-cell malignancies and/or mantle cell lymphoma, which expressed cyclin D1 predominantly. In myeloid cell lines, the levels of cyclin D1 expression varied and never exceeded the sum of cyclin D2 and D3 levels. Cyclin D3 was ubiquitously expressed while cyclins D1 and D2 were differentially used. The observations suggest that human cyclin D3 may play a fundamental role in hematopoiesis and that cyclins D1 and D2 may have different lineage- or differentiation-dependent functions. With this assay, small aliquots of clinical specimens such as 100 μL peripheral blood were enough to detect cyclin D1 overexpression without a well-controlled standard. The technique was validated as highly comparable with Northern analysis. This rapid and reliable detection of cyclin D1 overexpression may have practical clinical utility in the analysis and management of B-cell malignancies.

Abnormal expression of CCND1 and RB1 in resection margin epithelia of lung cancer patients

Tumours develop through the accumulation of genetic alterations associated with a progressive increase of the malignant phenotype. In lung cancer, chronic exposure of bronchial epithelium to carcinogens in cigarette smoke may lead to multiple dysplastic and hyperplastic lesions scattered throughout the tracheobronchial tree. Little is known about the genetic alterations in such lesions. This study was carried out to examine cyclin D1 (CCND1) and retinoblastoma (RB1) gene expression in the bronchial epithelium of patients with lung cancer. Lung tumours and their corresponding tumour-free resection margins from 33 patients who underwent resection of non-small-cell lung cancer (NSCLC) were examined by immunostaining with monoclonal antibodies against cyclin D1 (DCS-6; Novocastra) and pRb (NCL Rb-1; Novocastra). Examination of the resection margins revealed four carcinomas in situ, 19 hyperplasias and ten sections showing apparently normal bronchial epithelium. A control group of patients, without lung tumours and who had never smoked, revealed no or weak cyclin D1 and positive pRb staining within bronchial epithelia. Increased cyclin D1 and diminished pRb expression were found in 76% (n = 25) and 27% (n = 9) of the resection margins respectively, and in 12% (n = 4) both cyclin D1 and pRb expression were altered. In the corresponding tumours, 48% (n = 16) were normal, while altered expression was found for cyclin D1 in 33% (n = 11), pRb in 27% (n = 9) and both in 9% (n = 3) of cases. It appears that altered expression of cyclin D1 and pRb is an early event in NSCLC development in almost half of cases analysed. Further investigations are needed to determine the significance of immunostaining of bronchial specimens in individuals at risk of lung cancer, with the possibility that the observations are of importance in the early diagnosis of NSCLC.

Clinicopathologic study of PRAD1/cyclin D1 overexpressing lymphoma with special reference to mantle cell lymphoma. A distinct molecular pathologic entity

Mantle cell lymphomas (MCLs) are frequently associated with the overexpression of PRAD1/cyclin D1, activated by 11q13 translocation and its molecular counterpart BCL-1 gene rearrangement. We recently described the correlation of positive nuclear staining using monoclonal antibody against a PRAD1/cyclin D1 product with mRNA overexpression in MCLs. In the present study, we immunohistochemically investigated the PRAD1/cyclin D1 protein in a large series of 334 lymphoproliferative disorders, including 39 cases of MCLs on paraffin sections. Based on the cyclin D1 positivity, CD5 expression, and the morphologic features of the tumor tissue, four groups of MCL-related lesions were identified among the B-cell lymphomas examined: 36 cases with cyclin D1 overexpression, 35 (95%) of which exhibited CD5-positivity and MCL-morphology (Group 1); four cases of lymphomas with MCL morphology and CD5 expression but lacking cyclin D1 overexpression (Group II); four cases of lymphomas without cyclin D1 overexpression and surface CD5 but that fall within the morphologic boundaries of MCLs (Group III); and 11 cases of CD5-positive diffuse large cell lymphomas without cyclin D1 overexpression (Group IV). The Group I cases demonstrated quite homogeneous clinicopathologic features identical to those of MCLs. This group showed a poor prognosis (11% had 5-year survival), which is highly contrasted with that of Group II (100%). Although the four groups of MCL-related lesions sometimes overlapped in their histologic or phenotypic spectrums, each appeared to show distinct clinicopathologic and prognostic profiles. Our study provides a basis for further clarification of the nature of the neoplasms of Groups II, III, and IV. Moreover, this comprehensive study may indicate that the overexpression of PRAD1/cyclin D1 is biologically essential to defining MCLs.

Primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype

We report a rare case of primary hepatic lymphoma, Stage II disease, in a 48-year-old male who had a solitary hepatic tumour measuring 4 x 4.5 x 3 cm. The tumour showed a nodular growth pattern and lymphoepithelial lesions with bile ducts. Some neoplastic nodules had a non-neoplastic atrophic germinal centre and/or a thin mantle cell layer. Morphologically, the neoplastic cells were centrocyte-like cells or intermediate lymphocytes. They expressed L26(CD20)+/LN-1(CDw75)+/-/LN-2(CD74)+/cyclin D1- and had a monotypic immunoglobulin of cytoplasmic IgM (kappa) on paraffin sections. The neoplastic cells or neoplastic nodules expressed surface IgM+/surface IgD+/-/Leu-1(CD5)+/DRC-1+/alkaline phosphatase+/B1(CD20)+/B4(CD19)- on fresh frozen sections. We therefore diagnosed this case as primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype. We confirm that it is difficult to differentiate extranodal marginal zone B-cell lymphoma (low grade B-cell lymphoma of mucosa-associated lymphoid tissue type; MALT lymphoma) and mantle cell lymphoma.

Prognostic significance of CCND1 (cyclin D1) overexpression in primary resected non-small-cell lung cancer

Amplification of the CCDN1 gene encoding cyclin D1 was examined by Southern blotting and multiplex polymerase chain reaction (PCR) and occurred in 8 of 53 patients (15%) with primary resected non-small-cell lung cancer (NSCLC). These tumours and 17 additional tumours with a normal gene copy number showed overexpression of cyclin D1 (25/53, 47%), as assessed by immunostaining using a monoclonal antibody. In 22/25 cases, cyclin D1 was localised in the cytoplasm, but some (7/25) had simultaneous nuclear staining. This result is in marked contrast to that reported in breast, hepatocellular and colorectal carcinoma studies where immunostaining was invariably nuclear. Examination of a restriction fragment length polymorphic (RFLP) site within the 3'untranslated region of the cDNA following reverse transcriptase (RT)-PCR (29/53 informative cases) showed a strong association between cytoplasmic staining and imbalance in allele-specific message levels. Cyclin D1 overexpression was associated with a poorly differentiated histology (P = 0.04), less lymphocytic infiltration of the tumour (P = 0.02) and a reduction in local relapse rate (P = 0.01). The relative risk of local relapse was 9.1 in tumours without cyclin D1 overexpression (P = 0.01, Cox regression analysis). We conclude that genetic alteration of cyclin D1 is a key abnormality in lung carcinogenesis and may have diagnostic and prognostic importance in the treatment of resectable NSCLC.

Clinicopathologic study of primary gastric lymphoma of B cell phenotype with special reference to low-grade B cell lymphoma of mucosa-associated lymphoid tissue among the Japanese

Resection specimens from 83 patients with primary gastric lymphoma (PGL) of B cell phenotype at stage IE and at stage IIE according to the Ann Arbor classification were investigated. Histologically, these lymphomas could be divided into four types: Type I lesions (n = 24) were entirely made up of MALT lymphoma; Type II lesions (n = 13) were predominantly MALT lymphoma containing one to a few foci of high-grade B cell lymphoma; Type III lesions (n = 22) consisted largely of high-grade lymphoma with small areas of low-grade MALT lymphoma; and Type IV lesions (n = 24) were pure high-grade B cell lymphoma, mostly of the large cell type. All patients had undergone primary gastric resection, and 14 received additional chemotherapy (n = 12), or both chemotherapy and radiotherapy (n = 2). The survival probability was significantly higher for Types I and II lymphomas than for Types III and IV tumors (P < 0.05 by the generalized Wilcoxon test). According to The General Rules for the Gastric Cancer Study by the Japanese Research Society for Gastric Cancer, the stage of disease showed a clear distinction between each of them (P < 0.01 by the generalized Wilcoxon test). This staging method seemed to serve well as a prognostic indicator. The histological typing of the PGL of the present series also seemed to correlate with the gross appearance, pathologic stage and prognosis. Furthermore, the expression of cyclin D1, bcl-2 and p53 protein, and PCNA was immunohistochemically investigated in 42 cases of the present series. Most of the low-grade PGL (Types I and II) had less than 60% PCNA-positive cells, whereas the high-grade PGL (Types III and IV) had more than 60% positive cells. In a study for cyclin D1 protein, no cases showed the nuclear staining pattern characteristic for mantle cell lymphoma, and the cytoplasmic staining frequently observed in the node-based large B cell lymphoma was seldom identified in the PGL. This discrepancy might suggest a lineage difference among the morphologically similar, but site-different, lymphomas. On the other hand, bcl-2 protein overexpression was almost equal in frequency between the gastric and node-based high-grade B cell lymphomas. This is in contrast to the reports from Western countries, in which the majority of high-grade gastric tumors were bcl-2 negative.

The positive nuclear staining observed with monoclonal antibody against PRAD1/cyclin D1 correlates with mRNA expression in mantle cell lymphoma

Recently, we produced a monoclonal antibody, 5D4, against the PRAD1/cyclin D1 product and suggested positive nuclear staining to be associated with mantle cell lymphoma (MCL). Now we have further characterized the specificity of this antibody and studied the relation of immunohistochemical detection to PRAD1/cyclin D1 mRNA expression and DNA rearrangement. Immunofluorescence and immunoblotting studies demonstrated the 5D4 antibody to be crossreactive with cyclin D2, but not cyclin D3. On immunostaining, 15 of 19 MCL cases (79%) presented the nuclear staining pattern and PRAD1/cyclin D1 mRNA expression was detected by Northern blot analysis in 12 of 15 MCL cases studied (80%): all cases with the mRNA expression showed the nuclear staining pattern. Southern blot analysis with 11q13 BCL-1 probes detected DNA rearrangements in 8 of 19 MCL cases (42%), all 8 exhibiting PRAD1/cyclin D1 mRNA expression. In 21 lymphoma cases of types other than MCL, neither the mRNA expression nor the nuclear staining were observed, although cytoplasmic staining was often apparent. These results indicated that positive nuclear staining of lymphoma cells by 5D4 antibody reflects PRAD1/cyclin D1 mRNA expression, and showed that this monoclonal antibody has diagnostic value for differentiating MCL from other types of lymphomas.